diff options
| -rw-r--r-- | .gitattributes | 3 | ||||
| -rw-r--r-- | 14009-0.txt | 4747 | ||||
| -rw-r--r-- | 14009-h/14009-h.htm | 5677 | ||||
| -rw-r--r-- | 14009-h/images/1-boat.png | bin | 0 -> 465057 bytes | |||
| -rw-r--r-- | 14009-h/images/1-boat_th.jpg | bin | 0 -> 43298 bytes | |||
| -rw-r--r-- | 14009-h/images/12-boat.png | bin | 0 -> 115553 bytes | |||
| -rw-r--r-- | 14009-h/images/12-circus.png | bin | 0 -> 156598 bytes | |||
| -rw-r--r-- | 14009-h/images/13-fig1.png | bin | 0 -> 282272 bytes | |||
| -rw-r--r-- | 14009-h/images/13-fig1_th.jpg | bin | 0 -> 37476 bytes | |||
| -rw-r--r-- | 14009-h/images/13-fig2.png | bin | 0 -> 449184 bytes | |||
| -rw-r--r-- | 14009-h/images/13-fig2_th.jpg | bin | 0 -> 45939 bytes | |||
| -rw-r--r-- | 14009-h/images/13-fig3.png | bin | 0 -> 388310 bytes | |||
| -rw-r--r-- | 14009-h/images/13-fig3_th.jpg | bin | 0 -> 39728 bytes | |||
| -rw-r--r-- | 14009-h/images/13-fig4.png | bin | 0 -> 216675 bytes | |||
| -rw-r--r-- | 14009-h/images/2-fig1.png | bin | 0 -> 26158 bytes | |||
| -rw-r--r-- | 14009-h/images/2-fig2.png | bin | 0 -> 42506 bytes | |||
| -rw-r--r-- | 14009-h/images/2-fig3.png | bin | 0 -> 38598 bytes | |||
| -rw-r--r-- | 14009-h/images/2-fig4.png | bin | 0 -> 39835 bytes | |||
| -rw-r--r-- | 14009-h/images/2-fig5.png | bin | 0 -> 139921 bytes | |||
| -rw-r--r-- | 14009-h/images/2-fig6.png | bin | 0 -> 90551 bytes | |||
| -rw-r--r-- | 14009-h/images/3-station.png | bin | 0 -> 695073 bytes | |||
| -rw-r--r-- | 14009-h/images/3-station_th.jpg | bin | 0 -> 75012 bytes | |||
| -rw-r--r-- | 14009-h/images/4-fig1.png | bin | 0 -> 23538 bytes | |||
| -rw-r--r-- | 14009-h/images/4-fig2.png | bin | 0 -> 20105 bytes | |||
| -rw-r--r-- | 14009-h/images/4-water.png | bin | 0 -> 133660 bytes | |||
| -rw-r--r-- | 14009-h/images/4-water_th.jpg | bin | 0 -> 22143 bytes | |||
| -rw-r--r-- | 14009-h/images/5-goodyear.png | bin | 0 -> 263081 bytes | |||
| -rw-r--r-- | 14009-h/images/5-goodyear_th.jpg | bin | 0 -> 28388 bytes | |||
| -rw-r--r-- | 14009-h/images/6-fig51.png | bin | 0 -> 101149 bytes | |||
| -rw-r--r-- | 14009-h/images/6-fig52.png | bin | 0 -> 56744 bytes | |||
| -rw-r--r-- | 14009-h/images/7-fig53.png | bin | 0 -> 23877 bytes | |||
| -rw-r--r-- | 14009-h/images/7-fig54.png | bin | 0 -> 43111 bytes | |||
| -rw-r--r-- | 14009-h/images/8-fig55.png | bin | 0 -> 31637 bytes | |||
| -rw-r--r-- | 14009-h/images/8-fig56.png | bin | 0 -> 36496 bytes | |||
| -rw-r--r-- | 14009-h/images/8-scope.png | bin | 0 -> 210290 bytes | |||
| -rw-r--r-- | 14009-h/images/8-scope_th.jpg | bin | 0 -> 27167 bytes | |||
| -rw-r--r-- | 14009-h/images/8-target.png | bin | 0 -> 37250 bytes | |||
| -rw-r--r-- | 14009-h/images/8-target_th.jpg | bin | 0 -> 9155 bytes | |||
| -rw-r--r-- | 14009-h/images/title.png | bin | 0 -> 183600 bytes | |||
| -rw-r--r-- | 14009-h/images/title_th.jpg | bin | 0 -> 37955 bytes | |||
| -rw-r--r-- | LICENSE.txt | 11 | ||||
| -rw-r--r-- | README.md | 2 | ||||
| -rw-r--r-- | old/14009-8.txt | 5136 | ||||
| -rw-r--r-- | old/14009-8.zip | bin | 0 -> 100333 bytes | |||
| -rw-r--r-- | old/14009-h.zip | bin | 0 -> 4785622 bytes | |||
| -rw-r--r-- | old/14009-h/14009-h.htm | 6092 | ||||
| -rw-r--r-- | old/14009-h/images/1-boat.png | bin | 0 -> 465057 bytes | |||
| -rw-r--r-- | old/14009-h/images/1-boat_th.jpg | bin | 0 -> 43298 bytes | |||
| -rw-r--r-- | old/14009-h/images/12-boat.png | bin | 0 -> 115553 bytes | |||
| -rw-r--r-- | old/14009-h/images/12-circus.png | bin | 0 -> 156598 bytes | |||
| -rw-r--r-- | old/14009-h/images/13-fig1.png | bin | 0 -> 282272 bytes | |||
| -rw-r--r-- | old/14009-h/images/13-fig1_th.jpg | bin | 0 -> 37476 bytes | |||
| -rw-r--r-- | old/14009-h/images/13-fig2.png | bin | 0 -> 449184 bytes | |||
| -rw-r--r-- | old/14009-h/images/13-fig2_th.jpg | bin | 0 -> 45939 bytes | |||
| -rw-r--r-- | old/14009-h/images/13-fig3.png | bin | 0 -> 388310 bytes | |||
| -rw-r--r-- | old/14009-h/images/13-fig3_th.jpg | bin | 0 -> 39728 bytes | |||
| -rw-r--r-- | old/14009-h/images/13-fig4.png | bin | 0 -> 216675 bytes | |||
| -rw-r--r-- | old/14009-h/images/2-fig1.png | bin | 0 -> 26158 bytes | |||
| -rw-r--r-- | old/14009-h/images/2-fig2.png | bin | 0 -> 42506 bytes | |||
| -rw-r--r-- | old/14009-h/images/2-fig3.png | bin | 0 -> 38598 bytes | |||
| -rw-r--r-- | old/14009-h/images/2-fig4.png | bin | 0 -> 39835 bytes | |||
| -rw-r--r-- | old/14009-h/images/2-fig5.png | bin | 0 -> 139921 bytes | |||
| -rw-r--r-- | old/14009-h/images/2-fig6.png | bin | 0 -> 90551 bytes | |||
| -rw-r--r-- | old/14009-h/images/3-station.png | bin | 0 -> 695073 bytes | |||
| -rw-r--r-- | old/14009-h/images/3-station_th.jpg | bin | 0 -> 75012 bytes | |||
| -rw-r--r-- | old/14009-h/images/4-fig1.png | bin | 0 -> 23538 bytes | |||
| -rw-r--r-- | old/14009-h/images/4-fig2.png | bin | 0 -> 20105 bytes | |||
| -rw-r--r-- | old/14009-h/images/4-water.png | bin | 0 -> 133660 bytes | |||
| -rw-r--r-- | old/14009-h/images/4-water_th.jpg | bin | 0 -> 22143 bytes | |||
| -rw-r--r-- | old/14009-h/images/5-goodyear.png | bin | 0 -> 263081 bytes | |||
| -rw-r--r-- | old/14009-h/images/5-goodyear_th.jpg | bin | 0 -> 28388 bytes | |||
| -rw-r--r-- | old/14009-h/images/6-fig51.png | bin | 0 -> 101149 bytes | |||
| -rw-r--r-- | old/14009-h/images/6-fig52.png | bin | 0 -> 56744 bytes | |||
| -rw-r--r-- | old/14009-h/images/7-fig53.png | bin | 0 -> 23877 bytes | |||
| -rw-r--r-- | old/14009-h/images/7-fig54.png | bin | 0 -> 43111 bytes | |||
| -rw-r--r-- | old/14009-h/images/8-fig55.png | bin | 0 -> 31637 bytes | |||
| -rw-r--r-- | old/14009-h/images/8-fig56.png | bin | 0 -> 36496 bytes | |||
| -rw-r--r-- | old/14009-h/images/8-scope.png | bin | 0 -> 210290 bytes | |||
| -rw-r--r-- | old/14009-h/images/8-scope_th.jpg | bin | 0 -> 27167 bytes | |||
| -rw-r--r-- | old/14009-h/images/8-target.png | bin | 0 -> 37250 bytes | |||
| -rw-r--r-- | old/14009-h/images/8-target_th.jpg | bin | 0 -> 9155 bytes | |||
| -rw-r--r-- | old/14009-h/images/title.png | bin | 0 -> 183600 bytes | |||
| -rw-r--r-- | old/14009-h/images/title_th.jpg | bin | 0 -> 37955 bytes | |||
| -rw-r--r-- | old/14009.txt | 5136 | ||||
| -rw-r--r-- | old/14009.zip | bin | 0 -> 100315 bytes |
85 files changed, 26804 insertions, 0 deletions
diff --git a/.gitattributes b/.gitattributes new file mode 100644 index 0000000..6833f05 --- /dev/null +++ b/.gitattributes @@ -0,0 +1,3 @@ +* text=auto +*.txt text +*.md text diff --git a/14009-0.txt b/14009-0.txt new file mode 100644 index 0000000..0a565df --- /dev/null +++ b/14009-0.txt @@ -0,0 +1,4747 @@ +*** START OF THE PROJECT GUTENBERG EBOOK 14009 *** + +[Illustration] + + + + +SCIENTIFIC AMERICAN SUPPLEMENT NO. 787 + + + + +NEW YORK, January 31, 1891 + +Scientific American Supplement. Vol. XXXI., No. 787. + +Scientific American established 1845 + +Scientific American Supplement, $5 a year. + +Scientific American and Supplement, $7 a year. + + * * * * * + + + + +TABLE OF CONTENTS. + + +I. BIOGRAPHY.--CHARLES GOODYEAR.--The life and discoveries of + the inventor of vulcanized India rubber, with portrait.--1 + illustration + +II. BIOLOGY.--Can we Separate Animals from Plants?--By ANDREW + WILSON.--A debated point well discussed.--The bases on which + distinctions must be drawn + +III. ELECTRICITY.--A New Electric Ballistic Target.--A target + for investigations of the velocity of projectiles, now in use at + the United States Military Academy, West Point, N.Y.--1 + illustration. + + Electric Erygmascope.--An electric lighting apparatus for + examining earth strata in bore holes for geologists' and + prospectors' use.--1 illustration + + The Electro-Magnet.--By Prof. SILVANUS THOMPSON.--Continuation + of this exhaustive treatise, giving further details on special + points of construction.--1 illustrations + +IV. ENTOMOLOGY.--Potash Salts.--The use of potash salts as + insecticides, with accounts of experiments + + The Outlook for Applied Entomology.--By Dr. C.V. RILEY, U.S. + entomologist.--The conclusion of Prof. Riley's lecture, treating + of the branch of entomology with which his name is so honorably + associated + +V. INSURANCE.--The Expense Margin in Life Insurance.--Elaborate + review of the necessary expenses of conducting the insurance of + lives, with tables and calculations + +VI. MATHEMATICS.--The Trisection of Any Angle.--By FREDERIC R. + HONEY, Ph.B.--A very ingenious demonstration of this problem, + based on the properties of conjugate hyperbolas + +VII. METEOROLOGY.--Note on the Mt. Blanc Meteorological Station + + The Flood at Karlsbad.--Account of the recent flood and of its + destructive effects.--1 illustration + +VIII. MECHANICAL ENGINEERING.--Station for Testing Agricultural + Machines.--A proposed establishment for applying dynamometer + tests to agricultural machines.--1 illustration + + Steam Engine Valves.--By THOMAS HAWLEY.--A review of modern + slide valve practice, the lap, cut-off, and other points.--6 + illustrations + +IX. MISCELLANEOUS.--Science in the Theater.--Curious examples of + stage effect in fictitious mesmerizing and hypnotizing.--4 + illustrations + + Theatrical Water Plays.--Recent episodes in real water plays at + Hengler's Circus, London.--2 illustrations + +X. NAVAL ENGINEERING.--The French Ironclad War Ship Colbert.--An + armored wood and iron ship, with central battery.--1 + illustration + +XI. PHYSIOLOGY AND HYGIENE.--Newer Physiology and Pathology.--By + Prof. SAMUEL BELL. M.D.--An excellent presentation of modern + practice in the light of bacteriology + + Test Card Hints.--How to test the eyes for selecting eyeglasses + and spectacles + + The Composition of Koch's Lymph.--What Prof. Koch says it is and + what it can do.--The cabled account of the disclosure so long + waited for + +XII. TECHNOLOGY.--Firing Points of Various Explosives.--The + leading explosives, with the temperature of their exploding + points tabulated + + The Recovery of Gold and Silver from Plating and Gilding + Solutions--A paper of interest to silver and gold platers, as + well as photographers + + Water Softening and Purifying Apparatus.--An apparatus for + treatment of sewage, etc., chemically and by deposition.--1 + illustration + + * * * * * + + + + +THE FRENCH IRONCLAD WAR SHIP COLBERT. + + +The central battery ironclad Colbert is one of the ten ships of the +French navy that constitute the group ranking next in importance to +the squadron of great turret ships, of which the Formidable is the +largest. The group consists of six types, as follows: + + 1. The Ocean type; three vessels; the Marengo, Ocean, and Suffren. + 2. The Friedland type, of which no others are built. + 3. The Richelieu type, of which no others are built. + 4. The Colbert type, of which there are two; the Colbert and the + Trident. + 5. The Redoubtable type, of which no others are built. + 6. The Devastation type, of which no others are built. + +[Illustration: THE FRENCH IRONCLAD WAR SHIP COLBERT.] + +The Colbert was launched at Brest in 1875, and her sister ship, the +Trident, in 1876. Both are of iron and wood, and the following are the +principal dimensions of the Colbert, which apply very closely to the +Trident: She is 321 ft. 6 in. long, 59 ft. 6 in. beam, and 29 ft. 6 +in. draught aft. Her displacement is 8,457 tons, her indicated horse +power is 4,652, and her speed 14.4 knots. She has coal carrying +capacity for 700 tons, and her crew numbers 706. The thickness of her +armor belt is 8.66 in., that protecting the central battery is 6.29 +in. thick, which is also the thickness of the transverse armored +bulkheads, while the deck is 0.43 in. in thickness. The armament of +the Colbert consists of eight 10.63 in. guns, two 9.45 in., six 5.51 +in., two quick firing guns, and fourteen revolving and machine +guns.--_Engineering._ + + * * * * * + +A compound locomotive, built by the Rhode Island Locomotive Works, has +been tried on the Union Elevated Railroad, Brooklyn, N.Y. The engine +can be run either single or compound. The economy in fuel was 37.7 per +cent, and in water 23.8 per cent, over a simple engine which was +tested at the same time. The smoothness of running and the stillness +and comparative absence of cinders was fully demonstrated. + + * * * * * + + + + +STEAM ENGINE VALVES. + +[Footnote: Lecture delivered at Wells Memorial Institute, Boston, in +the Lowell Free Course for Engineers. From report in the _Boston +Journal of Commerce_.] + +By THOMAS HAWLEY. + +RIDING CUT-OFF VALVES--PECULIARITIES AND MERITS OF THE DIFFERENT +STYLES. + + +In considering the slide valve in its simple form with or without lap, +we find there are certain limitations to its use as a valve that would +give the best results. The limitation of most importance is that its +construction will not allow of the proper cut off to obtain all the +benefits of expansion without hindering the perfect action of the +valve in other particulars. At this economical cut off the opening of +the steam port is very little and very narrow, and although this is +attempted to be overcome by exceedingly wide ports, sixteen inches in +width in many cases in locomotive work, this great width adds largely +to the unbalanced area of the valve. The exhausting functions of the +valve are materially changed at the short cut off, and when much lap +is added to overcome this defect, there usually takes place a choking +of the exhaust port. You might inquire, why not make the port wider, +but this would increase the minimum amount of load on the valve, and +this must not be overlooked. Then the cut off is a fixed one, and we +can govern only by throttling the pressure we have raised in the +boiler or by using a cut off governor and the consequent wastes of an +enormous clearance space. You will observe, therefore, that the plain +slide valve engine gives the most general satisfaction at about +two-thirds cut off and a very low economic result. The best of such +engines will require forty-five to fifty pounds of steam per horse +power per hour, and to generate this, assuming an evaporation of nine +pounds of water to a pound of coal, would require between five and six +pounds of coal per horse power per hour. And the only feature that the +valve has specially to commend it is its extreme simplicity and the +very little mechanism required to operate it. + +Yet this is of considerable importance, and in consideration of some +special features at its latest cut off, the attempt has been many +times made to take advantage of these features. For instance, at 90° +advance, the valve opens very rapidly indeed and fully satisfies our +requirements of a perfect valve. This is one good point, and in this +position also the exhaust and compression can be regulated very +closely and as desired without much lap, and as the opening of the +exhaust port comes with the eccentric at its most rapid movement the +release is very quick and as we would have it. This is only possible +at the most uneconomic position of the valve as regards cut off. + +The aim of many engineers has been to take advantage of these matters +by using the valve with 90° angular advance of eccentric ahead of +crank, for the admission, release, and compression of the steam, and +provide another means of cutting off, besides the one already referred +to, viz., cutting off the supply of steam to the chest, and overcome +the objection in this one of large clearance spaces. This is done by +means of riding cut off valves, often called expansion valves, of +which, perhaps, the most widely known types in this vicinity are the +Kendall & Roberts engine and the Buckeye. The former is used in the +simplest form of riding cut off, while the Buckeye has many peculiar +features that engineers, I find, are too prone to overlook in a casual +examination of the engine. In these uses of the slide valve, too, +means are suggested and carried out of practically balancing the +valve. + +The origin of the riding cut off is most generally attributed to +Gonzenbach. His arrangement had two steam chests, the lower one +provided with the ordinary slide valve of late cut off, and steam was +cut off from this steam chest by the expansion valve covering the +ports connecting with the upper steam chest. This had the old +disadvantage that all the steam in the lower chest expanded with that +in the cylinder, at a consequent considerable loss. This was further +improved by causing the riding cut off to be upon the top of the main +valve, instead of its chest, and resulted in a considerable reduction +of the clearance space. + +This is the simplest form, and is shown in Fig. 1. The steam is +supplied by a passage through the main valve which operates exactly as +an ordinary slide valve would. That is, the inside edges of the steam +passage are the same as the ordinary valve, the additional piece on +each end, if I may so term it, being merely to provide a passage for +the steam which can be closed, instead of allowing the steam to pass +the edge. The eccentric of the main valve is fastened to the shaft to +give the proper amount of lead, and the desired release and +compression, and the expansion valve is operated by a separate +eccentric fastened in line with or 180° ahead of the crank. When the +piston, therefore, commences to move from the crank end to open the +port, D, the expansion valve is forced by its eccentric in the +opposite direction, and is closing the steam port and would have +closed it before the piston reached quarter stroke, thus allowing the +steam then in the cylinder to do work by expansion. The eccentric +operating this expansion valve may be set to close this steam port at +any point in the stroke that is desired, the closing occurring when +the expansion valve has covered the steam port. Continuing the +movements of the valves, the two would move together until one or the +other reached its dead center, when the movements would be in opposite +directions. + +[Illustration: FIG. 1.] + +There are three ways of effecting the cut off in such engines, the +main valve meanwhile being undisturbed, its eccentric fastened +securely so as not to disturb the points of lead, release, and +compression. All that is required is to cause the edge of the +expansion valve to cover the steam port earlier in the stroke, and +this can be done, first, by increasing the angular advance of the cut +off eccentric; second, by adding lap to the cut off valve; and third +by changing the throw of the eccentric. In all these instances the +riding valve is caused to reach the edge of the steam port earlier in +the stroke. We will take first, as the simplest, those methods by +which the lap of the cut off valve is increased. + +It will be noted that there is but one edge of this valve that is +required to do any work, and that is to close the valve. The +eccentrics are so placed that the passage in the main valve is opened +long before the main valve itself is ready to admit steam to the +cylinder, so that only the outer edges are the ones to be considered, +and it will be readily seen that the two valves traveling in opposite +directions, any lap added to the working edge of the cut off valve +will cause it to reach the edge and therefore close the port earlier +than it would if there was less lap. And we might carry it to the +extreme that we could add lap enough that the steam passage would not +be opened at all. + +In Fig. 2 is shown the method by which this is accomplished, in what +is called Meyer's valve, and such as is used in the Kendall & Roberts +engine. We have only one point to look after, the cut off, so we can +add all the lap we wish without disturbing anything else. In this +engine the lap is changed by hand by means of a little hand wheel on a +stem that extends out of the rear of the steam chest. The valve is in +two sections, and when it is desired to cut off earlier, the hand +wheel is turned in such a direction that the right and left hand +screws controlling the cut off valve move one valve portion back and +the other forward, which would, if they were one valve and they should +be so considered, have the effect of lengthening them, or adding lap +to them. The result would be that the riding valve would reach the +edge of the steam port earlier in the stroke, bringing about an +earlier cut off. If the cut off is desired to be later, the hand wheel +is so turned that the right and left hand screws will bring the valve +sections nearer together, thus practically taking off lap. Now this +may be done by hand or it may be done by the action of a governor. + +[Illustration: FIG. 2.] + +In the latter case the governor at each change of load turns the right +and left hand screws to add or take away lap, as the load demands an +earlier or later cut off; in other cases the governor moves a rack in +mesh with a gear by which the valve sections are brought closer +together or are separated. The difficulty with the case where the hand +wheel is turned by hand is that the cut off is fixed where you leave +it, and governing can only be at the throttle. For this reason +anywhere near full boiler pressure would not be obtained in the +cylinder of the engine. If the load was a constant one, and the cut +off could be fixed at about one-third, causing the throttle to open +its widest, very good results would be obtained, but there is no +margin left for governing. + +If the load should increase at such a time the governor could not +control it under these conditions, and it would lead to a decrease in +speed unless the lap was again changed to give a later cut off. On +this account the general practice soon becomes to leave the cut off at +the later point and give range to the throttle, and we come back once +more to the plain slide valve cutting off at half stroke, and the only +gain there is, is in a quick port opening and quick cut off. But these +matters are more than offset by the wire drawing between the steam +pipe and chest, through the throttle, and the fact that there is added +to the friction of the engine the friction of this additional slide +valve and a considerable liability to have a leaky valve. + +In the case where the governor changes the position of the cut off +valve a greater decree of economy would result. In this engine, of +which the Lambertville engine is a type, the main valve is a long D +slide, with multiple ports at the ends through which the steam enters +the cylinders. It is operated from an eccentric on the crank shaft in +the usual manner. The cut off valve is also operated from the motion +on an eccentric fixed upon the crank shaft. The rod or stem of the cut +off valve passes through the main valve rod and slide. Upon the outer +end of the cut off valve rod are tappets fastened to engage with +tappets on the eccentric valve rod. Connection between the cut off +eccentric, therefore, and the cut off valve is only by means of the +engagement of these tappets. The eccentric rod is fastened to a rocker +arm having motion swinging about a pin or bearing in the governor +slide, which may be raised or lowered by a cam operated by the +governor. The cut off slide is of cylindrical shape and incloses a +spring and dash pot with disks attached by means of which the valve is +closed. The motion for operating the valves is relatively in the same +direction, the cut off eccentric having the greatest throw and greater +angular advance to cause it to open earlier and quickly before the +main valve is ready to admit steam. The cut off eccentric rod swinging +the rocker arm, the tappets thereon engage with those upon the cut off +valve rod and open the passages to the main valve, and in their +movement compress the spring in the main valve. According as the speed +of the engine, the rock arm will be raised or lowered so that the +tappets upon the eccentric rod may keep in engagement a shorter or +longer time before they disengage, thus allowing the spring that has +been compressed by the movement of the cut off valve to close that +valve quickly and the supply of steam to the engine, the cut off valve +traveling with the main valve for the balance of the stroke. This +device will give a remarkably quick opening and a quick cut off, but +in view of the fact that the governor has so much to do, its delicacy +is impaired and a quick response to the demands of the load changing +not so likely to occur. The cut off cannot be as quick as in some +other engines, because the valves are moving in opposite directions, +and while this fact would help, so far as shortening the distance to +be traveled before cut off, the resistance of the valves to travel in +opposite directions, or rather the tendency of the valve to travel +with the main valve, hinders its rapid action. + +[Illustration: FIG. 3.] + +This is one great objection to the rack and gear operated by the +governor, that two flat valves riding upon each other and sliding in +opposite directions at times require a considerable amount of force to +move them, and as only a slight change in load is required by the +load, the governor cannot handle the work as delicately as it should. +It is too much for the governor to do well. To overcome this +difficulty the Ryder cut-off, shown in Fig. 3, was made by the +Delamater people, of New York. The main slide valve is hollowed in the +back and the ports cut diagonally across the valve to form almost a +letter V. The expansion valve is V-shaped, and circular to fit its +circular-seat. The valve rod of the expansion valve has a sector upon +it and operated by a gear upon the governor stem, which rotates the +valve rod, and the edge of the valve rod is brought farther over the +steam port, thus practically adding lap to the valve. Little movement +is found necessary to make the ordinary change in cut-off, and it is +found to be much easier to move the riding valve across the valve than +in a direction directly opposite. It would require considerable force +to move the upper valve by the governor faster than the lower, or in a +direction opposite to that in which it is moving, but very little +force applied sideways at the same time it is moving forward will give +it a sideways motion. In this device the governor has only to exert +this side pressure and therefore has less to do than if it were called +upon to move the upper valve directly against the movement of the +lower. + +Something similar is the valve of the Woodbury engine, of Rochester, +N.Y. The cut-off valve is cylindrical, covering diagonal ports +directly opposite, and is caused to be rotated by the action of the +governor that operates a rack in mesh with a segment. Very little +movement will effect a considerable change in the lappage of the +valve, the valve turning about one-quarter a revolution for the +extremes of cut off. The cut off valve rod works through a bracket and +its end terminates in a ball in a socket on the end of the eccentric +rod. In this case the governor has not as much to do as in other +instances. + +[Illustration: FIG. 4.] + +Still another method of effecting this change in cut off, but hardly +by increasing the lap of the valve, is shown in the next drawing, Fig. +4. The cut off valve is held upon the main valve by the pressure of +steam upon its back and rides with it until it comes in contact with +the cut off wedge-shaped blocks, when its motion is arrested, and the +main valve continuing its movement the steam port is closed by the +main valve passing beneath the cut off valve. Thus the main valve +travels and carries the cut off valve upon its back again until the +cut off valve strikes the wedge on the other end and the cut off is +effected. The relative positions of the blocks are determined by the +governor, that will raise or lower them so that the cut off valve will +engage with them earlier or later as desired. This device was designed +specially as an inexpensive method of changing the common slide valve +into an automatic cut off. The cut off would not be as quick as in +other cases we have cited, depending here upon the movement of the +lower valve alone, and that, too, is in its slowest movement; whereas +in the other cases, the edges approaching each other, by the differing +movement of the valves the cut off is very rapid, provided the +distance to travel is not long. In this device considerable noise must +result by the cut off valve striking the cut off blocks, and a +considerable amount of leakage is likely to occur past this valve. + +But there is one great objection in the valve gears thus far cited, +that the travel of the expansion valve upon the main valve is +variable. I have in mind the case of a Kendall & Roberts engine, which +had been run for a long time at no better economy than would be +obtained from a plain slide valve engine, and when it was attempted to +get an earlier cut off by separating the two cut off valves, they had +worn so much in their old place on the valve that shoulders were found +sufficient to cause a disagreeable noise and a leaky valve. This is +very apt to occur, not only where the valve is run for a long time on +one seat, but in cases of variation of the travel of the expansion +valve. The result is that a change will bring about a leaky valve, +something that every engineer abhors. + +The construction of the Buckeye engine, which is also of this type, is +such that the travel of the valve on the back of the main valve is +always the same, no matter what the cut off may be. Then this engine +makes use of our second proposition as a means of effecting the cut +off, viz., by advancing the eccentric. You will readily observe that +anything that will cause the cut off valve to reach a certain point +earlier in the stroke will bring about an earlier cut off as it +hastens everything all around. This is the plan pursued in the +Buckeye, in which the governor, of the shaft type, turns the eccentric +forward or back according as the load demands. Then, in addition, the +valve is balanced partially, the attempt not being made to produce an +absolutely balanced valve, on the ground that there should be friction +enough to keep the surfaces bright and to prevent leakage. The most +perfect valve will, of course, be entirely balanced under all +conditions of pressure so as to move with perfect ease. With the +riding cut off valve in connection with the plain slide valve, this is +not accomplished, and it does not matter whether it is partially +unbalanced to prevent leakage or not, the fact that it is not entirely +balanced prevents it reaching the ideal valve. + +[Illustration: Fig. 5] + +This valve, Fig. 5, differs from the others also in this particular, +that the exhaust takes place at the end of the valve instead of under +the arch. Two eccentrics are used, the one for the main valve being +fastened to the shaft and the other riding loosely upon it and +connected to the fly wheel governor, by which it may be turned forward +or back as the load requires. The three points of lead, or admission +and exhaust and compression, are fixed and independent of the changes +and cut off. The motion of the main eccentric is given to a rocker +arm, the pivot of which is at the bottom, and from the upper end the +valve rod transfers the motion to the valve without reversing the +motion, as is done sometimes in the slide valve to overcome the +effects of the angularity of the connecting rod. The action of the +rocker arm, therefore, so far as the main valve in the Buckeye is +concerned, is no different than that which would occur if no rocker +arm intervened. The motion of the cut off eccentric, through its +eccentric rod, is given to a rocker rocking in a bearing in the center +of the main rocker arm (see Fig. 6). The motion of this eccentric is +reversed, so far as the cut off valve is concerned, and when the cut +off eccentric is moving forward, the cut off valve is being pushed +back. The main valve rod is hollow, and the cut off valve rod passes +through it. + +[Illustration: Fig. 6] + +The cut off eccentric can be placed in any position to cause it to cut +off as desired, and by drawing the valve forward, by increasing the +angular advance of the eccentric, the cut off valve is caused to reach +and cover the steam passage in the main valve earlier in the stroke. +Instead of being ahead of the crank, the main eccentric in this +arrangement follows the crank, on account of the exhaust and steam +edges being exactly opposite from those in the ordinary slide. What is +the steam edge of the common slide is in this the exhaust edge, and +what is the exhaust edge in the common valve is the steam edge in this +one. The valve, therefore, must be moved in the opposite direction +from what is ordinarily the case, the main eccentric being not 90 deg. +behind the crank. It has a rapid and full opening just the same, for +it is at this point behind the crank, or ahead of it, that the +eccentric gives to the valve its quickest movement, or between the +eccentric dead centers. The cut off eccentric is considerably ahead of +the main eccentric, and about even with the crank. If it was not for +the reversal of motion of the cut off valve through the rocker arm +this eccentric would be about in line with the crank, but on the other +end. The movement of the cut off valve, therefore, at the time of port +opening is very little, being about on its dead center, passing which, +it immediately commences to close. + +The object of the peculiar construction of the rocker arm, and the +pivot for the cut off rocker being placed thereon, is to provide equal +travel on the back of the main valve, no matter what the cut off. I +have already explained, in connection with the slide valve, that +advancing the eccentric does not change the movement of the valve on +its seat, but simply its relation to the movement of the piston. You +will see that this is unchanged as using the main valve as a seat or +any other seat. If the main valve was to remain stationary, and only +the cut off valve to be operated by its eccentric, the movement of +this cut off valve on a certain plane would be the same for all +positions of the eccentric. + +Moving the main slide does not affect the matter in any way, for it +moves at the same time the pivot of the cut off, and while the cut off +seat has assumed a different position with reference to the engine, it +is still as though stationary so far as the cut off valve is +concerned. This is the object of this peculiar construction, and not, +as some engineers suppose, simply to make an odd way of doing things. +And the object of it all is to give at all cut offs the same amount of +travel, so that there might be no unequal wear to bring about a leak, +to prevent which a perfect balancing has been sacrificed. + +Referring to the valve and this engine as to how it will satisfy our +requirements of a perfect valve gear, we find that the first +requirement of a rapid and full opening is met, in that the opening +occurs when the main eccentric is moving very rapidly, yet not its +fastest, and while this opening will be very satisfactory, it is not +so rapid an opening as is obtained in some other forms of valves and +valve gears, but this could be overcome very readily by increasing the +lead a trifle, and in my experience with these engines I find that the +practice is very general by engineers and by builders themselves to +give them a considerable amount of lead. As to the second requirement, +the maintenance of initial pressure until cut off, giving a straight +steam line, cards from this engine will not be found to show that the +engine satisfies this requirement, and for this reason, that the +cut-off valve commences to close the port immediately after the piston +commences to move. The cut off eccentric you will remember is set to +move with the crank or very nearly so, and the lighter the load, the +greater will this fact appear. For the lightest loads the governor +places the eccentric in advance of the crank, so that the cut off +valve will commence to close the port before steam is admitted by the +main valve to the engine. Now, the later the cut off, the less will +this wire drawing appear at first, and the shorter the cut off, the +amount of wire drawing increases sensibly. The operation of the valve, +therefore, in this particular, cannot be considered as meeting our +requirement that the port shall be held open full width until ready to +be closed. Many men claim for this engine that the closing occurs when +the cut off eccentric is moving its fastest. This is a fact, and if we +consider the point of cut off only to be the point of absolute cut +off, the cut off must be instantaneous, for there is an instantaneous +point where the cut off is final only to be considered. The reasoning +applied here would hold good also to a less extent on the slide valve, +but is not the point of absolute cut off. We want to note how long it +is from the time the valve commences to close at all until finally +closed, and, as I have shown you, this is considerable in this engine. + +Referring to the point of cut off finally, it is determined upon by a +governor of the fly wheel type. The eccentric is loose about the +shaft, and arms projecting therefrom are connected by other arms to +the extremity of an arm upon which is mounted a weight, and which is +attached to the spokes of the fly wheel, or special governor wheel in +this case, and which is fastened to the crank shaft. As the speed +increases through throwing off a portion of the load the governor +weights fly out, and this movement is transferred through the lever +connections to the eccentric, causing it to be turned ahead, and the +manner hastening the movement of the cut off valve on its seat and +causing it to reach and cover the edge of the steam port earlier in +the stroke. This engine was the pioneer in governors of this +character, the advantage being, in addition to its necessity for the +work of turning the eccentric ahead or back, that the liability of the +engine to run away, as very often happens from the breaking of the +governor belt or a similar cause, was not possible. + +The cut off valve has a travel considerably beyond the edge of the +steam passage after the valve is closed, and this has one advantage, +that the valve is less liable to leak, and to this must be added the +loss from the friction of this moving valve, and moving too in +opposition to the main valve. In our perfect valve, as we outlined it, +the valve does not move after the port is closed. The exhausting +functions of the valve are very good, giving a quick opening and a +full opening, because this opening occurs when the eccentric is moving +its fastest. The engine also possesses a distinct advantage in having +remarkably small clearance spaces. The length of the steam passage is +very small in comparison with any form of engine, and having but two +ports instead of four, as in the Corliss and four valve type. + +In these there must be included in the clearance, that to the exhaust +port as well as the steam port, adding a considerable amount where the +piston comes close to the head. As the engines leave the maker's hand +the engines are provided with a considerable amount of lap to give +plenty of compression, but are, of course, capable of having more +added to increase compression, or some planed off to decrease it. + +One of the peculiar things about this engine is the failure to realize +anywhere near boiler pressure, noticeable in every case that has come +under my notice. The considerable lead gives it for an instant, but it +soon falls away, indicating the steam chest pressure only by a peak at +the junction of the admission and steam lines. This is probably due to +the fact that the cut off valve commences closing the steam passage so +soon after steam is admitted, and in this particular does not satisfy +the requirements of a perfect valve. There is this about the engine, +that above all others of this type there has come under my notice +fewer engines of this type with a maladjustment of valves from +tampering by incompetent engineers. + + * * * * * + + + + +FIRING POINTS OF VARIOUS EXPLOSIVES. + + +An apparatus, devised by Horsley, was used, which consisted of an iron +stand with a ring support holding a hemispherical iron vessel, in +which paraffin or tin was put. Above this was another movable support, +from which a thermometer was suspended and so adjusted that its bulb +was immersed in molten material in the iron vessel. A thin copper +cartridge case, 5/8 in. in diameter and 1-5/16 in. long, was suspended +over the bath by means of a triangle, so that the end of the case was +1 in. below the surface of the liquid. On beginning the experiment the +material in the bath was heated to just above the melting point, the +thermometer was inserted in it, and a minute quantity of the explosive +was placed in the bottom of the cartridge case. The temperature marked +by the thermometer was noted as the _initial temperature_, the +cartridge case containing the explosive was inserted in the bath, and +the temperature quickly raised until the explosive flashed off or +exploded, when the temperature marked by the thermometer was again +noted as the _firing point_. The tables given show the results of +about six experiments with each explosive. The initial temperatures +range from 65° to 280° C. in some cases, but as the firing points +remained fairly constant, only the extremes of the latter are quoted +in the following table: + + + --------------------------------+----------------------- + Description of Explosive. | Firing Point in ° C. + --------------------------------+----------------------- + Compressed military gun-cotton. | 186 - 201 + Air-dried military gun-cotton. | 179 - 186 + " " " | 186 - 189 + " " " | 137 - 139 + " " " | 154 - 161 + Gun-cotton dried at 65° C. | 136 - 141 + Air-dried collodion gun-cotton. | 186 - 191 + " " " | 197 - 199 + " " " | 193 - 195 + Air-dried gun-cotton. | 192 - 197 + " " | 194 - 199 + Hydro-nitrocellulose. | 201 - 213 + Nitroglycerin. | 203 - 205 + Kieselghur dynamite. No. 1. | 197 - 200 + Explosive gelatin. | 203 - 209 + Explosive gelatin, camphorated. | 174 - 182 + Mercury fulminate. | 175 - 181 + Gunpowder. | 278 - 287 + Hill's picric powder. | 273 - 283 + " " " | 273 - 290 + Forcite, No. 1. | 184 - 200 + Atlas powder, 75 per cent. | 175 - 185 + Emmensite, No. 1. | 167 - 184 + Emmensite, No. 2. | 165 - 177 + Emmensite, No. 5. | 205 - 217 + --------------------------------+----------------------- + _--C.E. Munroe, J. Amer. Chem. Soc._ + + + * * * * * + + + + +STATION FOR TESTING AGRICULTURAL MACHINES. + + +The minister of agriculture has recently established a special +laboratory for testing agricultural _materiel_. This establishment, +which is as yet but little known, is destined to render the greatest +services to manufacturers and cultivators. + +In fact, agriculture now has recourse to physics and mechanics as well +as to chemistry. Now, although there were agricultural laboratories +whose mission it was to fix the choice of the cultivator upon such or +such a seed or fertilizer, there was no official establishment +designed to inform him as to the value of machines, the models of +which are often very numerous. _Chemical_ advice was to be had, but +_mechanical_ advice was wanting. It is such a want that has just been +supplied. Upon the report presented by Mr. Tisserand, director of +agriculture, a ministerial decree of the 24th of January, 1888, +ordered the establishment of an experimental station. Mr. Ringelmann, +professor of rural engineering at the school of Grignon, was put in +charge of the installation of it, and was appointed its director. He +immediately began to look around for a site, and on the 17th of +December, 1888, the Municipal Council of Paris, taking into +consideration the value of such an establishment to the city's +industries, decided that a plot of ground of an area of 3,309 square +meters, situated on Jenner Street, should be put at the disposal of +the minister of agriculture for fifteen years for the establishment +thereon of a trial station. This land, bordering on a very wide street +and easy of access, opposite the municipal buildings, offers, through +its area, its situation, and its neigborhood, indisputable advantages. +A fence 70 meters in extent surrounds the station. An iron gate opens +upon a paved path that ends at the station. + +The year 1889 was devoted to the installation, and the station is now +in full operation. The tests that can be made here are many, and +concern all kinds of apparatus, even those connected with the electric +lighting that the agriculturist may employ to facilitate his +exploitation. However, the tests that are oftenest made are (1) of +rotary apparatus, such as mills, thrashing machines, etc.; (2) of +traction machines, such as wagons, carts, plows, etc.; and (3) of +lifting apparatus. It is possible, also, to make experiments on the +resistance of materials. + +The experimental hall contains a 7 horse power gas motor, dynamometers +with automatic registering apparatus, counters, balances, etc. A small +machine shop contains a lathe, a forge, a drilling machine, etc. The +main shaft is 12 meters in length and is 7 centimeters in diameter. It +is supported at a distance of one meter from the floor by four pillow +blocks, and is formed of three sections united by movable coupling +boxes. Out of these 12 meters, 9 are in the hall and 3 extend beyond +the hall to an annex, 14 meters in length and 4 in width, in which +tests are made of machines whose operation creates dust. When the +machines to be tested require more than the power of seven horses that +the motor gives, the persons interested furnish a movable engine, +which, placed under the annex, actuates the driving shaft. Alongside +of the main building there is a ring for experimenting upon machines +actuated by a horse whim. There will soon be erected in the center of +the grounds an 18 meter tower for experiments on pumps. Platforms +spaced 5 meters apart, a crane at the top, and some gauging apparatus +will complete this hydraulic installation. + +The equipment of the hall is very complete, and is fitted for all +kinds of experiments. + +[Illustration: STATION FOR TESTING AGRICULTURAL MACHINES--DYNAMOMETER + FOR TESTING ROTARY MACHINES.] + +The tests of rotary machines are made by means of a dynamometer (see +figure). Two fast pulleys and one loose pulley are interposed between +the machine to be tested and the motor. The pulley connected with the +motor carries along the one connected with the machine, through the +intermedium of spring plates, whose strength varies with the nature of +the apparatus to be tested. The greater or less elongation of these +plates gives the tangential stress exerted by the driving pulley to +carry along the pulley that actuates the machine to be tested. This +elongation is registered by means of a pencil connected with the +spring plates, and which draws a diagram upon a sheet of paper. At the +same time, a special totalizer gives the stress in kilogrammeters. +Besides, the pulley shaft actuates a revolution counter, and a clock +measures the time employed in the experiment. In order to obtain a +simultaneous starting and stopping point for all these apparatus, they +are connected electrically, and, through the maneuver of a commutator, +are all controlled at once. The electric current is furnished by two +series of bichromate batteries. + +The tests of traction machines are effected by means of a +three-wheeled vehicle carrying a dynamometer. The front wheel is +capable of turning freely in the horizontal plane, and the dynamometer +is mounted upon a frame provided with a screw that permits of +regulating its position according to the slope of the ground. The +method of suspension of the dynamometer allows it to take +automatically the inclination of the line of traction without any +torsion of the plates. There are two models of this vehicle, one +designed to be drawn by a man, and the other by a horse. + +The station is provided, in addition, with registering pressure +gauges, a large double dynamometric indicator, a counter of +electricity, balances of precision, etc. + +An apparatus designed for measuring the rendering of presses is now in +course of construction. + +Although the station has been in operation only from the 1st of +January, twenty-five machines have already been presented to be +tested.--_Extract from Le Genie Civil_. + + * * * * * + + + + +WATER SOFTENING AND PURIFYING APPARATUS. + + +We have recently had brought under our notice a system of water and +sewage purification which appears to possess several substantial +advantages. Chief among these are simplicity in construction and +operation, economy in first cost and working and efficiency in action. +This system is the invention of Messrs. Slack & Brownlow, of Canning +Works, Upper Medlock Street, Manchester, and the apparatus adopted in +carrying it out is here illustrated. It consists of an iron +cylindrical tank having inside a series of plates arranged in a spiral +direction around a fixed center, and sloping downward at a +considerable angle outward. The water to be purified and softened +flows through the large inlet tube to the bottom, mixing on its way +with the necessary chemicals, and entering the apparatus at the +bottom, rises to the top, passing spirally round the whole +circumference, and depositing on the plates all solids and impurities. + +All that is needed in the way of attention, even when dealing with +sewage, or the most polluted waters, is stated to be the mixing in the +small tanks the necessary chemical reagents, at the commencement of +the working day; and at the close of the day the opening of the mud +cocks shown in our engraving, to remove the collected deposit upon the +plates. For the past six months this system has been in operation at a +dye works in Manchester, successfully purifying and softening the +foul waters of the river Medlock. It is stated that 84,000 gallons per +day can be easily purified by an apparatus 7 feet in diameter. The +chemicals used are chiefly lime, soda, and alumina, and the cost of +treatment is stated to vary from a farthing to twopence per 1,000 +gallons, according to the degree of impurity of the water or sewage +treated. + +The results of working at Manchester show that all the visible filth +is removed from the Medlock's inky waters, besides which the hardness +of the water is reduced to about 6° from a normal condition of about +30°. The effluent is fit for all the varied uses of a dye works, and +is stated to be perfectly capable of sustaining fish life. With +results such as these the system should have a promising future before +it in respect of sewage treatment, as well as the purification and +softening of water generally for industrial and manufacturing +purposes.--_Iron._ + +[Illustration: WATER SOFTENING AND PURIFYING APPARATUS.] + + * * * * * + + + + +THE TRISECTION OF ANY ANGLE. + +By FREDERIC R. HONEY, Ph.B., Yale University. + + +The following analysis shows that with the aid of an hyperbola any +arc, and therefore any angle, may be trisected. + +If the reader should not care to follow the analytical work, the +construction is described in the last paragraph--referring to Fig. II. + +Let a b c d (Fig. I.) be the arc subtending a given angle. Draw the +chord a d and bisect it at o. Through o draw e f perpendicular +to a d. + +We wish to find the locus of a point c whose distance from a given +straight line e f is one-half the distance from a given point d. + +In order to write the equation of this curve, refer it to the +co-ordinate axes a d (axis of X) and e f (axis of Y), intersecting +at the origin o. + + Let g c = x + +Therefore, from the definition c d = 2x + + Let o d = D + [Hence] h d = D-x + + Let c h = y + [Hence] (2x)² = y² + (D-x)² + or 4x² = y² + D²-2Dx + x² + [Hence] y²-3x² + D²-2Dx = o [I.] + +This is the equation of an hyperbola whose center is on the axis of +abscisses. In order to determine the position of the center, eliminate +the x term, and find the distance from the origin o to a new origin +o'. + + Let E = distance from o to o' + [Hence] x = x' + E + +Substituting this value of x in equation I. + + y²-3(x' + E)² + D²-2D(x' + E) = o + or y²-3x²-6Ex'-3E² + D²-2Dx'-2DE = o [II.] + +In this equation the x' terms should disappear. + + [Hence] -6Ex' - 2Dx' = o + [Hence] -E = - D/3 + +That is, the distance from the origin o to the new origin or the +center of the hyperbola o' is equal to one-third of the distance +from o to d; and the minus sign indicates that the measurement +should be laid off to the left of the origin o. Substituting this +value of E in equation II., and omitting accents-- + + We have + + y² - 3x² + 2Dx - D²/3 + D² - 2Dx + 2D²/3 = o + [Hence] y² - 3x² = - 4D²/3 + +[Illustration: Fig I] + +[Illustration: Fig II] + +This is the equation of an hyperbola referred to its center o' as +the origin of co-ordinates. To write it in the ordinary form, that is +in terms of the transverse and conjugate axes, multiply each term by +C, i.e., + __ + Let \/C = semi-transverse axis. + +[TEX: \sqrt{C} = \text{semi-transverse axis.}] + + Thus Cy² - 3Cx² = - 4CD²/3. [III.] + +When in this form the product of the coefficients of the x² and y² +terms should be equal to the remaining term. + +That is + + 3C² = - 4CD²/3. + [Hence] C = 4D²/9. + +And equation III. becomes: + + + 4D² 4D² 16D^{4} + ----- y² - ----- x² = - --------- + 9 3 27 + +[TEX: \frac{4D^2}{9} y^2 - \frac{4D^2}{3} x^2 = -\frac{16D^4}{27}] + ____ + / 4D² 2D + The semi-transverse axis = \/ ----- = ---- + 9 3 + +[TEX: \text{The semi-transverse axis} = \sqrt{\frac{4D^2}{9}} += \frac{2D}{3}] + ____ + / 4D² 2D + The semi-conjugate axis = \/ ----- = ----- + 3 ___ + \/ 3 + +[TEX: \text{The semi-conjugate axis} = \sqrt{\frac{4D^2}{3}} += \frac{2D}{\sqrt{3}}] + +Since the distance from the center of the curve to either focus is +equal to the square root of the sum of the squares of the semi-axes, +the distance from o' to either focus + + ____________ + /4D² 4D² 4D + = /\ /----- + ----- = ---- + \/ 9 3 3 + +[TEX: \sqrt{\frac{4D^2}{9} + \frac{4D^2}{3}} = \frac{4D}{3}] + +We can therefore make the following construction (Fig. II.) Draw a d +the chord of the arc a c d. Trisect a d at o' and k. Produce +d a to l, making a l = a o' = o' k = k d. With a k as a +transverse axis, and l and d as foci, construct the branch of the +hyperbola k c c' c", which will intersect all arcs having the common +chord a d at c, c', c", etc., making the arcs c d, c' d, c" +d, etc., respectively, equal to one-third of the arcs a c d, a c' d, +a c" d, etc. + + * * * * * + + + + +TEST CARD HINTS. + +By Dr. F. OGDEN STOUT. + + +I know it is the custom with a great many if not the majority of +opticians to fit a customer without knowing whether he has presbyopia, +hypermetropia, or any of the other errors of refraction. Their method +is first to try a convex, and if this does not improve, a concave, +etc., until the proper one is found. This, of course, amounts to the +same thing if the right glass is found. But in practice it will be +found both time saving and more satisfactory to first decide with what +error you have to deal. It is very simple, and, where you have no +other means of diagnosing (such as the ophthalmoscope), it does away +with the necessity of trying so many lenses before the proper one is +found. You should have a distance test card placed at a distance of +twenty feet from the person you are examining, and in a good light. + +A distance test card consists of letters of various sizes which it has +been found can be seen at certain distances by people with good +vision. Thus the largest letter is marked with a cc, meaning that this +should be seen at two hundred feet, and another line, XX, at twenty +feet, which is the proper distance for testing vision for distance, +for the reason that a normal eye is at rest when looking at any object +twenty feet from it or beyond, and the rays coming from it are +parallel and come to a focus on the retina. You must also have a near +vision test card with lines that should be seen by a normal eye from +ten to seventy-two inches, and a card of radiating lines for +astigmatism. With this preparation you are ready to proceed. To +illustrate, the first customer comes and tells you that up to six +months ago he had very good vision, but he finds now that, especially +at night, he has trouble in reading or writing, and that he finds he +can see better a little farther away. His head aches and eyes smart. +You will of course say that this is a very simple case. It must be old +sight (presbyopia). Probably it is if he is old enough (45), but you +must prove this for yourself, without asking his age, which is +embarrassing in the case of a lady. If you direct him to the distance +card twenty feet away, and find that he can see every one down to and +including the one marked XX, his vision is up to the standard for +distance, and you know that he can have no astigmatism worth +correcting, nor any near sight, as both of these affect vision for +distance, but he may have far sight or old sight or both combined. You +must find which it is. + +If, while he is still looking at the twenty-foot line, you place in +front of the eyes a weak convex and he tells you he sees just as well +with as without, it proves the existence of far-sight or +hypermetropia, and the strongest convex that still leaves vision as +good for distance as without any, corrects the manifest. But if the +weak convex blurs it, it shows that there is some defect in focusing, +if the near vision is below normal. You therefore know that you have a +case of old sight or presbyopia, requiring the weakest convex to +correct it, that will enable your customer to see the finest line on +the near card at the required distance. + +The next customer that comes to be fitted with glasses can only see +the line marked XL on the distance card at 20 feet or about one-half +of what he should see, which leads you to think that there is no far +sight, for vision for distance is good except in very high degrees of +this error. Nor can there be old-sight, for vision for distance is +good in old-sight until after the fifty-fifth year, but it can be near +sight (myopia) or astigmatism, or both. We next try the near card and +find that even the finest line can be seen clearly if held +sufficiently close to the eyes. We now know that this is a case of +near sight, and we must fit them with glasses for distance. The +weakest concave that will enable him to see the line that should be +seen on the distance card at 20 feet is the proper one to give him for +use.--_The Optician._ + + * * * * * + + + + +CHARLES GOODYEAR. + + +CHARLES GOODYEAR was born in New Haven, December 29, 1800. He was the +son of Amasa Goodyear, and the eldest among six children. His father +was quite proud of being a descendant of Stephen Goodyear, one of the +founders of the colony of New Haven in 1638. + +Amasa Goodyear owned a little farm on the neck of land in New Haven +which is now known as Oyster Point, and it was here that Charles spent +the earliest years of his life. When, however, he was quite young, his +father secured an interest in a patent for the manufacture of ivory +buttons, and looking for a convenient location for a small mill, +settled at Naugatuck, Conn., where he made use of the valuable water +power that is there. Aside from his manufacturing, the elder Goodyear +ran a farm, and between the two lines of industry kept young Charles +pretty busy. + +In 1816, Charles left his home and went to Philadelphia to learn the +hardware business. He worked at this very industriously until he was +twenty-one years old, and then, returning to Connecticut, entered into +partnership with his father at the old stand in Naugatuck, where they +manufactured not only ivory and metal buttons, but a variety of +agricultural implements, which were just beginning to be appreciated +by the farmers. In August of 1824 he was united in marriage with +Clarissa Beecher, a woman of remarkable strength of character and +kindness of disposition, and one who in after years was of the +greatest assistance to the impulsive inventor. Two years later he +removed again to Philadelphia, and there opened a hardware store. His +specialties were the valuable agricultural implements that his firm +had been manufacturing, and after the first distrust of home made +goods had worn away--for all agricultural implements were imported +from England at that time--he found himself established at the head of +a successful business. + +This continued to increase until it seemed but a question of a few +years until he would be a very wealthy man. Between 1829 and 1830 he +suddenly broke down in health, being troubled with dyspepsia. At the +same time came the failure of a number of business houses that +seriously embarrassed his firm. They struggled on, however, for some +time, but were finally obliged to fail. The ten years that followed +this were full of the bitterest struggles and trials to Goodyear. +Under the law that then existed he was imprisoned time after time for +debts, even while he was trying to perfect inventions that should pay +off his indebtedness. + +Between the years 1831 and 1832 he began to hear about gum elastic and +very carefully examined every article that appeared in the newspapers +relative to this new material. The Roxbury Rubber Company, of Boston, +had been for some time experimenting with the gum, and believing that +they had found means for manufacturing goods from it, had a large +plant and were sending their goods all over the country. It was some +of their goods that first attracted his attention. Soon after this +Goodyear visited New York, and went at once to the store of the +Roxbury Rubber Company. While there, he examined with considerable +care some of their life preservers, and it struck him that the tube +used for inflation was not very perfect. He, therefore, on his return +to Philadelphia, made some tubes and brought them down to New York and +showed them to the manager of the Roxbury Rubber Company. + +This gentlemen was so pleased with the ingenuity that Goodyear had +shown in manufacturing these tubes, that he talked very freely with +him and confessed to him that the business was on the verge of ruin, +that the goods had to be tested for a year before they could tell +whether they were perfect or not, and to their surprise, thousands of +dollars worth of goods that they had supposed were all right were +coming back to them, the gum having rotted and made them so offensive +that it was necessary to bury them in the ground to get them out of +the way. + +Goodyear at once made up his mind to experiment on this gum and see if +he could not overcome its stickiness. + +He, therefore, returned to Philadelphia, and, as usual, met a +creditor, who had him arrested and thrown into prison. While there, he +tried his first experiments with India rubber. The gum was very cheap +then, and by heating it and working it in his hands, he managed to +incorporate in it a certain amount of magnesia which produced a +beautiful white compound and appeared to take away the stickiness. + +He therefore thought he had discovered the secret, and through the +kindness of friends was put in the way of further perfecting his +invention at a little place in New Haven. The first thing that he made +here was shoes, and he used his own house for grinding room, calender +room, and vulcanizing department, and his wife and children helped to +make up the goods. His compound at this time was India rubber, +lampblack, and magnesia, the whole dissolved in turpentine and spread +upon the flannel cloth which served as the lining for the shoes. It +was not long, however, before he discovered that the gum, even treated +this way, became sticky, and then those who had supplied the money for +the furtherance of these experiments, completely discouraged, made up +their minds that they could go no further, and so told the inventor. + +[Illustration: CHARLES GOODYEAR.] + +He, however, had no mind to stop here in his experiments, but, selling +his furniture and placing his family in a quiet boarding place, he +went to New York, and there, in an attic, helped by a friendly +druggist, continued his experiments. His next step in this line was to +compound the rubber with magnesia and then boil it in quicklime and +water. This appeared to really solve the problem, and he made some +beautiful goods. At once it was noised abroad that India rubber had +been so treated that it lost its stickiness, and he received medals +and testimonials and seemed on the high road to success, till one day +he noticed that a drop of weak acid, falling on the cloth, neutralized +the alkali, and immediately the rubber was soft again. To see this, +with his knowledge of what rubber should do, proved to him at once +that his process was not a successful one. He therefore continued +experimenting, and after preparing his mixtures in his attic in New +York, would walk three miles to the mill of a Mr. Pike, at Greenwich +village, and there try various experiments. + +In the line of these, he discovered that rubber, dipped in nitric +acid, formed a surface cure, and he made a great many goods with this +acid cure which were spoken of, and which even received a letter of +commendation from Andrew Jackson. + +The constant and varied experiments that Goodyear went through with +affected his health more or less, and at one time he came very near +being suffocated by gas generated in his laboratory. That he did not +die then everybody knows, but he was thrown then into a fever by the +accident and came very near losing his life. + +It was there that he formed an acquaintance with Dr. Bradshaw, who was +very much pleased with the samples of rubber goods that he saw in +Goodyear's room, and when the doctor went to Europe he took them with +him, where they attracted a great deal of attention, but beyond that +nothing was done about them. Now that he appeared to have success, he +found no difficulty in obtaining a partner, and together the two +gentlemen fitted up a factory and began to make clothing, life +preservers, rubber shoes, and a great variety of rubber goods. They +also had a large factory, with special machinery, built at Staten +Island, where he removed his family and again had a home of his own. +Just about this time, when everything looked bright, the great panic +of 1836-1837 came, and swept away the entire fortune of his associate +and left Goodyear without a cent, and no means of earning one. + +His next move was to go to Boston, where he became acquainted with J. +Haskins, of the Roxbury Rubber Company, and found in him a firm +friend, who loaned him money and stood by him when no one would have +anything to do with the visionary inventor. Mr. Chaffee was also +exceedingly kind and ever ready to lend a listening ear to his plans, +and to also assist him in a pecuniary way. It was about this time that +it occurred to Mr. Chaffee that much of the trouble that they had +experienced in working India rubber might come from the solvent that +was used. He therefore invented a huge machine for doing the mixing +by mechanical means. The goods that were made in this way were +beautiful to look at, and it appeared, as it had before, that all +difficulties were overcome. + +Goodyear discovered a new method for making rubber shoes and got a +patent on it, which he sold to the Providence Company, in Rhode +Island. + +The secret of making the rubber so that it would stand heat and cold +and acids, however, had not been discovered, and the goods were +constantly growing sticky and decomposing and being returned. + +In 1838 he, for the first time, met Nathaniel Hayward, who was then +running a factory in Woburn. Some time after this Goodyear himself +moved to Woburn, all the time continuing his experiments. He was very +much interested in Hayward's sulphur experiments for drying rubber, +but it appears that neither of them at that time appreciated the fact +that it needed heat to make the sulphur combine with the rubber and to +vulcanize it. + +The circumstances attending the discovery of his celebrated process is +thus described by Mr. Goodyear himself in his book, "Gum Elastic." It +will be observed that he makes use of the third person in all +references to himself: + + "In the summer of 1838 he became acquainted with Mr. Nathaniel + Hayward, of Woburn, Mass., who had been employed as the foreman of + the Eagle Company at Woburn, where he had made use of sulphur by + impregnating the solvent with it. It was through him that the + writer (Charles Goodyear, who makes use all through his book of + the third person) received the first knowledge of the use of + sulphur as a drier of gum elastic. + + "Mr. Hayward was left in possession of the factory which was + abandoned by the Eagle Company. Soon after this it was occupied by + the writer, who employed him for the purpose of manufacturing life + preservers and other articles by the acid gas process. At this + period he made many novel and useful applications of this + substance. Among other fancy articles he had newspapers printed on + the gum elastic drapery, and the improvement began to be highly + appreciated. He therefore now entered, as he thought, upon a + successful career for the future. A far different result awaited + him. + + "It was supposed by others as well as himself that a change was + wrought through the mass of the goods acted upon by the acid gas, + and that the whole body of the article was made better than the + native gum. The surface of the goods really was so, but owing to + the eventual decomposition of the goods beneath the surface, the + process was pronounced by the public a complete failure. Thus + instead of realizing the large fortune which by all acquainted + with his prospects was considered certain, his whole invention + would not bring him a week's living. + + "He was obliged for the want of means to discontinue + manufacturing, and Mr. Hayward left his employment. The inventor + now applied himself alone, with unabated ardor and diligence, to + detect the cause of his misfortune and if possible to retrieve the + lost reputation of his invention. On one occasion he made some + experiments to ascertain the effect of heat upon the same compound + that had decomposed in the articles previously manufactured, and + was surprised to find that the specimen, being carelessly brought + in contact with a hot stove, charred like leather. He endeavored + to call the attention of his brother as well as some other + individuals who were present, and who were acquainted with the + manufacture of gum elastic, to this effect as remarkable and + unlike any before known, since gum elastic always melted when + exposed to a high degree of heat. The occurrence did not at the + time appear to them to be worthy of notice. It was considered as + one of the frequent appeals that he was in the habit of making in + behalf of some new experiment. He, however, directly inferred that + if the process of charring could be stopped at the right point, it + might divest the gum of its native adhesiveness throughout, which + would make it better than the native gum. + + "He made another trial of heating a similar fabric, before an open + fire. The same effect, that of charring the gum, followed, but + there were further and very satisfactory indications of ultimate + success in producing the desired result, as upon the edge of the + charred portions of the fabric there appeared a line, or border, + that was not charred, but perfectly cured. + + "These facts have been stated precisely as they occurred in + reference to the acid gas, as well as the vulcanizing process. + + "The incidents attending the discovery of both have a strong + resemblance, so much so they may be considered parallel cases. It + being now known that the results of the vulcanizing process are + produced by means and in a manner which would not have been + anticipated from any reasoning on the subject, and that they have + not yet been satisfactorily accounted for, it has been sometimes + asked, how the inventor came to make the discovery? The answer has + already been given. It may be added that he was many years seeking + to accomplish this object, and that he allowed nothing to escape + his notice that related to the subject. Like the falling of an + apple, it was suggestive of an important fact to one whose mind + was previously prepared to draw an inference from any occurrence + which might favor the object of his research. While the inventor + admits that these discoveries were not the results of scientific + chemical investigations, _he is not willing to admit that they + were the result of what is commonly termed accident_; he claims + them to be the result of the closest application and observation. + + "The discoloring and charring of the specimens proved nothing and + discovered nothing of value, but quite the contrary, for in the + first instance, as stated in the acid gas improvement, the + specimen acted upon was thrown away as worthless and left for some + time; in the latter instance, the specimen that was charred was in + like manner disregarded by others. + + "It may, therefore, be considered as one of those cases where the + leading of the Creator providentially aids his creatures, by what + are termed 'accidents,' to attain those things which are not + attainable by the powers of reasoning he has conferred on them." + +Now that Goodyear was sure that he had the key to the intricate puzzle +that he had worked over for so many years, he began at once to tell +his friends about it and to try to secure capital, but they had +listened to their sorrow so many times that his efforts were futile. +For a number of years be struggled and experimented and worked along +in a small way, his family suffering with himself the pangs of the +extremest poverty. At last he went to New York and showed some of his +samples to William Ryder, who, with his brother Emory, at once +appreciated the value of the discovery and started in to +manufacturing. Even here Goodyear's bad luck seemed to follow him, for +the Ryder Bros. failed and it was impossible to continue the business. + +He had, however, started a small factory at Springfield, Mass., and +his brother-in-law, Mr. De Forest, who was a wealthy woolen +manufacturer, took Ryder's place, and the work of making the invention +practical was continued. In 1844 it was so far perfected that Goodyear +felt it safe to take out a patent. The factory at Springfield was run +by his brothers, Nelson and Henry. + +In 1843 Henry started one in Naugatuck, and in 1844 introduced +mechanical mixing in place of the mixture by the use of solvents. + +In the year 1852 Goodyear went to Europe, a trip that he had long +planned, and saw Hancock, then in the employ of Charles Macintosh & +Co. Hancock admitted in evidence that the first piece of vulcanized +rubber he ever saw came from America, but claimed to have reinvented +vulcanization and secured patents in Great Britain, but it is _a +remarkable fact_ that Charles Goodyear's French patent was the first +publication in Europe of this discovery. + +In 1852 a French company were licensed by Mr. Goodyear to make shoes, +and a great deal of interest was felt in the new business. In 1855 the +French emperor gave to Charles Goodyear the grand medal of honor and +decorated him with the cross of the legion of honor in recognition of +his services as a public benefactor, but the French courts +subsequently set aside his French patents on the ground of the +importation of vulcanized goods from America by licenses under the +United States patents. He died July 1, 1860, at the Fifth Avenue +Hotel, New York City.--_India Rubber World_. + + * * * * * + +[Continued from SUPPLEMENT, No. 786, page 12558.] + + + + +THE ELECTROMAGNET. + +[Footnote: Lectures delivered before the Society of Arts, London, +1890. From the Journal of the Society.] + +BY PROFESSOR SILVANUS P. THOMPSON, D. SC., B.A., M.I.E.E. + +III. + +RESEARCHES OF PROFESSOR HUGHES. + + +[Illustration: FIG. 51.--HUGHES' ELECTROMAGNET.] + +His object was to find out the best form of electromagnet, the best +distance between the poles, and the best form of armature for the +rapid work required in Hughes' printing telegraphs. One word about +Hughes' magnets. This diagram (Fig. 51) shows the form of the well +known Hughes' electromagnet. I feel almost ashamed to say those words +"well known," because on the Continent everybody knows what you mean +by a Hughes' electromagnet. In England scarcely anyone knows what you +mean. Englishmen do not even know that Professor Hughes has invented a +special form of electromagnet. Hughes' special form is this: A +permanent steel magnet, generally a compound one, having soft iron +pole pieces, and a couple of coils on the pole pieces only. As I have +to speak of Hughes' special contrivance among the mechanisms that will +occupy our attention later on, I only now refer to this magnet in one +particular. If you wish a magnet to work rapidly, you will secure the +most rapid action, not when the coils are distributed all along, but +when they are heaped up near, not necessarily entirely on, the poles. +Hughes made a number of researches to find out what the right length +and thickness of these pole pieces should be. It was found an +advantage not to use too thin pole pieces, otherwise the magnetism +from the permanent magnet did not pass through the iron without +considerable reluctance, being choked by insufficiency of section: +also not to use too thick pieces, otherwise they presented too much +surface for leakage across from one to the other. Eventually a +particular length was settled upon, in proportion about six times the +diameter, or rather longer. In the further researches that Hughes made +he used a magnet of shorter form, not shown here, more like those +employed in relays, and with an armature from 2 to 3 millimeters +thick, 1 centimeter wide and 5 centimeters long. The poles were turned +over at the top toward one another. Hughes tried whether there was any +advantage in making those poles approach one another, and whether +there was any advantage in having as long an armature as 5 +centimeters. He tried all the different kinds, and plotted out the +results of observations in curves, which could be compared and +studied. His object was to ascertain the conditions which would give +the strongest pull, not with a steady current, but with such currents +as were required for operating his printing telegraph instruments; +currents which lasted but one to twenty hundredths of a second. He +found it was decidedly an advantage to shorten the length of the +armature, so that it did not protrude far over the poles. In fact, he +got a sufficient magnetic circuit to secure all the attractive power +that he needed, without allowing as much chance of leakage as there +would have been had the armature extended a longer distance over the +poles. He also tried various forms of armature having very various +cross sections. + + +POSITION AND FORM OF ARMATURE. + +In one of Du Moncel's papers on electromagnets[1] you will also find a +discussion on armatures, and the best forms for working in different +positions. Among other things in Du Moncel you will find this paradox: +that whereas using a horseshoe magnet with fat poles, and a flat piece +of soft iron for armature, it sticks on far tighter when put on +edgeways; on the other hand, if you are going to work at a distance, +across air, the attraction is far greater when it is set flatways. I +explained the advantage of narrowing the surfaces of contact by the +law of traction, B², coming in. Why should we have for action at a +distance the greater advantage from placing the armature flatway to +the poles? It is simply that you thereby reduce the reluctance offered +by the air gap to the flow of the magnetic lines. Du Moncel also tried +the difference between round armatures and flat ones, and found that a +cylindrical armature was only attracted about half as strongly as a +prismatic armature having the same surface when at the same distance. +Let us examine this fact in the light of the magnetic circuit. The +poles are flat. You have at a certain distance away a round armature; +there is a certain distance between its nearest side and the polar +surfaces. If you have at the same distance away a flat armature having +the same surface, and, therefore, about the same tendency to leak, why +do you get a greater pull in this case than in that? I think it is +clear that if they are at the same distance away, giving the same +range of motion, there is a greater magnetic reluctance in the case of +the round armature, although there is the same periphery, because, +though the nearest part of the surface is at the prescribed distance, +the rest of the under surface is farther away; so that the gain found +in substituting an armature with a flat surface is a gain resulting +from the diminution in the resistance offered by the air gap. + +[Footnote 1: "La Lumiere Electrique," vol. ii.] + + +POLE PIECES ON HORSESHOE MAGNETS. + +Another of Du Moncel's researches[2] relates to the effect of polar +projections or shoes--movable pole pieces, if you like--upon a +horseshoe electromagnet. The core of this magnet was of round iron 4 +centimeters in diameter, and the parallel limbs were 10 centimeters +long and 6 centimeters apart. The shoes consisted of two flat pieces +of iron slotted out at one end, so that they could be slid along over +the poles and brought nearer together. The attraction exerted on a +flat armature across air gaps 2 millimeters thick was measured by +counterpoising. Exciting this electromagnet with a certain battery, it +was found that the attraction was greatest when the shoes were pushed +to about 15 millimeters, or about one-quarter of the interpolar +distance, apart. The numbers were as follows: + + Distance between + shoes. Attraction, + Millimeters. in grammes. + + 2 900 + 10 1,012 + 15 1,025 + 25 965 + 40 890 + 60 550 + +[Footnote 2: "La Lumiere Electrique," vol. iv., p. 129.] + +With a stronger battery the magnet without shoes had an attraction of +885 grammes, but with the shoes 15 millimeters apart, 1,195 grammes. +When one pole only was employed, the attraction, which was 88 grammes +without a shoe, was _diminished_ by adding a shoe to 39 grammes! + + +CONTRAST BETWEEN ELECTROMAGNETS AND PERMANENT MAGNETS. + +Now I want particularly to ask you to guard against the idea that all +these results obtained from electromagnets are equally applicable to +permanent magnets of steel; they are not, for this simple reason. With +an electromagnet, when you put the armature near, and make the +magnetic circuit better, you not only get more magnetic lines going +through that armature, but you get more magnetic lines going through +the whole of the iron. You get more magnetic lines round the bend when +you put an armature on to the poles, because you have a magnetic +circuit of less reluctance with the same external magnetizing power in +the coils acting around it. Therefore, in that case, you will have a +greater magnetic flux all the way round. The data obtained with the +electromagnet (Fig. 42), with the exploring coil, C, on the bend of +the core, where the armature was in contact, and when it was removed +are most significant. When the armature was present it multiplied the +total magnetic flow tenfold for weak currents and nearly threefold for +strong currents. But with a steel horseshoe, magnetized once for all, +the magnetic lines that flow around the bend of the steel are a fixed +quantity, and, however much you diminish the reluctance of the +magnetic circuit, you do not create or evoke any more. When the +armature is away the magnetic lines arch across, not at the ends of +the horseshoe only, but from its flanks; the whole of the magnetic +lines leaking somehow across the space. Where you have put the +armature on, these lines, instead of arching out into space as freely +as they did, pass for the most part along the steel limbs and through +the iron armature. You may still have a considerable amount of +leakage, but you have not made one line more go through the bent part. +You have absolutely the same number going through the bend with the +armature off as with the armature on. You do not add to the total +number by reducing the magnetic reluctance, because you are not +working under the influence of a constantly impressed magnetizing +force. By putting the armature on to a steel horseshoe magnet you +only _collect_ the magnetic lines, you do not _multiply_ them. This is +not a matter of conjecture. A group of my students have been making +experiments in the following way: They took this large steel horseshoe +magnet (Fig. 52), the length of which, from end to end, through the +steel, is 42½ inches. A light, narrow frame was constructed so that it +could be slipped on over the magnet, and on it were wound 30 turns of +fine wire, to serve as an exploring coil. The ends of this coil were +carried to a distant part of the laboratory, and connected to a +sensitive ballistic galvanometer. The mode of experimenting is as +follows: + +The coil is slipped on over the magnet (or over its armature) to any +desired position. The armature of the magnet is placed gently upon the +poles, and time enough is allowed to elapse for the galvanometer +needle to settle to zero. The armature is then suddenly detached. The +first swing measures the change, due to removing the armature, in the +number of magnetic lines that pass through the coil in the particular +position. + +[Illustration: FIG. 52.--EXPERIMENT WITH PERMANENT MAGNET.] + +I will roughly repeat the experiment before you: The spot of light on +the screen is reflected from my galvanometer at the far end of the +table. I place the exploring coil just over the pole, and slide on the +armature; then close the galvanometer circuit. Now I detach the +armature, and you observe the large swing. I shift the exploring coil, +right up to the bend; replace the armature; wait until the spot of +light is brought to rest at the zero of the scale. Now, on detaching +the armature, the movement of the spot of light is quite +imperceptible. In our careful laboratory experiments, the effect was +noticed inch by inch all along the magnet. The effect when the +exploring coil was over the bend was not as great as 1-3000th part of +the effect when the coil was hard up to the pole. We are, therefore, +justified in saying that the number of magnetic lines in a permanently +magnetized steel horseshoe magnet is not altered by the presence or +absence of the armature. + +You will have noticed that I always put on the armature gently. It +does not do to slam on the armature; every time you do so, you knock +some of the so-called permanent magnetism out of it. But you may pull +off the armature as suddenly as you like. It does the magnet good +rather than harm. There is a popular superstition that you ought never +to pull off the keeper of a magnet suddenly. On investigation, it is +found that the facts are just the other way. You may pull off the +keeper as suddenly as you like, but you should never slam it on. + +From these experimental results I pass to the special design of +electromagnets for special purposes. + + +ELECTROMAGNETS FOR MAXIMUM TRACTION. + +These have already been dealt with in the preceding lecture; the +characteristic feature of all the forms suitable for traction being +the compact magnetic circuit. + +Several times it has been proposed to increase the power of +electromagnets by constructing them with intermediate masses of iron +between the central core and the outside, between the layers of +windings. All these constructions are founded on fallacies. Such iron +is far better placed either right inside the coils or right outside +them, so that it may properly constitute a part of the magnetic +circuit. The constructions known as Camacho's and Cance's, and one +patented by Mr. S.A. Varley, in 1877, belonging to this delusive order +of ideas, are now entirely obsolete. + +Another construction which is periodically brought forward as a +novelty is the use of iron windings of wire or strip in place of +copper winding. The lower electric conductivity of iron, as compared +with copper, makes such a construction wasteful of exciting power. To +apply equal magnetizing power by means of an iron coil implies the +expenditure of about six times as many watts as need be expended if +the coil is of copper. + + +ELECTROMAGNETS FOR MAXIMUM RANGE OF ATTRACTION. + +We have already laid down the principle which will enable us to design +electromagnets to act at a distance. We want our magnet to project, as +it were, its force across the greatest length of air gap. Clearly, +then, such a magnet must have a very large magnetizing power, with +many ampere turns upon it, to be able to make the required number of +magnetic lines pass across the air resistance. Also it is clear that +the poles must not be too close together for its work, otherwise the +magnetic lines at one pole will be likely to curl round and take short +cuts to the other pole. There must be a wider width between the poles +than is desirable in electromagnets for traction. + + +ELECTROMAGNETS OF MINIMUM WEIGHT. + +In designing an apparatus to put on board a boat or a balloon, where +weight is a consideration of primary importance, there is again a +difference. There are three things that come into play--iron, copper, +and electric current. The current weighs nothing, therefore, if you +are going to sacrifice everything else to weight, you may have +comparatively little iron, but you must have enough copper to be able +to carry the electric current; and under such circumstances you must +not mind heating your wires nearly red hot to pass the biggest +possible current. Provide as little copper as you conveniently can, +sacrificing economy in that case to the attainment of your object; +but, of course, you must use fireproof material, such as asbestos, for +insulating, instead of cotton or silk. + + +A USEFUL GUIDING PRINCIPLE. + +In all cases of design there is one leading principle which will be +found of great assistance, namely, that a magnet always tends so to +act as though it tried to diminish the length of its magnetic circuit. +It tries to grow more compact. This is the reverse of that which holds +good with an electric current. The electric circuit always tries to +enlarge itself, so as to inclose as much space as possible, but the +magnetic circuit always tries to make itself as compact as possible. +Armatures are drawn in as near as can be, to close up the magnetic +circuit. Many two-pole electromagnets show a tendency to bend together +when the current is turned on. One form in particular, which was +devised by Ruhmkorff for the purpose of repeating Faraday's celebrated +experiment on the magnetic rotation of polarized light, is liable to +this defect. Indeed, this form of electromagnet is often designed very +badly, the yoke being too thin, both mechanically and magnetically, +for the purpose which it has to fulfill. + +Here is a small electric bell, constructed by Wagener, of Wiesbaden, +the construction of which illustrates this principle. The +electromagnet, a horseshoe, lies horizontally; its poles are provided +with protruding curved pins of brass. Through the armature are drilled +two holes, so that it can be hung upon the two brass pins; and when so +hung up it touches the ends of the iron cores just at one edge, being +held from more perfect contact by a spring. There is no complete gap, +therefore, in the magnetic circuit. When the current comes and applies +a magnetizing power, it finds the magnetic circuit already complete in +the sense that there are no absolute gaps. But the circuit can be +bettered by tilting the armature to bring it flat against the polar +ends, that being indeed the mode of motion. This is a most reliable +and sensitive pattern of bell. + +[Illustration: FIG. 53.--ELECTROMAGNETIC POP-GUN.] + +_Electromagnetic Pop-gun._--Here is another curious illustration of +the tendency to complete the magnetic circuit. Here is a tubular +electromagnet (Fig. 53), consisting of a small bobbin, the core of +which is an iron tube about two inches long. There is nothing very +unusual about it; it will stick on, as you see, to pieces of iron when +the current is turned on. It clearly is an ordinary electromagnet in +that respect. Now suppose I take a little round rod of iron, about an +inch long, and put it into the end of the tube, what will happen when +I turn on my current? In this apparatus as it stands, the magnetic +circuit consists of a short length of iron, and then all the rest is +air. The magnetic circuit will try to complete itself, not by +shortening the iron, but by _lengthening_ it; by pushing the piece of +iron out so as to afford more surface for leakage. That is exactly +what happens; for, as you see, when I turn on the current, the little +piece of iron shoots out and drops down. You see that little piece of +iron shoot out with considerable force. It becomes a sort of magnetic +popgun. This is an experiment which has been twice discovered. I found +it first described by Count Du Moncel, in the pages of _La Lumiere +Electrique_, under the name of the "pistolet electromagnetique;" and +Mr. Shelford Bidwell invented it independently. I am indebted to him +for the use of this apparatus. He gave an account of it to the +Physical Society, in 1885, but the reporter missed it, I suppose, as +there is no record in the society's proceedings. + + +ELECTROMAGNETS FOR USE WITH ALTERNATING CURRENTS. + +When you are designing electromagnets for use with alternating +currents, it is necessary to make a change in one respect, namely, you +must so laminate the iron that internal eddy currents shall not occur; +indeed, for all rapid-acting electromagnetic apparatus it is a good +rule that the iron must not be solid. It is not usual with telegraphic +instruments to laminate them by making up the core of bundles of iron +plates or wires, but they are often made with tubular cores, that is +to say, the cylindrical iron core is drilled with a hole down the +middle, and the tube so formed is slit with a saw cut to prevent the +circulation of currents in the substance of the tube. Now when +electromagnets are to be employed with rapidly alternating currents, +such as are used for electric lighting, the frequency of the +alternations being usually about 100 periods per second, slitting the +cores is insufficient to guard against eddy currents; nothing short of +completely laminating the cores is a satisfactory remedy. I have here, +thanks to the Brush Electric Engineering Company, an electromagnet of +the special form that is used in the Brush arc lamp when required for +the purpose of working in an alternating current circuit. It has two +bobbins that are screwed up against the top of an iron box at the head +of the lamp. The iron slab serves as a kind of yoke to carry the +magnetism across the top. There are no fixed cores In the bobbins, +which are entered by the ends of a pair of yoked plungers. Now in the +ordinary Brush lamp for use with a steady current, the plungers are +simply two round pieces of iron tapped into a common yoke; but for +alternate current working this construction must not be used, and +instead a U-shaped double plunger is used, made up of laminated iron, +riveted together. Of course it is no novelty to use a laminated core; +that device, first used by Joule, and then by Cowper, has been +repatented rather too often during the past fifty years to be +considered as a recent invention. + +The alternate rapid reversals of the magnetism in the magnetic field +of an electromagnet, when excited by alternating electric currents, +sets up eddy currents in every piece of undivided metal within range. +All frames, bobbin tubes, bobbin ends, and the like, must be most +carefully slit, otherwise they will overheat. If a domestic flat iron +is placed on the top of the poles of a properly laminated +electromagnet, supplied with alternating currents, the flat iron is +speedily heated up by the eddy currents that are generated internally +within it. The eddy currents set up by induction in neighboring masses +of metal, especially in good conducting metals such as copper, give +rise to many curious phenomena. For example, a copper disk or copper +ring placed over the pole of a straight electromagnet so excited is +violently repelled. These remarkable phenomena have been recently +investigated by Professor Elihu Thomson, with whose beautiful and +elaborate researches we have lately been made conversant in the pages +of the technical journals. He rightly attributes many of the repulsion +phenomena to the lag in phase of the alternating currents thus induced +in the conducting metal. The electromagnetic inertia, or +self-inductive property of the electric circuit, causes the currents +to rise and fall later in time than the electromotive forces by which +they are occasioned. In all such cases the impedance which the circuit +offers is made up of two things--resistance and inductance. Both these +causes tend to diminish the amount of current that flows, and the +inductance also tends to delay the flow. + + +ELECTROMAGNETS FOR QUICKEST ACTION. + +I have already mentioned Hughes' researches on the form of +electromagnet best adapted for rapid signaling. I have also +incidentally mentioned the fact that where rapidly varying currents +are employed, the strength of the electric current that a given +battery can yield is determined not so much by the resistance of the +electric circuit as by its electric inertia. It is not a very easy +task to explain precisely what happens to an electric circuit when the +current is turned on suddenly. The current does not suddenly rise to +its full value, being retarded by inertia. The ordinary law of Ohm in +its simple form no longer applies; one needs to apply that other law +which bears the name of the law of Helmholtz, the use of which is to +give us an expression, not for the final value of the current, but for +its value at any short time, t, after the current has been turned on. +The strength of the current after a lapse of a short time, t, cannot +be calculated by the simple process of taking the electromotive force +and dividing it by the resistance, as you would calculate steady +currents. + +In symbols, Helmholtz's law is: + + i_{t} = E/R ( 1 - e^{-(R/L)t} ) + +In this formula i_{t} means the strength of the current after the +lapse of a short time t; E is the electromotive force; R, the +resistance of the whole circuit; L, its coefficient of self-induction; +and _e_ the number 2.7183, which is the base of the Napierian +logarithms. Let us look at this formula; in its general form it +resembles Ohm's law, but with a new factor, namely, the expression +contained within the brackets. The factor is necessarily a fractional +quantity, for it consists of unity less a certain negative +exponential, which we will presently further consider. If the factor +within brackets is a quantity less than unity, that signifies that +i_{t} will be less than E ÷ R. Now the exponential of negative sign, +and with negative fractional index, is rather a troublesome thing to +deal with in a popular lecture. Our best way is to calculate some +values, and then plot it out as a curve. When once you have got it +into the form of a curve, you can begin to think about it, for the +curve gives you a mental picture of the facts that the long formula +expresses in the abstract. Accordingly we will take the following +case. Let E = 2 volts; R = 1 ohm; and let us take a relatively large +self-induction, so as to exaggerate the effect; say let L = 10 quads. +This gives us the following: + + ________________________________________ + | | | | + | t_{(sec.)} | e^{+(R/L)t} | i_{t} | + --------------+--------------+---------| + | 0 | 1 | 0 | + | 1 | 1.105 | 0.950 | + | 2 | 1.221 | 1.810 | + | 5 | 1.649 | 3.936 | + | 10 | 2.718 | 6.343 | + | 20 | 7.389 | 8.646 | + | 30 | 20.08 | 9.501 | + | 60 | 403.4 | 9.975 | + | 120 | 16200.0 | 9.999 | + ---------------------------------------- + +In this case the value of the steady current as calculated by Ohm's +law is 10 amperes, but Helmholtz's law shows us that with the great +self-induction which we have assumed to be present, the current, even +at the end of 30 seconds, has only risen up to within 5 percent. of +its final value; and only at the end of two minutes has practically +attained full strength. These values are set out in the highest curve +in Fig. 54, in which, however, the further supposition is made that +the number of spirals, S, in the coils of the electromagnet is 100, so +that when the current attains its full value of 10 amperes, the full +magnetizing power will be Si = 1000. It will be noticed that the +curve rises from zero at first steeply and nearly in a straight line, +then bends over, and then becomes nearly straight again, as it +gradually rises to its limiting value. The first part of the +curve--that relating to the strength of the current after _very small_ +interval of time--is the period within which the strength of the +current is governed by inertia (i.e., the self-induction) rather than +by resistance. In reality the current is not governed either by the +self-induction or by the resistance alone, but by the ratio of the +two. This ratio is sometimes called the "time constant" of the +circuit, for it represents _the time_ which the current takes in that +circuit to rise to a definite fraction of its final value. + + E = 10 + r = 1 + R = 100 + L = 10 + + Si + 1000 + _..------------------------------- + | . _ _--------- + | . .---- + | . .- 2 IN SERIES + | . .- + | - + | .: - : + | .: . : + 500 | . : __- -:--------------------------- + | . : _.- - : 2 IN PARALLEL + | . :. - : + | . / : - : + | . / - : + |. / - : : + |./. : : + |/_____:_____________:____________________________ t + 10 20 40 60 80 100 120 + + FIG. 54.--CURVES OF RISE OF CURRENTS. + +This definite fraction is the fraction (e - 1)/e; or in decimals, +0.634. All curves of rise of current are alike in general shape, they +differ only in scale, that is to say, they differ only in the height +to which they will ultimately rise, and in the time they will take to +attain this fraction of their final value. + +_Example (1)._--Suppose E = 10; R = 200 ohms; L = 8. The final value +of the current will be 0.025 amp. or 25 milliamperes. Then the time +constant will be 8 ÷ 400 = 1-50th sec. + +_Example (2)._--The P.O. Standard "A" relay has R = 400 ohms; L = +3.25. It works with 0.5 milliampere current, and therefore will work +with 5 Daniell cells through a line of 9,600 ohms. Under these +circumstances the time constant of the instrument on short circuit is +0.0081 sec. + +It will be noted that the time constant of a circuit can be reduced +either by diminishing the self-induction or by increasing the +resistance. In Fig. 54 the position of the time constant for the top +curve is shown by the vertical dotted line at 10 seconds. The current +will take 10 seconds to rise to 0.634 of its final value. This +retardation of the rise of current is simply due to the presence of +coils and electromagnets in the circuit; the current as it grows being +retarded because it has to create magnetic fields in these coils, and +so sets up opposing electromotive forces that prevent it from growing +all at once to its full strength. Many electricians, unacquainted with +Helmholtz's law, have been in the habit of accounting for this by +saying that there is a lag in the iron of the electromagnet cores. +They tell you that an iron core cannot be magnetized suddenly, that it +takes time to acquire its magnetism. They think it is one of the +properties of iron. But we know that the only true time lag in the +magnetization of iron, that which is properly termed "viscous +hysteresis," does not amount to any great percentage of the whole +amount of magnetization, takes comparatively a long time to show +itself, and cannot therefore be the cause of the retardation which we +are considering. There are also electricians who will tell you that +when magnetization is suddenly evoked in an iron bar, there are +induction currents set up in the iron which oppose and delay its +magnetization. That they oppose the magnetization is perfectly true, +but if you carefully laminate the iron so as to eliminate eddy +currents, you will find, strangely enough, that the magnetism rises +still more slowly to its final value. For by laminating the iron you +have virtually increased the self-inductive action, and increased the +time constant of the circuit, so that the currents rise more slowly +than before. The lag is not in the iron, but in the magnetizing +current, and the current being retarded, the magnetization is of +course retarded also. + + +CONNECTING COILS FOR QUICKEST ACTION. + +Now let us apply these most important though rather intricate +considerations to the practical problems of the quick working of the +electromagnet. Take the case of an electromagnet forming some part of +the receiving apparatus of a telegraph system in which it is desired +to secure very rapid working. Suppose the two coils that are wound +upon the horseshoe core are connected together in series. The +coefficient of self-induction for these two is four times as great as +that of either separately; coefficients of self-induction being +proportional to the square of the number of turns of wire that +surround a given core. Now if the two coils instead of being put in +series are put in parallel, the coefficient of self-induction will be +reduced to the same value as if there were only one coil, because half +the line current (which is practically unaltered) will go through each +coil. Hence the time constant of the circuit when the coils are in +parallel will be a quarter of that which it is when the coils are in +series; on the other hand, for a given line current, the final +magnetizing power of the two coils in parallel is only half what it +would be with the coil in series. The two lower curves in Fig. 54 +illustrate this, from which it is at once plain that the magnetizing +power for very brief currents is greater when the two coils are put in +parallel with one another than when they are joined in series. + +Now this circumstance has been known for some time to telegraph +engineers. It has been patented several times over. It has formed the +theme of scientific papers, which have been read both in France and in +England. The explanation generally given of the advantage of uniting +the coils in parallel is, I think, fallacious; namely that the "extra +currents" (i.e., currents due to self-induction) set up in the two +coils are induced in such directions as tend to help one another when +the coils are in series, and to neutralize one another when they are +in parallel. It is a fallacy, because in neither case do they +neutralize one another. Whichever way the current flows to make the +magnetism, it is opposed in the coils while the current is rising, +and helped in the coils while the current is falling, by the so-called +extra currents. If the current is rising in both coils at the same +moment, then, whether the coils are in series or in parallel, the +effect of self-induction is to retard the rise of the current. The +advantage of parallel grouping is simply that it reduces the time +constant. + + +BATTERY GROUPING FOR QUICKEST ACTION. + +One may consider the question of grouping the battery cells from the +same point of view. How does the need for rapid working, and the +question of time constant, affect the best mode of grouping the +battery cells? The amateur's rule, which tells you to so arrange your +battery that its internal resistance should be equal to the external +resistance, gives you a result wholly wrong for rapid working. The +supposed best arrangement will not give you (at the expense even of +economy) the best result that might be got out of the given number of +cells. Let us take an example and calculate it out, and place the +results graphically before our eyes in the form of curves. Suppose the +line and electromagnet have together a resistance of 6 ohms, and that +we have 24 small Daniell cells, each of electromotive force say 1 volt, +and of internal resistance 4 ohms. Also let the coefficient of +self-induction of the electromagnet and circuit be 6 quadrants. When +all the cells are in series, the resistance of the battery will be 96 +ohms, the total resistance of the circuit 102 ohms, and the full value +of the current 0.235 ampere. When all the cells are in parallel, the +resistance of the battery will be 0.133 ohm, the total resistance +6.133 ohms, and the full value of the current 0.162 ampere. According +to the amateur rule of grouping cells so that internal resistance +equals external, we must arrange the cells in 4 parallels, each having +6 cells in series, so that the internal resistance of the battery will +be 6 ohms, total resistance of circuit 12 ohms, full value of current +0.5 ampere. Now the corresponding time constants of the circuit in the +three cases (calculated by dividing the coefficient of self-induction +by the total resistance) will be respectively--in series, 0.06 sec.; +in parallel, 0.5 sec.; grouped for maximum steady current, 0.96 sec. +From these data we may now draw the three curves, as in Fig. 55, +wherein the abscissæ are the values of time in seconds and the +ordinates the current. The faint vertical dotted lines mark the time +constants in the three cases. It will be seen that when rapid working +is required the magnetizing current will rise, during short intervals +of time, more rapidly if all the cells are put in series than it will +do if the cells are grouped according to the amateur rule. + + | + 5| . + | . + | . + 4| MAXIMUM . + | OUTPUT \ . + | . + 3| . + | . : ALL IN SERIES + | _-------------------:------------------------------ + 2| .- - : + | - - : + | -: - : + 1| / : - : ALL IN PARALLEL + |. : . : _________-------- + |- :__ : ---------- + +-----------------------------:------------------------------- + 0 1 2 3 4 5 6 7 8 9 10 + +FIG. 55.--CURVES OF RISE OF CURRENT WITH DIFFERENT GROUPINGS OF BATTERY. + +When they are all put in series, so that the battery has a much +greater resistance than the rest of the circuit, the current rises +much more rapidly, because of the smallness of the time constant, +although it never attains the same ultimate maximum as when grouped in +the other way. That is to say, if there is self-induction as well as +resistance in the circuit, the amateur rule does not tell you the best +way of arranging the battery. There is another mode of regarding the +matter which is helpful. Self-induction, while the current is growing, +acts as if there were a sort of spurious addition to the resistance of +the circuit; and while the current is dying away it acts of course in +the other way, as if there were a subtraction from the resistance. +Therefore you ought to arrange the battery so that the internal +resistance is equal to the real resistance of the circuit, plus the +spurious resistance during that time. But how much is the spurious +resistance during that time? It is a resistance proportional to the +time that has elapsed since the current was turned on. So then it +comes to a question of the length of time for which you want to work +it. What fraction of a second do you require your signal to be given +in? What is the rate of the vibrator of your electric bell? Suppose +you have settled that point, and that the short time during which the +current is required to rise is called t; then the apparent resistance +at time t after the current is turned on is given by the formula: + + R_{t} = R × e^{(R/L)t} + ( e^{(R/L)t} - 1 ) + + +TIME CONSTANTS OF ELECTROMAGNETS. + +I may here refer to some determinations made by M. Vaschy,[1] +respecting the coefficients of self-induction of the electromagnets of +a number of pieces of telegraphic apparatus. Of these I must only +quote one result, which is very significant. It relates to the +electromagnet of a Morse receiver of the pattern habitually used on +the French telegraph lines. + + L, in quadrants. + Bobbins, separately, without iron cores. 0.233 and 0.265 + Bobbins, separately, with iron cores. 1.65 and 1.71 + Bobbins, with cores joined by yoke, + coils in series 6.37 + Bobbins, with armature resting on poles. 10.68 + +[Footnote 1: "Bulletin de la Societe Internationale des Electriciens," +1886.] + +It is interesting to note how the perfecting of the magnetic circuit +increases the self-induction. + +Thanks to the kindness of Mr. Preece, I have been furnished with some +most valuable information about the coefficients of self-induction, +and the resistance of the standard pattern of relays, and other +instruments which are used in the British postal telegraph service, +from which data one is able to say exactly what the time constants of +those instruments will be on a given circuit, and how long in their +case the current will take to rise to any given fraction of its final +value. Here let me refer to a very capital paper by Mr. Preece in an +old number of the "Journal of the Society of Telegraph Engineers," a +paper "On Shunts," in which he treats this question, not as perfectly +as it could now be treated with the fuller knowledge we have in 1890 +about the coefficients of self-induction, but in a very useful and +practical way. He showed most completely that the more perfect the +magnetic circuit is--though of course you are getting more magnetism +from your current--the more is that current retarded. Mr. Preece'e +mode of experiment was extremely simple. He observed the throw of the +galvanometer when the circuit which contained the battery and the +electromagnet was opened by a key which at the same moment connected +the electromagnet wires to the galvanometer. The throw of the +galvanometer was assumed to represent the extra current which flowed +out. Fig. 56 represents a few of the results of Mr. Preece's paper. + + +==========+ + |=| |=| |=| |=| |=| + \======= \======= =======/ ======= ======= + | | | | | | | | | | + | | | | | | | | | | + | | | |--| | | | | | + ======= ======= ======= /======= =======\ + |=| |=| |=| |=| |=| + + +===========+ +==========+ +===== ======+ + |=| |=| |=| |=| |=| |=| + ======= =======/ B\======= =======/A A\======= =======/B + | | | | | | | | | | | | + | | | | | | | | | | | | + | |--| | | | | | | | | | + ======= ======= A======= =======B =======B =======A + |=| |=| |=| |=| |=| |=| + +==========+ +==========+ +====== =====+ + + FIG. 56.--ELECTROMAGNETS OF RELAY, AND THEIR EFFECTS. + +Take from an ordinary relay a coil, with its iron core, half the +electromagnet, so to speak, without any yoke or armature. Connect it +up as described, and observe the throw given to the galvanometer. The +amount of throw obtained from the single coil was taken as unity, and +all others were compared with it. If you join up two such coils as +they are usually joined, in series, but without any iron yoke across +the cores, the throw was 17. Putting the iron yoke across the cores, +to constitute a horseshoe form, 496 was the throw; that is to say, the +tendency of this electromagnet to retard the current was 496 times as +great as that of the simple coil. But when an armature was put over +the top, the effect ran up to 2,238. By the mere device of putting the +coils in parallel, instead of in series, the 2,238 came down to 502, a +little less than the quarter value which would have been expected. +Lastly, when the armature and yoke were both of them split in the +middle, as is done in fact in all the standard patterns of the British +postal telegraph relays, the throw of the galvanometer was brought +down from 502 to 26. Relays so constructed will work excessively +rapidly. Mr. Preece states that with the old pattern of relay having +so much self-induction as to give a galvanometer throw of 1,688, the +speed of signaling was only from 50 to 60 words per minute, whereas, +with the standard relays constructed on the new plan, the speed of +signaling is from 400 to 450 words per minute. It is a very +interesting and beautiful result to arrive at from the experimental +study of these magnetic circuits. + + +SHORT CORES _versus_ LONG CORES. + +In considering the forms that are best for rapid action, it ought to +be mentioned that the effects of hysteresis in retarding changes in +the magnetization of iron cores are much more noticeable in the case +of nearly closed magnetic circuits than in short pieces. +Electromagnets with iron armatures in contact across their poles will +retain, after the current has been cut off, a very large part of their +magnetism, even if the cores be of the softest of iron. But so soon as +the armature is wrenched off, the magnetism disappears. An air gap in +a magnetic circuit always tends to hasten demagnetizing. A magnetic +circuit composed of a long air path and a short iron path demagnetizes +itself much more rapidly than one composed of a short air path and a +long iron path. In long pieces of iron the mutual action of the +various parts tends to keep in them any magnetization that they may +possess; hence they are less readily demagnetized. In short pieces, +where these mutual actions are feeble or almost absent, the +magnetization is less stable, and disappears almost instantly on the +cessation of the magnetizing force. Short bits and small spheres of +iron have no magnetic memory. Hence the cause of the commonly received +opinion among telegraph engineers that for rapid work electromagnets +must have short cores. As we have seen, the only reason for employing +long cores is to afford the requisite length for winding the wire +which is necessary for carrying the needful circulation of current to +force the magnetism across the air gaps. If, for the sake of rapidity +of action, length has to be sacrificed, then the coils must be heaped +up more thickly on the short cores. The electromagnets in American +patterns of telegraphic apparatus usually have shorter cores, and a +relatively greater thickness of winding upon them, than those of +European patterns. + + * * * * * + + + + +ELECTRIC ERYGMASCOPE. + + +The erygmascope is the name of an electric lighting apparatus designed +for the examination of the strata of earth traversed by boring +apparatus. + +It consists of a very powerful incandescent lamp inclosed in a +metallic cylinder. One of the two semi-cylindrical sides constitutes +the reflector, and the other, which is of thick glass, allows of the +passage of the luminous rays, which thus illuminate with great +brilliancy the strata of earth traversed by the instrument. The base, +which is inclined at an angle of 45°, is an elliptical mirror, and the +top, of straight section, is open in order to permit the observer +standing at the mouth of the well, and provided with a powerful +spyglass, to see in the mirror the image of the earth. The lamp is so +mounted that its upwardly emitted rays are intercepted. + +The whole apparatus is suspended from a long cable, formed of two +conducting wires, which winds around a windlass with metallic +journals which are electrically insulated. These journals communicate, +through the intermedium of two friction springs, with the conductors +on the one hand and, on the other, with the poles of an automatic and +portable battery. + +[Illustration: THE TROUVE ERYGMASCOPE.] + +This permits of lowering and raising the apparatus at will, without +derangement, and without its being necessary to interrupt the light +and the observation.--_Revue Industrielle._ + + * * * * * + + + + +A NEW ELECTRIC BALLISTIC TARGET. + + +The electrical target usually employed in determining velocities of +projectiles consists of a wooden frame on which is strung a copper +wire so as to make a continuous circuit arranged in parallel vertical +lines about one inch or one and one half inches apart. + +It frequently happens that a projectile will pass through this target +without breaking the circuit, either by squeezing between the wires or +because, when last repaired, the target was short-circuited unnoticed, +so that the cutting of the wires did not break the circuit. The repair +of this target takes considerable time. + + _______________________________________________________ + | { + | +-------------__ --------------__---------------- } + | | _ // \\ // \\ } { + | | |_| || C_{0} || A || || || A { } + | | P \\ // \\ // } { + | +------------- --------------- ---------------- } + | F { + |_______________________________________________________} + + Plan. + P C + =|= _________ + |===| ========= A A + ========| | S |========\_______/================= + |spring | | | + | | | | | + |S_ | __| |__ __| + ||| | | + ___________|||______________| |_____________________ + | + | Section. + H / + \+/ + | + | + | + | + | + | + _____+_____ + | | + | W | + | | + |___________| + + +Besides these objections to this target, another and more serious one +is the irregularity in the manner of breaking the circuit. It has been +proved that times required for a flat headed and an ogival headed +projectile to rupture the current are very different. + +To remedy these defects a new and very ingenious target has been +devised and used with great success at the United States Military +Academy at West Point. The top of the target is a wooden strip, F, on +the upper side of which are screwed strips of copper, A A, about 1/2 +in. wide, and 1/8 in. thick. The connection between two adjoining +strips is made by a copper cartridge, C, which is dropped in a hole in +the frame bored to receive it. This cartridge is the one used in the +Springfield rifle. Inside the cartridge is a spiral spring, S, which, +acting on the bottom of the hole and the head of the cartridge, tends +to make the latter spring up, and so break the circuit. + +To the hook, H, which is attached to the cartridge, is suspended, by +means of a string, the lead weight, W, thus drawing down the cartridge +and making the circuit between A and A'. All the weights being +suspended the current comes in through the post, P, passes along the +copper strips and out of the corresponding post on the other end. + +On firing the projectile cuts a string, and the spring at once causes +the cartridge to spring up, thus breaking the circuit. + +It is not possible for the projectile to squeeze between the strings +and not break the current, for in so doing the cartridge is tipped +slightly, which is sufficient, as it breaks the current on one side. + +This target is used in connection with the Boulenge chronograph. Two +targets are established at a known distance apart, say 50 ft., and the +time required for the projectile to pass over this distance is +determined by finding the difference in the time of cutting of the two +targets, by finding the difference in the time of falling of the two +rods, caused by the demagnetization of two electromagnets in the same +circuit with the targets. + +By means of a disjunctor both rods are dropped at the same time, the +shorter one releasing a knife blade which makes a cut on the longer +one. Now both rods are hung from the magnets again and the gun is +fired. + +The projectile passes through the first target, breaks the circuit, +demagnetizes the magnet of the longer rod, and it begins to fall. On +passing through the second target, the projectile causes the shorter +rod to fall. This releases the knife blade, and a second cut is made. +The time corresponding to the distance between these cuts is the time +the longer rod was falling before the second rod began to fall or the +time between the cutting of the two targets by the projectile. + +The distance between the cuts is measured, and the time corresponding +to it can easily be found. Then the velocity of the projectile is +equal to 50/t. + +To repair this target, strings are prepared in advance of suitable +length and looped at both ends, so that by placing the hook of the +cartridge in one loop and that of the weight in the other the repair +is quickly made. + +This target has been used on the West Point proving ground to +determine velocities over distances of 100 ft. interval to distances +of only 9 ft. interval, and has given most satisfactory results. + + * * * * * + +[Continued from SUPPLEMENT, No. 786, page 12566.] + + + + +THE OUTLOOK FOR APPLIED ENTOMOLOGY. + +[Footnote: Address of Dr. C.V. Riley at the annual meeting of the +Association of Economic Entomologists, Champaign, Ills., November 11 +to 14, 1890.] + +LEGISLATION. + + +The amount of legislation in different countries that has of late +years been deemed necessary or sufficiently important, in view of +injurious insects, is a striking evidence of the increased attention +paid to applied entomology; and while modern legislation of this kind +has been, on the whole, far more intelligent than similar efforts in +years gone by, many of the laws passed have nevertheless been unwise, +futile, and impracticable, and even unnecessarily oppressive to other +interests. The chief danger here is the intervention of politics or +political methods. Expert counsel should guide our legislators and the +steps taken should be thorough in order to be effective. We have had +of late years in Germany very good evidence of the excellent results +flowing from thorough methods, and the recent legislation in +Massachusetts against the gypsy moth (_Ocneria dispar_), which at one +time threatened to become farcical, has, fortunately, proved more than +usually successful; the commission appointed to deal with the subject +having worked with energy and followed competent advice. + + +PUBLICATION. + +On the question of publication of the results of our labors it is +perhaps premature to dwell at length. Each of the experiment stations +is publishing its own bulletins and reports quite independently of the +others, but after a uniform plan recommended by the association with +which we meet here; and with but one exception that has come to my +notice, another important recommendation of the same association--that +these publications shall be void of all personal matter--has been kept +in mind. The National Bureau of Experiment Stations at Washington is +doing what it can with the means at command to further the general +work by issuing the Experiment Station Record, devoted chiefly to +digests of the State station bulletins. There is a serious question in +my mind as to the utility of State digests by the national department +of results already published extensively by the different States and +distributed under government frank to all similar institutions and to +whomsoever is interested enough to ask for them. + +Such digests may or may not be intelligently made, and, even under the +most favorable circumstances, will hardly serve any other purpose than +helping to the reference to the original articles, and this could +undoubtedly be done more satisfactorily to the stations and to the +people at large by general and classified indices to all the State +documents, made as full as possible and issued at stated intervals. +Only a small proportion of the bulletins have been so far noticed by +digest in this record, with no particular rule, so far as I can see, +in the selection. In point of fact, those will be most apt to be +noticed whose authors can find time to themselves send or make for the +purpose their own abstracts. This is, perhaps, inevitable under +present arrangements. Complete and satisfactory digests of all, if +intelligent and critical, imply a far greater force than is at present +at Prof. Atwater's command. + +Under these circumstances, it would seem wiser to devote all the +energies of the bureau to digests of the similar literature of other +countries, which would be of immense advantage to our people and to +the different station workers. Judging from the recommendations and +resolutions of the general association, this is the view very +generally held, but except in chemistry and special industries like +that of beet sugar, very little of that kind of work has yet been +attempted. + +What is true of the station publications in general is equally true of +special publications. As entomologist of the department, I have been +urged to bring together, at stated intervals, digests of the +entomological publications of the different stations. Such digests to +be of any value, however, should also be critical, and it were a +thankless task for any one to be critic or censor even of that which +needs correction or criticism. Moreover, to do this work intelligently +would require increase of the divisional force, which at present is +more advantageously employed, for, as already intimated, I should have +great doubts of the utility of these digests. + +I believe, however, that the division should strive for such increase +of means as would justify the periodic publication, either +independently or as a part of the department record, of general and +classified indices to the entomological matter of the station +bulletins, and should work more and more toward giving results from +other parts of the world. This could, perhaps, best be done by titles +of subject and of author so spaced and printed on stout paper that +they could be cut and used in the ordinary card catalogue. The +recipient could cut and systematically place the titles as fast as +received. + +As to the character of the matter of the entomological bulletins, it +will inevitably be influenced by the needs and demands of the people +of the respective States, and while originality should be kept in +mind, there must needs be in the earlier years of the work much +restatement of what is already well known. That some results have been +published of work which reflects no particular credit upon our calling +is a mere incident of the new positions created. Yet we may expect +marked improvement from year to year in this direction, and without +being invidious, I would cite those of Prof. Gillette's on his +spraying experiments and on the plum curculio and plum gouger, as +models of what such bulletins should be. + +Although the resolution offered at our last meeting by Prof. Cook, to +the effect that purely descriptive matter should be excluded from the +station bulletins, met with no favor, but was laid on the table, by +the general association, I am in full sympathy with this position and +am strongly of the opinion that in the ordinary bulletins such purely +technical and descriptive matter should be reduced to the necessary +minimum consistent with clearness of statement and accuracy, and that +if it is desired, on the part of the station entomologists, to issue +technical and descriptive papers, a separate series of bulletins were +better instituted for this class of matter. + +Finally, for results which it is desired to promptly get before the +people, the agricultural press is at our disposal, and so far as the +entomological work of the department of agriculture is concerned, the +periodical bulletin, _Insect Life_, was established for this purpose. +Its columns are open to all station workers, and I would here appeal +to the members of the association to help make it, as far as possible, +national, by sending brief notes and digests of their work as it +progresses. Hitherto we have been unable to make as much effort in +this direction as we desired, but in future it is our hope to make the +bulletin, as far as possible, a national medium through which the +results of work done in all parts of the country may quickly be put on +record and distributed, not only to all parts of our own country, but +to all parts of the world. + +The rapid growth and development of the national department and the +multiplication of its divisions have necessitated special modes of +publication and rendered the annual report almost an anachronism so +far as it pretends to be what it at one time was--a pretty complete +report of the scientific and other work of the department. The +attempts which I have made through the proper authorities to get +Congress to order more pretentious monographic works in quarto volume +similar to those issued by other departments of the government have +not met with encouragement, and in this direction many of the stations +will, let us hope, be able to do better. + + +CO-OPERATION. + +Every other subject that might be considered on this occasion must be +subordinate to the one great question of co-operation. With the large +increase of actual workers in our favorite field, distributed all over +the country, the necessity for some co-operation and co-ordination +must be apparent to every one. Just how this should be brought about +or in what direction we may work toward it, will be for this +association in its deliberations to decide. Nor will I venture to +anticipate the deliberations and conclusions of the special committee +appointed to take the matter into consideration, beyond the statement +that there are many directions in which we can adopt plans for mutual +benefit. Take, for instance, the introduction and dissemination of +parasites. How much greater will be the chance of success in any +particular case if we have all the different station entomologists +interested in some specific plan to be carried out in co-operation +with the national department, which ought to have better facilities of +introducing specimens to foreign countries or to different sections of +our own country than any of the State stations. + +Let us suppose that the fruit growers of one section of the country, +comprising several States in area, need the benefit in their warfare +against any particularly injurious insect of such natural enemy or +enemies as are known to help the fruit growers of some other section. +There will certainly be much greater chances of success in the +carrying out of any scheme of introduction if all the workers in the +one section may be called upon through some central or national body +to help in the introduction and disposition of the desired material +into the other section. Or, take the case of the boll worm +investigation already alluded to. The chances of success would be much +greater if the entomologists in all the States interested were to give +some attention to such lepidopterous larvæ as are found to be affected +with contagious diseases and to follow out some specific plan of +cultivating and transmitting them to the party or parties with whom +the actual trials are intrusted. The argument applies with still +greater force to any international efforts. I need hardly multiply +instances. There is, it is true, nothing to prevent any individual +station entomologist from requesting co-operation of the other +stations, nor is there anything to prevent the national department +from doing likewise; but in all organization results are more apt to +flow from the power to direct rather than from mere liberty to request +or to plead. The station entomologist may be engrossed in some line of +research which he deems of more importance to the people of his State, +and may resent being called upon to divert his energies; and with no +central or national power to decide upon plans of co-operation for the +common weal, we are left to voluntary methods, mutually devised, and +it is here that this association can, it seems to me, most fully +justify its organization. And this brings me to the question of + + +THE DEPARTMENT AND THE STATIONS. + +Immediately connected with the question of co-operation is the +relation of the National Department of Agriculture and the State +experiment stations. The relation, instead of being vital and +authoritative, is, in reality, a subordinate one. Many persons +interested in the advancement of agriculture foresaw the advantage of +having experiment stations attached to the State agricultural colleges +founded under the Morrill act of 1862; but I think that in the minds +of most persons the establishment of these stations implied some such +connection with the national department as that outlined in an address +on Agricultural Advancement in the United States, which I had the +honor to deliver in 1879 before the National Agricultural Congress, at +Rochester, and in which the following language was used: + + "In the light of the past history of the German experimental + stations and their work, or of that in our own State of + Connecticut, the expediency of purchasing an experimental farm of + large dimensions in the vicinity of Washington is very + questionable. There can be no doubt, however, of the value of a + good experimental station there that shall have its branches in + every State of the Union. The results to flow from such stations + will not depend upon the number of acres at command, and it will + be far wiser and more economical for the commissioner to make each + agricultural college that accepted the government endowment + auxiliary to the national bureau, so that the experimental farm + that is now, or should be, connected with each of these + institutions might be at its service and under the general + management of the superintendent of the main station. There is + reason to believe that the directors of these colleges would + cheerfully have them constituted as experimental stations under + the direction of the department, and thus help to make it really + national--the head of a vast system that should ramify through all + parts of the land.... + + "With the different State agricultural colleges, and the State + agricultural societies, or boards, we have every advantage for + building up a national bureau of agriculture worthy of the country + and its vast productive interests, and on a thoroughly economical + basis, such as that of Prussia, for instance." + +In short, the view in mind was something in the nature of that which +has since been adopted by our neighbors of the North, where there is a +central or national station or farm at Ottawa and sub-stations or +branch farms at Nappan, Nova Scotia, Brandon, Manitoba, Indian Head, +N.W.T., and Agassiz, British Columbia, all under the able direction of +Mr. William Saunders, one of our esteemed fellow workers. It was my +privilege to be a good deal with Mr. Saunders when he was in Europe +studying the experience of other countries in this matter, and the +policy finally adopted in Canada as a result of his labors is an +eminently wise one, preventing some of the difficulties and dangers +which beset our plan, whether as between State and nation or college +and station. + +Under the present laws and with the vast influence which the +Association of Agricultural Colleges and Experiment Stations will +wield, both in Congress and in the different States, there is great +danger of transposition, in this agricultural body politic, of those +parts which in the animal body are denominated head and tail, and the +old saw to the effect that "the dog wags the tail because the tail +cannot wag the dog," will find another application. So far as the law +goes, the national department, which should hold a truly national +position toward State agricultural institutions depending on federal +support, can do little except by suggestion, whether in the line of +directing plans or in any way co-ordinating or controlling the work of +the different stations throughout the country. The men who influenced +and shaped the legislation which resulted in the Hatch bill were +careful that the department's function should be to indicate, not to +dictate; to advise and assist, not to govern or regulate. We have, +therefore, to depend on such relationships and such plans of +co-operation as will appear advantageous to all concerned, and these +can best be brought about through such associations as are now in +convention here. + +Without such plans there is great danger of such waste of energy and +means and duplication of results as will bring the work into popular +disfavor and invite disintegration, for already there is a growing +feeling that agricultural experiment is and will be subordinated to +the ordinary college work in the disposition of the federal +appropriations. + +What is true of the national department as a whole in its connection +with the State stations is true in a greater or less degree of the +different divisions of the department in connection with the different +specialists of the stations. With the multiplicity of workers in any +given direction in the different States, the necessity for national +work lessens. A favorite scheme of mine in the past, for instance (and +one I am glad to say fully indorsed by Prof. Willits), was to endeavor +to have a permanent agent located in every section of the country that +was sufficiently distinctive in its agricultural resources and +climate, or, as a yet further elaboration of the same plan, one in +each of the more important agricultural States. The necessity for such +State agents has been lessened, if not obviated, by the Hatch bill, +and the subsequent modifications looking to permanent appropriations +to the State stations or colleges, which give no central power at +Washington. The question then arises, What function shall the national +department perform? Its influence and field for usefulness have been +lessened rather than augmented in the lines of actual investigation in +very many directions. Many a State is already far better equipped both +as to valuable surrounding land, laboratory and library facilities, +more liberal salaries, and greater freedom from red tape, +administrative routine, and restrictions as to expenditures, than we +are at Washington; and, except as a directing agent and a useful +servant, I cannot see where the future growth of the department's +influence is to be outside of those federal functions which are +executive. Just what that directing influence is to be is the question +of the hour, not only in the broader but in the special sense. The +same question, in a narrower sense, had arisen in the case of the few +States which employed State entomologists. In the event, for instance, +of an outbreak of some injurious insect, or in the event of any +particular economic entomological question within the limits of the +State having such an officer, the United States entomologist would +naturally feel that any effort on his part would be unnecessary, or +might even be looked upon as an interference. He would feel that there +was always danger of mere duplication of observation or experiment, +except where appealed to for aid or co-operation. This is, perhaps, +true only of insects which are local or sectional, and is rather a +narrow view of the matter, but it is one brought home from experience, +and is certainly to be considered in our future plans. The favor with +which the museum work of the national division was viewed by you at +the meeting last November and the amount of material sent on for +determination would indicate that the building up of a grand national +reference collection will be most useful to the station workers. But +to do this satisfactorily we need your co-operation, and I appeal to +all entomologists to aid in this effort by sending duplicates of their +types to Washington, and thus more fully insuring against ultimate +loss thereof. + + +STATUS OF OUR SOCIETY. + +This train of thought brings up the question of the status of our +society with the station entomologists as represented by the committee +of the general association. Those of us who had desired a national +association for the various purposes for which such associations are +formed, felt, I believe, if I may speak for them, that the creation of +the different experimental stations rendered such an organization +feasible. Your organization at Toronto and the constitution adopted +and amended at the meeting at Washington all indicate that the chief +object was the advancement of our chosen work and that the strength of +the association would come from the experiment station entomologists. +There was then no other organization of the kind, nor any intimation +that such a one would be founded. Some of us therefore were surprised +to learn from the circular sent out by Prof. Forbes, its chairman, +that the committee appointed by the association of agricultural +colleges and experiment stations, and through which we had hoped to +communicate and co-operate with that association, was not in the +proper sense a committee, but a section which has prepared (and in +fact was required by the executive committee and the rules of the +superior body to prepare) a programme of papers and discussions for +the meeting to be held at the same time and place with our own. I +cannot but feel that this is in some respects a misfortune, and it +will devolve upon you to decide upon several questions of importance +that will materially affect our future existence. That there is not +room for two national organizations having the same objects in view +and meeting at the same time and place goes, I think, without saying; +and if the committee of the general association is to be anything more +than a committee in the proper sense of the word, or if it is to +assume with or without formal constitution the functions of our own +association, then our own must necessarily be crippled, and to do any +good at all must meet at a different time and a different place. A +committee or section, or whatever it may be called, of the general +association with which we meet, would preclude active membership of +any but those who come within the constitution of that body. Our +Canadian friends and many others who have identified themselves with +applied entomology, and do not belong to any of our State or +government institutions, would be debarred from active representation, +however liberal the association may have been in inviting such to +participate, without power to vote in its deliberations. Our own +association has, or should have, no such limitations. Some of us who +are entitled to membership in both bodies may feel indifferent as to +the course finally decided upon, and that it will not make any +difference whether we have an outside and independent organization, as +that of the association of official chemists, or whether we do, as did +the botanists and horticulturists, waive independence in favor of more +direct connection with the general association, provided there is some +way whereby the committees of the general association are given +sufficient latitude and time to properly present their papers and +deliberate; but there are others who feel more sensitive as to their +action and are more immediately influenced by the feelings of the main +body. I hope that whatever action be taken at this meeting, the +general good and the promotion of economic entomology will be kept in +mind and that no sectional or personal feeling will be allowed to +influence our deliberations. + + +SUGGESTION AND COMMENT. + +You will, I know, pardon me if, before concluding these remarks, I +venture to make a few comments which, though not altogether agreeable, +are made in all sincerity and in the hope of doing good. The question +as to how far purely technical and especially descriptive and +monographic work should be done by the different stations or by the +national department is one which I have already alluded to and upon +which we shall probably hold differing opinions, and which will be +settled according to the views of the authorities at the different +stations. Individually, I have ever felt that one ostensibly engaged +in applied entomology and paid by the State or national government to +the end that he may benefit the agricultural community can be true to +his trust only by largely overcoming the pleasure of entomological +work having no practical bearing. I would, therefore, draw the line at +descriptive work except where it is incidental to the economic work +and for the purpose of giving accuracy to the popular and economic +statements. This would make our work essentially biological, for all +biologic investigation would be justified, not only because the life +habits of any insect, once ascertained, throw light on those of +species which are closely related to it, but because we can never know +when a species at present harmless may subsequently prove harmful, and +have to be classed among the species injurious to agriculture. + +On the question of credit to their original sources of results already +on record, it is hardly necessary for me to advise, because good sense +and the consensus of opinion will in the end justify or condemn a +writer according as he prove just and conscientious in this regard. + +There is one principle that should guide every careful writer, viz., +that in any publications whatever, where facts or opinions are put +forth, it should always be made clear as to which are based upon the +author's personal experience and which are compiled or stated upon the +authority of others. We should have no patience with a very common +tendency to set forth facts, even those relating to the most common +and best known species, without the indications to which I have +referred. The tendency belittles our calling and is generally +misleading and confusing, especially for bibliographic work, and +cannot be too strongly deprecated. + +On this point there will hardly be any difference of opinion, but I +will allude to another question of credit upon which there prevails a +good deal of loose opinion and custom. It is the habit of using +illustrations of other authors without any indication of their +original source. + +This is an equally vicious custom and one to be condemned, though I +know that some have fallen into the habit, without appreciation of its +evil effect. It is, in my judgment, almost as blameworthy as to use +the language or the facts of another without citing the authority. + +Every member of this association who has due appreciation of the time +and labor and special knowledge required to produce a good and true +illustration of the transformations and chief characteristics of an +insect will appreciate this criticism. However pardonable in fugitive +newspaper articles in respect of cuts which, from repeated use, have +become common or which have no individuality, the habit inevitably +gives a certain spurious character to more serious and official +publications, for assumption of originality, whether intended or not, +goes with uncredited matter whether of text or figure. Nor is mere +acknowledgment of loan or purchase to the publisher, institution or +individual who may own the block or stone what I refer to. But that +acknowledgment to the author of the figure or the work in which it +first appears which is part of conscientious writing, and often a +valuable index as to the reliability of the figure. + +It were supererogation to point out to a body of this kind the value +of the most careful and thorough work in connection with life +histories and habits, often involving as it does much microscopic +study of structure. The officers of our institutions who control the +funds, and more or less fully our conduct, are apt to be somewhat +impatient and inappreciative of the time given to anatomic work, and +where it is given for the purpose of describing species and of +synopsizing or monographing higher groups, without reference to +agriculture, I am firmly of the belief that it diverts one from +economic work, but where pursued for a definite economic purpose it +cannot be too careful or too thorough and I know of no instances +better calculated to appeal to and modify the views of those inclined +to belittle such structural study than Phylloxera and Icerya. On the +careful comparison of the European and American specimens of +_Phylloxera vastatrix_, involving the most minute structures and +details, depended originally those important economic questions which +have resulted in legislation by many different nations and the +regeneration of the affected vineyards of Europe, of our own Pacific +coast, and of other parts of the world by the use of American +resistant stocks. In the case of _Icerya purchasi_ the possibilities +of success in checking it by its natural enemies hung at one time upon +a question of specific difference between it and the _Icerya sacchari_ +of Signoret--a question of minute structure which the descriptions +left unsettled and which could only be settled by the most careful +structural study and the comparison of the types, involving a trip to +Europe. + + +CONCLUSION. + +I have thus touched, gentlemen, upon a few of the many subjects that +crowd upon the mind for consideration on an occasion like this--a few +gleanings from a field which is passing rich in promise and +possibility. It is a field that some of us have cultivated for many +years and yet have only scratched the surface, and if I have ventured +to suggest or admonish, it is with the feeling that my own labors in +this field are ere long about to end and that I may not have another +occasion. + +At no time in the history of the world has there, I trow, been +gathered together such a body of devoted and capable workers in +applied entomology. It marks an era in our calling and, looking back +at the progress of the past fifteen years, we may well ponder the +possibilities of the next fifteen. They will be fruitful of grand +results in proportion as we persistently and combinedly pursue the yet +unsolved problems and are not tempted to the immediate presentation of +separate facts, which are so innumerable and so easily observed that +their very wealth becomes an element of weakness. Epoch-making +discoveries result only from this power of following up unswervingly +any given problem, or any fixed ideal. The kerosene emulsion, the +Cyclone nozzle, the history of _Phylloxera vastatrix_, of _Phorodon +humuli_, of _Vedalia cardinalis_, are illustrations in point, and +while we may not expect frequent results as striking or of as wide +application as these, there is no end of important problems yet to be +solved and from the solution of which we may look for similar +beneficial results. Applied entomology is often considered a sordid +pursuit, but it only becomes so when the object is sordid. When +pursued with unselfish enthusiasm born of the love of investigation +and the delight in benefiting our fellow men, it is inspiring, and +there are few pursuits more deservedly so, considering the vast losses +to our farmers from insect injury and the pressing need that the +distressed husbandman has for every aid that can be given him. Our +work is elevating in its sympathies for the struggles and suffering of +others. Our standard should be high--the pursuit of knowledge for the +advancement of agriculture. No official entomologist should lower it +by sordid aims. + +During the recent political campaign the farmer must have been sorely +puzzled to know whether his interests needed protection or not. On the +abstract question of tariff protection to his products we, as +entomologists, may no more agree than do the politicians or than does +the farmer himself. But ours is a case of protection from injurious +insects, and upon that there can nowhere be division of opinion. It is +our duty to see that he gets it with as little tax for the means as +possible. + + * * * * * + + + + +POTASH SALTS. + +[Footnote: By John B. Smith, entomologist. Potash as an insecticide is +not entirely new, but has never been brought out with the prominence I +think it deserves.--_N.J. Ag. Col. Exp. St., Bulletin 75._] + + +My attention was attracted to potash salts as an insecticide, by the +casual remark of an intelligent farmer, that washing his young pear +trees with a muriate of potash solution cleared them of scales. The +value of this substance for insecticide purposes, should its powers be +sufficient, struck me at once, and I began investigation. It was +unluckily too late in the season for field experiments of the nature +desired; but it is the uniform testimony of farmers who have used +either the muriate or the kainit in the cornfields, that they have +there no trouble with grubs or cut worms. Mr. E.B. Voorhees, the +senior chemist of the station, assures me that on his father's farm +the fields were badly infested, and replanting cornhills killed by +grubs or wire worms was a recognized part of the programme. Since +using the potash salts, however, they have had absolutely no trouble, +and even their previously worst-infested fields show no further trace +of injury. The same testimony comes from others, and I feel safe in +recommending these salts, preferably kainit, to those who are troubled +with cut worms or wire worms in corn. + + +EXPERIMENTS. + +A lot of wire worms (_Iulus_ sp.) brought in from potato hills were +put into a tin can with about three inches of soil and some potato +cuttings, and the soil was thoroughly moistened with kainit, one ounce +to one pint of water. Next morning all the specimens were dead. A +check lot in another can, moistened with water only, were healthy and +lived for some days afterward. + +A number of cabbage maggots placed on the soil impregnated with the +solution died within twelve hours. + +To test its actual killing power, used the solution, one ounce kainit +to one pint water, to spray a rose bush badly infested with plant +lice. Effect, all the lice dead ten hours later; the younger forms +were dropping within an hour. + +Sprayed several heads of wheat with the solution, and within three +hours all the aphides infesting them were dead. + +Some experiments on hairy caterpillars resulted unsatisfactorily, the +hair serving as a perfect protection against the spray, even from the +atomizer. + +To test its effect on the foliage, sprayed some tender shoots of rose +and grape leaves, blossoms, and clusters of young fruit. No bad effect +observable 24 hours later. There was on some of the leaves a fine +glaze of salt crystals, and a decided salt taste was manifest on all. + +Muriate of potash of the same strength was tested as follows: Sprayed +on some greenhouse camellias badly infested by mealy bugs, it killed +nearly all within three hours, and six hours later not a living insect +was found. The plants were entirely uninjured by the application. + +Thoroughly sprayed some rose bushes badly infested with aphides, and +carried off some of the worst branches. On these the lice were dead +next morning; but on the bushes the effect was not so satisfactory, +most of the winged forms and many mature wingless specimens were +unaffected, while the terminal shoots and very young leaves were +drooping as though frosted. All, however, recovered later. + +The same experiment repeated on other, hardier roses, resulted +similarly so far as the effect on the aphides was concerned, but there +was no injury to the plant. + +Used this same mixture on the caterpillars of _Orgyia leucostigma_ +with unsatisfactory effect, and with the same results used it on a +number of other larvæ. Used on the rose leaf roller, _Cacæcia +rosaceana_, it was promptly effective. + +Tested for injury to plants, it injured the foliage and flowers of +wisteria, the younger leaves of maple and grape, and the finer kinds +of roses. + +From these few experiments kainit seems preferable to the muriate, as +acting more effectively on insects and not injuriously on plants. For +general use on plants it is not to be recommended. It is otherwise on +underground species, where the soil will be penetrated by the salts +and where the moisture evaporates but slowly, and the salt has a +longer and better chance to act. The best method of application would +be a broadcasting in fertilizing quantity before or during a rain, so +as to carry the material into the soil at once. In cornfields infested +with grubs or wire worms, the application should be made before +planting. Where it is to be used to reach root lice, it should be used +when the injury is beginning. When strawberry beds are infested by the +white grub, the application should be made when cultivating or before +setting out. + +The potash salts have a high value as fertilizers, and any application +made will act as a stimulant as well as insecticide, thus enabling the +plants to overcome the insect injury as well as destroying the insect. + +In speaking on this subject in Salem county, I learned from farmers +present that those using potash were not troubled with the corn root +louse to any extent, and also that young peach trees have been +successfully grown in old lice-infested orchards, where previously all +died, by first treating the soil with kainit of potash. + + * * * * * + + +A meteorological station has been built on Mont Blanc, at an elevation +of 13,300 feet, under the direction of M. Vallot. It required six +weeks to deliver the materials. The instruments are self-registering +and are to be visited in summer every fifteen days if possible, the +instruments being left to register between the visits. In the winter +the observatory will be entirely inaccessible. This is the highest +scientific station in Europe, but is 847 feet lower than the Pike's +Peak station in Colorado. + + * * * * * + + + + +THE EXPENSE MARGIN IN LIFE INSURANCE. + + +The principle of mutuality requires that the burden of expense in life +insurance should be borne by all the members equally; but, even with +the most careful adjustment, the allowance usually made is +considerably in excess of what is needed in the regular companies +doing business on the "level premium" plan. + +It is customary in these companies to add to the net premium a +percentage thereof to cover the expense account. This practice, though +in harmony with the "commission system," is so clearly defective and +so far removed from the spirit of life insurance mathematics, that it +scarcely deserves even this passing notice. + +It is generally understood that these corporations combine the +functions of the savings bank and life insurance company, and it is +only by separating the two in our minds as far as possible that we can +obtain a clear conception of the laws that should govern the +apportionment of the expenses among the great variety of policies. + +While it is a comparatively simple matter to state the amount of +either the insurance or savings bank element in a single policy, it is +by no means easy, as things go, to classify the company's actual +expenses on this basis. + +Fortunately, we can pretty accurately determine what these amounts +should be in any particular case. + +In the first place, there are institutions in our midst devoted solely +to receiving and conserving small sums of money; doing, in fact, +exactly what our insurance companies are undertaking to do with the +reserve and contributions thereto. These savings banks are required by +law to make returns to the State commissioner, from whose official +report we can get a very good idea of the expense attendant on doing +this business. + +Confining ourselves to the city banks, where the conditions more +nearly resemble those of the insurance companies, we find in +thirty-eight combined institutions for saving in the State of +Massachusetts a deposit in 1888 of $192,174,566, taken care of at an +aggregate cost of $455,387, or about 24-100 of one per cent. + +The same ratio carried out for all the savings banks in Massachusetts +gives a trifle over 25-100 of one per cent.; we may, therefore, +consider ¼ of one per cent. as expressing pretty nearly the cost of +receiving, paying out, and investing the savings of the people. + +We must remember in this connection that in the popular estimation, +the savings bank is an important factor in the public welfare, and in +the towns and smaller cities there are often found public spirited men +willing to give their services to encourage this mode of saving; but +public sentiment has not yet given to life insurance the place which +it is destined, sooner or later, to occupy by the side of the savings +bank. Hence the services of able managers can only be obtained by a +liberal outlay of the corporate funds. A satisfactory adjustment of +the matter of expenses will, perhaps, do more than anything else to +bring about this recognition on the part of the public. + +In the case of the savings bank it is safe to say that for double the +present outlay a liberal salary could be paid to all the officers. +Following the analogy, we are led to infer that if this be the case in +savings banks, then ½ of one per cent. of the reserve should be an +ample allowance for the special labor required in the purely banking +portion of the business. + +In this we have the concurrence of the late Elizur Wright. In an essay +on this subject he says: + + "The expenses of the five largest savings banks in Boston, in + 1869, did not exceed 4-10 of one per cent. on $28,000,000 + deposited in them. They certainly had twice as many transactions, + in proportion to the deposits, as any life insurance company could + have with the same amount of reserve, so that ½ of one per cent. + on the reserve seems to be ample for all working expenses save + those of maintaining the agencies and collecting the premiums." + +This need hardly be looked upon as an admission that it costs twice as +much to care for the funds of a life insurance company as for those of +a savings bank. A liberal expense allowance must be made at the +outset, seeing that an error in this particular cannot easily be +rectified after the policy is issued. The dividend, or, to speak more +correctly, the annual return of surplus, will correct any overpayment +on this account. + +There is another expense which seems inevitable. This is the +government tax on insurance companies, amounting in the aggregate to +nearly 1/3 of one per cent. on the reserve. + +When we consider that these institutions are intended to encourage +thrift and to relieve the community from the care of numberless widows +and orphans, it seems a clear violation of the principles of political +economy to levy a tax on this business; still, whatever our opinion +may be as to the justice or injustice of the imposition, the tax is +maintained and must be provided for. Consequently a further allowance +of ½ of one per cent. must be added to the net premium to cover the +same, making a total of 1 per cent. of the reserve for banking +expenses and taxes. Considering this point as settled for the time +being, let us proceed to investigate the insurance expenses. + +Here, again, we are fortunate in being able to refer to the official +reports of a class of corporations doing nearly, if not quite pure +insurance. + +The assessment societies, outside of the fraternal and benevolent, +reporting in 1889 to the insurance commissioner of Massachusetts, show +outstanding risks amounting to $733,515,366. Losses to the amount of +$7,270,238 were paid during the year at a cost for transacting the +business of $2,403,053, which includes among other items "agency +expenses and commissions," which amount to about $1,203,000, or 17 per +cent. of the cost value of the insurance actually done. It would seem +as if an allowance of 20 per cent. would be a liberal one in the case +of the regular companies, which surely have as good facilities for +doing business as the assessment societies. + +As far as insurance is concerned, there is less difference between +regular and co-operative companies than is generally supposed. Regular +companies assess each policy in advance for a year's insurance at a +time, while co-operative societies furnish insurance only from one +assessment to another. The difficulty in the way of collecting the +assessment in the latter case would seem to be greater than in the +former, owing to the more permanent nature of the regular insurance +contract. + +In compensating agents the assessment companies naturally pay in +proportion to the insurance obtained, inasmuch as there is no other +basis to go upon, but regular companies usually pay the agent a +percentage of the premium _which includes a considerable trust fund_ +over and above the assessment for actual insurance. It is easily seen +that by the last method the agent's compensation increases in +proportion to the amount of savings bank business forced upon the +company. + +To realize how far we are from anything like a scientific, not to say +common sense basis for insurance expenses, we have but to examine the +following list, which gives the ratios between the expenditures for +general expenses in 1889, and those for the extension of the business. +For every $100 used in a general way, the different companies spend +for commissions and agency expenses: $37, $66, $67, $78, $91, $106, +$110, $113, $120, $140, $157, $161, $173, $175, $186, $189, $200, +$202, $222, $264, $311, $346. + +It will doubtless be said that I am taking a very advanced position +when I say that in the ideal life insurance scheme there is no place +for the commission system. Solicitors will be a necessity only so long +as they are in the field, but fifty years of life insurance has taught +our community its true value and, thanks to the modern press, the +institution it is no more likely to fall into desuetude than is +Christianity or the moral law. + +For the convenience of bringing the company to the individual, the +latter should be willing to pay a fee. The man who renders another a +service or puts his superior knowledge at another's disposal should +look to the party benefited for his remuneration. Any compensation +given for such service to a go-between by a mutual company is paid by +all, and the question arises, Is the advantage to the company of +sufficient importance to warrant the imposition of this tax upon all +its members promiscuously? The following, from the Massachusetts +Insurance Commissioner's Report for 1885, leaves no doubt as to the +convictions of the writer on this important matter: + + "The expensiveness of the life insurance policy is not because the + level net premium is too high, for the premium is absolutely just, + and the policy holder gets full value; but the complaint justly + applies to the excessive expense charge. A person who wants + insurance, life or fire or other, should be able to buy it at + first cost without paying tribute of profits to middlemen. To that + complexion the matter will finally be brought by the force of + intelligent opinion, whatever resistance may be opposed by persons + whose thrift lies in the perpetuation of the expensive system now + in fashion." + +It requires but a slight degree of prophetic vision to predict that in +a very few years the companies in self defense will be obliged to +change their method of compensating agents. + +Several companies have already begun the reform by grading +commissions; granting a percentage proportional to the amount of +insurance likely to be done on the policy. Other companies have simply +reduced the amount of the commission rate, thus virtually withdrawing +from active competition. + +This will, in a certain degree, explain the wide variation in the +figures given above, where it is noticed that, in five companies out +of twenty-two, the total agency expenditures amount to less than the +general expenses, while in six cases the companies spend more than +double as much on the former as on the latter. In either class we find +representatives of the five largest companies in the country. + +On applying the foregoing ratios to the business of the existing +companies we find that, calling the theoretical expenses $100, the +actual expenditures for 1889 were as follows: $112.67, $118.34, +$150.40, $194.48, $208.16, $208.53, $228.66, $235.89, $248.44, +$250.79, $258.33, $258.57, $265.14, $267.19, $267.92, $274.47, +$294.17, $314.96, $335.70, $377.94, $616.70. + +In this discouraging exhibit there is one ray of comfort. The combined +assets of the two companies heading the list amount to over +$100,000,000. There is no question as to their financial standing, and +both show a large increase in membership over the previous year. I may +also say here that it is a difficult matter to get at the actual "cost +of insurance" in the various companies. Many of them, on their own +acknowledgment, do not compute the advance cost of carrying their +"amount at risk," and others, for reasons of their own, do not care to +state the figures. In cases where the correct figures were not +obtainable, I have assumed the cost to have been 1-1/3 per cent. of +the mean amount at risk. + +If we should, in our comparison, omit the actual agency expenses and +commissions, the ratios would stand as follows: + +Where I would allow $100 the companies actually used: $43.17, $55.90, +$65.21, $77.21, $82.39, $88.34, $91.99. $91.98. $92.19, $94.65, +$97.15. $99.55. $99.11. $102.86, $109.35, $125.05, $133.03, $141.92, +$195.90, $207.06, $287.72. + +As might be supposed, the first two ratios are those companies before +alluded to. These companies might have doubled their advertising +account and expended $300,000 between them on agents' salaries, and +still have kept within my allowance. + +Admitting, for the present at least, the reasonableness of the +proposed allowance for the expenses of the banking and insurance +departments of the business, we have before us the problem how to +equitably adjust the burden among the great variety of policies. + +In the first place, _there should be no policy in the company that +does not contribute its proportionate share of the expense allowance +during every year of its life_. I make a special point of this, for at +present the policies which have become paid up, either by the payment +of a single premium at the outset or by the completion of a stipulated +number of payments, contribute practically nothing to the expense +account after the premium payments cease. + +The following plan, I think, complies with all the requirements of the +problem. By the proposed method every policy, at all stages of its +existence, contributes its exact share to the expense fund, whatever +its plan of payment may be. + +Let us, as an illustration, examine the case of a ten year endowment +policy, taken out at age 30, and consider it under three aspects, +first, as paid for in advance by a single payment, second, as paid by +five annual payments, and third, as paid for annually throughout the +term. I have used this short term endowment policy simply for +convenience, the rule applying equally to policies of longer term or +to the ordinary life policy, which is, in fact, an endowment policy +payable at death or age 100.[1] + +[Footnote 1: The expense allowance on a plain life policy for $1,000, +taken at age 33, would be about $5.29; net premium (com. ex. 4 per +cent.), $18.04; total office premium, $23.33; present rate $24.10.] + +Taking the case of the single premium endowment policy for $1,000, we +find that the following sums are required, each year to provide for +the care of the reserve and to pay the government fees (1 per cent. of +reserve): + + 1st year $6.9982 | 6th year $8.4136 + 2d " 7.2560 | 7th " 8.7381 + 3d " 7.5258 | 8th " 9.0781 + 4th " 7.8082 | 9th " 9.4346 + 5th " 8.1039 | 10th " 9.8086 + +The insurance expenses should be covered by the 20 per cent. allowance +given below: + + 1st year $ .4422 | 6th year $ .2566 + 2d " .4100 | 7th " .2076 + 3d " .3762 | 8th " .1556 + 4th " .3402 | 9th " .0988 + 5th " .2996 | 10th " .0344 + +Consequently the total contribution required from this policy each +year is: + + 1st year $7.4404 | 6th year $8.6702 + 2d " 7.6660 | 7th " 8.9457 + 3d " 7.9020 | 8th " 9.2337 + 4th " 8.1484 | 9th " 9.5334 + 5th " 8.4034 | 10th " 9.8430 + +The present value of all these contributions is found to be, at 4 per +cent. interest, $71.6394; in other words, this sum paid at the outset, +provides a fund from which we may deduct the current expenses of each +year in advance, and by accumulating the balance at the assumed rate +of interest from year to year, we shall have enough to pay the +anticipated expenses, leaving nothing over. + +In the above case the sums in hand at the beginning of the year are as +follows: + + 1st year $71.3694 | 6th year $42.6981 + 2d " 66.7669 | 7th " 35.3890 + 3d " 61.4650 | 8th " 27.5009 + 4th " 55.7055 | 9th " 18.9979 + 5th " 49.4594 | 10th " 9.8430 + +We find a somewhat different condition existing during the first years +of a 5-year endowment policy. As there is more insurance and less +banking, the requirements are as follows: + + ------------+----------+-----------+--------+---------+ + | 1 P. Ct. | 20 P. Ct. | | | + | on | on | Total. | Initial | + | Reserve. | Cost. | | Fund. | + ------------+----------+-----------+--------+---------+ + 1st year | $1.5038 | $1.2572 |$2.7610 |$12.9769 | + 2d " | 3.0406 | 1.0216 | 4.0622 | 23.6015 | + 3d " | 4.6503 | .7852 | 5.4355 | 33.2979 | + 4th " | 6.3367 | .5378 | 6.8745 | 41.9538 | + 5th " | 8.1039 | .2996 | 8.4035 | 49.4594 | + 6th " | 8.4136 | .2566 | 8.6702 | 42.6981 | + 7th " | 8.7381 | .2076 | 8.9257 | 35.3890 | + 8th " | 9.0781 | .1556 | 9.2337 | 27.5009 | + 9th " | 9.4346 | .0988 | 9.5334 | 18.9979 | + 10th " | 9.8086 | .0344 | 9.8430 | 9.8430 | + ------------+----------+-----------+--------+---------+ + +As the premium payments extend over only five years, the expense +contributions must all be paid during that time and are most +conveniently made by a uniform addition to the net premium. + +The present value of the amounts in column 3 is $60.0819, and the +equivalent annuity for five years is $12.9769. This amount, received +for five consecutive years, will put the company in funds to pay +current expenses and leave a reserve of $42.6981 at the beginning of +the sixth year, which, as we have seen in the analysis of the +single-premium policy, is the sum required for future expenses on the +paid up basis. + +In like manner we find that the 10-year annuity equivalent to the +present value of the annual contributions in the case of an +annual-payment policy is $5.534, thus: + + ------------+----------+-----------+--------+---------+ + | 1 P. Ct. | 20 P. Ct. | | | + | on | on | Total. | Initial | + | Reserve. | Cost. | | Fund. | + ------------+----------+-----------+--------+---------+ + 1st year | $.8234 | $1.3514 |$2.1748 |$ 5.5340 | + 2d " | 1.6473 | 1.2478 | 2.8951 | 9.0275 | + 3d " | 2.5096 | 1.1388 | 3.6484 | 11.9116 | + 4th " | 3.4124 | 1.0210 | 4.4334 | 14.1277 | + 5th " | 4.3572 | .8916 | 5.2488 | 15.6161 | + 6th " | 5.3479 | .7534 | 6.1013 | 16.3160 | + 7th " | 6.3853 | .5966 | 6.9819 | 16.1572 | + 8th " | 7.4726 | .4270 | 7.8996 | 15.0763 | + 9th " | 8.6127 | .2418 | 8.8545 | 12.9977 | + 10th " | 9.8086 | .0344 | 9.8430 | 9.8430 | + ------------+----------+-----------+--------+---------+ + +The present value of the ten yearly expense items given in the "total" +column above is $46.6812, which is equal to a ten-year annuity of +$5.534. The several premiums stand now as follows: + + ENDOWMENT: $1,000, AGE 30, PAYABLE AT DEATH OR 40 + + Net Prem.[2] Margin. Total. + +At single premium. $687.228 $71.6394 $758.8674 +At five premiums. 150.615 12.9769 163.5939 +At annual premiums. 84.172 5.5340 89.7060 + +[Footnote 2: Thirty American offices. Discount from middle of year, +Vx-½ or (M x 1.01961) / Dx.] + +By the actuaries' rate we have, with the customary loading for +expense: + + Single premium: $721.66 (loaded, $34.36). Five premiums, $188.70 + (loaded $37.78). Annual premium, $105.65 (loaded $21.11). + +Admitting the correctness of the new method, we must conclude that the +present single premium is not sufficiently loaded to cover its own +expenses, while the annual payment policy pays more than its just +share. A prominent and thoroughly informed life insurance president +says in this connection: "Many of the policies, particularly the short +term endowments, are charged with too high a percentage of expenses to +prove a good investment at maturity or profitable to the insured in +case of surrender." This is not to be wondered at when the applicant +for a 10-year endowment policy sees at a glance that he must pay, in +the gross, more than is returned unless he should die in the interim, +in which case a plain "life" or "term" policy would have answered the +purpose. Under the new system of assessing expenses one form is as +desirable as another, from the standpoint of the insured or the +company. + +The new premium for the 10-year endowment policy, $89.71, commends +itself at once to the applicant, who can easily see that his total +outlay must fall short of the amount ultimately to be realized, of +course, disregarding interest and probable dividends in both cases. + +In discounting the future expense contributions I have not taken the +chances of dying into account. Hence the expense reserve in any +instance applies only to that individual case, and, in the event of +death or surrender before the maturity of the policy, the amount of +the expense fund not used would naturally revert to the insured. + +The scheme of expense assessment outlined above will doubtless be +pronounced impracticable by the majority of insurance men. + +Such a far reaching reform is too much to hope for, at least in the +immediate future. + +No well informed life insurance expert will deny that there are +opportunities for improvement in the business, but to graft new +methods on old companies is a hopeless undertaking. + +It is well, however, to have new methods well matured in advance of +the public demand, and I feel convinced that the ideas here set forth +are in the line of the reform which, before long, must be instituted +by the companies if they would retain the confidence and patronage of +the community. + +Doubtless many insurance presidents could tell of suggestions which +have impressed them favorably and which they would gladly have adopted +were it not for the injustice done thereby to older members and the +changes necessary to bring existing contracts into conformity with the +new system. Similar objections may be urged against the ideas here +advanced, and I must confess I hardly see a way by which the present +suggestions can be utilized by existing companies. We can only hope +that sooner or later some of the new theories may be practically +tested. Meanwhile the companies at present in the field are doing a +great work for the good of humanity, even though their methods may be, +in some particulars, more practical than scientific. + +Winchester, Mass. FRANK J. WILLS. + + * * * * * + + + + +THE FLOOD AT KARLSBAD. + + +During the flood which occurred in Germany and Bohemia, the last week +of November, Karlsbad was especially unfortunate; it suffered such an +inundation as had never before been known in the "Sprudelstadt." On +the evening of November 23, the Tepl was very much swollen by the +rain, which had continued for several days, but it was supposed that +there was no danger of a flood, as the bed of the river had been put +in proper condition. During the forenoon of November 24, the water +suddenly began to rise with such astonishing rapidity that within half +an hour all the lower streets were like turbulent rivers and the Alte +and Neue Wiese were transformed into a lake. The stores on the Alte +Wiese were under water to the roofs, and the proprietors, who were +trying to save their goods, were surprised by the water and had to +take refuge in the trees. They were rescued by having ropes thrown to +them, and during this work a catastrophe occurred which was a great +misfortune to all classes of citizens. The beloved burgermeister of +Karlsbad, Dr. Rudolf Knoll, who had just recovered from a severe +illness, was, with others, directing the work from the balcony of one +of the houses, when a rope by which a man was being drawn through the +water broke, and the man was carried off by the waves. The fright and +excitement of the scene gave the burgermeister a shock which caused +his instant death, but the man who was in danger was brought safely +out of the water. + +The water was 9 ft. in Marienbaderstrasse, the Marktplatz, +Muhlbadgasse, the Sprudelgasse, Kreuzgasse, Kaiserstrasse, and +Egerstrasse, and flooded the quay, causing great destruction. All +places of business were flooded, the doors and iron shutters were +pushed in by the force of the water and the goods were carried away or +ruined. + +The house called "Zum Kaffeebaum" was undermined and part of it fell +to the ground; the same fate was feared for other buildings. The +Sophien and Curhaus bridges were carried away. Other bridges were +greatly damaged, and the masonry along the banks of the river was +partially destroyed. The Sprudelgasse was completely washed out, and +the condition of the Muhlbadgasse was almost as bad. The fire +department with its apparatus had great difficulty in saving the +inhabitants and guests, as there were very few boats or pontoons at +their command, and the soldiers (Pionniere) from Prague and the +firemen from the neighboring towns did not arrive until evening. +Fortunately the water began to fall in the night, and the next day it +had gone down so that it left its terrible work visible. The Sprudel +and the mineral springs were not injured, but, on the other hand, the +water pipes of the bathing establishments and the gas pipes were +completely destroyed.--_Illustrirte Zeitung._ + + * * * * * + + + + +THEATRICAL WATER PLAYS. + + +In one of the plays at Hengler's Circus in London a water scene is +introduced, for which purpose the main ring is flooded with water in a +manner which is both striking and interesting. + +[Illustration: FLOODING A CIRCUS RING.] + +The ring is entirely lined with stout macintosh sheeting, and into +this, from two large conduits. 23,000 gallons of water are poured, the +tank being filled to a depth of some 2 ft. in the remarkably short +time of 35 seconds. A steamboat and other small craft are then +launched and the adventures of the heroine then proceed. She falls +overboard, we believe, but is saved after desperate and amusing +struggles. Our engravings, which are from the _Graphic_, illustrate +the mode of filling the ring with water, and the steamboat launch. + +[Illustration: A THEATRICAL STEAMBOAT.] + + * * * * * + + + + +SCIENCE IN THE THEATER. + + +In the pretty little hall of the Boulevard des Italiens, at Paris, a +striking exhibition of simulated hypnotism is given every evening. + +This entertainment, which has met with much success, was devised by +Mr. Melies, director of the establishment, which was founded many +years ago by the celebrated prestidigitator whose popular name (Robert +Houdin) it still bears. This performance carries instruction with it, +for it shows how easily the most surprising phenomena of the +pathologic state can be imitated. To this effect, several exhibitions +are given every evening. + +Mr. Harmington, a convinced disciple of Mesmer, asks for a subject, +and finds one in the hall. A young artist named Marius presents +himself. Mr. Harmington makes him perform all sorts of extravagant +acts, accompanied with a continuous round of pantomimes that are +rendered the more striking by the supposed state of somnipathy of the +subject. At the moment at which Marius is finishing his most +extraordinary exercises, a policeman suddenly breaks in upon the stage +in order to execute the recent orders relative to hypnotism. But he +himself is subjugated by Mr. Harmington and thrown down by the +vibrations of which the encephalus of this terrible magnetizer is the +center. When the curtain falls, the representative of authority is +struggling against the catalepsy that is overcoming him. + +All the phenomena of induced sleep are successively simulated with +much naturalness by Mr. Jules David, who plays the part of Marius in +this pleasing little performance. + +At a certain moment, after skillfully simulated passes made by the +magnetizer, Mr. David suddenly becomes as rigid as a stick of wood, +and falls in pivoting on his heels (Fig. 1). Did not Mr. Harmington +run to his assistance, he would inevitably crack his skull upon the +floor, but the magnetizer stands just behind him in order to receive +him in his arms. Then he lifts him, and places him upon two chairs +just as he would do with a simple board. He places the head of the +subject upon the seat of one of the chairs and the heels upon that of +the other. Mr. David then remains in a state of perfect immobility. +Not a muscle is seen to relax, and not a motion betrays the +persistence of life in him. The simulation is perfect. + +[Illustration: FIG. 1.--CATALEPTIC RIGIDITY.] + +In order to complete the astonishment of the spectators, Mr. +Harmington seats himself triumphantly upon the abdomen of the subject +and slowly raises his feet and holds them suspended in the air to show +that it is the subject only that supports him, without the need of +any other point of support than the two chairs (Fig. 2). + +[Illustration: FIG. 2.--EXPERIMENT ON THE SAME SUBJECT.] + +Usually, there are plenty of persons ingenuous enough to think that +Mr. David is actually in a cataleptic sleep, one of the characters of +which is cadaveric rigidity. + +As Mr. David's neck is entirely bare, it is not possible to suppose +that the simulator of catalepsy wears an iron corset concealed beneath +his clothing. He has performed a feat of strength and skill rendered +easy by the exercise that he has given to the muscles occupying the +_colliciæ_ of his vertebral column. This part of the muscular system +is greatly developed in the weakest and least hardy persons. In fact, +in order that man may keep a vertical position and execute an infinite +multitude of motions in which stability is involved, nature has had to +give him a large number of different organs. The muscles of the back +are arranged upon several superposed layers, the vertebral column is +doubly recurved in order that it may have more strength, and, finally, +rachidion nerves issue from each vertebra in order to regulate the +contraction of each muscular fasciculus according to the requirements +of equilibrium. The trick is so easy that we have seen youths +belonging to the Ligue d'Education Physique immediately imitate Mr. +David after seeing him operate but once. + +For the sake of those who would like to perform it, we shall add that +Mr. David takes care to bend his body in the form of an arch in such a +way that the convexity shall be beneath. As Mr. Harmington never fails +to place himself in the center of the line that joins Mr. David's head +and heels, his weight is divided into two parts, that is to say, 88 +pounds on each side of the point of support. The result is that the +stress necessary is less than that of a strong man of the Halle +lifting a bag of wheat to his shoulder or of an athlete supporting a +human pyramid. The force of contraction of the muscular fibers brought +into play in this experiment is much greater than is commonly +believed. In his lectures on physiology, Milne-Edwards cites some +facts that prove that it may exceed 600 pounds per square inch of +section. + +[Illustration: FIG. 3.--THE PERFORATE ARM.] + +The experiment on cadaveric rigidity is followed by others in +insensibility. Mr. David, without wincing, allows a poignard to be +thrust into his arm, which Mr. Harmington has previously +"cataleptized" (Fig. 3). This trick is performed by means of a blade +divided into two parts that are connected by a semicircle. This +process is well known to prestidigitators, but it might be executed in +a genuine manner. In fact, on replacing the poignard by one of the +gold needles used by physicians for acupuncture, it would be possible +to dispense with prestidigitation. Under such conditions it is +possible to transpierce a person's arm. The pain is supportable, and +consists in the sensation of a prick produced in the passage of the +needle through the skin. As for the muscular flesh, that is of itself +perfectly insensible. The needle, upon the necessary antiseptic +precautions being taken, may traverse the veins and arteries with +impunity, provided that it is not allowed to remain long enough to +bring about the formation of a clot of coagulated blood (Fig. 4). + +[Illustration: FIG. 4.--AN ARM TRANSPIERCED BY A NEEDLE.] + +We think it of interest to add that it is necessary that the +experiment be performed by a practitioner if one desires to +demonstrate upon himself a very curious physiological fact that has +been known from the remotest antiquity. It has been employed for +several thousand years in Chinese medicine, for opening a passage for +the bad spirits that produce diseases. For some years past a much more +serious use has been made of it in European medicine for introducing +electric currents into the interior of the organism. In this case the +perimeter of the needle is insulated, and the electricity flows into +the organism through the point. We have several times had these +operations performed upon ourselves, and this permits us to assert +that the above mentioned facts are absolutely true.--_La Nature._ + + * * * * * + + + + +NEWER PHYSIOLOGY AND PATHOLOGY. + +By Prof. SAMUEL BELL, M.D. + + +Physiology has for many decades been a science founded on experiment, +and pathology has been rapidly pressing forward in the same direction. +To read the accounts of how certain conclusions have been arrived at +in the laboratory, by ingenious devices and by skillful manipulations, +is as fascinating as any tale of adventure. + +When the microscope began its work, how discouraging was the vastness +and complexity of the discoveries which it brought to light; how many +years has it been diligently used, and how uncertain are we still +about many of its revelations! But what a happy conjecture of man, and +as proper environment takes place we may reach better results! Let me +give an illustration: + +Some thirty years ago, Virchow began his studies and lectures upon +cellular pathology. The enthusiasm which he awakened spread over the +whole medical world. The wonderful attention to detail, the broad +philosophy which signalized his observations, were alike remarkable. +His class room was packed with students from every country, who +thought it no hardship to struggle for a seat at eight o'clock in the +morning. With his blackboard behind him and specimens of pathology +before him, and microscopes coursing upon railway tracks around the +tables which filled the room, he was the embodiment of the teacher; +his highest honor was as discoverer. The life and importance of the +cell, both in health and disease, it has been his work to discover and +to teach. The point of view from which he has classified tumors is +founded on this basis, and remains the accepted method. The light +which he cast upon the nature of inflammation has not yet been +obscured, and while other phenomena appear, the multiplication of +cells and nuclei and the formation of connective tissue in the process +of inflammation will always call to mind his labors. + +To one of Virchow's pupils, Prof. Recklinghausen, we chiefly owe our +knowledge of the phenomena of diapedesis as a part of the inflammatory +activity. How incredible it seems that masses of living matter can +make their way through the walls of blood vessels which do not rupture +and which have no visible apertures! + +Virchow fixed his attention upon the forms and activities of the +cells, their multiplication and degradation, and how they build up +tissues, both healthy and morbid. + +To another matter with which, both literally and metaphorically, the +air is filled, we must also make allusion. The existence of +micro-organisms in countless numbers is no new fact, but the influence +they may exert over living tissues has only lately become the subject +of earnest attention. So long as they were not known to have any +practical bearing upon human welfare, they interested almost nobody, +but when, however, it was shown that putrefaction of meat is due to +the agency of the _bacterium termo_, and the decomposition of albumen +to the _bacillus subtilis_; when anthrax in cattle and sheep was found +to depend on the _bacillus anthracis_, and that in human beings it +caused malignant pustules; when suppuration of wounds was found to be +associated with micrococci; and when it was announced that by a +process of inoculation cattle could be protected against anthrax, and +that by carbolic spray and other well known precautions the +suppuration of wounds could be prevented--all the world lent its ears +and investigation at once began. + +Because labors in bacteriology promised to be fruitful in practical +results, the workers speedily became innumerable, and we are +accumulating a wondrous store of facts. How long now is the list of +diseases in which germs make their appearance--in pneumonia, in +endocarditis, in erysipelas, in pyæmia, in tuberculosis, and so on and +so on. One of the most striking illustrations is the gonococcus of +gonorrhoea, whose presence in and around gives to the pus cells +their virulent properties, and when transferred to the eye works such +lamentable mischief. Without their existence the inoculation of pus in +the healthy eye is harmless; pus bearing the gonococci excites the +most intense inflammation. Similar suppurative action in the cornea is +often caused by infection of cocci. The proof of causation may be +found in the fact that the most effective cure now practiced for such +suppuration is to sterilize them by the actual cautery. Rosenbach says +that he knows six distinct microbes which are capable of exciting +suppuration in man. Their activity may be productive of a poison, or +putrefactive alkaloid, which is absorbed. + +There are at present two prominent theories in regard to the +infections which produce disease. The first is based upon chemical +processes, the second upon the multiplication of living organisms. The +chemical theory maintains that after the infectious element has been +received into the body it acts as a ferment, and gives rise to certain +morbid processes, upon the principle of catalysis. The theory of +organisms, or the germ theory, maintains that the infectious elements +are living organisms, which, being received into the system, are +reproduced indefinitely, and excite morbid processes which are +characteristic of certain types of disease. This latter theory so +readily explains many of the facts connected with the development and +reproduction of infectious diseases, that it has been unqualifiedly +adopted by a large number of investigators. The proofs of this theory +had not, however, advanced beyond the demonstrations of the presence +of certain forms of bacteria in the pathological changes of a very +limited number of infectious diseases, until February, 1882, when Koch +announced his discovery of the tubercle bacillus, since which time +nearly every disease has its supposed microbe, and the race is, +indeed, swift in which the would-be discoverers press forward with new +germs for public favor. + +The term bacteria or microbe refers to particles of matter, +microscopic in size, which belong to the vegetable kingdom, where they +are known as fungi. If we examine a drop of stagnant water under the +microscope, amplifying say four hundred diameters, we see it loaded +with minute bodies, some mere points, others slightly elongated into +rods, all actively in motion and in various positions, a countless +confusion. If evaporation now takes place, all is still. If we now +apply moisture, the dried-up granules will show activity, as though +they had not been disturbed. + +All these different organisms have become familiar to us under the +generic term bacteria, which is a very unfortunate application, as it +really applies to only a single class of fungi. Cohn calls them +schizomycetes, and makes the following classifications: + + 1. _Sphero-bacteria_, or microbes. + 2. _Micro-bacteria_, or bacteria. + 3. _Desmo-bacteria_, or bacilli. + 4. _Spiroteria_, or spirillæ. + +The _spiro-bacteria_, or micrococci, are the simplest of the fungi, +and appear as minute organisms of spherical form. They multiply by +fission, a single coccus forming two, these two producing four, and so +on. They present a variety of appearances under the microscope. From +single isolated specimens (which under the highest magnifying power +present nothing beyond minute points) you will observe them in pairs, +again in fours, or in clusters of hundreds (forming zoöglea) and still +adhering together, forming chains. When a given specimen is about to +divide, it is seen to elongate slightly, then a constriction is +formed, which deepens until complete fission ensues. + +Micrococci possess no visible structure. They consist of a minute +droplet of protoplasm (mycroprotein) surrounded by a delicate cell +membrane. Certain forms are embedded in a capsule (diameter 0.0008 to +0.0001 millimeter). + +These little organisms, when observed in a fluid like blood, sputum, +etc., are found to present very active movements, although provided +with no organs of locomotion. + +This Brownian motion is possessed by almost every minute particle of +matter, organic and inorganic, and is not due to any inherent power of +the individual. They are almost omnipresent, abounding in the air, the +earth, the water, are always found in millions where moist organic +matter is undergoing decomposition, and are associated with the +processes of fermentation--in fact, they are essential to it. The +souring of milk succeeds the multiplication of these germs. Certain +varieties are pigmented, and we observe colonies of chromogenic cocci +multiplying upon slices of boiled potato, eggs, etc., presenting all +the colors of the rainbow. All of these germs are not the cause of +disease. Certain species, however (termed pathogenic), are always +associated with certain diseased conditions. + +The _bacteria-termo_--micro-bacteria--are slightly elongated, and +inasmuch as they multiply by division, frequently appear coupled +together, linked in pairs, and in chains. They are generally found in +putrefying liquids, especially infusions of vegetable matter. They +possess mobility to a remarkable degree. Observing a field of +bacteria-termo under the microscope, they may be seen actively engaged +in twining and twisting. A flagellum has been demonstrated as attached +to one or both extremities. This is too minute to be generally +resolved, even if it is a common appendage. + +_Desmo-bacteria_ (or bacilli) are rod-like organisms, occurring of +various lengths and different thicknesses. In a slide of the bacillus +of tuberculosis and anthrax, we notice at intervals dots which +represent the spores from which, as the rods break up, future bacilli +are developed. + +Then we have _spiro-bacteria,_ the spirilla and the spirochetæ; the +former having short open spirals, the latter long and closely wound +spirals. The _spirillum, volutans_ is often found in drinking water, +and in common with some other specimens of this class is provided with +flagellæ, sometimes at both extremities, which furnish the means of +rapid locomotion. The spiro-bacteria multiply by spores, although +little is at present known of their life history. They frequently are +attached together at their extremities, forming zigzag chains. + +We have seen that bacteria differ greatly in appearance from the +elongated dot of the bacterium proper, to the elongated rod or +cylinder of the bacillus, and the long spirals of spiro-bacteria. It +is unfortunate that they are not sufficiently constant in habit to +always attach themselves to one or the other of these genera. The +micrococcus has a habit of elongating at times until it is impossible +to recognize him except as a bacterium; while bacilli, again, break up +until their particles exactly resemble micrococci. + +Bacteria cannot exist without water; certain forms require oxygen, +while others thrive equally well without it; some thrive in solution +of simple salts, while others require albuminoid material. + +Bacteriology, with its relation to the science of medicine, is of +importance to every investigating physician; it covers our knowledge +of the relation of these minute organisms to the ætiology of disease. +What has been gained as to practical application in the treatment of +disease? This question is not infrequently asked in a sneering manner. +We can, in reply, say that the results are not all in the future. It +is encouraging that results have been attained which have had a very +important practical bearing, and that these complaints come generally +from individuals least acquainted with scientific investigations in +bacteriology. + +In the study of the relation of a given bacterium to a certain +disease, it becomes necessary to attend carefully to three different +operations: First, the organism supposed to cause the disease must be +found and isolated. Second, it must be cultivated through several +generations in order that absolute purity may be secured. Lastly, the +germ must be again introduced into a healthy living being. If the +preceding steps be carried out, and the original disease be +communicated by inoculation, and the germs be again found in the +diseased body, we have no alternative; we must conclude that we have +ascertained the cause of the disease. The importance of being familiar +with the ætiology of the disease before we can expect to combat it +with any well-grounded hope of success is evident. + +If the sputum of a phthisical patient be submitted to the skilled +microscopist, he is nearly always able to demonstrate bacilli, but +this goes for very little. Because bacilli are found in phthisis, it +is no more certain that they are the cause of phthisis than it is +certain that cheese mites are the cause of cheese. Well, suppose we +were to inject sputum from a phthisical person into the lower animal +and tuberculosis follows, and then announce to the profession that we +have demonstrated the relation of the cause and effect between bacilli +and phthisis? Why we would start such an uproar of objections as would +speedily convince us that there was much work yet in the domain of +bacteriology. + +The scientific investigators would say you have injected with the +sputum into the blood of your unfortunate patient, pus, morphological +elements, and perhaps half a dozen other forms of bacteria, any one of +which is just as likely to produce the disease as the bacillus you +have selected. + +The first important step is, first isolate your bacillus. If I were to +take a glass plate, one side of which is coated with a thick solution +of peptonized gelatin, and allow the water to collect, the gelatinous +matter will become solid. If now, with a wire dipped in some +tuberculous matter, I draw a line along the gelatin, I have deposited +at intervals along this line, specimens of tubercle bacilli. If this +plate be now kept at a proper temperature, after a few days, wherever +the bacilli have been caught, a grayish spot will appear, which, +easily seen with the naked eye, gradually spreads and becomes larger. +These spots are colonies containing thousands of bacilli. Let us +return to our gelatin plate. + +We find a spot which answers to the description of a colony of +tubercle bacilli. We now take a minute particle from this colony on a +wire and convey it to the surface of some hardened blood serum in a +test tube. We plug the tube so that no air germs may drop in, and +place it in an incubator at the proper temperature. After several +days, if no contamination be present, a colony of bacilli will appear +around the spot where we sowed the spores. Let us repeat the process. + +Take a particle from this colony, and transfer it to another tube. +This is our second culture. This must be repeated until we are +satisfied that we have secured a _pure_ culture. If this be carried to +the twenty-fifth generation, we may be assured that there remains no +pus, no ptomaines, nothing but the desired bacilli. + +It is a proper material now for inoculation, and if we inoculate some +of the lower animals, for instance the monkey, we produce a disease +identical with phthisis pulmpnalis. Bacteria also afford peculiar +chemical reactions. For example, nitric acid will discharge all the +color from all bacilli artificially dyed with anilin, except those of +tubercle and anthrax. One species is stained readily with a dye that +leaves another unaltered. Thus we are enabled in the laboratory to +determine whether the bacilli found in sputum, for example, are from +tubercle or are the bacteria of decomposition. + +From what I have said of the tubercle bacillus, it would seem +thoroughly demonstrated that it is the cause of tubercle in these +animals. But we must walk cautiously here. These are not human beings, +who know that like results would follow their inoculation. The animals +used by Koch are animals very subject to tubercle. + +We must, from the very nature of our environment, be constantly +inhaling these germs as we pass through the wards of our hospitals; +yes, they are floating in the air of our streets and dwellings. It +becomes necessary then for us to inquire: If bacteria cause disease, +in what manner do they produce it? The healthy organism is always +beset with a multitude of non-pathogenic bacteria. They occupy the +natural cavities, especially the alimentary canal. They feed on the +substances lying in their neighborhood, whether brought into the body +or secreted by the tissues. In so doing they set up chemical changes +in their substances. Where the organs are acting normally these fungi +work no mischief. The products of decomposition thus set up are +harmless, or are conveyed out of the body before they begin to be +active. + +If bacteria develop to an inordinate degree, if the contents of organs +are not frequently discharged, fermentative processes may be set up, +which result in disease. Bacteria must always multiply and exist at +the expense of the body which they infest, and the more weakened the +vital forces become, the more favorable is the soil for their +development. + +Septicæmia is caused by the absorption of the products of +putrefaction, induced before bacteria can multiply inside or outside +the body. Bacteria must find a congenial soil. The so-called cholera +bacillus must gain access to the intestinal tract before it finds +conditions suitable to colonization. It does not seem to multiply in +the stomach or in the blood, but once injected into the duodenum +develops with astonishing rapidity, and the delicate epithelial cells +of the villi become swollen, soften and break down, exposing the +mucosa. + +It has been shown that _bouillon_ in which Loeffler's diphtheria +bacillus has grown, and which has been passed through unglazed +porcelain filters, shows the presence of a poison which is capable of +producing the same results upon inoculation as the pure culture of the +bacillus itself. Zarniko, working upon the same organism, obtained a +number of positive results that led him to declare this bacillus is +the cause of epidemic diphtheria, in spite of many assertions to the +contrary. Chantmesse and Widal record the results of their work as to +what will most easily and effectively destroy the bacillus of +diphtheria. + +The only three substances that actually checked and destroyed its +vitality were phenic acid (5 per cent.), camphor (20 per cent.), olive +oil (25 per cent.), in combination. For the last I substitute +glycerine, because this allows the mixture to penetrate farther into +the mucous membrane than oil, the latter favoring a tendency to pass +over the surface. This mixture when heated separates into two layers, +the upper one viscid and forming a sort of "glycerol," the lower +clear. The latter will completely sterilize a thread dipped in a pure +culture of the diphtheria bacillus. Corrosive sublimate was not +examined because in strong enough doses it would be dangerous and in +weaker ones it would be useless. + +The facts obtained in regards to the streptococcus of erysipelas are +reported as follows: That both chemical and experimental evidence +teach the extreme ease of a renewed attack of the disease; that it is +possible to kill guinea pigs by an intoxication when they are immune +to an inoculation of the culture in ordinary quantities. And this +latter fact should warn experimenters trying to obtain immunity in man +by the inoculation of non-pathogenic bacteria, because the same +results may be reached. + +A new theory in regard to fevers and the relation of micro-organisms +is suggested by Roussy, viz.: That it is a fermentation produced by a +diastase or soluble ferment found in all micro-organisms and cells, +and which they use in attacking and transforming matter, either inside +their substance or without it. + +The resemblance of the malaria parasite to that of recurrent fever is +noted in the work of Sacharoff. He states that there exists in the +blood of those suffering from recurrent fever a hæmatozoon, which is +most prominent after the fever has begun to fall, when it is of +enormous proportions, twenty or more diameters of a red blood +corpuscle, although smaller ones may still be found. The parasite +consists of a delicate amoeboid body containing a multitude of dark, +round, uniform, sharply outlined, movable granules. Besides these, the +protoplasm contains a generally grayish homogeneous nucleus as large +as one or two red blood corpuscles. The protoplasm sends out +pseudopodia (with granules), which sometimes separate and appear as +small delicate pieces of protoplasm. They vary in size, and are often +swallowed by the red blood corpuscles in which they grow, and finally +develop into the above mentioned amoeboid bodies. + +Prof. J. Lewis Smith has made a great many autopsies of children dead +from cholera infantum, and almost invariably found the stomach and +liver in a comparatively healthy condition. Ganghen, who has given +this subject considerable study, denies the existence of any specific +germ in the summer diarrhea of infants, but claims to have found three +different germs in the intestines of children suffering from cholera +infantum, each producing a chemical poison which is capable of +producing vomiting, purging, and even death. A great variety of germs +are found in drinking water, and no doubt countless numbers are taken +into the digestive tract, and the principal reason why pathological +conditions do not occur more frequently is on account of the +germicidal qualities of the gastric juice. + +The comma bacillus of Koch, and the typhoid fever germ of Eberth, are +especially destroyed in normal gastric juice. When the germs are very +numerous, they run the gauntlet of the stomach (as the gastric juice +is secreted only during digestion); and once in the alkaline +intestinal canal they are capable of setting up disease, other +conditions contributing--ill health, deranged digestion, etc. + +Mittnam has made a study of bacteria beneath the nails, and reports, +after examining persons following different occupations, having found +numerous varieties of micro-organisms; which are interesting from a +scientific standpoint relative to the importance of thoroughly +cleansing the hands before undertaking any surgical procedure. He +found, out of twenty-five experiments, 78 varieties of bacteria, of +which 36 were classed as micrococci, 21 diplococci, 18 rods, 3 +sarcinæ, and 1 yeast. Cooks, barbers, waiters, etc., were examined. + +The blood, defibrinated and freshly drawn, has marked germicidal +action; for bacteria its action is decidedly deadly, even hours after +it has been drawn from the body. Especially were anti-germic qualities +noticed upon pathogenic bacteria. Buchner put the bacilli of anthrax +in a quantity of blood, and in two hours the number was reduced from +4,800 to 56, and in three hours only 3 living bacteria remained. Other +bacteria were experimented upon in blood with similar results, but the +destruction of the organism from putrefaction was much less marked, +and on some varieties the blood had little or no action. + +It is not the object of these remarks to even give a _résumé_ of the +_status præsens_ of bacteriology, but simply to stimulate thought in +that direction. The claims of some of the ultra-bacteriologists may +never be realized, but enough has been accomplished to revolutionize +the treatment of certain diseases, and the observing student will do +well to keep his eye on the microbe, as it seems from the latest +investigations that its star is in the ascendant. And who can +prognosticate but that in the next decade an entire revolution in the +ætiology and treatment of many diseases may take place? + +Detroit, Mich. + + * * * * * + + + + +THE COMPOSITION OF KOCH'S LYMPH. + +WHAT PROFESSOR KOCH SAYS IT IS, AND WHAT IT CAN DO. + +(By Cable to the _Medical Record_.) + +BERLIN, January 15, 1891. + + +The curiosity to know the composition of the famous lymph has been +gratified by the publication to-day of an article by Professor Koch on +the subject. In the following, as will be seen, he reaffirms his +original convictions and acknowledges the valuable assistance he has +received from those who have used his fluid, and thus helped him in +the accumulation of experience. + +Professor Koch says: Two months ago I published the results of my +experiments with the new remedy for tuberculosis, since which time +many physicians who received the preparation have been enabled to +become acquainted with its properties through their own experiments. +So far as I have been able to review the statements published and the +communications received by letter, my predictions have been fully and +completely confirmed. The general consensus of opinion is that the +remedy has a specific action upon tubercular tissues, and is, +therefore, applicable as a very delicate and sure reagent for +discovering latent and diagnosing doubtful tuberculous processes. +Regarding the curative effects of the remedy, most reports agree that, +despite the comparatively short duration of its application, many +patients have shown more or less pronounced improvement. It has been +affirmed that in not a few cases even a cure has been established. +Standing quite by itself is the assertion that the remedy may not only +be dangerous in cases which have advanced too far--a fact which may +forthwith be conceded--but also that it actually promotes the +tuberculous process, being therefore injurious. + +During the past six weeks I myself have had opportunity to bring +together further experiences touching the curative effects and +diagnostic application of the remedy in the cases of about one hundred +and fifty sufferers from tuberculosis of the most varied types in this +city and in the Moabit Hospital. + +I can only say that everything I have latterly seen accords with my +previous observations. There has been nothing to modify in what I +before reported. As long as it was only a question of proving the +accuracy of my indications, it was needless for any one to know what +the remedy contained or whence it was derived. On the contrary, +subsequent testing would necessarily be more unbiased, the less people +knew of the remedy itself. Now, after sufficient confirmatory testing, +the importance of the remedy is proved, my next task is to extend my +study of the remedy beyond the field where it has hitherto been +applied, and if possible to apply the principle underlying the +discovery to other diseases. + +This task naturally demands a full knowledge of the remedy. I +therefore consider that the time has arrived when the requisite +indications in this direction shall be made. This is done in what +follows. + +Before going into the remedy itself, I deem it necessary for the +better understanding of its mode of operation to state briefly the way +by which I arrived at the discovery. If a healthy guinea pig be +inoculated with the pure cultivation of German Kultur of tubercle +bacilli, the wound caused by the inoculation mostly closes over with a +sticky matter, and appears in its early days to heal. Only after ten +to fourteen days a hard nodule presents itself, which, soon breaking, +forms an ulcerating sore, which continues until the animal dies. Quite +a different condition of things occurs when a guinea pig already +suffering from tuberculosis is inoculated. An animal successfully +inoculated from four to six weeks before is best adapted for this +purpose. In such an animal the small indentation assumes the same +sticky covering at the beginning, but no nodules form. On the +contrary, on the day following, or the second day after the +inoculation, the place where the lymph is injected shows a strange +change. It becomes hard and assumes a darker coloring, which is not +confined to the inoculation spot, but spreads to the neighboring parts +until it attains a diameter of from 0.05 to 1 cm. + +In a few days it becomes more and more manifest that the skin thus +changed is necrotic, finally falling off, leaving a flat ulceration +which usually heals rapidly and permanently without any involvement of +the adjacent lymphatic glands. Thus the injected tubercular bacilli +quite differently affect the skin of a healthy guinea pig from one +affected with tuberculosis. This effect is not exclusively produced +with living tubercular bacilli, but is also observed with the dead +bacilli, the result being the same whether, as I discovered by +experiments at the outset, the bacilli are killed by a somewhat +prolonged application of a low temperature or boiling heat or by means +of certain chemicals. This peculiar fact I followed up in all +directions, and this further result was obtained--that killed pure +cultivations of tubercular bacilli, after rinsing in water, might be +injected in great quantities under healthy guinea pig's skin without +anything occurring beyond local suppuration. Such injections belong to +the simplest and surest means of producing suppurations free from +living bacteria. + +Tuberculous guinea pigs, on the other hand, are killed by the +injection of very small quantities of such diluted cultivations. In +fact, within six to forty-eight hours, according to the strength of +the dose, an injection which is not sufficient to produce the death of +the animal may cause extended necrosis to the skin in the vicinity of +the place of injection. If the dilution is still further diluted until +it is scarcely visibly clouded, the animals inoculated remain alive +and a noticeable improvement in their condition soon supervenes. If +the injections are continued at intervals of from one to two days, the +ulcerating inoculation wound becomes smaller and finally scars over, +which otherwise it never does; the size of the swollen lymphatic +glands is reduced, the body becomes better nourished, and the morbid +process ceases, unless it has gone too far, in which case the animal +perishes from exhaustion. By this means the basis of a curative +process against tuberculosis was established. + +Against the practical application of such dilutions of dead tubercle +bacilli there presented itself the fact that the tubercle bacilli are +not absorbed at the inoculation points, nor do they disappear in +another way, but for a long time remain unchanged, and engender +greater or smaller suppurative foci. Anything, therefore, intended to +exercise a healing effect on the tuberculous process must be a soluble +substance which would be liberated to a certain extent by the fluids +of the body floating around the tubercle bacilli, and be transferred +in a fairly rapid manner to the juices of the body; while the +substance producing suppuration apparently remains behind in the +tubercular bacilli, or dissolves but very slowly. The only important +point was, therefore, to induce outside the body the process going on +inside, if possible, and to extract from the tubercular bacilli alone +the curative substance. This demanded time and toil, until I finally +succeeded, with the aid of a forty to fifty per cent. solution of +glycerine, in obtaining an effective substance from the tubercular +bacilli. With the fluid so obtained I made further experiments on +animals, and finally on human beings. These fluids were given to other +physicians to enable them to repeat the experiments. + +The remedy which is used in the new treatment consists of a glycerine +extract, derived from the pure cultivation of tubercle bacilli. Into +the simple extract there naturally passes from the tubercular bacilli, +besides the effective substance, all the other matter soluble in fifty +per cent. glycerine. + +Consequently, it contains a certain quantity of mineral salts, +coloring substances, and other unknown extractive matters. Some of +these substances can be removed from it tolerably easily. The +effective substance is insoluble in absolute alcohol. It can be +precipitated by it, though not, indeed, in a pure condition, but still +combined with the other extractive matter. It is likewise insoluble in +alcohol. The coloring matter may also be removed, rendering it +possible to obtain from the extract a colorless, dry substance +containing the effective principle in a much more concentrated form +than the original glycerine solution. For application in practice this +purification of the glycerine extract offers no advantage, because the +substances so eliminated are unessential for the human organism. The +process of purification would make the cost of the remedy +unnecessarily high. + +Regarding the constitution of the more effective substances, only +surmises may for the present be expressed. It appears to me to be +derivative from albuminous bodies, having a close affinity to them. It +does not belong to the group of so-called toxalbumins, because it +bears high temperatures, and in the dialyzer goes easily and quickly +through the membrane. The proportion of the substance in the extract +to all appearance is very small. It is estimated at fractions of one +per cent., which, if correct, we should have to do with a matter whose +effects upon organisms attacked with tuberculosis go far beyond what +is known to us of the strongest drugs. + +Regarding the manner in which the specific action of the remedy on +tuberculous tissue is to be represented, various hypotheses may +naturally be put forward. Without wishing to affirm that my view +affords the best explanation, I represent the process myself in the +following manner: + +The tubercle bacilli produced when growing in living tissues, the same +as in artificial cultivations, contain substances which variously and +notably unfavorably influence living elements in their vicinity. Among +these is a substance which in a certain degree of concentration kills +or so alters living protoplasm that it passes into a condition that +Weigert describes as coagulation necrosis. In tissue thus become +necrotic the bacillus finds such unfavorable conditions of nourishment +that it can grow no more and sometimes dies. + +This explains the remarkable phenomenon that in organs newly attacked +with tuberculosis, for instance in guinea pigs' spleen and liver, +which then are covered with gray nodules, numbers of bacilli are +found, whereas they are rare or wholly absent when the enormously +enlarged spleen consists almost entirely of whitish substance in a +condition of coagulation necrosis, such as is often found in cases of +natural death in tuberculous guinea pigs. The single bacillus cannot, +therefore, induce necrosis at a great distance, for as soon as +necrosis attains a certain extension the growth of the bacillus +subsides, and therewith the production of the necrotizing substance. A +kind of reciprocal compensation thus occurs, causing the vegetation of +isolated bacilli to remain so extraordinarily restricted, as, for +instance, in lupus and scrofulous glands. + +In such cases the necrosis generally extends only to a part of the +cells, which then, with further growth, assume the peculiar form of +riesen zelle, or giant cells. Thus, in this interpretation, follow +first the explanation Weigert gives of the production of giant cells. + +If now one increased artificially in the vicinity of the bacillus the +amount of necrotizing substance in the tissue, the necrosis would +spread a greater distance. The conditions of nourishment for the +bacillus would thereby become more unfavorable than usual. + +In the first place the tissue which had become necrotic over a large +extent would decay and detach itself, and where such were possible +would carry off the inclosed bacilli and eject them outwardly, so far +disturbing their vegetation that they would much more speedily be +killed than under ordinary circumstances. + +It is just in looking at such changes that the effect of the remedy +appears to consist. It contains a certain quantity of necrotizing +substance, a correspondingly large dose of which injures certain +tissue elements even in a healthy person, and perhaps the white blood +corpuscles or adjacent cells, thereby producing fever and a +complication of symptoms, whereas with tuberculous patients a much +smaller quantity suffices to induce at certain places, namely, where +tubercle bacilli are vegetating and have already impregnated the +adjacent region with the same necrotizing matter, more or less +extensive necrosis of the cells, with the phenomena in the whole +organism which result from and are connected with it. + +For the present, at least, it is impossible to explain the specific +influence which the remedy, in accurately defined doses, exercises +upon tuberculous tissue, and the possibility of increasing the doses +with such remarkable rapidity, and the remedial effects which have +unquestionably been produced under not too favorable circumstances. + +Of the consumptive patients whom he described as temporarily cured, +two have been returned to the Moabit Hospital for further observation. + +No bacilli have appeared in their sputum for the past three months, +and their phthisical symptoms have gradually and completely +disappeared. + + * * * * * + + + + +CAN WE SEPARATE ANIMALS FROM PLANTS? + +By ANDREW WILSON. + + +One of the plainest points connected with the study of living things +is the power we apparently possess of separating animals from plants. +So self-evident appears this power that the popular notion scoffs at +the idea of science modestly disclaiming its ability to separate the +one group of living beings from the other. Is there any danger of +confusing a bird with the tree amid the foliage of which it builds its +nest, or of mistaking a cow for the grass it eats? These queries are, +of course, answerable in one way only. Unfortunately (for the +querists), however, they do not include or comprehend the whole +difficulty. They merely assert, what is perfectly true, that we are +able, without trouble, to mark off the higher animals from the higher +plants. What science inquires is, whether we are able to separate +_all_ animals from _all_ plants, and to fix a definite boundary line, +so as to say that all the organisms on the one side of the line are +assuredly animals, while all the others on the opposite side of the +line may be declared to be truly plants. It is exactly this task which +science declares to be among the impossibilities of knowledge. Away +down in the depths of existence and among the groundlings of life the +identity of living things becomes of a nature which is worse than +confusing, and which renders it a futile task to attempt to separate +the two worlds of life. The hopelessness of the task, indeed, has +struck some observers so forcibly that they have proposed to +constitute a third kingdom--the _Regnum Protisticum_--between the +animal and the plant worlds, for the reception of the host of doubtful +organisms. This third kingdom would resemble the casual ward of a +workhouse, in that it would receive the waifs and strays of life which +could not find a refuge anywhere else. + +A very slight incursion into biological fields may serve to show forth +the difficulties of naturalists when the task of separating animals +from plants is mooted for discussion. To begin with, if we suppose our +popular disbeliever to assert that animals and plants are always to be +distinguished by shape and form, it is easy enough to show him that +here, as elsewhere, appearances are deceptive. What are we to say of a +sponge, or a sea anemone, of corals, of zoophytes growing rooted from +oyster shells, of sea squirts, and of sea mats? These, each and all of +them, are true animals, but they are so plant-like that, as a matter +of fact, they are often mistaken by seaside visitors for plants. This +last remark holds especially true of the zoophytes and the sea mats. +Then, on the other hand, we can point to hundreds of lower plants, +from the yeast plant onward, which show none of the ordinary features +of plant life at all. They possess neither roots, stems, branches, +leaves, nor flowers, so that on this first count of the indictment the +naturalist gains the day. + +Power of movement, to which the popular doubter is certain to appeal, +is an equally baseless ground of separation. For all the animals I +have above named are rooted and fixed, while many true plants of lower +grade are never rooted at all. The yeast plant, the _Algæ_ that swarm +in our ponds, and the diatoms that crowd the waters, exemplify plants +that are as free as animals; and many of them, besides, in their young +state especially (e.g., the seaweeds), swim about freely in the water +as if they were roving animalcules. On the second count, also, science +gains the day; power of motion is no legitimate ground at all for +distinguishing one living being as an animal, while absence of +movement is similarly no reason for assuming that the fixed organism +must of necessity be a plant. Then comes the microscopic evidence. +What can this wonder glass do in the way of drawing boundary lines +betwixt the living worlds? The reply again is disappointing to the +doubter; for the microscope teaches us that the tissues of animals and +plants are built upon kindred lines. We meet with cells and fibers in +both. The cell is in each case the primitive expression of the whole +organism. Beyond cells and fibers we see the wonderful living +substance, _protoplasm_, which is alike to our senses in the two +kingdoms, although, indeed, differing much here and there in the +results of its work. On purely microscopic grounds, we cannot separate +animals from plants. There is no justification for rigidly assuming +that this is a plant or that an animal on account of anything the +microscope can disclose. A still more important point in connection +with this protoplasm question consists in the fact that as we go +backward to the beginnings of life, both in animals and plants, we +seem to approach nearer and nearer to an identity of substance which +baffles the microscope with all its powers of discernment. Every +animal and every plant begins existence as a mere speck of this living +jelly. The germ of each is a protoplasm particle, which, whatever +traces of structure it may exhibit, is practically unrecognizable as +being definitely animal or plant in respect of its nature. Later on, +as we know, the egg or germ shows traces of structure in the case of +the higher animals and plants; while even lowly forms of life exhibit +more or less characteristic phases when they reach their adult stage. +But, of life's beginnings, the microscope is as futile as a kind +scientific touchstone for distinguishing animals from plants as is +power of movement, or shape, or form. + +A fourth point of appeal in the matter is found within the domain of +the chemist. Chemistry, with its subtile powers of analysis, with its +many-sided possibilities of discovering the composition of things, and +with its ability to analyze for us even the light of the far distant +stars, only complicates the difficulties of the biologist. For, while +of old it was assumed that a particular element, nitrogen, was +peculiar to animals, and that carbon was an element peculiar to +plants, we now know that both elements are found in animals, just as +both occur in plants. The chemistry of living things, moreover, when +it did grow to become a staple part of science, revealed other and +greater anomalies than these. It showed that certain substances which +were supposed to be peculiar to plants, and to be made and +manufactured by them alone, were also found in animals. Chlorophyl is +the green coloring matter of plants, and is, of course, a typical +product of the vegetable world; yet it is made by such animals as the +hydra of the brooks and ponds, and by many animalcules and some worms. +Starch is surely a typical plant product, yet it is undoubtedly +manufactured, or at least stored up, by animals--a work illustrated by +the liver of man himself, which occasionally produces sugar out of its +starch. + +Again, there is a substance called _cellulose_, found well nigh +universally in plants. Of this substance, which is akin to starch, the +walls or envelopes of the cells of plant tissues are composed. Yet we +find those curious animals, the sea squirts, found on rocks and stones +at low-water mark, manufacturing cellulose to form part and parcel of +the outer covering of their sac-like bodies. Here it is as if the +animal, like a dishonest manufacturer, had infringed the patent rights +of the plant. On the fourth count, then--that of chemical +composition--the verdict is that nothing that chemistry can teach us +may serve definitely, clearly, and exactly to set a boundary line or +to erect a partition wall between the two worlds of life. There yet +remains for us to consider a fifth head--that of the food. + +In the matter of the feeding of the two great living worlds we might +perchance light upon some adequate grounds for making up the one +kingdom from the other. What the consideration of form, movement, +chemical composition, and microscopic structure could not effect for +us in this way, it might be supposed the investigation of the diet of +animals and plants would render clear. Our hopes of distinguishing the +one group from the other by reference to the food on which animals and +plants subsist are, however, dashed to the ground; and the diet +question leaves us, therefore, when it has been discussed, in the same +quandary as before. + +Nevertheless, it is an interesting story, this of the nutrition of +animals and plants. A large amount of scientific information is to be +gleaned from such a study, which may very well be commenced by our +having regard to the matters on which a _green_ plant feeds. I +emphasize the word "green," because it so happens that when a plant +has no chlorophyl (as green color is named in the plant world) its +feeding is of diverse kind to that which a green plant exhibits. The +mushroom or other fungus may be taken as an illustration of a plant +which represents the non-green race, while every common plant, from a +bit of grass to an oak tree, exemplifies the green-bearing order of +the vegetable tribes. + +Suppose we were to invite a green plant to dinner, the _menu_ would +have to be very differently arranged from that which would satisfy a +human or other animal guest. The soup would be represented for the +plant's delectation by water, the fish by minerals, the joint by +carbonic acid gas, and the dessert by ammonia. On these four items a +green plant feeds, out of them it builds up its living frame. Note +that its diet is of inorganic or non-living matter. It derives its +sustenance from soil and air, yet out of these lifeless matters the +green plant elaborates and manufactures its living matter, or +protoplasm. It is a more wonderful organism than the animal, for while +the latter can only make new protoplasm when living matter is included +in its food supply, the green plant, by the exercise of its vital +chemistry, can transform that which is not living into that which is +life-possessing. + +The green plant in other words, raises non-living into living matter, +while the animal can only transform living matters into its like. This +is why the plant is called a constructive organism, while the animal +is, contrariwise, named a destructive one. The result of the plant's +existence is to build up, that of the animal's life is to break down +its substance, as the result of its work, into non-living matter. The +animal's body is, in fact, breaking down into the very things on which +the green plant feeds. We ourselves are perpetually dissipating our +substance in our acts of life and work into the carbonic acid, water, +ammonia, and minerals on which plants feed. We "die daily" in as true +a sense as that in which the apostle used the term. And out of the +debris of the animal frame the green plant builds up leaf and flower, +stein and branch, and all the other tokens of its beauty and its life. + +If, then, an animal can only live upon living matter--that is to say +on the bodies of other animals or of plants--with water, minerals and +oxygen gas from the air thrown in to boot, we might be tempted to hold +that in such distinctive ways and works we had at last found a means +of separating animals from plants. Unfortunately, this view may be +legitimately disputed and rendered null and void, on two grounds. +First of all, the mushrooms and their friends and neighbors, all true +plants, do not feed as do the green tribes. And secondly, many of the +green plants themselves can be shown to have taken very kindly to an +animal mode of diet. + +A mushroom, thus, because it has no green color, lives upon water, +oxygen, minerals, and organic matter. You can only grow mushrooms +where there is plenty of animal matter in a state of decay, and as for +the oxygen, they habitually inhale that gas as if they were animals. +Non-green plants thus want a most characteristic action of their green +neighbors. For the latter in daylight take in the carbonic acid gas, +which is composed of carbon and oxygen. Under the combined influence +of the green color and the light, they split up the gas into its two +elements, retaining the carbon for food and allowing the oxygen to +escape to the atmosphere. Alas! however, in the dark our green plant +becomes essentially like an animal as regards its gas food, for then +it is an absorber of oxygen, while it gives off carbonic acid. If to +take in carbonic acid and to give out oxygen be held to be a feature +characteristic of a plant, it is one, as has been well said, which +disappears with the daylight in green plants, and which is not +witnessed at all in plants that have no green color. + +So far, we have seen that not even the food of plants and animals can +separate the one kingdom of life from the other. The mushroom bars the +way and the green plant's curious behavior by night and by day +respectively, in the matter of its gas food, once more assimilates +animal life and plant life in a remarkable manner. Still more +interesting is the fact, already noticed, that even among the green +tribes there are to be found many and various lapses from the stated +rules of their feeding. Thus what are we to say of the parasitic +mistletoe, which, while it has grown leaves of its own, and can, +therefore, obtain so much carbon food from the air on its own account, +nevertheless drinks up the sap of the oak or apple which forms its +host, and thus illustrates the spectacle of a green plant feeding like +an animal, on living matter? Or, what may we think of such plants as +the sundew, the Venus' fly trap, the pitcher plants, the side saddle +plants, the butterworts and bladderworts, and others of their kind, +which not only capture insects, often by ingenious and complex lures, +but also digest the animal food thus captured? A sundew thus spreads +out its lure in the shape of its leaf studded with sensitive +tentacles, each capped by a glistening drop of gummy secretion. +Entangled in this secretion, the fly is further fixed to the leaf by +the tentacles which bend over it and inclose it in their fold. Then is +poured out upon the insect's body a digestive acid fluid, and the +substance of the dissolved and digested animal is duly absorbed by the +plant. So also the Venus' fly trap captures insects by means of its +leaf, which closes upon the prey when certain sensitive hairs have +given the signal that the animal has been trapped. Within the leaf the +insect is duly digested as before, and its substance applied to the +nutrition of the plant. Such plants, moreover, cannot flourish +perfectly unless duly supplied with their animal food. Such +illustrations of exceptions to the rule of green plant feeding simply +have the effect of abolishing the distinctions which the diet question +might be supposed to raise between animals and plants. We may return +to the sundews and other insect catchers; meanwhile, I have said +enough to show that to the question, "Can we separate animals from +plants?" a very decided negative reply must be given. Life everywhere +exhibits too many points of contact to admit of any boundary line +being drawn between the two great groups which make up the sum total +of organic existence.--_Illustrated London News._ + + * * * * * + + + + +THE RECOVERY OF SILVER AND GOLD FROM PLATING AND GILDING SOLUTIONS. + + +In view of the rapid development and extension of the methods of +electro-plating with silver and gold, and of the large amount of spent +liquors containing silver or gold thus produced, it has long been +desirable to find methods by which these metals can be recovered from +the spent liquors. The processes hitherto adopted generally +necessitate the tedious and unpleasant evaporation of the cyanide +liquors, or else involve a series of chemical operations which are +somewhat difficult to carry out, so that actually the used-up baths +are sold to some firm which undertakes this recovery as a particular +branch of its business. + +A process invented by Stockmuir and Fleischmann, and worked out by +them in the chemical laboratory of the Bavarian Industrial Museum, is, +however, exceedingly simple, and is employed in many establishments. + +In order to remove silver from a potassium cyanide silver solution, it +is only necessary to allow a clean piece of plate zinc to remain in +the liquid for two days; even better results are obtained by the use +of iron conjointly with the zinc. In the first case, the silver often +adheres firmly to the zinc, while in the second it always separates +out as a powder. It is then only necessary to wash the precipitated +powder, which usually contains copper (since spent silver solutions +always contain copper), dry it, and then dissolve it in hot +concentrated sulphuric acid, water being added, and the dissolved +silver precipitated by strips of copper. The silver thus obtained is +perfectly pure. If the amount of copper present is only small, it can +usually be removed by fusing the precipitated powder with a little +niter and borax. + +In this way a spent silver bath was found to contain per liter + + 1st experiment 1.5706 grms. + 2d " 1.5694 " + ------ + Mean 1.5700 " + +The presence of silver could not be qualitatively ascertained in the +residual liquor. + +Although sheet zinc, or zinc and iron sheets, serve so well for the +precipitation of silver, they cannot be employed for the recovery of +gold. The latter separates out in such a case very incompletely and as +a firmly adhering lustrous film in the zinc. On the other hand, finely +divided zinc, the so-called zinc dust, is an excellent substance to +employ for precipitating gold quantitatively and in the form of powder +from spent cyanide liquors. When zinc dust is added to a spent gold +bath and the liquid periodically stirred or shaken, all the gold is +precipitated in two or three days. The amount of zinc to be added +naturally depends on the quantity of gold present. Freshly prepared +gold baths for gilding in the cold contain on the average 3.5 grms. +gold per liter, while those used for the hot process contain 10.75 +grms. To precipitate all the gold in the original bath, 1.74 grms. or +0.37-0.5 grms. zinc dust would be necessary, and, of course, a much +smaller quantity would be sufficient for the spent liquors. Since the +precipitation takes place more rapidly when an excess of zinc dust is +present, it is generally advisable to add ¼ or at the most ½ kilo, of +zinc dust to every 100 liters of solution. + +The precipitated gold, which contains zinc dust and usually silver and +copper, is washed, freed from zinc by hydrochloric acid, and then from +silver and copper by nitric acid and thus obtained pure. + +A spent bath treated in this way gave the following amounts of gold +per liter: + + 1st experiment 0.2626 + 2d " 0.2634 + Mean 0.2630 grms. + +The presence of gold in the residual cyanide solution could not be +qualitatively detected. The potassium cyanide of the solutions +obtained by this process should be converted into ferrocyanide by +heating with ferrous sulphate and milk of lime, since this substance +is not poisonous and can therefore be got rid of without danger. It +would, however, be more economical and, considering the large amount +of cyanide present, more profitable to work it up into Prussian blue. + + * * * * * + + +A NEW CATALOGUE OF VALUABLE PAPERS + +Contained in SCIENTIFIC AMERICAN SUPPLEMENT during the past ten years, +sent _free of charge_ to any address. MUNN & CO., 361 Broadway, New +York. + + * * * * * + + +THE SCIENTIFIC AMERICAN + +ARCHITECTS AND BUILDERS EDITION + +$2.50 A YEAR. SINGLE COPIES, 25 CTS. + +This is a Special Edition of the SCIENTIFIC AMERICAN, issued +monthly--on the first day of the month. Each number contains about +forty large quarto pages, equal to about two hundred ordinary book +pages, forming, practically, a large and splendid Magazine of +Architecture, richly adorned with _elegant platen in colors_ and with +fine engravings, illustrating the most interesting examples of modern +Architectural Construction and allied subjects. + +A special feature is the presentation in each number of a variety of +the latest and best plans for private residences, city and country, +including those of very moderate cost as well as the more expensive. +Drawings in perspective and in color are given, together with full +Plans, Specifications, Costs, Bills of Estimate, and Sheets of +Details. + +No other building paper contains so many plans, details, and +specifications regularly presented as the SCIENTIFIC AMERICAN. +Hundreds of dwellings have already been erected on the various plans +we have issued during the past year, and many others are in process of +construction. + +Architects, Builders, and Owners will find this work valuable in +furnishing fresh and useful suggestions. All who contemplate building +or improving homes, or erecting structures of any kind, have before +them in this work an almost _endless series of the latest and best +examples_ from which to make selections, thus saving time and money. + +Many other subjects, including Sewerage, Piping, Lighting, Warming, +Ventilating, Decorating, Laying out of Grounds, etc., are illustrated. +An extensive Compendium of Manufacturers' Announcements is also given, +in which the most reliable and approved Building Materials, Goods, +Machines, Tools, and Appliances are described and illustrated, with +addresses of the makers, etc. + +The fullness, richness, cheapness, and convenience of this work have +won for it the Largest Circulation of any Architectural publication in +the world. + +A Catalogue of valuable books on Architecture, Building, Carpentry, +Masonry, Heating, Warming, Lighting, Ventilation, and all branches of +industry pertaining to the art of Building, is supplied free of +charge, sent to any address. + +MUNN & CO., Publishers, + +361 Broadway, New York. + + * * * * * + + +BUILDING PLANS AND SPECIFICATIONS. + +In connection with the publication of the BUILDING EDITION of the +SCIENTIFIC AMERICAN, Messrs. Munn & Co. furnish plans and +specifications for buildings of every kind, including Churches, +Schools, Stores, Dwellings, Carriage Houses, Barns, etc. + +In this work they are assisted by able and experienced architects. +Full plans, details, and specifications for the various buildings +illustrated in this paper can be supplied. + +Those who contemplate building, or who wish to alter, improve, extend, +or add to existing buildings, whether wings, porches, bay windows, or +attic rooms, are invited to communicate with the undersigned. Our work +extends to all parts of the country. Estimates, plans, and drawings +promptly prepared. Terms moderate. Address + +MUNN & CO., 361 BROADWAY, NEW YORK. + + * * * * * + + +SCIENTIFIC AMERICAN SUPPLEMENT. + +PUBLISHED WEEKLY. + +Terms of Subscription, $5 a year. + +Sent by mail, postage prepaid, to subscribers in any part of the +United States or Canada. Six dollars a year, sent, prepaid, to any +foreign country. + +All the back numbers of THE SUPPLEMENT, from the commencement, January +1, 1876, can be had. Price, 10 cents each. + +All the back volumes of THE SUPPLEMENT can likewise be supplied. Two +volumes are issued yearly. Price of each volume, $2.50 stitched in +paper, or $3.50 bound in stiff covers. + +COMBINED RATES.--One copy of SCIENTIFIC AMERICAN and one copy of +SCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, $7.00. + +A liberal discount to booksellers, news agents, and canvassers. + +MUNN & CO., Publishers, +361 Broadway, New York, N.Y. + + * * * * * + + +USEFUL ENGINEERING BOOKS + +Manufacturers, Agriculturists, Chemists, Engineers, Mechanics, +Builders, men of leisure, and professional men, of all classes, need +good books in the line of their respective callings. Our post office +department permits the transmission of books through the mails at very +small cost. A comprehensive catalogue of useful books by different +authors, on more than fifty different subjects, has recently been +published, for free circulation, at the office of this paper. Subjects +classified with names of author. Persons desiring a copy have only to +ask for it, and it will be mailed to them. Address, MUNN & CO., 361 +Broadway, New York. + + * * * * * + + +PATENTS. + +In connection with the Scientific American, Messrs. MUNN & Co. are +solicitors of American and Foreign Patents, have had 42 years' +experience, and now have the largest establishment in the world. +Patents are obtained on the best terms. + +A special notice is made in the Scientific American of all inventions +patented through this Agency, with the name and residence of the +Patentee. By the immense circulation thus given, public attention is +directed to the merits of the new patent, and sales or introduction +often easily effected. + +Any person who has made a new discovery or invention can ascertain, +free of charge, whether a patent can probably be obtained, by writing +to MUNN & Co. We also send free our Hand Book about the Patent Laws, +Patents, Caveats, Trade Marks, their costs and how procured. Address + +MUNN & Co., + 361 Broadway, New York. +Branch Office, 622 and 624 F St., Washington, D.C. + + + + + + + +End of the Project Gutenberg EBook of Scientific American Supplement, No. +787, January 31, 1891, by Various + +*** END OF THE PROJECT GUTENBERG EBOOK 14009 *** diff --git a/14009-h/14009-h.htm b/14009-h/14009-h.htm new file mode 100644 index 0000000..bd2724e --- /dev/null +++ b/14009-h/14009-h.htm @@ -0,0 +1,5677 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" +"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"> +<head> +<meta name="generator" content= +"HTML Tidy for Linux/x86 (vers 1st November 2002), see www.w3.org" /> +<meta http-equiv="Content-Type" content= +"text/html; charset=UTF-8" /> +<title>The Project Gutenberg eBook of Scientific American +Supplement, January 31, 1891</title> +<style type="text/css"> + /*<![CDATA[*/ +<!-- + body { margin-left: 15%; margin-right: 15%; background-color: white} + img { border: 0;} + h1,h2,h3 { text-align: center;} + .note { margin-left: 2em; margin-right: 2em; margin-bottom: 1em;} + .ind { margin-left: 10%; margin-right: 10%;} + hr { text-align: center; width: 50%;} + .ctr { text-align: center;} +--> + /*]]>*/ + +</style> +</head> +<body> +<div>*** START OF THE PROJECT GUTENBERG EBOOK 14009 ***</div> + +<p class="ctr"><a href="./images/title.png"><img src= +"./images/title_th.jpg" alt="" /></a></p> + +<h1>SCIENTIFIC AMERICAN SUPPLEMENT NO. 787</h1> + +<h2>NEW YORK, January 31, 1891</h2> + +<h4>Scientific American Supplement. Vol. XXXI., No. 787.</h4> + +<h4>Scientific American established 1845</h4> + +<h4>Scientific American Supplement, $5 a year.</h4> + +<h4>Scientific American and Supplement, $7 a year.</h4> + +<hr /> +<table summary="Contents" border="0" cellspacing="5"> +<tr> +<th colspan="2">TABLE OF CONTENTS.</th> +</tr> + +<tr> +<td valign="top">I.</td> +<td><a href="#i_1">BIOGRAPHY.—CHARLES GOODYEAR.—The +life and discoveries of the inventor of vulcanized India rubber, +with portrait.—1 illustration</a></td> +</tr> + +<tr> +<td valign="top">II.</td> +<td><a href="#ii_1">BIOLOGY.—Can we Separate Animals from +Plants?—By ANDREW WILSON.—A debated point well +discussed.—The bases on which distinctions must be +drawn</a></td> +</tr> + +<tr> +<td valign="top">III.</td> +<td><a href="#iii_1">ELECTRICITY.—A New Electric Ballistic +Target.—A target for investigations of the velocity of +projectiles, now in use at the United States Military Academy, West +Point, N. Y.—1 illustration.</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#iii_2">Electric Erygmascope.—An electric +lighting apparatus for examining earth strata in bore holes for +geologists' and prospectors' use.—1 illustration</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#iii_3">The Electro-Magnet.—By Prof. SILVANUS +THOMPSON.—Continuation of this exhaustive treatise, giving +further details on special points of construction.—1 +illustrations</a></td> +</tr> + +<tr> +<td valign="top">IV.</td> +<td><a href="#iv_1">ENTOMOLOGY.—Potash Salts.—The use +of potash salts as insecticides, with accounts of +experiments</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#iv_2">The Outlook for Applied Entomology.—By +Dr. C.V. RILEY, U.S. entomologist.—The conclusion of Prof. +Riley's lecture, treating of the branch of entomology with which +his name is so honorably associated</a></td> +</tr> + +<tr> +<td valign="top">V.</td> +<td><a href="#v_1">INSURANCE.—The Expense Margin in Life +Insurance.—Elaborate review of the necessary expenses of +conducting the insurance of lives, with tables and +calculations</a></td> +</tr> + +<tr> +<td valign="top">VI.</td> +<td><a href="#vi_1">MATHEMATICS.—The Trisection of Any +Angle.—By FREDERIC R. HONEY, Ph.B.—A very ingenious +demonstration of this problem, based on the properties of conjugate +hyperbolas</a></td> +</tr> + +<tr> +<td valign="top">VII.</td> +<td><a href="#vii_1">METEOROLOGY.—Note on the Mt. Blanc +Meteorological Station</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#vii_2">The Flood at Karlsbad.—Account of the +recent flood and of its destructive effects.—1 +illustration</a></td> +</tr> + +<tr> +<td valign="top">VIII.</td> +<td><a href="#viii_1">MECHANICAL ENGINEERING.—Station for +Testing Agricultural Machines.—A proposed establishment for +applying dynamometer tests to agricultural machines.—1 +illustration</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#viii_2">Steam Engine Valves.—By THOMAS +HAWLEY.—A review of modern slide valve practice, the lap, +cut-off, and other points.—6 illustrations</a></td> +</tr> + +<tr> +<td valign="top">IX.</td> +<td><a href="#ix_1">MISCELLANEOUS.—Science in the +Theater.—Curious examples of stage effect in fictitious +mesmerizing and hypnotizing.—4 illustrations</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#ix_2">Theatrical Water Plays.—Recent episodes +in real water plays at Hengler's Circus, London.—2 +illustrations</a></td> +</tr> + +<tr> +<td valign="top">X.</td> +<td><a href="#x_1">NAVAL ENGINEERING.—The French Ironclad War Ship +Colbert.—An armored wood and iron ship, with central +battery.—1 illustration</a></td> +</tr> + +<tr> +<td valign="top">XI.</td> +<td><a href="#xi_1">PHYSIOLOGY AND HYGIENE.—Newer Physiology +and Pathology.—By Prof. SAMUEL BELL. M.D.—An excellent +presentation of modern practice in the light of +bacteriology</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#xi_2">Test Card Hints.—How to test the eyes for +selecting eyeglasses and spectacles</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#xi_3">The Composition of Koch's Lymph.—What +Prof. Koch says it is and what it can do.—The cabled account +of the disclosure so long waited for</a></td> +</tr> + +<tr> +<td valign="top">XII.</td> +<td><a href="#xii_1">TECHNOLOGY.—Firing Points of Various +Explosives.—The leading explosives, with the temperature of +their exploding points tabulated</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#xii_2">The Recovery of Gold and Silver from Plating +and Gilding Solutions—A paper of interest to silver and gold +platers, as well as photographers</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#xii_3">Water Softening and Purifying +Apparatus.—An apparatus for treatment of sewage, etc., +chemically and by deposition.—1 illustration</a></td> +</tr> +</table> + +<hr /> +<h2><a id="x_1" name="x_1"></a>THE FRENCH IRONCLAD WAR SHIP +COLBERT.</h2> + +<p class="ctr"><a href="./images/1-boat.png"><img src= +"./images/1-boat_th.jpg" alt= +"THE FRENCH IRONCLAD WAR SHIP COLBERT." title= +"IRONCLAD" /></a><br /> + THE FRENCH IRONCLAD WAR SHIP COLBERT.</p> + +<p>The central battery ironclad Colbert is one of the ten ships of +the French navy that constitute the group ranking next in +importance to the squadron of great turret ships, of which the +Formidable is the largest. The group consists of six types, as +follows:</p> + +<div class="note"> +<p>1. The Ocean type; three vessels; the Marengo, Ocean, and +Suffren.</p> + +<p>2. The Friedland type, of which no others are built.</p> + +<p>3. The Richelieu type, of which no others are built.</p> + +<p>4. The Colbert type, of which there are two; the Colbert and the +Trident.</p> + +<p>5. The Redoubtable type, of which no others are built.</p> + +<p>6. The Devastation type, of which no others are built.</p> +</div> + +<p>The Colbert was launched at Brest in 1875, and her sister ship, +the Trident, in 1876. Both are of iron and wood, and the following +are the principal dimensions of the Colbert, which apply very +closely to the Trident: She is 321 ft. 6 in. long, 59 ft. 6 in. +beam, and 29 ft. 6 in. draught aft. Her displacement is 8,457 tons, +her indicated horse power is 4,652, and her speed 14.4 knots. She +has coal carrying capacity for 700 tons, and her crew numbers 706. +The thickness of her armor belt is 8.66 in., that protecting the +central battery is 6.29 in. thick, which is also the thickness of +the transverse armored bulkheads, while the deck is 0.43 in. in +thickness. The armament of the Colbert consists of eight 10.63 in. +guns, two 9.45 in., six 5.51 in., two quick firing guns, and +fourteen revolving and machine guns.—<i>Engineering.</i></p> + +<hr /> +<p>A compound locomotive, built by the Rhode Island Locomotive +Works, has been tried on the Union Elevated Railroad, Brooklyn, +N.Y. The engine can be run either single or compound. The economy +in fuel was 37.7 per cent, and in water 23.8 per cent, over a +simple engine which was tested at the same time. The smoothness of +running and the stillness and comparative absence of cinders was +fully demonstrated.</p> + +<hr /> +<h2><a id="viii_2" name="viii_2"></a>STEAM ENGINE VALVES.<a id= +"FNanchor_1a" name="FNanchor_1a"></a><a href= +"#Footnote_1a"><sup>1</sup></a></h2> + +<h3>By THOMAS HAWLEY.</h3> + +<h3>RIDING CUT-OFF VALVES—PECULIARITIES AND MERITS OF THE +DIFFERENT STYLES.</h3> + +<p>In considering the slide valve in its simple form with or +without lap, we find there are certain limitations to its use as a +valve that would give the best results. The limitation of most +importance is that its construction will not allow of the proper +cut off to obtain all the benefits of expansion without hindering +the perfect action of the valve in other particulars. At this +economical cut off the opening of the steam port is very little and +very narrow, and although this is attempted to be overcome by +exceedingly wide ports, sixteen inches in width in many cases in +locomotive work, this great width adds largely to the unbalanced +area of the valve. The exhausting functions of the valve are +materially changed at the short cut off, and when much lap is added +to overcome this defect, there usually takes place a choking of the +exhaust port. You might inquire, why not make the port wider, but +this would increase the minimum amount of load on the valve, and +this must not be overlooked. Then the cut off is a fixed one, and +we can govern only by throttling the pressure we have raised in the +boiler or by using a cut off governor and the consequent wastes of +an enormous clearance space. You will observe, therefore, that the +plain slide valve engine gives the most general satisfaction at +about two-thirds cut off and a very low economic result. The best +of such engines will require forty-five to fifty pounds of steam +per horse power per hour, and to generate this, assuming an +evaporation of nine pounds of water to a pound of coal, would +require between five and six pounds of coal per horse power per +hour. And the only feature that the valve has specially to commend +it is its extreme simplicity and the very little mechanism required +to operate it.</p> + +<p>Yet this is of considerable importance, and in consideration of +some special features at its latest cut off, the attempt has been +many times made to take advantage of these features. For instance, +at 90° advance, the valve opens very rapidly indeed and fully +satisfies our requirements of a perfect valve. This is one good +point, and in this position also the exhaust and compression can be +regulated very closely and as desired without much lap, and as the +opening of the exhaust port comes with the eccentric at its most +rapid movement the release is very quick and as we would have it. +This is only possible at the most uneconomic position of the valve +as regards cut off.</p> + +<p>The aim of many engineers has been to take advantage of these +matters by using the valve with 90° angular advance of +eccentric ahead of crank, for the admission, release, and +compression of the steam, and provide another means of cutting off, +besides the one already referred to, viz., cutting off the supply +of steam to the chest, and overcome the objection in this one of +large clearance spaces. This is done by means of riding cut off +valves, often called expansion valves, of which, perhaps, the most +widely known types in this vicinity are the Kendall & Roberts +engine and the Buckeye. The former is used in the simplest form of +riding cut off, while the Buckeye has many peculiar features that +engineers, I find, are too prone to overlook in a casual +examination of the engine. In these uses of the slide valve, too, +means are suggested and carried out of practically balancing the +valve.</p> + +<p>The origin of the riding cut off is most generally attributed to +Gonzenbach. His arrangement had two steam chests, the lower one +provided with the ordinary slide valve of late cut off, and steam +was cut off from this steam chest by the expansion valve covering +the ports connecting with the upper steam chest. This had the old +disadvantage that all the steam in the lower chest expanded with +that in the cylinder, at a consequent considerable loss. This was +further improved by causing the riding cut off to be upon the top +of the main valve, instead of its chest, and resulted in a +considerable reduction of the clearance space.</p> + +<p>This is the simplest form, and is shown in Fig. 1. The steam is +supplied by a passage through the main valve which operates exactly +as an ordinary slide valve would. That is, the inside edges of the +steam passage are the same as the ordinary valve, the additional +piece on each end, if I may so term it, being merely to provide a +passage for the steam which can be closed, instead of allowing the +steam to pass the edge. The eccentric of the main valve is fastened +to the shaft to give the proper amount of lead, and the desired +release and compression, and the expansion valve is operated by a +separate eccentric fastened in line with or 180° ahead of the +crank. When the piston, therefore, commences to move from the crank +end to open the port, D, the expansion valve is forced by its +eccentric in the opposite direction, and is closing the steam port +and would have closed it before the piston reached quarter stroke, +thus allowing the steam then in the cylinder to do work by +expansion. The eccentric operating this expansion valve may be set +to close this steam port at any point in the stroke that is +desired, the closing occurring when the expansion valve has covered +the steam port. Continuing the movements of the valves, the two +would move together until one or the other reached its dead center, +when the movements would be in opposite directions.</p> + +<p class="ctr"><img src="./images/2-fig1.png" alt="FIG. 1." title= +"FIG. 1" /><br /> + FIG. 1</p> + +<p>There are three ways of effecting the cut off in such engines, +the main valve meanwhile being undisturbed, its eccentric fastened +securely so as not to disturb the points of lead, release, and +compression. All that is required is to cause the edge of the +expansion valve to cover the steam port earlier in the stroke, and +this can be done, first, by increasing the angular advance of the +cut off eccentric; second, by adding lap to the cut off valve; and +third by changing the throw of the eccentric. In all these +instances the riding valve is caused to reach the edge of the steam +port earlier in the stroke. We will take first, as the simplest, +those methods by which the lap of the cut off valve is +increased.</p> + +<p>It will be noted that there is but one edge of this valve that +is required to do any work, and that is to close the valve. The +eccentrics are so placed that the passage in the main valve is +opened long before the main valve itself is ready to admit steam to +the cylinder, so that only the outer edges are the ones to be +considered, and it will be readily seen that the two valves +traveling in opposite directions, any lap added to the working edge +of the cut off valve will cause it to reach the edge and therefore +close the port earlier than it would if there was less lap. And we +might carry it to the extreme that we could add lap enough that the +steam passage would not be opened at all.</p> + +<p>In Fig. 2 is shown the method by which this is accomplished, in +what is called Meyer's valve, and such as is used in the Kendall +& Roberts engine. We have only one point to look after, the cut +off, so we can add all the lap we wish without disturbing anything +else. In this engine the lap is changed by hand by means of a +little hand wheel on a stem that extends out of the rear of the +steam chest. The valve is in two sections, and when it is desired +to cut off earlier, the hand wheel is turned in such a direction +that the right and left hand screws controlling the cut off valve +move one valve portion back and the other forward, which would, if +they were one valve and they should be so considered, have the +effect of lengthening them, or adding lap to them. The result would +be that the riding valve would reach the edge of the steam port +earlier in the stroke, bringing about an earlier cut off. If the +cut off is desired to be later, the hand wheel is so turned that +the right and left hand screws will bring the valve sections nearer +together, thus practically taking off lap. Now this may be done by +hand or it may be done by the action of a governor.</p> + +<p class="ctr"><img src="./images/2-fig2.png" alt="FIG. 2." title= +"FIG. 2" /><br /> + FIG. 2</p> + +<p>In the latter case the governor at each change of load turns the +right and left hand screws to add or take away lap, as the load +demands an earlier or later cut off; in other cases the governor +moves a rack in mesh with a gear by which the valve sections are +brought closer together or are separated. The difficulty with the +case where the hand wheel is turned by hand is that the cut off is +fixed where you leave it, and governing can only be at the +throttle. For this reason anywhere near full boiler pressure would +not be obtained in the cylinder of the engine. If the load was a +constant one, and the cut off could be fixed at about one-third, +causing the throttle to open its widest, very good results would be +obtained, but there is no margin left for governing.</p> + +<p>If the load should increase at such a time the governor could +not control it under these conditions, and it would lead to a +decrease in speed unless the lap was again changed to give a later +cut off. On this account the general practice soon becomes to leave +the cut off at the later point and give range to the throttle, and +we come back once more to the plain slide valve cutting off at half +stroke, and the only gain there is, is in a quick port opening and +quick cut off. But these matters are more than offset by the wire +drawing between the steam pipe and chest, through the throttle, and +the fact that there is added to the friction of the engine the +friction of this additional slide valve and a considerable +liability to have a leaky valve.</p> + +<p>In the case where the governor changes the position of the cut +off valve a greater decree of economy would result. In this engine, +of which the Lambertville engine is a type, the main valve is a +long D slide, with multiple ports at the ends through which the +steam enters the cylinders. It is operated from an eccentric on the +crank shaft in the usual manner. The cut off valve is also operated +from the motion on an eccentric fixed upon the crank shaft. The rod +or stem of the cut off valve passes through the main valve rod and +slide. Upon the outer end of the cut off valve rod are tappets +fastened to engage with tappets on the eccentric valve rod. +Connection between the cut off eccentric, therefore, and the cut +off valve is only by means of the engagement of these tappets. The +eccentric rod is fastened to a rocker arm having motion swinging +about a pin or bearing in the governor slide, which may be raised +or lowered by a cam operated by the governor. The cut off slide is +of cylindrical shape and incloses a spring and dash pot with disks +attached by means of which the valve is closed. The motion for +operating the valves is relatively in the same direction, the cut +off eccentric having the greatest throw and greater angular advance +to cause it to open earlier and quickly before the main valve is +ready to admit steam. The cut off eccentric rod swinging the rocker +arm, the tappets thereon engage with those upon the cut off valve +rod and open the passages to the main valve, and in their movement +compress the spring in the main valve. According as the speed of +the engine, the rock arm will be raised or lowered so that the +tappets upon the eccentric rod may keep in engagement a shorter or +longer time before they disengage, thus allowing the spring that +has been compressed by the movement of the cut off valve to close +that valve quickly and the supply of steam to the engine, the cut +off valve traveling with the main valve for the balance of the +stroke. This device will give a remarkably quick opening and a +quick cut off, but in view of the fact that the governor has so +much to do, its delicacy is impaired and a quick response to the +demands of the load changing not so likely to occur. The cut off +cannot be as quick as in some other engines, because the valves are +moving in opposite directions, and while this fact would help, so +far as shortening the distance to be traveled before cut off, the +resistance of the valves to travel in opposite directions, or +rather the tendency of the valve to travel with the main valve, +hinders its rapid action.</p> + +<p class="ctr"><img src="./images/2-fig3.png" alt="FIG. 3." title= +"FIG. 3" /><br /> + FIG. 3</p> + +<p>This is one great objection to the rack and gear operated by the +governor, that two flat valves riding upon each other and sliding +in opposite directions at times require a considerable amount of +force to move them, and as only a slight change in load is required +by the load, the governor cannot handle the work as delicately as +it should. It is too much for the governor to do well. To overcome +this difficulty the Ryder cut-off, shown in Fig. 3, was made by the +Delamater people, of New York. The main slide valve is hollowed in +the back and the ports cut diagonally across the valve to form +almost a letter V. The expansion valve is V-shaped, and circular to +fit its circular-seat. The valve rod of the expansion valve has a +sector upon it and operated by a gear upon the governor stem, which +rotates the valve rod, and the edge of the valve rod is brought +farther over the steam port, thus practically adding lap to the +valve. Little movement is found necessary to make the ordinary +change in cut-off, and it is found to be much easier to move the +riding valve across the valve than in a direction directly +opposite. It would require considerable force to move the upper +valve by the governor faster than the lower, or in a direction +opposite to that in which it is moving, but very little force +applied sideways at the same time it is moving forward will give it +a sideways motion. In this device the governor has only to exert +this side pressure and therefore has less to do than if it were +called upon to move the upper valve directly against the movement +of the lower.</p> + +<p>Something similar is the valve of the Woodbury engine, of +Rochester, N.Y. The cut-off valve is cylindrical, covering diagonal +ports directly opposite, and is caused to be rotated by the action +of the governor that operates a rack in mesh with a segment. Very +little movement will effect a considerable change in the lappage of +the valve, the valve turning about one-quarter a revolution for the +extremes of cut off. The cut off valve rod works through a bracket +and its end terminates in a ball in a socket on the end of the +eccentric rod. In this case the governor has not as much to do as +in other instances.</p> + +<p class="ctr"><img src="./images/2-fig4.png" alt="FIG. 4." title= +"FIG. 4" /><br /> + FIG. 4</p> + +<p>Still another method of effecting this change in cut off, but +hardly by increasing the lap of the valve, is shown in the next +drawing, Fig. 4. The cut off valve is held upon the main valve by +the pressure of steam upon its back and rides with it until it +comes in contact with the cut off wedge-shaped blocks, when its +motion is arrested, and the main valve continuing its movement the +steam port is closed by the main valve passing beneath the cut off +valve. Thus the main valve travels and carries the cut off valve +upon its back again until the cut off valve strikes the wedge on +the other end and the cut off is effected. The relative positions +of the blocks are determined by the governor, that will raise or +lower them so that the cut off valve will engage with them earlier +or later as desired. This device was designed specially as an +inexpensive method of changing the common slide valve into an +automatic cut off. The cut off would not be as quick as in other +cases we have cited, depending here upon the movement of the lower +valve alone, and that, too, is in its slowest movement; whereas in +the other cases, the edges approaching each other, by the differing +movement of the valves the cut off is very rapid, provided the +distance to travel is not long. In this device considerable noise +must result by the cut off valve striking the cut off blocks, and a +considerable amount of leakage is likely to occur past this +valve.</p> + +<p>But there is one great objection in the valve gears thus far +cited, that the travel of the expansion valve upon the main valve +is variable. I have in mind the case of a Kendall & Roberts +engine, which had been run for a long time at no better economy +than would be obtained from a plain slide valve engine, and when it +was attempted to get an earlier cut off by separating the two cut +off valves, they had worn so much in their old place on the valve +that shoulders were found sufficient to cause a disagreeable noise +and a leaky valve. This is very apt to occur, not only where the +valve is run for a long time on one seat, but in cases of variation +of the travel of the expansion valve. The result is that a change +will bring about a leaky valve, something that every engineer +abhors.</p> + +<p>The construction of the Buckeye engine, which is also of this +type, is such that the travel of the valve on the back of the main +valve is always the same, no matter what the cut off may be. Then +this engine makes use of our second proposition as a means of +effecting the cut off, viz., by advancing the eccentric. You will +readily observe that anything that will cause the cut off valve to +reach a certain point earlier in the stroke will bring about an +earlier cut off as it hastens everything all around. This is the +plan pursued in the Buckeye, in which the governor, of the shaft +type, turns the eccentric forward or back according as the load +demands. Then, in addition, the valve is balanced partially, the +attempt not being made to produce an absolutely balanced valve, on +the ground that there should be friction enough to keep the +surfaces bright and to prevent leakage. The most perfect valve +will, of course, be entirely balanced under all conditions of +pressure so as to move with perfect ease. With the riding cut off +valve in connection with the plain slide valve, this is not +accomplished, and it does not matter whether it is partially +unbalanced to prevent leakage or not, the fact that it is not +entirely balanced prevents it reaching the ideal valve.</p> + +<p class="ctr"><img src="./images/2-fig5.png" alt="FIG. 5." title= +"FIG. 5" /><br /> + FIG. 5</p> + +<p>This valve, Fig. 5, differs from the others also in this +particular, that the exhaust takes place at the end of the valve +instead of under the arch. Two eccentrics are used, the one for the +main valve being fastened to the shaft and the other riding loosely +upon it and connected to the fly wheel governor, by which it may be +turned forward or back as the load requires. The three points of +lead, or admission and exhaust and compression, are fixed and +independent of the changes and cut off. The motion of the main +eccentric is given to a rocker arm, the pivot of which is at the +bottom, and from the upper end the valve rod transfers the motion +to the valve without reversing the motion, as is done sometimes in +the slide valve to overcome the effects of the angularity of the +connecting rod. The action of the rocker arm, therefore, so far as +the main valve in the Buckeye is concerned, is no different than +that which would occur if no rocker arm intervened. The motion of +the cut off eccentric, through its eccentric rod, is given to a +rocker rocking in a bearing in the center of the main rocker arm +(see Fig. 6). The motion of this eccentric is reversed, so far as +the cut off valve is concerned, and when the cut off eccentric is +moving forward, the cut off valve is being pushed back. The main +valve rod is hollow, and the cut off valve rod passes through +it.</p> + +<p class="ctr"><img src="./images/2-fig6.png" alt="FIG. 6." title= +"FIG. 6" /><br /> + FIG. 6</p> + +<p>The cut off eccentric can be placed in any position to cause it +to cut off as desired, and by drawing the valve forward, by +increasing the angular advance of the eccentric, the cut off valve +is caused to reach and cover the steam passage in the main valve +earlier in the stroke. Instead of being ahead of the crank, the +main eccentric in this arrangement follows the crank, on account of +the exhaust and steam edges being exactly opposite from those in +the ordinary slide. What is the steam edge of the common slide is +in this the exhaust edge, and what is the exhaust edge in the +common valve is the steam edge in this one. The valve, therefore, +must be moved in the opposite direction from what is ordinarily the +case, the main eccentric being not 90 deg. behind the crank. It has +a rapid and full opening just the same, for it is at this point +behind the crank, or ahead of it, that the eccentric gives to the +valve its quickest movement, or between the eccentric dead centers. +The cut off eccentric is considerably ahead of the main eccentric, +and about even with the crank. If it was not for the reversal of +motion of the cut off valve through the rocker arm this eccentric +would be about in line with the crank, but on the other end. The +movement of the cut off valve, therefore, at the time of port +opening is very little, being about on its dead center, passing +which, it immediately commences to close.</p> + +<p>The object of the peculiar construction of the rocker arm, and +the pivot for the cut off rocker being placed thereon, is to +provide equal travel on the back of the main valve, no matter what +the cut off. I have already explained, in connection with the slide +valve, that advancing the eccentric does not change the movement of +the valve on its seat, but simply its relation to the movement of +the piston. You will see that this is unchanged as using the main +valve as a seat or any other seat. If the main valve was to remain +stationary, and only the cut off valve to be operated by its +eccentric, the movement of this cut off valve on a certain plane +would be the same for all positions of the eccentric.</p> + +<p>Moving the main slide does not affect the matter in any way, for +it moves at the same time the pivot of the cut off, and while the +cut off seat has assumed a different position with reference to the +engine, it is still as though stationary so far as the cut off +valve is concerned. This is the object of this peculiar +construction, and not, as some engineers suppose, simply to make an +odd way of doing things. And the object of it all is to give at all +cut offs the same amount of travel, so that there might be no +unequal wear to bring about a leak, to prevent which a perfect +balancing has been sacrificed.</p> + +<p>Referring to the valve and this engine as to how it will satisfy +our requirements of a perfect valve gear, we find that the first +requirement of a rapid and full opening is met, in that the opening +occurs when the main eccentric is moving very rapidly, yet not its +fastest, and while this opening will be very satisfactory, it is +not so rapid an opening as is obtained in some other forms of +valves and valve gears, but this could be overcome very readily by +increasing the lead a trifle, and in my experience with these +engines I find that the practice is very general by engineers and +by builders themselves to give them a considerable amount of lead. +As to the second requirement, the maintenance of initial pressure +until cut off, giving a straight steam line, cards from this engine +will not be found to show that the engine satisfies this +requirement, and for this reason, that the cut-off valve commences +to close the port immediately after the piston commences to move. +The cut off eccentric you will remember is set to move with the +crank or very nearly so, and the lighter the load, the greater will +this fact appear. For the lightest loads the governor places the +eccentric in advance of the crank, so that the cut off valve will +commence to close the port before steam is admitted by the main +valve to the engine. Now, the later the cut off, the less will this +wire drawing appear at first, and the shorter the cut off, the +amount of wire drawing increases sensibly. The operation of the +valve, therefore, in this particular, cannot be considered as +meeting our requirement that the port shall be held open full width +until ready to be closed. Many men claim for this engine that the +closing occurs when the cut off eccentric is moving its fastest. +This is a fact, and if we consider the point of cut off only to be +the point of absolute cut off, the cut off must be instantaneous, +for there is an instantaneous point where the cut off is final only +to be considered. The reasoning applied here would hold good also +to a less extent on the slide valve, but is not the point of +absolute cut off. We want to note how long it is from the time the +valve commences to close at all until finally closed, and, as I +have shown you, this is considerable in this engine.</p> + +<p>Referring to the point of cut off finally, it is determined upon +by a governor of the fly wheel type. The eccentric is loose about +the shaft, and arms projecting therefrom are connected by other +arms to the extremity of an arm upon which is mounted a weight, and +which is attached to the spokes of the fly wheel, or special +governor wheel in this case, and which is fastened to the crank +shaft. As the speed increases through throwing off a portion of the +load the governor weights fly out, and this movement is transferred +through the lever connections to the eccentric, causing it to be +turned ahead, and the manner hastening the movement of the cut off +valve on its seat and causing it to reach and cover the edge of the +steam port earlier in the stroke. This engine was the pioneer in +governors of this character, the advantage being, in addition to +its necessity for the work of turning the eccentric ahead or back, +that the liability of the engine to run away, as very often happens +from the breaking of the governor belt or a similar cause, was not +possible.</p> + +<p>The cut off valve has a travel considerably beyond the edge of +the steam passage after the valve is closed, and this has one +advantage, that the valve is less liable to leak, and to this must +be added the loss from the friction of this moving valve, and +moving too in opposition to the main valve. In our perfect valve, +as we outlined it, the valve does not move after the port is +closed. The exhausting functions of the valve are very good, giving +a quick opening and a full opening, because this opening occurs +when the eccentric is moving its fastest. The engine also possesses +a distinct advantage in having remarkably small clearance spaces. +The length of the steam passage is very small in comparison with +any form of engine, and having but two ports instead of four, as in +the Corliss and four valve type.</p> + +<p>In these there must be included in the clearance, that to the +exhaust port as well as the steam port, adding a considerable +amount where the piston comes close to the head. As the engines +leave the maker's hand the engines are provided with a considerable +amount of lap to give plenty of compression, but are, of course, +capable of having more added to increase compression, or some +planed off to decrease it.</p> + +<p>One of the peculiar things about this engine is the failure to +realize anywhere near boiler pressure, noticeable in every case +that has come under my notice. The considerable lead gives it for +an instant, but it soon falls away, indicating the steam chest +pressure only by a peak at the junction of the admission and steam +lines. This is probably due to the fact that the cut off valve +commences closing the steam passage so soon after steam is +admitted, and in this particular does not satisfy the requirements +of a perfect valve. There is this about the engine, that above all +others of this type there has come under my notice fewer engines of +this type with a maladjustment of valves from tampering by +incompetent engineers.</p> + +<a id="Footnote_1a" name="Footnote_1a"></a><a href= +"#FNanchor_1a">[1]</a> + +<div class="note">Lecture delivered at Wells Memorial Institute, +Boston, in the Lowell Free Course for Engineers. From report in the +<i>Boston Journal of Commerce</i>.</div> + +<hr /> +<h2><a id="xii_1" name="xii_1"></a>FIRING POINTS OF VARIOUS +EXPLOSIVES.</h2> + +<p>An apparatus, devised by Horsley, was used, which consisted of +an iron stand with a ring support holding a hemispherical iron +vessel, in which paraffin or tin was put. Above this was another +movable support, from which a thermometer was suspended and so +adjusted that its bulb was immersed in molten material in the iron +vessel. A thin copper cartridge case, 5/8 in. in diameter and +1-5/16 in. long, was suspended over the bath by means of a +triangle, so that the end of the case was 1 in. below the surface +of the liquid. On beginning the experiment the material in the bath +was heated to just above the melting point, the thermometer was +inserted in it, and a minute quantity of the explosive was placed +in the bottom of the cartridge case. The temperature marked by the +thermometer was noted as the <i>initial temperature</i>, the +cartridge case containing the explosive was inserted in the bath, +and the temperature quickly raised until the explosive flashed off +or exploded, when the temperature marked by the thermometer was +again noted as the <i>firing point</i>. The tables given show the +results of about six experiments with each explosive. The initial +temperatures range from 65° to 280° C. in some cases, but +as the firing points remained fairly constant, only the extremes of +the latter are quoted in the following table:</p> + +<div class="ctr"> +<table border="1" cellspacing="3" summary= +"EXPLOSIVE AND FIRING POINT"> +<colgroup span="2"> +<col align="left" /> +<col align="center" /></colgroup> + +<tr> +<th>Description of Explosive.</th> +<th>Firing Point in ° C.</th> +</tr> + +<tr> +<td>Compressed military gun-cotton.</td> +<td>186 - 201</td> +</tr> + +<tr> +<td>Air-dried military gun-cotton.</td> +<td>179 - 186</td> +</tr> + +<tr> +<td align="center">"</td> +<td>186 - 189</td> +</tr> + +<tr> +<td align="center">"</td> +<td>137 - 139</td> +</tr> + +<tr> +<td align="center">"</td> +<td>154 - 161</td> +</tr> + +<tr> +<td>Gun-cotton dried at 65° C.</td> +<td>136 - 141</td> +</tr> + +<tr> +<td>Air-dried collodion gun-cotton.</td> +<td>186 - 191</td> +</tr> + +<tr> +<td align="center">"</td> +<td>197 - 199</td> +</tr> + +<tr> +<td align="center">"</td> +<td>193 - 195</td> +</tr> + +<tr> +<td>Air-dried gun-cotton.</td> +<td>192 - 197</td> +</tr> + +<tr> +<td align="center">"</td> +<td>194 - 199</td> +</tr> + +<tr> +<td>Hydro-nitrocellulose.</td> +<td>201 - 213</td> +</tr> + +<tr> +<td>Nitroglycerin.</td> +<td>203 - 205</td> +</tr> + +<tr> +<td>Kieselghur dynamite. No. 1.</td> +<td>197 - 200</td> +</tr> + +<tr> +<td>Explosive gelatin.</td> +<td>203 - 209</td> +</tr> + +<tr> +<td>Explosive gelatin, camphorated.</td> +<td>174 - 182</td> +</tr> + +<tr> +<td>Mercury fulminate.</td> +<td>175 - 181</td> +</tr> + +<tr> +<td>Gunpowder.</td> +<td>278 - 287</td> +</tr> + +<tr> +<td>Hill's picric powder.</td> +<td>273 - 283</td> +</tr> + +<tr> +<td align="center">"</td> +<td>273 - 290</td> +</tr> + +<tr> +<td>Forcite, No. 1.</td> +<td>184 - 200</td> +</tr> + +<tr> +<td>Atlas powder, 75 per cent.</td> +<td>175 - 185</td> +</tr> + +<tr> +<td>Emmensite, No. 1.</td> +<td>167 - 184</td> +</tr> + +<tr> +<td>Emmensite, No. 2.</td> +<td>165 - 177</td> +</tr> + +<tr> +<td>Emmensite, No. 5.</td> +<td>205 - 217</td> +</tr> +</table> +</div> + +<p class="ctr"><i>—C.E. Munroe, J. Amer. Chem. Soc.</i></p> + +<hr /> +<h2><a id="viii_1" name="viii_1"></a>STATION FOR TESTING +AGRICULTURAL MACHINES.</h2> + +<p>The minister of agriculture has recently established a special +laboratory for testing agricultural <i>materiel</i>. This +establishment, which is as yet but little known, is destined to +render the greatest services to manufacturers and cultivators.</p> + +<p>In fact, agriculture now has recourse to physics and mechanics +as well as to chemistry. Now, although there were agricultural +laboratories whose mission it was to fix the choice of the +cultivator upon such or such a seed or fertilizer, there was no +official establishment designed to inform him as to the value of +machines, the models of which are often very numerous. +<i>Chemical</i> advice was to be had, but <i>mechanical</i> advice +was wanting. It is such a want that has just been supplied. Upon +the report presented by Mr. Tisserand, director of agriculture, a +ministerial decree of the 24th of January, 1888, ordered the +establishment of an experimental station. Mr. Ringelmann, professor +of rural engineering at the school of Grignon, was put in charge of +the installation of it, and was appointed its director. He +immediately began to look around for a site, and on the 17th of +December, 1888, the Municipal Council of Paris, taking into +consideration the value of such an establishment to the city's +industries, decided that a plot of ground of an area of 3,309 +square meters, situated on Jenner Street, should be put at the +disposal of the minister of agriculture for fifteen years for the +establishment thereon of a trial station. This land, bordering on a +very wide street and easy of access, opposite the municipal +buildings, offers, through its area, its situation, and its +neigborhood, indisputable advantages. A fence 70 meters in extent +surrounds the station. An iron gate opens upon a paved path that +ends at the station.</p> + +<p>The year 1889 was devoted to the installation, and the station +is now in full operation. The tests that can be made here are many, +and concern all kinds of apparatus, even those connected with the +electric lighting that the agriculturist may employ to facilitate +his exploitation. However, the tests that are oftenest made are (1) +of rotary apparatus, such as mills, thrashing machines, etc.; (2) +of traction machines, such as wagons, carts, plows, etc.; and (3) +of lifting apparatus. It is possible, also, to make experiments on +the resistance of materials.</p> + +<p>The experimental hall contains a 7 horse power gas motor, +dynamometers with automatic registering apparatus, counters, +balances, etc. A small machine shop contains a lathe, a forge, a +drilling machine, etc. The main shaft is 12 meters in length and is +7 centimeters in diameter. It is supported at a distance of one +meter from the floor by four pillow blocks, and is formed of three +sections united by movable coupling boxes. Out of these 12 meters, +9 are in the hall and 3 extend beyond the hall to an annex, 14 +meters in length and 4 in width, in which tests are made of +machines whose operation creates dust. When the machines to be +tested require more than the power of seven horses that the motor +gives, the persons interested furnish a movable engine, which, +placed under the annex, actuates the driving shaft. Alongside of +the main building there is a ring for experimenting upon machines +actuated by a horse whim. There will soon be erected in the center +of the grounds an 18 meter tower for experiments on pumps. +Platforms spaced 5 meters apart, a crane at the top, and some +gauging apparatus will complete this hydraulic installation.</p> + +<p>The equipment of the hall is very complete, and is fitted for +all kinds of experiments.</p> + +<p class="ctr"><a href="./images/3-station.png"><img src= +"./images/3-station_th.jpg" alt= +"STATION FOR TESTING AGRICULTURAL MACHINES" title= +"TESTING STATION" /></a> STATION FOR TESTING AGRICULTURAL +MACHINES—DYNAMOMETER FOR TESTING ROTARY MACHINES.</p> + +<p>The tests of rotary machines are made by means of a dynamometer +(see figure). Two fast pulleys and one loose pulley are interposed +between the machine to be tested and the motor. The pulley +connected with the motor carries along the one connected with the +machine, through the intermedium of spring plates, whose strength +varies with the nature of the apparatus to be tested. The greater +or less elongation of these plates gives the tangential stress +exerted by the driving pulley to carry along the pulley that +actuates the machine to be tested. This elongation is registered by +means of a pencil connected with the spring plates, and which draws +a diagram upon a sheet of paper. At the same time, a special +totalizer gives the stress in kilogrammeters. Besides, the pulley +shaft actuates a revolution counter, and a clock measures the time +employed in the experiment. In order to obtain a simultaneous +starting and stopping point for all these apparatus, they are +connected electrically, and, through the maneuver of a commutator, +are all controlled at once. The electric current is furnished by +two series of bichromate batteries.</p> + +<p>The tests of traction machines are effected by means of a +three-wheeled vehicle carrying a dynamometer. The front wheel is +capable of turning freely in the horizontal plane, and the +dynamometer is mounted upon a frame provided with a screw that +permits of regulating its position according to the slope of the +ground. The method of suspension of the dynamometer allows it to +take automatically the inclination of the line of traction without +any torsion of the plates. There are two models of this vehicle, +one designed to be drawn by a man, and the other by a horse.</p> + +<p>The station is provided, in addition, with registering pressure +gauges, a large double dynamometric indicator, a counter of +electricity, balances of precision, etc.</p> + +<p>An apparatus designed for measuring the rendering of presses is +now in course of construction.</p> + +<p>Although the station has been in operation only from the 1st of +January, twenty-five machines have already been presented to be +tested.—<i>Extract from Le Genie Civil</i>.</p> + +<hr /> +<h2><a id="xii_3" name="xii_3"></a>WATER SOFTENING AND PURIFYING +APPARATUS.</h2> + +<p>We have recently had brought under our notice a system of water +and sewage purification which appears to possess several +substantial advantages. Chief among these are simplicity in +construction and operation, economy in first cost and working and +efficiency in action. This system is the invention of Messrs. Slack +& Brownlow, of Canning Works, Upper Medlock Street, Manchester, +and the apparatus adopted in carrying it out is here illustrated. +It consists of an iron cylindrical tank having inside a series of +plates arranged in a spiral direction around a fixed center, and +sloping downward at a considerable angle outward. The water to be +purified and softened flows through the large inlet tube to the +bottom, mixing on its way with the necessary chemicals, and +entering the apparatus at the bottom, rises to the top, passing +spirally round the whole circumference, and depositing on the +plates all solids and impurities.</p> + +<p>All that is needed in the way of attention, even when dealing +with sewage, or the most polluted waters, is stated to be the +mixing in the small tanks the necessary chemical reagents, at the +commencement of the working day; and at the close of the day the +opening of the mud cocks shown in our engraving, to remove the +collected deposit upon the plates. For the past six months this +system has been in operation at a dye works in Manchester, +successfully purifying and softening the foul waters of the river +Medlock. It is stated that 84,000 gallons per day can be easily +purified by an apparatus 7 feet in diameter. The chemicals used are +chiefly lime, soda, and alumina, and the cost of treatment is +stated to vary from a farthing to twopence per 1,000 gallons, +according to the degree of impurity of the water or sewage +treated.</p> + +<p>The results of working at Manchester show that all the visible +filth is removed from the Medlock's inky waters, besides which the +hardness of the water is reduced to about 6° from a normal +condition of about 30°. The effluent is fit for all the varied +uses of a dye works, and is stated to be perfectly capable of +sustaining fish life. With results such as these the system should +have a promising future before it in respect of sewage treatment, +as well as the purification and softening of water generally for +industrial and manufacturing purposes.—<i>Iron.</i></p> + +<p class="ctr"><a href="./images/4-water.png"><img src= +"./images/4-water_th.jpg" alt= +"WATER SOFTENING AND PURIFYING APPARATUS" title= +"WATER SOFTENER" /></a><br clear="all" /> + WATER SOFTENING AND PURIFYING APPARATUS.</p> + +<hr /> +<h2><a id="vi_1" name="vi_1"></a>THE TRISECTION OF ANY ANGLE.</h2> + +<h3>By FREDERIC R. HONEY, Ph.B., Yale University.</h3> + +<p>The following analysis shows that with the aid of an hyperbola +any arc, and therefore any angle, may be trisected.</p> + +<p>If the reader should not care to follow the analytical work, the +construction is described in the last paragraph—referring to +Fig. II.</p> + +<p>Let <i>a b c d</i> (Fig. I.) be the arc subtending a given +angle. Draw the chord <i>a d</i> and bisect it at <i>o</i>. Through +<i>o</i> draw <i>e f</i> perpendicular to <i>a d</i>.</p> + +<p class="ctr"><img src="./images/4-fig1.png" alt="FIG 1." title= +"" /></p> + +<p>We wish to find the locus of a point <i>c</i> whose distance +from a given straight line <i>e f</i> is one-half the distance from +a given point <i>d</i>.</p> + +<p>In order to write the equation of this curve, refer it to the +co-ordinate axes <i>a d</i> (axis of X) and <i>e f</i> (axis of Y), +intersecting at the origin <i>o</i>.</p> + +<div class="ctr"> +<p>Let g c = x</p> + +<p>Therefore, from the definition c d = 2x</p> + +<p>Let o d = D</p> + +<p>[Hence] h d = D-x</p> + +<p>Let c h = y</p> + +<p>[Hence] (2x)² = y² + (D-x)²</p> + +<p>or 4x² = y² + D²-2Dx + x²</p> + +<p>[Hence] y²-3x² + D²-2Dx = o [I.]</p> +</div> + +<p>This is the equation of an hyperbola whose center is on the axis +of abscisses. In order to determine the position of the center, +eliminate the x term, and find the distance from the origin o to a +new origin o'.</p> + +<div class="ctr"> +<p>Let E = distance from o to o'</p> + +<p>[Hence] x = x' + E</p> +</div> + +<p>Substituting this value of x in equation I.</p> + +<div class="ctr"> +<p>y²-3(x' + E)² + D²-2D(x' + E) = o</p> + +<p>or y²-3x²-6Ex'-3E² + D²-2Dx'-2DE = o +[II.]</p> +</div> + +<p>In this equation the <i>x'</i> terms should disappear.</p> + +<div class="ctr"> +<p>[Hence] -6Ex' - 2Dx' = o</p> + +<p>[Hence] -E = - D/3</p> +</div> + +<p>That is, the distance from the origin <i>o</i> to the new origin +or the center of the hyperbola <i>o'</i> is equal to one-third of +the distance from <i>o</i> to <i>d</i>; and the minus sign +indicates that the measurement should be laid off to the left of +the origin <i>o</i>. Substituting this value of E in equation II., +and omitting accents—</p> + +<p>We have</p> + +<div class="ctr"> +<p>y² - 3x² + 2Dx - D²/3 + D² - 2Dx + +2D²/3 = o</p> + +<p>[Hence] y² - 3x² = - 4D²/3</p> +</div> + +<p>This is the equation of an hyperbola referred to its center +<i>o'</i> as the origin of co-ordinates. To write it in the +ordinary form, that is in terms of the transverse and conjugate +axes, multiply each term by C, i.e.,</p> + +<div class="ctr"> +<p>Let √<span style="text-decoration: overline;">C</span> = +semi-transverse axis.</p> + +<p>Thus Cy² - 3Cx² = - 4CD² / 3. [III.]</p> +</div> + +<p>When in this form the product of the coefficients of the +<i>x²</i> and <i>y²</i> terms should be equal to the +remaining term.</p> + +<p>That is</p> + +<div class="ctr"> +<p>3C² = - 4CD² / 3.</p> + +<p>[Hence] C = 4D² / 9.</p> +</div> + +<p>And equation III. becomes:</p> + +<p class="ctr">(4D² / 9) y² - (4D² / 3) x² = +16D<sup>4</sup> / 27</p> + +<p class="ctr">The semi-transverse axis = √<span style= +"text-decoration: overline;">4D² /9</span> = 2D / 3</p> + +<p class="ctr">The semi-conjugate axis = √<span style= +"text-decoration: overline;">4D² / 3</span> = 2D / +√<span style="text-decoration: overline;">3</span></p> + +<p>Since the distance from the center of the curve to either focus +is equal to the square root of the sum of the squares of the +semi-axes, the distance from <i>o</i>' to either focus</p> + +<p class="ctr">= √<span style= +"text-decoration: overline;">4D²/9 + 4D²/ 3</span> = 4D / +3</p> + +<p class="ctr"><img src="./images/4-fig2.png" alt="FIG. 2." title= +"" /></p> + +<p>We can therefore make the following construction (Fig. II.) Draw +<i>a d</i> the chord of the arc <i>a c d</i>. Trisect <i>a d</i> at +<i>o'</i> and <i>k</i>. Produce <i>d a</i> to <i>l</i>, making <i>a +l</i> = <i>a o'</i> = <i>o' k</i> = <i>k d</i>. With <i>a k</i> as +a transverse axis, and <i>l</i> and <i>d</i> as foci, construct the +branch of the hyperbola <i>k c c' c"</i>, which will intersect all +arcs having the common chord <i>a d</i> at <i>c, c', c"</i>, etc., +making the arcs <i>c d</i>, <i>c' d</i>, <i>c" d</i>, etc., +respectively, equal to one-third of the arcs <i>a c d</i>, <i>a c' +d</i>, <i>a c" d</i>, etc.</p> + +<hr /> +<h2><a id="xi_2" name="xi_2"></a>TEST CARD HINTS.</h2> + +<h3>By Dr. F. OGDEN STOUT.</h3> + +<p>I know it is the custom with a great many if not the majority of +opticians to fit a customer without knowing whether he has +presbyopia, hypermetropia, or any of the other errors of +refraction. Their method is first to try a convex, and if this does +not improve, a concave, etc., until the proper one is found. This, +of course, amounts to the same thing if the right glass is found. +But in practice it will be found both time saving and more +satisfactory to first decide with what error you have to deal. It +is very simple, and, where you have no other means of diagnosing +(such as the ophthalmoscope), it does away with the necessity of +trying so many lenses before the proper one is found. You should +have a distance test card placed at a distance of twenty feet from +the person you are examining, and in a good light.</p> + +<p>A distance test card consists of letters of various sizes which +it has been found can be seen at certain distances by people with +good vision. Thus the largest letter is marked with a cc, meaning +that this should be seen at two hundred feet, and another line, XX, +at twenty feet, which is the proper distance for testing vision for +distance, for the reason that a normal eye is at rest when looking +at any object twenty feet from it or beyond, and the rays coming +from it are parallel and come to a focus on the retina. You must +also have a near vision test card with lines that should be seen by +a normal eye from ten to seventy-two inches, and a card of +radiating lines for astigmatism. With this preparation you are +ready to proceed. To illustrate, the first customer comes and tells +you that up to six months ago he had very good vision, but he finds +now that, especially at night, he has trouble in reading or +writing, and that he finds he can see better a little farther away. +His head aches and eyes smart. You will of course say that this is +a very simple case. It must be old sight (presbyopia). Probably it +is if he is old enough (45), but you must prove this for yourself, +without asking his age, which is embarrassing in the case of a +lady. If you direct him to the distance card twenty feet away, and +find that he can see every one down to and including the one marked +XX, his vision is up to the standard for distance, and you know +that he can have no astigmatism worth correcting, nor any near +sight, as both of these affect vision for distance, but he may have +far sight or old sight or both combined. You must find which it +is.</p> + +<p>If, while he is still looking at the twenty-foot line, you place +in front of the eyes a weak convex and he tells you he sees just as +well with as without, it proves the existence of far-sight or +hypermetropia, and the strongest convex that still leaves vision as +good for distance as without any, corrects the manifest. But if the +weak convex blurs it, it shows that there is some defect in +focusing, if the near vision is below normal. You therefore know +that you have a case of old sight or presbyopia, requiring the +weakest convex to correct it, that will enable your customer to see +the finest line on the near card at the required distance.</p> + +<p>The next customer that comes to be fitted with glasses can only +see the line marked XL on the distance card at 20 feet or about +one-half of what he should see, which leads you to think that there +is no far sight, for vision for distance is good except in very +high degrees of this error. Nor can there be old-sight, for vision +for distance is good in old-sight until after the fifty-fifth year, +but it can be near sight (myopia) or astigmatism, or both. We next +try the near card and find that even the finest line can be seen +clearly if held sufficiently close to the eyes. We now know that +this is a case of near sight, and we must fit them with glasses for +distance. The weakest concave that will enable him to see the line +that should be seen on the distance card at 20 feet is the proper +one to give him for use.—<i>The Optician.</i></p> + +<hr /> +<h2><a id="i_1" name="i_1"></a>CHARLES GOODYEAR.</h2> + +<p>CHARLES GOODYEAR was born in New Haven, December 29, 1800. He +was the son of Amasa Goodyear, and the eldest among six children. +His father was quite proud of being a descendant of Stephen +Goodyear, one of the founders of the colony of New Haven in +1638.</p> + +<p>Amasa Goodyear owned a little farm on the neck of land in New +Haven which is now known as Oyster Point, and it was here that +Charles spent the earliest years of his life. When, however, he was +quite young, his father secured an interest in a patent for the +manufacture of ivory buttons, and looking for a convenient location +for a small mill, settled at Naugatuck, Conn., where he made use of +the valuable water power that is there. Aside from his +manufacturing, the elder Goodyear ran a farm, and between the two +lines of industry kept young Charles pretty busy.</p> + +<p>In 1816, Charles left his home and went to Philadelphia to learn +the hardware business. He worked at this very industriously until +he was twenty-one years old, and then, returning to Connecticut, +entered into partnership with his father at the old stand in +Naugatuck, where they manufactured not only ivory and metal +buttons, but a variety of agricultural implements, which were just +beginning to be appreciated by the farmers. In August of 1824 he +was united in marriage with Clarissa Beecher, a woman of remarkable +strength of character and kindness of disposition, and one who in +after years was of the greatest assistance to the impulsive +inventor. Two years later he removed again to Philadelphia, and +there opened a hardware store. His specialties were the valuable +agricultural implements that his firm had been manufacturing, and +after the first distrust of home made goods had worn away—for +all agricultural implements were imported from England at that +time—he found himself established at the head of a successful +business.</p> + +<p>This continued to increase until it seemed but a question of a +few years until he would be a very wealthy man. Between 1829 and +1830 he suddenly broke down in health, being troubled with +dyspepsia. At the same time came the failure of a number of +business houses that seriously embarrassed his firm. They struggled +on, however, for some time, but were finally obliged to fail. The +ten years that followed this were full of the bitterest struggles +and trials to Goodyear. Under the law that then existed he was +imprisoned time after time for debts, even while he was trying to +perfect inventions that should pay off his indebtedness.</p> + +<p>Between the years 1831 and 1832 he began to hear about gum +elastic and very carefully examined every article that appeared in +the newspapers relative to this new material. The Roxbury Rubber +Company, of Boston, had been for some time experimenting with the +gum, and believing that they had found means for manufacturing +goods from it, had a large plant and were sending their goods all +over the country. It was some of their goods that first attracted +his attention. Soon after this Goodyear visited New York, and went +at once to the store of the Roxbury Rubber Company. While there, he +examined with considerable care some of their life preservers, and +it struck him that the tube used for inflation was not very +perfect. He, therefore, on his return to Philadelphia, made some +tubes and brought them down to New York and showed them to the +manager of the Roxbury Rubber Company.</p> + +<p>This gentlemen was so pleased with the ingenuity that Goodyear +had shown in manufacturing these tubes, that he talked very freely +with him and confessed to him that the business was on the verge of +ruin, that the goods had to be tested for a year before they could +tell whether they were perfect or not, and to their surprise, +thousands of dollars worth of goods that they had supposed were all +right were coming back to them, the gum having rotted and made them +so offensive that it was necessary to bury them in the ground to +get them out of the way.</p> + +<p>Goodyear at once made up his mind to experiment on this gum and +see if he could not overcome its stickiness.</p> + +<p>He, therefore, returned to Philadelphia, and, as usual, met a +creditor, who had him arrested and thrown into prison. While there, +he tried his first experiments with India rubber. The gum was very +cheap then, and by heating it and working it in his hands, he +managed to incorporate in it a certain amount of magnesia which +produced a beautiful white compound and appeared to take away the +stickiness.</p> + +<p>He therefore thought he had discovered the secret, and through +the kindness of friends was put in the way of further perfecting +his invention at a little place in New Haven. The first thing that +he made here was shoes, and he used his own house for grinding +room, calender room, and vulcanizing department, and his wife and +children helped to make up the goods. His compound at this time was +India rubber, lampblack, and magnesia, the whole dissolved in +turpentine and spread upon the flannel cloth which served as the +lining for the shoes. It was not long, however, before he +discovered that the gum, even treated this way, became sticky, and +then those who had supplied the money for the furtherance of these +experiments, completely discouraged, made up their minds that they +could go no further, and so told the inventor.</p> + +<p class="ctr"><a href="./images/5-goodyear.png"><img src= +"./images/5-goodyear_th.jpg" alt="CHARLES GOODYEAR." title= +"GOODYEAR" /></a><br clear="all" /> + CHARLES GOODYEAR.</p> + +<p>He, however, had no mind to stop here in his experiments, but, +selling his furniture and placing his family in a quiet boarding +place, he went to New York, and there, in an attic, helped by a +friendly druggist, continued his experiments. His next step in this +line was to compound the rubber with magnesia and then boil it in +quicklime and water. This appeared to really solve the problem, and +he made some beautiful goods. At once it was noised abroad that +India rubber had been so treated that it lost its stickiness, and +he received medals and testimonials and seemed on the high road to +success, till one day he noticed that a drop of weak acid, falling +on the cloth, neutralized the alkali, and immediately the rubber +was soft again. To see this, with his knowledge of what rubber +should do, proved to him at once that his process was not a +successful one. He therefore continued experimenting, and after +preparing his mixtures in his attic in New York, would walk three +miles to the mill of a Mr. Pike, at Greenwich village, and there +try various experiments.</p> + +<p>In the line of these, he discovered that rubber, dipped in +nitric acid, formed a surface cure, and he made a great many goods +with this acid cure which were spoken of, and which even received a +letter of commendation from Andrew Jackson.</p> + +<p>The constant and varied experiments that Goodyear went through +with affected his health more or less, and at one time he came very +near being suffocated by gas generated in his laboratory. That he +did not die then everybody knows, but he was thrown then into a +fever by the accident and came very near losing his life.</p> + +<p>It was there that he formed an acquaintance with Dr. Bradshaw, +who was very much pleased with the samples of rubber goods that he +saw in Goodyear's room, and when the doctor went to Europe he took +them with him, where they attracted a great deal of attention, but +beyond that nothing was done about them. Now that he appeared to +have success, he found no difficulty in obtaining a partner, and +together the two gentlemen fitted up a factory and began to make +clothing, life preservers, rubber shoes, and a great variety of +rubber goods. They also had a large factory, with special +machinery, built at Staten Island, where he removed his family and +again had a home of his own. Just about this time, when everything +looked bright, the great panic of 1836-1837 came, and swept away +the entire fortune of his associate and left Goodyear without a +cent, and no means of earning one.</p> + +<p>His next move was to go to Boston, where he became acquainted +with J. Haskins, of the Roxbury Rubber Company, and found in him a +firm friend, who loaned him money and stood by him when no one +would have anything to do with the visionary inventor. Mr. Chaffee +was also exceedingly kind and ever ready to lend a listening ear to +his plans, and to also assist him in a pecuniary way. It was about +this time that it occurred to Mr. Chaffee that much of the trouble +that they had experienced in working India rubber might come from +the solvent that was used. He therefore invented a huge machine for +doing the mixing by mechanical means. The goods that were made in +this way were beautiful to look at, and it appeared, as it had +before, that all difficulties were overcome.</p> + +<p>Goodyear discovered a new method for making rubber shoes and got +a patent on it, which he sold to the Providence Company, in Rhode +Island.</p> + +<p>The secret of making the rubber so that it would stand heat and +cold and acids, however, had not been discovered, and the goods +were constantly growing sticky and decomposing and being +returned.</p> + +<p>In 1838 he, for the first time, met Nathaniel Hayward, who was +then running a factory in Woburn. Some time after this Goodyear +himself moved to Woburn, all the time continuing his experiments. +He was very much interested in Hayward's sulphur experiments for +drying rubber, but it appears that neither of them at that time +appreciated the fact that it needed heat to make the sulphur +combine with the rubber and to vulcanize it.</p> + +<p>The circumstances attending the discovery of his celebrated +process is thus described by Mr. Goodyear himself in his book, "Gum +Elastic." It will be observed that he makes use of the third person +in all references to himself:</p> + +<blockquote> +<p>"In the summer of 1838 he became acquainted with Mr. Nathaniel +Hayward, of Woburn, Mass., who had been employed as the foreman of +the Eagle Company at Woburn, where he had made use of sulphur by +impregnating the solvent with it. It was through him that the +writer (Charles Goodyear, who makes use all through his book of the +third person) received the first knowledge of the use of sulphur as +a drier of gum elastic.</p> + +<p>"Mr. Hayward was left in possession of the factory which was +abandoned by the Eagle Company. Soon after this it was occupied by +the writer, who employed him for the purpose of manufacturing life +preservers and other articles by the acid gas process. At this +period he made many novel and useful applications of this +substance. Among other fancy articles he had newspapers printed on +the gum elastic drapery, and the improvement began to be highly +appreciated. He therefore now entered, as he thought, upon a +successful career for the future. A far different result awaited +him.</p> + +<p>"It was supposed by others as well as himself that a change was +wrought through the mass of the goods acted upon by the acid gas, +and that the whole body of the article was made better than the +native gum. The surface of the goods really was so, but owing to +the eventual decomposition of the goods beneath the surface, the +process was pronounced by the public a complete failure. Thus +instead of realizing the large fortune which by all acquainted with +his prospects was considered certain, his whole invention would not +bring him a week's living.</p> + +<p>"He was obliged for the want of means to discontinue +manufacturing, and Mr. Hayward left his employment. The inventor +now applied himself alone, with unabated ardor and diligence, to +detect the cause of his misfortune and if possible to retrieve the +lost reputation of his invention. On one occasion he made some +experiments to ascertain the effect of heat upon the same compound +that had decomposed in the articles previously manufactured, and +was surprised to find that the specimen, being carelessly brought +in contact with a hot stove, charred like leather. He endeavored to +call the attention of his brother as well as some other individuals +who were present, and who were acquainted with the manufacture of +gum elastic, to this effect as remarkable and unlike any before +known, since gum elastic always melted when exposed to a high +degree of heat. The occurrence did not at the time appear to them +to be worthy of notice. It was considered as one of the frequent +appeals that he was in the habit of making in behalf of some new +experiment. He, however, directly inferred that if the process of +charring could be stopped at the right point, it might divest the +gum of its native adhesiveness throughout, which would make it +better than the native gum.</p> + +<p>"He made another trial of heating a similar fabric, before an +open fire. The same effect, that of charring the gum, followed, but +there were further and very satisfactory indications of ultimate +success in producing the desired result, as upon the edge of the +charred portions of the fabric there appeared a line, or border, +that was not charred, but perfectly cured.</p> + +<p>"These facts have been stated precisely as they occurred in +reference to the acid gas, as well as the vulcanizing process.</p> + +<p>"The incidents attending the discovery of both have a strong +resemblance, so much so they may be considered parallel cases. It +being now known that the results of the vulcanizing process are +produced by means and in a manner which would not have been +anticipated from any reasoning on the subject, and that they have +not yet been satisfactorily accounted for, it has been sometimes +asked, how the inventor came to make the discovery? The answer has +already been given. It may be added that he was many years seeking +to accomplish this object, and that he allowed nothing to escape +his notice that related to the subject. Like the falling of an +apple, it was suggestive of an important fact to one whose mind was +previously prepared to draw an inference from any occurrence which +might favor the object of his research. While the inventor admits +that these discoveries were not the results of scientific chemical +investigations, <i>he is not willing to admit that they were the +result of what is commonly termed accident</i>; he claims them to +be the result of the closest application and observation.</p> + +<p>"The discoloring and charring of the specimens proved nothing +and discovered nothing of value, but quite the contrary, for in the +first instance, as stated in the acid gas improvement, the specimen +acted upon was thrown away as worthless and left for some time; in +the latter instance, the specimen that was charred was in like +manner disregarded by others.</p> + +<p>"It may, therefore, be considered as one of those cases where +the leading of the Creator providentially aids his creatures, by +what are termed 'accidents,' to attain those things which are not +attainable by the powers of reasoning he has conferred on +them."</p> +</blockquote> + +<p>Now that Goodyear was sure that he had the key to the intricate +puzzle that he had worked over for so many years, he began at once +to tell his friends about it and to try to secure capital, but they +had listened to their sorrow so many times that his efforts were +futile. For a number of years be struggled and experimented and +worked along in a small way, his family suffering with himself the +pangs of the extremest poverty. At last he went to New York and +showed some of his samples to William Ryder, who, with his brother +Emory, at once appreciated the value of the discovery and started +in to manufacturing. Even here Goodyear's bad luck seemed to follow +him, for the Ryder Bros. failed and it was impossible to continue +the business.</p> + +<p>He had, however, started a small factory at Springfield, Mass., +and his brother-in-law, Mr. De Forest, who was a wealthy woolen +manufacturer, took Ryder's place, and the work of making the +invention practical was continued. In 1844 it was so far perfected +that Goodyear felt it safe to take out a patent. The factory at +Springfield was run by his brothers, Nelson and Henry.</p> + +<p>In 1843 Henry started one in Naugatuck, and in 1844 introduced +mechanical mixing in place of the mixture by the use of +solvents.</p> + +<p>In the year 1852 Goodyear went to Europe, a trip that he had +long planned, and saw Hancock, then in the employ of Charles +Macintosh & Co. Hancock admitted in evidence that the first +piece of vulcanized rubber he ever saw came from America, but +claimed to have reinvented vulcanization and secured patents in +Great Britain, but it is <i>a remarkable fact</i> that Charles +Goodyear's French patent was the first publication in Europe of +this discovery.</p> + +<p>In 1852 a French company were licensed by Mr. Goodyear to make +shoes, and a great deal of interest was felt in the new business. +In 1855 the French emperor gave to Charles Goodyear the grand medal +of honor and decorated him with the cross of the legion of honor in +recognition of his services as a public benefactor, but the French +courts subsequently set aside his French patents on the ground of +the importation of vulcanized goods from America by licenses under +the United States patents. He died July 1, 1860, at the Fifth +Avenue Hotel, New York City.—<i>India Rubber World</i>.</p> + +<hr /> +<p class="ctr">[Continued from SUPPLEMENT, No. 786, page +12558.]</p> + +<h2><a id="iii_3" name="iii_3"></a>THE ELECTROMAGNET.<a id= +"FNanchor_1b" name="FNanchor_1b"></a><a href= +"#Footnote_1b"><sup>1</sup></a></h2> + +<h3>By Professor SILVANUS P. THOMPSON, D.Sc., B.A., M.I.E.E.</h3> + +<h3>III.</h3> + +<h3>RESEARCHES OF PROFESSOR HUGHES.</h3> + +<p class="ctr"><img src="./images/6-fig51.png" alt= +"FIG. 51.—HUGHES' ELECTROMAGNET." title="FIG. 51" /><br /> + FIG. 51.—HUGHES' ELECTROMAGNET.</p> + +<p>His object was to find out the best form of electromagnet, the +best distance between the poles, and the best form of armature for +the rapid work required in Hughes' printing telegraphs. One word +about Hughes' magnets. This diagram (Fig. 51) shows the form of the +well known Hughes' electromagnet. I feel almost ashamed to say +those words "well known," because on the Continent everybody knows +what you mean by a Hughes' electromagnet. In England scarcely +anyone knows what you mean. Englishmen do not even know that +Professor Hughes has invented a special form of electromagnet. +Hughes' special form is this: A permanent steel magnet, generally a +compound one, having soft iron pole pieces, and a couple of coils +on the pole pieces only. As I have to speak of Hughes' special +contrivance among the mechanisms that will occupy our attention +later on, I only now refer to this magnet in one particular. If you +wish a magnet to work rapidly, you will secure the most rapid +action, not when the coils are distributed all along, but when they +are heaped up near, not necessarily entirely on, the poles. Hughes +made a number of researches to find out what the right length and +thickness of these pole pieces should be. It was found an advantage +not to use too thin pole pieces, otherwise the magnetism from the +permanent magnet did not pass through the iron without considerable +reluctance, being choked by insufficiency of section: also not to +use too thick pieces, otherwise they presented too much surface for +leakage across from one to the other. Eventually a particular +length was settled upon, in proportion about six times the +diameter, or rather longer. In the further researches that Hughes +made he used a magnet of shorter form, not shown here, more like +those employed in relays, and with an armature from 2 to 3 +millimeters thick, 1 centimeter wide and 5 centimeters long. The +poles were turned over at the top toward one another. Hughes tried +whether there was any advantage in making those poles approach one +another, and whether there was any advantage in having as long an +armature as 5 centimeters. He tried all the different kinds, and +plotted out the results of observations in curves, which could be +compared and studied. His object was to ascertain the conditions +which would give the strongest pull, not with a steady current, but +with such currents as were required for operating his printing +telegraph instruments; currents which lasted but one to twenty +hundredths of a second. He found it was decidedly an advantage to +shorten the length of the armature, so that it did not protrude far +over the poles. In fact, he got a sufficient magnetic circuit to +secure all the attractive power that he needed, without allowing as +much chance of leakage as there would have been had the armature +extended a longer distance over the poles. He also tried various +forms of armature having very various cross sections.</p> + +<h3>POSITION AND FORM OF ARMATURE.</h3> + +<p>In one of Du Moncel's papers on electromagnets<a id= +"FNanchor_2b" name="FNanchor_2b"></a><a href= +"#Footnote_2b"><sup>2</sup></a> you will also find a discussion on +armatures, and the best forms for working in different positions. +Among other things in Du Moncel you will find this paradox: that +whereas using a horseshoe magnet with fat poles, and a flat piece +of soft iron for armature, it sticks on far tighter when put on +edgeways; on the other hand, if you are going to work at a +distance, across air, the attraction is far greater when it is set +flatways. I explained the advantage of narrowing the surfaces of +contact by the law of traction, <b>B²</b>, coming in. Why +should we have for action at a distance the greater advantage from +placing the armature flatway to the poles? It is simply that you +thereby reduce the reluctance offered by the air gap to the flow of +the magnetic lines. Du Moncel also tried the difference between +round armatures and flat ones, and found that a cylindrical +armature was only attracted about half as strongly as a prismatic +armature having the same surface when at the same distance. Let us +examine this fact in the light of the magnetic circuit. The poles +are flat. You have at a certain distance away a round armature; +there is a certain distance between its nearest side and the polar +surfaces. If you have at the same distance away a flat armature +having the same surface, and, therefore, about the same tendency to +leak, why do you get a greater pull in this case than in that? I +think it is clear that if they are at the same distance away, +giving the same range of motion, there is a greater magnetic +reluctance in the case of the round armature, although there is the +same periphery, because, though the nearest part of the surface is +at the prescribed distance, the rest of the under surface is +farther away; so that the gain found in substituting an armature +with a flat surface is a gain resulting from the diminution in the +resistance offered by the air gap.</p> + +<h3>POLE PIECES ON HORSESHOE MAGNETS.</h3> + +<p>Another of Du Moncel's researches<a id="FNanchor_3b" name= +"FNanchor_3b"></a><a href="#Footnote_3b"><sup>3</sup></a> relates +to the effect of polar projections or shoes—movable pole +pieces, if you like—upon a horseshoe electromagnet. The core +of this magnet was of round iron 4 centimeters in diameter, and the +parallel limbs were 10 centimeters long and 6 centimeters apart. +The shoes consisted of two flat pieces of iron slotted out at one +end, so that they could be slid along over the poles and brought +nearer together. The attraction exerted on a flat armature across +air gaps 2 millimeters thick was measured by counterpoising. +Exciting this electromagnet with a certain battery, it was found +that the attraction was greatest when the shoes were pushed to +about 15 millimeters, or about one-quarter of the interpolar +distance, apart. The numbers were as follows:</p> + +<div class="ctr"> +<table width="40%" summary="DISTANCE AND ATTRACTION" border="0" +cellspacing="3"> +<colgroup span="2" align="right"></colgroup> + +<tr> +<th>Distance<br /> + between shoes.<br /> + Millimeters.</th> +<th align="center">Attraction,<br /> + in grammes.</th> +</tr> + +<tr> +<td>2</td> +<td>900</td> +</tr> + +<tr> +<td>10</td> +<td>1,012</td> +</tr> + +<tr> +<td>15</td> +<td>1,025</td> +</tr> + +<tr> +<td>25</td> +<td>965</td> +</tr> + +<tr> +<td>40</td> +<td>890</td> +</tr> + +<tr> +<td>60</td> +<td>550</td> +</tr> +</table> +</div> + +<p>With a stronger battery the magnet without shoes had an +attraction of 885 grammes, but with the shoes 15 millimeters apart, +1,195 grammes. When one pole only was employed, the attraction, +which was 88 grammes without a shoe, was <i>diminished</i> by +adding a shoe to 39 grammes!</p> + +<h3>CONTRAST BETWEEN ELECTROMAGNETS AND PERMANENT MAGNETS.</h3> + +<p>Now I want particularly to ask you to guard against the idea +that all these results obtained from electromagnets are equally +applicable to permanent magnets of steel; they are not, for this +simple reason. With an electromagnet, when you put the armature +near, and make the magnetic circuit better, you not only get more +magnetic lines going through that armature, but you get more +magnetic lines going through the whole of the iron. You get more +magnetic lines round the bend when you put an armature on to the +poles, because you have a magnetic circuit of less reluctance with +the same external magnetizing power in the coils acting around it. +Therefore, in that case, you will have a greater magnetic flux all +the way round. The data obtained with the electromagnet (Fig. 42), +with the exploring coil, C, on the bend of the core, where the +armature was in contact, and when it was removed are most +significant. When the armature was present it multiplied the total +magnetic flow tenfold for weak currents and nearly threefold for +strong currents. But with a steel horseshoe, magnetized once for +all, the magnetic lines that flow around the bend of the steel are +a fixed quantity, and, however much you diminish the reluctance of +the magnetic circuit, you do not create or evoke any more. When the +armature is away the magnetic lines arch across, not at the ends of +the horseshoe only, but from its flanks; the whole of the magnetic +lines leaking somehow across the space. Where you have put the +armature on, these lines, instead of arching out into space as +freely as they did, pass for the most part along the steel limbs +and through the iron armature. You may still have a considerable +amount of leakage, but you have not made one line more go through +the bent part. You have absolutely the same number going through +the bend with the armature off as with the armature on. You do not +add to the total number by reducing the magnetic reluctance, +because you are not working under the influence of a constantly +impressed magnetizing force. By putting the armature on to a steel +horseshoe magnet you only <i>collect</i> the magnetic lines, you do +not <i>multiply</i> them. This is not a matter of conjecture. A +group of my students have been making experiments in the following +way: They took this large steel horseshoe magnet (Fig. 52), the +length of which, from end to end, through the steel, is 42½ +inches. A light, narrow frame was constructed so that it could be +slipped on over the magnet, and on it were wound 30 turns of fine +wire, to serve as an exploring coil. The ends of this coil were +carried to a distant part of the laboratory, and connected to a +sensitive ballistic galvanometer. The mode of experimenting is as +follows:</p> + +<p>The coil is slipped on over the magnet (or over its armature) to +any desired position. The armature of the magnet is placed gently +upon the poles, and time enough is allowed to elapse for the +galvanometer needle to settle to zero. The armature is then +suddenly detached. The first swing measures the change, due to +removing the armature, in the number of magnetic lines that pass +through the coil in the particular position.</p> + +<p class="ctr"><img src="./images/6-fig52.png" alt= +"FIG. 52.—EXPERIMENT WITH PERMANENT MAGNET." title= +"FIG. 52" /><br /> + FIG. 52.—EXPERIMENT WITH PERMANENT MAGNET.</p> + +<p>I will roughly repeat the experiment before you: The spot of +light on the screen is reflected from my galvanometer at the far +end of the table. I place the exploring coil just over the pole, +and slide on the armature; then close the galvanometer circuit. Now +I detach the armature, and you observe the large swing. I shift the +exploring coil, right up to the bend; replace the armature; wait +until the spot of light is brought to rest at the zero of the +scale. Now, on detaching the armature, the movement of the spot of +light is quite imperceptible. In our careful laboratory +experiments, the effect was noticed inch by inch all along the +magnet. The effect when the exploring coil was over the bend was +not as great as 1-3000th part of the effect when the coil was hard +up to the pole. We are, therefore, justified in saying that the +number of magnetic lines in a permanently magnetized steel +horseshoe magnet is not altered by the presence or absence of the +armature.</p> + +<p>You will have noticed that I always put on the armature gently. +It does not do to slam on the armature; every time you do so, you +knock some of the so-called permanent magnetism out of it. But you +may pull off the armature as suddenly as you like. It does the +magnet good rather than harm. There is a popular superstition that +you ought never to pull off the keeper of a magnet suddenly. On +investigation, it is found that the facts are just the other way. +You may pull off the keeper as suddenly as you like, but you should +never slam it on.</p> + +<p>From these experimental results I pass to the special design of +electromagnets for special purposes.</p> + +<h3>ELECTROMAGNETS FOR MAXIMUM TRACTION.</h3> + +<p>These have already been dealt with in the preceding lecture; the +characteristic feature of all the forms suitable for traction being +the compact magnetic circuit.</p> + +<p>Several times it has been proposed to increase the power of +electromagnets by constructing them with intermediate masses of +iron between the central core and the outside, between the layers +of windings. All these constructions are founded on fallacies. Such +iron is far better placed either right inside the coils or right +outside them, so that it may properly constitute a part of the +magnetic circuit. The constructions known as Camacho's and Cance's, +and one patented by Mr. S.A. Varley, in 1877, belonging to this +delusive order of ideas, are now entirely obsolete.</p> + +<p>Another construction which is periodically brought forward as a +novelty is the use of iron windings of wire or strip in place of +copper winding. The lower electric conductivity of iron, as +compared with copper, makes such a construction wasteful of +exciting power. To apply equal magnetizing power by means of an +iron coil implies the expenditure of about six times as many watts +as need be expended if the coil is of copper.</p> + +<h3>ELECTROMAGNETS FOR MAXIMUM RANGE OF ATTRACTION.</h3> + +<p>We have already laid down the principle which will enable us to +design electromagnets to act at a distance. We want our magnet to +project, as it were, its force across the greatest length of air +gap. Clearly, then, such a magnet must have a very large +magnetizing power, with many ampere turns upon it, to be able to +make the required number of magnetic lines pass across the air +resistance. Also it is clear that the poles must not be too close +together for its work, otherwise the magnetic lines at one pole +will be likely to curl round and take short cuts to the other pole. +There must be a wider width between the poles than is desirable in +electromagnets for traction.</p> + +<h3>ELECTROMAGNETS OF MINIMUM WEIGHT.</h3> + +<p>In designing an apparatus to put on board a boat or a balloon, +where weight is a consideration of primary importance, there is +again a difference. There are three things that come into +play—iron, copper, and electric current. The current weighs +nothing, therefore, if you are going to sacrifice everything else +to weight, you may have comparatively little iron, but you must +have enough copper to be able to carry the electric current; and +under such circumstances you must not mind heating your wires +nearly red hot to pass the biggest possible current. Provide as +little copper as you conveniently can, sacrificing economy in that +case to the attainment of your object; but, of course, you must use +fireproof material, such as asbestos, for insulating, instead of +cotton or silk.</p> + +<h2>A USEFUL GUIDING PRINCIPLE.</h2> + +<p>In all cases of design there is one leading principle which will +be found of great assistance, namely, that a magnet always tends so +to act as though it tried to diminish the length of its magnetic +circuit. It tries to grow more compact. This is the reverse of that +which holds good with an electric current. The electric circuit +always tries to enlarge itself, so as to inclose as much space as +possible, but the magnetic circuit always tries to make itself as +compact as possible. Armatures are drawn in as near as can be, to +close up the magnetic circuit. Many two-pole electromagnets show a +tendency to bend together when the current is turned on. One form +in particular, which was devised by Ruhmkorff for the purpose of +repeating Faraday's celebrated experiment on the magnetic rotation +of polarized light, is liable to this defect. Indeed, this form of +electromagnet is often designed very badly, the yoke being too +thin, both mechanically and magnetically, for the purpose which it +has to fulfill.</p> + +<p>Here is a small electric bell, constructed by Wagener, of +Wiesbaden, the construction of which illustrates this principle. +The electromagnet, a horseshoe, lies horizontally; its poles are +provided with protruding curved pins of brass. Through the armature +are drilled two holes, so that it can be hung upon the two brass +pins; and when so hung up it touches the ends of the iron cores +just at one edge, being held from more perfect contact by a spring. +There is no complete gap, therefore, in the magnetic circuit. When +the current comes and applies a magnetizing power, it finds the +magnetic circuit already complete in the sense that there are no +absolute gaps. But the circuit can be bettered by tilting the +armature to bring it flat against the polar ends, that being indeed +the mode of motion. This is a most reliable and sensitive pattern +of bell.</p> + +<p class="ctr"><img src="./images/7-fig53.png" alt= +"FIG. 53.—ELECTROMAGNETIC POP-GUN." title="FIG. 53" /><br /> + FIG. 53.—ELECTROMAGNETIC POP-GUN.</p> + +<p><i>Electromagnetic Pop-gun.</i>—Here is another curious +illustration of the tendency to complete the magnetic circuit. Here +is a tubular electromagnet (Fig. 53), consisting of a small bobbin, +the core of which is an iron tube about two inches long. There is +nothing very unusual about it; it will stick on, as you see, to +pieces of iron when the current is turned on. It clearly is an +ordinary electromagnet in that respect. Now suppose I take a little +round rod of iron, about an inch long, and put it into the end of +the tube, what will happen when I turn on my current? In this +apparatus as it stands, the magnetic circuit consists of a short +length of iron, and then all the rest is air. The magnetic circuit +will try to complete itself, not by shortening the iron, but by +<i>lengthening</i> it; by pushing the piece of iron out so as to +afford more surface for leakage. That is exactly what happens; for, +as you see, when I turn on the current, the little piece of iron +shoots out and drops down. You see that little piece of iron shoot +out with considerable force. It becomes a sort of magnetic popgun. +This is an experiment which has been twice discovered. I found it +first described by Count Du Moncel, in the pages of <i>La Lumiere +Electrique</i>, under the name of the "pistolet electromagnetique;" +and Mr. Shelford Bidwell invented it independently. I am indebted +to him for the use of this apparatus. He gave an account of it to +the Physical Society, in 1885, but the reporter missed it, I +suppose, as there is no record in the society's proceedings.</p> + +<h3>ELECTROMAGNETS FOR USE WITH ALTERNATING CURRENTS.</h3> + +<p>When you are designing electromagnets for use with alternating +currents, it is necessary to make a change in one respect, namely, +you must so laminate the iron that internal eddy currents shall not +occur; indeed, for all rapid-acting electromagnetic apparatus it is +a good rule that the iron must not be solid. It is not usual with +telegraphic instruments to laminate them by making up the core of +bundles of iron plates or wires, but they are often made with +tubular cores, that is to say, the cylindrical iron core is drilled +with a hole down the middle, and the tube so formed is slit with a +saw cut to prevent the circulation of currents in the substance of +the tube. Now when electromagnets are to be employed with rapidly +alternating currents, such as are used for electric lighting, the +frequency of the alternations being usually about 100 periods per +second, slitting the cores is insufficient to guard against eddy +currents; nothing short of completely laminating the cores is a +satisfactory remedy. I have here, thanks to the Brush Electric +Engineering Company, an electromagnet of the special form that is +used in the Brush arc lamp when required for the purpose of working +in an alternating current circuit. It has two bobbins that are +screwed up against the top of an iron box at the head of the lamp. +The iron slab serves as a kind of yoke to carry the magnetism +across the top. There are no fixed cores In the bobbins, which are +entered by the ends of a pair of yoked plungers. Now in the +ordinary Brush lamp for use with a steady current, the plungers are +simply two round pieces of iron tapped into a common yoke; but for +alternate current working this construction must not be used, and +instead a <b>U</b>-shaped double plunger is used, made up of +laminated iron, riveted together. Of course it is no novelty to use +a laminated core; that device, first used by Joule, and then by +Cowper, has been repatented rather too often during the past fifty +years to be considered as a recent invention.</p> + +<p>The alternate rapid reversals of the magnetism in the magnetic +field of an electromagnet, when excited by alternating electric +currents, sets up eddy currents in every piece of undivided metal +within range. All frames, bobbin tubes, bobbin ends, and the like, +must be most carefully slit, otherwise they will overheat. If a +domestic flat iron is placed on the top of the poles of a properly +laminated electromagnet, supplied with alternating currents, the +flat iron is speedily heated up by the eddy currents that are +generated internally within it. The eddy currents set up by +induction in neighboring masses of metal, especially in good +conducting metals such as copper, give rise to many curious +phenomena. For example, a copper disk or copper ring placed over +the pole of a straight electromagnet so excited is violently +repelled. These remarkable phenomena have been recently +investigated by Professor Elihu Thomson, with whose beautiful and +elaborate researches we have lately been made conversant in the +pages of the technical journals. He rightly attributes many of the +repulsion phenomena to the lag in phase of the alternating currents +thus induced in the conducting metal. The electromagnetic inertia, +or self-inductive property of the electric circuit, causes the +currents to rise and fall later in time than the electromotive +forces by which they are occasioned. In all such cases the +impedance which the circuit offers is made up of two +things—resistance and inductance. Both these causes tend to +diminish the amount of current that flows, and the inductance also +tends to delay the flow.</p> + +<h3>ELECTROMAGNETS FOR QUICKEST ACTION.</h3> + +<p>I have already mentioned Hughes' researches on the form of +electromagnet best adapted for rapid signaling. I have also +incidentally mentioned the fact that where rapidly varying currents +are employed, the strength of the electric current that a given +battery can yield is determined not so much by the resistance of +the electric circuit as by its electric inertia. It is not a very +easy task to explain precisely what happens to an electric circuit +when the current is turned on suddenly. The current does not +suddenly rise to its full value, being retarded by inertia. The +ordinary law of Ohm in its simple form no longer applies; one needs +to apply that other law which bears the name of the law of +Helmholtz, the use of which is to give us an expression, not for +the final value of the current, but for its value at any short +time, t, after the current has been turned on. The strength of the +current after a lapse of a short time, t, cannot be calculated by +the simple process of taking the electromotive force and dividing +it by the resistance, as you would calculate steady currents.</p> + +<p>In symbols, Helmholtz's law is:</p> + +<p class="ctr">i<sub>t</sub> = E/R ( 1 - e<sup>- (R/L)t</sup> )</p> + +<p>In this formula <i>i<sub>t</sub></i> means the strength of the +current after the lapse of a short time <i>t</i>; E is the +electromotive force; R, the resistance of the whole circuit; L, its +coefficient of self-induction; and <i>e</i> the number 2.7183, +which is the base of the Napierian logarithms. Let us look at this +formula; in its general form it resembles Ohm's law, but with a new +factor, namely, the expression contained within the brackets. The +factor is necessarily a fractional quantity, for it consists of +unity less a certain negative exponential, which we will presently +further consider. If the factor within brackets is a quantity less +than unity, that signifies that <i>i<sub>t</sub></i> will be less +than E ÷ R. Now the exponential of negative sign, and with +negative fractional index, is rather a troublesome thing to deal +with in a popular lecture. Our best way is to calculate some +values, and then plot it out as a curve. When once you have got it +into the form of a curve, you can begin to think about it, for the +curve gives you a mental picture of the facts that the long formula +expresses in the abstract. Accordingly we will take the following +case. Let E = 2 volts; R = 1 ohm; and let us take a relatively +large self-induction, so as to exaggerate the effect; say let L = +10 quads. This gives us the following:</p> + +<div class="ctr"> +<table border="0" width="40%" cellspacing="5" summary=""> +<colgroup span="3" align="right"></colgroup> + +<tr> +<th>t<sub>(sec.)</sub></th> +<th>e<sup>+(R/L)t</sup></th> +<th>i<sub>t</sub></th> +</tr> + +<tr> +<td>0</td> +<td>1</td> +<td>0</td> +<td></td> +</tr> + +<tr> +<td>1</td> +<td>1.105</td> +<td>0.950</td> +</tr> + +<tr> +<td>2</td> +<td>1.221</td> +<td>1.810</td> +</tr> + +<tr> +<td>5</td> +<td>1.649</td> +<td>3.936</td> +</tr> + +<tr> +<td>10</td> +<td>2.718</td> +<td>6.343</td> +</tr> + +<tr> +<td>20</td> +<td>7.389</td> +<td>8.646</td> +</tr> + +<tr> +<td>30</td> +<td>20.08</td> +<td>9.501</td> +</tr> + +<tr> +<td>60</td> +<td>403.4</td> +<td>9.975</td> +</tr> + +<tr> +<td>120</td> +<td>16200.0</td> +<td>9.999</td> +</tr> +</table> +</div> + +<p>In this case the value of the steady current as calculated by +Ohm's law is 10 amperes, but Helmholtz's law shows us that with the +great self-induction which we have assumed to be present, the +current, even at the end of 30 seconds, has only risen up to within +5 percent. of its final value; and only at the end of two minutes +has practically attained full strength. These values are set out in +the highest curve in Fig. 54, in which, however, the further +supposition is made that the number of spirals, S, in the coils of +the electromagnet is 100, so that when the current attains its full +value of 10 amperes, the full magnetizing power will be S<i>i</i> = +1000. It will be noticed that the curve rises from zero at first +steeply and nearly in a straight line, then bends over, and then +becomes nearly straight again, as it gradually rises to its +limiting value. The first part of the curve—that relating to +the strength of the current after <i>very small</i> interval of +time—is the period within which the strength of the current +is governed by inertia (i.e., the self-induction) rather than by +resistance. In reality the current is not governed either by the +self-induction or by the resistance alone, but by the ratio of the +two. This ratio is sometimes called the "time constant" of the +circuit, for it represents <i>the time</i> which the current takes +in that circuit to rise to a definite fraction of its final +value.</p> + +<p class="ctr"><img src="./images/7-fig54.png" alt= +"FIG. 54.—CURVES OF RISE OF CURRENTS." title="FIG. 54" /><br +clear="all" /> + FIG. 54.—CURVES OF RISE OF CURRENTS.</p> + +<p>This definite fraction is the fraction (e - 1)/e; or in +decimals, 0.634. All curves of rise of current are alike in general +shape, they differ only in scale, that is to say, they differ only +in the height to which they will ultimately rise, and in the time +they will take to attain this fraction of their final value.</p> + +<p><i>Example (1).</i>—Suppose E = 10; R = 200 ohms; L = 8. +The final value of the current will be 0.025 amp. or 25 +milliamperes. Then the time constant will be 8 ÷ 400 = +1-50th sec.</p> + +<p><i>Example (2).</i>—The P.O. Standard "A" relay has R = +400 ohms; L = 3.25. It works with 0.5 milliampere current, and +therefore will work with 5 Daniell cells through a line of 9,600 +ohms. Under these circumstances the time constant of the instrument +on short circuit is 0.0081 sec.</p> + +<p>It will be noted that the time constant of a circuit can be +reduced either by diminishing the self-induction or by increasing +the resistance. In Fig. 54 the position of the time constant for +the top curve is shown by the vertical dotted line at 10 seconds. +The current will take 10 seconds to rise to 0.634 of its final +value. This retardation of the rise of current is simply due to the +presence of coils and electromagnets in the circuit; the current as +it grows being retarded because it has to create magnetic fields in +these coils, and so sets up opposing electromotive forces that +prevent it from growing all at once to its full strength. Many +electricians, unacquainted with Helmholtz's law, have been in the +habit of accounting for this by saying that there is a lag in the +iron of the electromagnet cores. They tell you that an iron core +cannot be magnetized suddenly, that it takes time to acquire its +magnetism. They think it is one of the properties of iron. But we +know that the only true time lag in the magnetization of iron, that +which is properly termed "viscous hysteresis," does not amount to +any great percentage of the whole amount of magnetization, takes +comparatively a long time to show itself, and cannot therefore be +the cause of the retardation which we are considering. There are +also electricians who will tell you that when magnetization is +suddenly evoked in an iron bar, there are induction currents set up +in the iron which oppose and delay its magnetization. That they +oppose the magnetization is perfectly true, but if you carefully +laminate the iron so as to eliminate eddy currents, you will find, +strangely enough, that the magnetism rises still more slowly to its +final value. For by laminating the iron you have virtually +increased the self-inductive action, and increased the time +constant of the circuit, so that the currents rise more slowly than +before. The lag is not in the iron, but in the magnetizing current, +and the current being retarded, the magnetization is of course +retarded also.</p> + +<h3>CONNECTING COILS FOR QUICKEST ACTION.</h3> + +<p>Now let us apply these most important though rather intricate +considerations to the practical problems of the quick working of +the electromagnet. Take the case of an electromagnet forming some +part of the receiving apparatus of a telegraph system in which it +is desired to secure very rapid working. Suppose the two coils that +are wound upon the horseshoe core are connected together in series. +The coefficient of self-induction for these two is four times as +great as that of either separately; coefficients of self-induction +being proportional to the square of the number of turns of wire +that surround a given core. Now if the two coils instead of being +put in series are put in parallel, the coefficient of +self-induction will be reduced to the same value as if there were +only one coil, because half the line current (which is practically +unaltered) will go through each coil. Hence the time constant of +the circuit when the coils are in parallel will be a quarter of +that which it is when the coils are in series; on the other hand, +for a given line current, the final magnetizing power of the two +coils in parallel is only half what it would be with the coil in +series. The two lower curves in Fig. 54 illustrate this, from which +it is at once plain that the magnetizing power for very brief +currents is greater when the two coils are put in parallel with one +another than when they are joined in series.</p> + +<p>Now this circumstance has been known for some time to telegraph +engineers. It has been patented several times over. It has formed +the theme of scientific papers, which have been read both in France +and in England. The explanation generally given of the advantage of +uniting the coils in parallel is, I think, fallacious; namely that +the "extra currents" (i.e., currents due to self-induction) set up +in the two coils are induced in such directions as tend to help one +another when the coils are in series, and to neutralize one another +when they are in parallel. It is a fallacy, because in neither case +do they neutralize one another. Whichever way the current flows to +make the magnetism, it is opposed in the coils while the current is +rising, and helped in the coils while the current is falling, by +the so-called extra currents. If the current is rising in both +coils at the same moment, then, whether the coils are in series or +in parallel, the effect of self-induction is to retard the rise of +the current. The advantage of parallel grouping is simply that it +reduces the time constant.</p> + +<h3>BATTERY GROUPING FOR QUICKEST ACTION.</h3> + +<p>One may consider the question of grouping the battery cells from +the same point of view. How does the need for rapid working, and +the question of time constant, affect the best mode of grouping the +battery cells? The amateur's rule, which tells you to so arrange +your battery that its internal resistance should be equal to the +external resistance, gives you a result wholly wrong for rapid +working. The supposed best arrangement will not give you (at the +expense even of economy) the best result that might be got out of +the given number of cells. Let us take an example and calculate it +out, and place the results graphically before our eyes in the form +of curves. Suppose the line and electromagnet have together a +resistance of 6 ohms, and that we have 24 small Daniell cells, each +of electromotive force say 1 volt, and of internal resistance 4 +ohms. Also let the coefficient of self-induction of the +electromagnet and circuit be 6 quadrants. When all the cells are in +series, the resistance of the battery will be 96 ohms, the total +resistance of the circuit 102 ohms, and the full value of the +current 0.235 ampere. When all the cells are in parallel, the +resistance of the battery will be 0.133 ohm, the total resistance +6.133 ohms, and the full value of the current 0.162 ampere. +According to the amateur rule of grouping cells so that internal +resistance equals external, we must arrange the cells in 4 +parallels, each having 6 cells in series, so that the internal +resistance of the battery will be 6 ohms, total resistance of +circuit 12 ohms, full value of current 0.5 ampere. Now the +corresponding time constants of the circuit in the three cases +(calculated by dividing the coefficient of self-induction by the +total resistance) will be respectively—in series, 0.06 sec.; +in parallel, 0.5 sec.; grouped for maximum steady current, 0.96 +sec. From these data we may now draw the three curves, as in Fig. +55, wherein the abscissæ are the values of time in seconds +and the ordinates the current. The faint vertical dotted lines mark +the time constants in the three cases. It will be seen that when +rapid working is required the magnetizing current will rise, during +short intervals of time, more rapidly if all the cells are put in +series than it will do if the cells are grouped according to the +amateur rule.</p> + +<p class="ctr"><img src="./images/8-fig55.png" alt= +"FIG. 55.—CURVES OF RISE OF CURRENT WITH DIFFERENT GROUPINGS OF BATTERY." + title="FIG. 55" /><br /> + FIG. 55.—CURVES OF RISE OF CURRENT WITH DIFFERENT GROUPINGS +OF BATTERY.</p> + +<p>When they are all put in series, so that the battery has a much +greater resistance than the rest of the circuit, the current rises +much more rapidly, because of the smallness of the time constant, +although it never attains the same ultimate maximum as when grouped +in the other way. That is to say, if there is self-induction as +well as resistance in the circuit, the amateur rule does not tell +you the best way of arranging the battery. There is another mode of +regarding the matter which is helpful. Self-induction, while the +current is growing, acts as if there were a sort of spurious +addition to the resistance of the circuit; and while the current is +dying away it acts of course in the other way, as if there were a +subtraction from the resistance. Therefore you ought to arrange the +battery so that the internal resistance is equal to the real +resistance of the circuit, plus the spurious resistance during that +time. But how much is the spurious resistance during that time? It +is a resistance proportional to the time that has elapsed since the +current was turned on. So then it comes to a question of the length +of time for which you want to work it. What fraction of a second do +you require your signal to be given in? What is the rate of the +vibrator of your electric bell? Suppose you have settled that +point, and that the short time during which the current is required +to rise is called t; then the apparent resistance at time t after +the current is turned on is given by the formula:</p> + +<p class="ctr">R<sub>t</sub> = R × e<sup>(R/L)t</sup> + ( +e<sup>(R/L)t</sup> - 1 )</p> + +<h3>TIME CONSTANTS OF ELECTROMAGNETS.</h3> + +<p>I may here refer to some determinations made by M. Vaschy,<a id= +"FNanchor_4b" name="FNanchor_4b"></a><a href= +"#Footnote_4b"><sup>4</sup></a> respecting the coefficients of +self-induction of the electromagnets of a number of pieces of +telegraphic apparatus. Of these I must only quote one result, which +is very significant. It relates to the electromagnet of a Morse +receiver of the pattern habitually used on the French telegraph +lines.</p> + +<div class="ctr"> +<table align="center" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="2"> +<col align="left" /> +<col span="2" align="right" /></colgroup> + +<tr> +<td></td> +<td colspan="2">L, in quadrants.</td> +</tr> + +<tr> +<td>Bobbins, separately, without iron cores.</td> +<td>0.233</td> +<td>and 0.265</td> +</tr> + +<tr> +<td>Bobbins, separately, with iron cores.</td> +<td>1.65</td> +<td>and 1.71</td> +</tr> + +<tr> +<td>Bobbins, with cores joined by yoke, coils in series</td> +<td>6.37</td> +</tr> + +<tr> +<td>Bobbins, with armature resting on poles.</td> +<td>10.68</td> +</tr> +</table> +</div> + +<p>It is interesting to note how the perfecting of the magnetic +circuit increases the self-induction.</p> + +<p>Thanks to the kindness of Mr. Preece, I have been furnished with +some most valuable information about the coefficients of +self-induction, and the resistance of the standard pattern of +relays, and other instruments which are used in the British postal +telegraph service, from which data one is able to say exactly what +the time constants of those instruments will be on a given circuit, +and how long in their case the current will take to rise to any +given fraction of its final value. Here let me refer to a very +capital paper by Mr. Preece in an old number of the "Journal of the +Society of Telegraph Engineers," a paper "On Shunts," in which he +treats this question, not as perfectly as it could now be treated +with the fuller knowledge we have in 1890 about the coefficients of +self-induction, but in a very useful and practical way. He showed +most completely that the more perfect the magnetic circuit +is—though of course you are getting more magnetism from your +current—the more is that current retarded. Mr. Preece'e mode +of experiment was extremely simple. He observed the throw of the +galvanometer when the circuit which contained the battery and the +electromagnet was opened by a key which at the same moment +connected the electromagnet wires to the galvanometer. The throw of +the galvanometer was assumed to represent the extra current which +flowed out. Fig. 56 represents a few of the results of Mr. Preece's +paper.</p> + +<p class="ctr"><img src="./images/8-fig56.png" alt= +" FIG. 56.—ELECTROMAGNETS OF RELAY, AND THEIR EFFECTS." +title="FIG. 56" /><br /> + FIG. 56.—ELECTROMAGNETS OF RELAY, AND THEIR EFFECTS.</p> + +<p>Take from an ordinary relay a coil, with its iron core, half the +electromagnet, so to speak, without any yoke or armature. Connect +it up as described, and observe the throw given to the +galvanometer. The amount of throw obtained from the single coil was +taken as unity, and all others were compared with it. If you join +up two such coils as they are usually joined, in series, but +without any iron yoke across the cores, the throw was 17. Putting +the iron yoke across the cores, to constitute a horseshoe form, 496 +was the throw; that is to say, the tendency of this electromagnet +to retard the current was 496 times as great as that of the simple +coil. But when an armature was put over the top, the effect ran up +to 2,238. By the mere device of putting the coils in parallel, +instead of in series, the 2,238 came down to 502, a little less +than the quarter value which would have been expected. Lastly, when +the armature and yoke were both of them split in the middle, as is +done in fact in all the standard patterns of the British postal +telegraph relays, the throw of the galvanometer was brought down +from 502 to 26. Relays so constructed will work excessively +rapidly. Mr. Preece states that with the old pattern of relay +having so much self-induction as to give a galvanometer throw of +1,688, the speed of signaling was only from 50 to 60 words per +minute, whereas, with the standard relays constructed on the new +plan, the speed of signaling is from 400 to 450 words per minute. +It is a very interesting and beautiful result to arrive at from the +experimental study of these magnetic circuits.</p> + +<h3>SHORT CORES <i>versus</i> LONG CORES.</h3> + +<p>In considering the forms that are best for rapid action, it +ought to be mentioned that the effects of hysteresis in retarding +changes in the magnetization of iron cores are much more noticeable +in the case of nearly closed magnetic circuits than in short +pieces. Electromagnets with iron armatures in contact across their +poles will retain, after the current has been cut off, a very large +part of their magnetism, even if the cores be of the softest of +iron. But so soon as the armature is wrenched off, the magnetism +disappears. An air gap in a magnetic circuit always tends to hasten +demagnetizing. A magnetic circuit composed of a long air path and a +short iron path demagnetizes itself much more rapidly than one +composed of a short air path and a long iron path. In long pieces +of iron the mutual action of the various parts tends to keep in +them any magnetization that they may possess; hence they are less +readily demagnetized. In short pieces, where these mutual actions +are feeble or almost absent, the magnetization is less stable, and +disappears almost instantly on the cessation of the magnetizing +force. Short bits and small spheres of iron have no magnetic +memory. Hence the cause of the commonly received opinion among +telegraph engineers that for rapid work electromagnets must have +short cores. As we have seen, the only reason for employing long +cores is to afford the requisite length for winding the wire which +is necessary for carrying the needful circulation of current to +force the magnetism across the air gaps. If, for the sake of +rapidity of action, length has to be sacrificed, then the coils +must be heaped up more thickly on the short cores. The +electromagnets in American patterns of telegraphic apparatus +usually have shorter cores, and a relatively greater thickness of +winding upon them, than those of European patterns.</p> + +<a id="Footnote_1b" name="Footnote_1b"></a><a href= +"#FNanchor_1b">[1]</a> + +<div class="note">Lectures delivered before the Society of Arts, +London, 1890. From the Journal of the Society.</div> + +<a id="Footnote_2b" name="Footnote_2b"></a><a href= +"#FNanchor_2b">[2]</a> + +<div class="note">"La Lumiere Electrique," vol. ii.</div> + +<a id="Footnote_3b" name="Footnote_3b"></a><a href= +"#FNanchor_3b">[3]</a> + +<div class="note">"La Lumiere Electrique," vol. iv., p. 129.</div> + +<a id="Footnote_4b" name="Footnote_4b"></a><a href= +"#FNanchor_1c">[1]</a> + +<div class="note">"Bulletin de la Societe Internationale des +Electriciens," 1886.</div> + +<hr /> +<h2><a id="iii_2" name="iii_2"></a>ELECTRIC ERYGMASCOPE.</h2> + +<p>The erygmascope is the name of an electric lighting apparatus +designed for the examination of the strata of earth traversed by +boring apparatus.</p> + +<p>It consists of a very powerful incandescent lamp inclosed in a +metallic cylinder. One of the two semi-cylindrical sides +constitutes the reflector, and the other, which is of thick glass, +allows of the passage of the luminous rays, which thus illuminate +with great brilliancy the strata of earth traversed by the +instrument. The base, which is inclined at an angle of 45°, is +an elliptical mirror, and the top, of straight section, is open in +order to permit the observer standing at the mouth of the well, and +provided with a powerful spyglass, to see in the mirror the image +of the earth. The lamp is so mounted that its upwardly emitted rays +are intercepted.</p> + +<p>The whole apparatus is suspended from a long cable, formed of +two conducting wires, which winds around a windlass with metallic +journals which are electrically insulated. These journals +communicate, through the intermedium of two friction springs, with +the conductors on the one hand and, on the other, with the poles of +an automatic and portable battery.</p> + +<p class="ctr"><a href="./images/8-scope.png"><img src= +"./images/8-scope_th.jpg" alt="THE TROUVE ERYGMASCOPE." title= +"ERYGMASCOPE" /></a><br clear="all" /> + THE TROUVE ERYGMASCOPE.</p> + +<p>This permits of lowering and raising the apparatus at will, +without derangement, and without its being necessary to interrupt +the light and the observation.—<i>Revue Industrielle.</i></p> + +<hr /> +<h2><a id="iii_1" name="iii_1"></a>A NEW ELECTRIC BALLISTIC +TARGET.</h2> + +<p>The electrical target usually employed in determining velocities +of projectiles consists of a wooden frame on which is strung a +copper wire so as to make a continuous circuit arranged in parallel +vertical lines about one inch or one and one half inches apart.</p> + +<p>It frequently happens that a projectile will pass through this +target without breaking the circuit, either by squeezing between +the wires or because, when last repaired, the target was +short-circuited unnoticed, so that the cutting of the wires did not +break the circuit. The repair of this target takes considerable +time.</p> + +<p class="ctr"><a href="./images/8-target.png"><img src= +"./images/8-target_th.jpg" alt="BALLISTIC TARGET." title= +"TARGET" /></a></p> + +<p>Besides these objections to this target, another and more +serious one is the irregularity in the manner of breaking the +circuit. It has been proved that times required for a flat headed +and an ogival headed projectile to rupture the current are very +different.</p> + +<p>To remedy these defects a new and very ingenious target has been +devised and used with great success at the United States Military +Academy at West Point. The top of the target is a wooden strip, F, +on the upper side of which are screwed strips of copper, A A, about +1/2 in. wide, and 1/8 in. thick. The connection between two +adjoining strips is made by a copper cartridge, C, which is dropped +in a hole in the frame bored to receive it. This cartridge is the +one used in the Springfield rifle. Inside the cartridge is a spiral +spring, S, which, acting on the bottom of the hole and the head of +the cartridge, tends to make the latter spring up, and so break the +circuit.</p> + +<p>To the hook, H, which is attached to the cartridge, is +suspended, by means of a string, the lead weight, W, thus drawing +down the cartridge and making the circuit between A and A'. All the +weights being suspended the current comes in through the post, P, +passes along the copper strips and out of the corresponding post on +the other end.</p> + +<p>On firing the projectile cuts a string, and the spring at once +causes the cartridge to spring up, thus breaking the circuit.</p> + +<p>It is not possible for the projectile to squeeze between the +strings and not break the current, for in so doing the cartridge is +tipped slightly, which is sufficient, as it breaks the current on +one side.</p> + +<p>This target is used in connection with the Boulenge chronograph. +Two targets are established at a known distance apart, say 50 ft., +and the time required for the projectile to pass over this distance +is determined by finding the difference in the time of cutting of +the two targets, by finding the difference in the time of falling +of the two rods, caused by the demagnetization of two +electromagnets in the same circuit with the targets.</p> + +<p>By means of a disjunctor both rods are dropped at the same time, +the shorter one releasing a knife blade which makes a cut on the +longer one. Now both rods are hung from the magnets again and the +gun is fired.</p> + +<p>The projectile passes through the first target, breaks the +circuit, demagnetizes the magnet of the longer rod, and it begins +to fall. On passing through the second target, the projectile +causes the shorter rod to fall. This releases the knife blade, and +a second cut is made. The time corresponding to the distance +between these cuts is the time the longer rod was falling before +the second rod began to fall or the time between the cutting of the +two targets by the projectile.</p> + +<p>The distance between the cuts is measured, and the time +corresponding to it can easily be found. Then the velocity of the +projectile is equal to 50/t.</p> + +<p>To repair this target, strings are prepared in advance of +suitable length and looped at both ends, so that by placing the +hook of the cartridge in one loop and that of the weight in the +other the repair is quickly made.</p> + +<p>This target has been used on the West Point proving ground to +determine velocities over distances of 100 ft. interval to +distances of only 9 ft. interval, and has given most satisfactory +results.</p> + +<hr /> +<p class="ctr">[Continued from SUPPLEMENT, No. 786, page +12566.]</p> + +<h2><a id="iv_2" name="iv_2"></a>THE OUTLOOK FOR APPLIED +ENTOMOLOGY.<a id="FNanchor_1c" name="FNanchor_1c"></a><a href= +"#Footnote_1c"><sup>1</sup></a></h2> + +<h3>LEGISLATION.</h3> + +<p>The amount of legislation in different countries that has of +late years been deemed necessary or sufficiently important, in view +of injurious insects, is a striking evidence of the increased +attention paid to applied entomology; and while modern legislation +of this kind has been, on the whole, far more intelligent than +similar efforts in years gone by, many of the laws passed have +nevertheless been unwise, futile, and impracticable, and even +unnecessarily oppressive to other interests. The chief danger here +is the intervention of politics or political methods. Expert +counsel should guide our legislators and the steps taken should be +thorough in order to be effective. We have had of late years in +Germany very good evidence of the excellent results flowing from +thorough methods, and the recent legislation in Massachusetts +against the gypsy moth (<i>Ocneria dispar</i>), which at one time +threatened to become farcical, has, fortunately, proved more than +usually successful; the commission appointed to deal with the +subject having worked with energy and followed competent +advice.</p> + +<h3>PUBLICATION.</h3> + +<p>On the question of publication of the results of our labors it +is perhaps premature to dwell at length. Each of the experiment +stations is publishing its own bulletins and reports quite +independently of the others, but after a uniform plan recommended +by the association with which we meet here; and with but one +exception that has come to my notice, another important +recommendation of the same association—that these +publications shall be void of all personal matter—has been +kept in mind. The National Bureau of Experiment Stations at +Washington is doing what it can with the means at command to +further the general work by issuing the Experiment Station Record, +devoted chiefly to digests of the State station bulletins. There is +a serious question in my mind as to the utility of State digests by +the national department of results already published extensively by +the different States and distributed under government frank to all +similar institutions and to whomsoever is interested enough to ask +for them.</p> + +<p>Such digests may or may not be intelligently made, and, even +under the most favorable circumstances, will hardly serve any other +purpose than helping to the reference to the original articles, and +this could undoubtedly be done more satisfactorily to the stations +and to the people at large by general and classified indices to all +the State documents, made as full as possible and issued at stated +intervals. Only a small proportion of the bulletins have been so +far noticed by digest in this record, with no particular rule, so +far as I can see, in the selection. In point of fact, those will be +most apt to be noticed whose authors can find time to themselves +send or make for the purpose their own abstracts. This is, perhaps, +inevitable under present arrangements. Complete and satisfactory +digests of all, if intelligent and critical, imply a far greater +force than is at present at Prof. Atwater's command.</p> + +<p>Under these circumstances, it would seem wiser to devote all the +energies of the bureau to digests of the similar literature of +other countries, which would be of immense advantage to our people +and to the different station workers. Judging from the +recommendations and resolutions of the general association, this is +the view very generally held, but except in chemistry and special +industries like that of beet sugar, very little of that kind of +work has yet been attempted.</p> + +<p>What is true of the station publications in general is equally +true of special publications. As entomologist of the department, I +have been urged to bring together, at stated intervals, digests of +the entomological publications of the different stations. Such +digests to be of any value, however, should also be critical, and +it were a thankless task for any one to be critic or censor even of +that which needs correction or criticism. Moreover, to do this work +intelligently would require increase of the divisional force, which +at present is more advantageously employed, for, as already +intimated, I should have great doubts of the utility of these +digests.</p> + +<p>I believe, however, that the division should strive for such +increase of means as would justify the periodic publication, either +independently or as a part of the department record, of general and +classified indices to the entomological matter of the station +bulletins, and should work more and more toward giving results from +other parts of the world. This could, perhaps, best be done by +titles of subject and of author so spaced and printed on stout +paper that they could be cut and used in the ordinary card +catalogue. The recipient could cut and systematically place the +titles as fast as received.</p> + +<p>As to the character of the matter of the entomological +bulletins, it will inevitably be influenced by the needs and +demands of the people of the respective States, and while +originality should be kept in mind, there must needs be in the +earlier years of the work much restatement of what is already well +known. That some results have been published of work which reflects +no particular credit upon our calling is a mere incident of the new +positions created. Yet we may expect marked improvement from year +to year in this direction, and without being invidious, I would +cite those of Prof. Gillette's on his spraying experiments and on +the plum curculio and plum gouger, as models of what such bulletins +should be.</p> + +<p>Although the resolution offered at our last meeting by Prof. +Cook, to the effect that purely descriptive matter should be +excluded from the station bulletins, met with no favor, but was +laid on the table, by the general association, I am in full +sympathy with this position and am strongly of the opinion that in +the ordinary bulletins such purely technical and descriptive matter +should be reduced to the necessary minimum consistent with +clearness of statement and accuracy, and that if it is desired, on +the part of the station entomologists, to issue technical and +descriptive papers, a separate series of bulletins were better +instituted for this class of matter.</p> + +<p>Finally, for results which it is desired to promptly get before +the people, the agricultural press is at our disposal, and so far +as the entomological work of the department of agriculture is +concerned, the periodical bulletin, <i>Insect Life</i>, was +established for this purpose. Its columns are open to all station +workers, and I would here appeal to the members of the association +to help make it, as far as possible, national, by sending brief +notes and digests of their work as it progresses. Hitherto we have +been unable to make as much effort in this direction as we desired, +but in future it is our hope to make the bulletin, as far as +possible, a national medium through which the results of work done +in all parts of the country may quickly be put on record and +distributed, not only to all parts of our own country, but to all +parts of the world.</p> + +<p>The rapid growth and development of the national department and +the multiplication of its divisions have necessitated special modes +of publication and rendered the annual report almost an anachronism +so far as it pretends to be what it at one time was—a pretty +complete report of the scientific and other work of the department. +The attempts which I have made through the proper authorities to +get Congress to order more pretentious monographic works in quarto +volume similar to those issued by other departments of the +government have not met with encouragement, and in this direction +many of the stations will, let us hope, be able to do better.</p> + +<h3>CO-OPERATION.</h3> + +<p>Every other subject that might be considered on this occasion +must be subordinate to the one great question of co-operation. With +the large increase of actual workers in our favorite field, +distributed all over the country, the necessity for some +co-operation and co-ordination must be apparent to every one. Just +how this should be brought about or in what direction we may work +toward it, will be for this association in its deliberations to +decide. Nor will I venture to anticipate the deliberations and +conclusions of the special committee appointed to take the matter +into consideration, beyond the statement that there are many +directions in which we can adopt plans for mutual benefit. Take, +for instance, the introduction and dissemination of parasites. How +much greater will be the chance of success in any particular case +if we have all the different station entomologists interested in +some specific plan to be carried out in co-operation with the +national department, which ought to have better facilities of +introducing specimens to foreign countries or to different sections +of our own country than any of the State stations.</p> + +<p>Let us suppose that the fruit growers of one section of the +country, comprising several States in area, need the benefit in +their warfare against any particularly injurious insect of such +natural enemy or enemies as are known to help the fruit growers of +some other section. There will certainly be much greater chances of +success in the carrying out of any scheme of introduction if all +the workers in the one section may be called upon through some +central or national body to help in the introduction and +disposition of the desired material into the other section. Or, +take the case of the boll worm investigation already alluded to. +The chances of success would be much greater if the entomologists +in all the States interested were to give some attention to such +lepidopterous larvæ as are found to be affected with +contagious diseases and to follow out some specific plan of +cultivating and transmitting them to the party or parties with whom +the actual trials are intrusted. The argument applies with still +greater force to any international efforts. I need hardly multiply +instances. There is, it is true, nothing to prevent any individual +station entomologist from requesting co-operation of the other +stations, nor is there anything to prevent the national department +from doing likewise; but in all organization results are more apt +to flow from the power to direct rather than from mere liberty to +request or to plead. The station entomologist may be engrossed in +some line of research which he deems of more importance to the +people of his State, and may resent being called upon to divert his +energies; and with no central or national power to decide upon +plans of co-operation for the common weal, we are left to voluntary +methods, mutually devised, and it is here that this association +can, it seems to me, most fully justify its organization. And this +brings me to the question of</p> + +<h3>THE DEPARTMENT AND THE STATIONS.</h3> + +<p>Immediately connected with the question of co-operation is the +relation of the National Department of Agriculture and the State +experiment stations. The relation, instead of being vital and +authoritative, is, in reality, a subordinate one. Many persons +interested in the advancement of agriculture foresaw the advantage +of having experiment stations attached to the State agricultural +colleges founded under the Morrill act of 1862; but I think that in +the minds of most persons the establishment of these stations +implied some such connection with the national department as that +outlined in an address on Agricultural Advancement in the United +States, which I had the honor to deliver in 1879 before the +National Agricultural Congress, at Rochester, and in which the +following language was used:</p> + +<blockquote> +<p>"In the light of the past history of the German experimental +stations and their work, or of that in our own State of +Connecticut, the expediency of purchasing an experimental farm of +large dimensions in the vicinity of Washington is very +questionable. There can be no doubt, however, of the value of a +good experimental station there that shall have its branches in +every State of the Union. The results to flow from such stations +will not depend upon the number of acres at command, and it will be +far wiser and more economical for the commissioner to make each +agricultural college that accepted the government endowment +auxiliary to the national bureau, so that the experimental farm +that is now, or should be, connected with each of these +institutions might be at its service and under the general +management of the superintendent of the main station. There is +reason to believe that the directors of these colleges would +cheerfully have them constituted as experimental stations under the +direction of the department, and thus help to make it really +national—the head of a vast system that should ramify through +all parts of the land....</p> + +<p>"With the different State agricultural colleges, and the State +agricultural societies, or boards, we have every advantage for +building up a national bureau of agriculture worthy of the country +and its vast productive interests, and on a thoroughly economical +basis, such as that of Prussia, for instance."</p> +</blockquote> + +<p>In short, the view in mind was something in the nature of that +which has since been adopted by our neighbors of the North, where +there is a central or national station or farm at Ottawa and +sub-stations or branch farms at Nappan, Nova Scotia, Brandon, +Manitoba, Indian Head, N.W.T., and Agassiz, British Columbia, all +under the able direction of Mr. William Saunders, one of our +esteemed fellow workers. It was my privilege to be a good deal with +Mr. Saunders when he was in Europe studying the experience of other +countries in this matter, and the policy finally adopted in Canada +as a result of his labors is an eminently wise one, preventing some +of the difficulties and dangers which beset our plan, whether as +between State and nation or college and station.</p> + +<p>Under the present laws and with the vast influence which the +Association of Agricultural Colleges and Experiment Stations will +wield, both in Congress and in the different States, there is great +danger of transposition, in this agricultural body politic, of +those parts which in the animal body are denominated head and tail, +and the old saw to the effect that "the dog wags the tail because +the tail cannot wag the dog," will find another application. So far +as the law goes, the national department, which should hold a truly +national position toward State agricultural institutions depending +on federal support, can do little except by suggestion, whether in +the line of directing plans or in any way co-ordinating or +controlling the work of the different stations throughout the +country. The men who influenced and shaped the legislation which +resulted in the Hatch bill were careful that the department's +function should be to indicate, not to dictate; to advise and +assist, not to govern or regulate. We have, therefore, to depend on +such relationships and such plans of co-operation as will appear +advantageous to all concerned, and these can best be brought about +through such associations as are now in convention here.</p> + +<p>Without such plans there is great danger of such waste of energy +and means and duplication of results as will bring the work into +popular disfavor and invite disintegration, for already there is a +growing feeling that agricultural experiment is and will be +subordinated to the ordinary college work in the disposition of the +federal appropriations.</p> + +<p>What is true of the national department as a whole in its +connection with the State stations is true in a greater or less +degree of the different divisions of the department in connection +with the different specialists of the stations. With the +multiplicity of workers in any given direction in the different +States, the necessity for national work lessens. A favorite scheme +of mine in the past, for instance (and one I am glad to say fully +indorsed by Prof. Willits), was to endeavor to have a permanent +agent located in every section of the country that was sufficiently +distinctive in its agricultural resources and climate, or, as a yet +further elaboration of the same plan, one in each of the more +important agricultural States. The necessity for such State agents +has been lessened, if not obviated, by the Hatch bill, and the +subsequent modifications looking to permanent appropriations to the +State stations or colleges, which give no central power at +Washington. The question then arises, What function shall the +national department perform? Its influence and field for usefulness +have been lessened rather than augmented in the lines of actual +investigation in very many directions. Many a State is already far +better equipped both as to valuable surrounding land, laboratory +and library facilities, more liberal salaries, and greater freedom +from red tape, administrative routine, and restrictions as to +expenditures, than we are at Washington; and, except as a directing +agent and a useful servant, I cannot see where the future growth of +the department's influence is to be outside of those federal +functions which are executive. Just what that directing influence +is to be is the question of the hour, not only in the broader but +in the special sense. The same question, in a narrower sense, had +arisen in the case of the few States which employed State +entomologists. In the event, for instance, of an outbreak of some +injurious insect, or in the event of any particular economic +entomological question within the limits of the State having such +an officer, the United States entomologist would naturally feel +that any effort on his part would be unnecessary, or might even be +looked upon as an interference. He would feel that there was always +danger of mere duplication of observation or experiment, except +where appealed to for aid or co-operation. This is, perhaps, true +only of insects which are local or sectional, and is rather a +narrow view of the matter, but it is one brought home from +experience, and is certainly to be considered in our future plans. +The favor with which the museum work of the national division was +viewed by you at the meeting last November and the amount of +material sent on for determination would indicate that the building +up of a grand national reference collection will be most useful to +the station workers. But to do this satisfactorily we need your +co-operation, and I appeal to all entomologists to aid in this +effort by sending duplicates of their types to Washington, and thus +more fully insuring against ultimate loss thereof.</p> + +<h3>STATUS OF OUR SOCIETY.</h3> + +<p>This train of thought brings up the question of the status of +our society with the station entomologists as represented by the +committee of the general association. Those of us who had desired a +national association for the various purposes for which such +associations are formed, felt, I believe, if I may speak for them, +that the creation of the different experimental stations rendered +such an organization feasible. Your organization at Toronto and the +constitution adopted and amended at the meeting at Washington all +indicate that the chief object was the advancement of our chosen +work and that the strength of the association would come from the +experiment station entomologists. There was then no other +organization of the kind, nor any intimation that such a one would +be founded. Some of us therefore were surprised to learn from the +circular sent out by Prof. Forbes, its chairman, that the committee +appointed by the association of agricultural colleges and +experiment stations, and through which we had hoped to communicate +and co-operate with that association, was not in the proper sense a +committee, but a section which has prepared (and in fact was +required by the executive committee and the rules of the superior +body to prepare) a programme of papers and discussions for the +meeting to be held at the same time and place with our own. I +cannot but feel that this is in some respects a misfortune, and it +will devolve upon you to decide upon several questions of +importance that will materially affect our future existence. That +there is not room for two national organizations having the same +objects in view and meeting at the same time and place goes, I +think, without saying; and if the committee of the general +association is to be anything more than a committee in the proper +sense of the word, or if it is to assume with or without formal +constitution the functions of our own association, then our own +must necessarily be crippled, and to do any good at all must meet +at a different time and a different place. A committee or section, +or whatever it may be called, of the general association with which +we meet, would preclude active membership of any but those who come +within the constitution of that body. Our Canadian friends and many +others who have identified themselves with applied entomology, and +do not belong to any of our State or government institutions, would +be debarred from active representation, however liberal the +association may have been in inviting such to participate, without +power to vote in its deliberations. Our own association has, or +should have, no such limitations. Some of us who are entitled to +membership in both bodies may feel indifferent as to the course +finally decided upon, and that it will not make any difference +whether we have an outside and independent organization, as that of +the association of official chemists, or whether we do, as did the +botanists and horticulturists, waive independence in favor of more +direct connection with the general association, provided there is +some way whereby the committees of the general association are +given sufficient latitude and time to properly present their papers +and deliberate; but there are others who feel more sensitive as to +their action and are more immediately influenced by the feelings of +the main body. I hope that whatever action be taken at this +meeting, the general good and the promotion of economic entomology +will be kept in mind and that no sectional or personal feeling will +be allowed to influence our deliberations.</p> + +<h3>SUGGESTION AND COMMENT.</h3> + +<p>You will, I know, pardon me if, before concluding these remarks, +I venture to make a few comments which, though not altogether +agreeable, are made in all sincerity and in the hope of doing good. +The question as to how far purely technical and especially +descriptive and monographic work should be done by the different +stations or by the national department is one which I have already +alluded to and upon which we shall probably hold differing +opinions, and which will be settled according to the views of the +authorities at the different stations. Individually, I have ever +felt that one ostensibly engaged in applied entomology and paid by +the State or national government to the end that he may benefit the +agricultural community can be true to his trust only by largely +overcoming the pleasure of entomological work having no practical +bearing. I would, therefore, draw the line at descriptive work +except where it is incidental to the economic work and for the +purpose of giving accuracy to the popular and economic statements. +This would make our work essentially biological, for all biologic +investigation would be justified, not only because the life habits +of any insect, once ascertained, throw light on those of species +which are closely related to it, but because we can never know when +a species at present harmless may subsequently prove harmful, and +have to be classed among the species injurious to agriculture.</p> + +<p>On the question of credit to their original sources of results +already on record, it is hardly necessary for me to advise, because +good sense and the consensus of opinion will in the end justify or +condemn a writer according as he prove just and conscientious in +this regard.</p> + +<p>There is one principle that should guide every careful writer, +viz., that in any publications whatever, where facts or opinions +are put forth, it should always be made clear as to which are based +upon the author's personal experience and which are compiled or +stated upon the authority of others. We should have no patience +with a very common tendency to set forth facts, even those relating +to the most common and best known species, without the indications +to which I have referred. The tendency belittles our calling and is +generally misleading and confusing, especially for bibliographic +work, and cannot be too strongly deprecated.</p> + +<p>On this point there will hardly be any difference of opinion, +but I will allude to another question of credit upon which there +prevails a good deal of loose opinion and custom. It is the habit +of using illustrations of other authors without any indication of +their original source.</p> + +<p>This is an equally vicious custom and one to be condemned, +though I know that some have fallen into the habit, without +appreciation of its evil effect. It is, in my judgment, almost as +blameworthy as to use the language or the facts of another without +citing the authority.</p> + +<p>Every member of this association who has due appreciation of the +time and labor and special knowledge required to produce a good and +true illustration of the transformations and chief characteristics +of an insect will appreciate this criticism. However pardonable in +fugitive newspaper articles in respect of cuts which, from repeated +use, have become common or which have no individuality, the habit +inevitably gives a certain spurious character to more serious and +official publications, for assumption of originality, whether +intended or not, goes with uncredited matter whether of text or +figure. Nor is mere acknowledgment of loan or purchase to the +publisher, institution or individual who may own the block or stone +what I refer to. But that acknowledgment to the author of the +figure or the work in which it first appears which is part of +conscientious writing, and often a valuable index as to the +reliability of the figure.</p> + +<p>It were supererogation to point out to a body of this kind the +value of the most careful and thorough work in connection with life +histories and habits, often involving as it does much microscopic +study of structure. The officers of our institutions who control +the funds, and more or less fully our conduct, are apt to be +somewhat impatient and inappreciative of the time given to anatomic +work, and where it is given for the purpose of describing species +and of synopsizing or monographing higher groups, without reference +to agriculture, I am firmly of the belief that it diverts one from +economic work, but where pursued for a definite economic purpose it +cannot be too careful or too thorough and I know of no instances +better calculated to appeal to and modify the views of those +inclined to belittle such structural study than Phylloxera and +Icerya. On the careful comparison of the European and American +specimens of <i>Phylloxera vastatrix</i>, involving the most minute +structures and details, depended originally those important +economic questions which have resulted in legislation by many +different nations and the regeneration of the affected vineyards of +Europe, of our own Pacific coast, and of other parts of the world +by the use of American resistant stocks. In the case of <i>Icerya +purchasi</i> the possibilities of success in checking it by its +natural enemies hung at one time upon a question of specific +difference between it and the <i>Icerya sacchari</i> of +Signoret—a question of minute structure which the +descriptions left unsettled and which could only be settled by the +most careful structural study and the comparison of the types, +involving a trip to Europe.</p> + +<h3>CONCLUSION.</h3> + +<p>I have thus touched, gentlemen, upon a few of the many subjects +that crowd upon the mind for consideration on an occasion like +this—a few gleanings from a field which is passing rich in +promise and possibility. It is a field that some of us have +cultivated for many years and yet have only scratched the surface, +and if I have ventured to suggest or admonish, it is with the +feeling that my own labors in this field are ere long about to end +and that I may not have another occasion.</p> + +<p>At no time in the history of the world has there, I trow, been +gathered together such a body of devoted and capable workers in +applied entomology. It marks an era in our calling and, looking +back at the progress of the past fifteen years, we may well ponder +the possibilities of the next fifteen. They will be fruitful of +grand results in proportion as we persistently and combinedly +pursue the yet unsolved problems and are not tempted to the +immediate presentation of separate facts, which are so innumerable +and so easily observed that their very wealth becomes an element of +weakness. Epoch-making discoveries result only from this power of +following up unswervingly any given problem, or any fixed ideal. +The kerosene emulsion, the Cyclone nozzle, the history of +<i>Phylloxera vastatrix</i>, of <i>Phorodon humuli</i>, of +<i>Vedalia cardinalis</i>, are illustrations in point, and while we +may not expect frequent results as striking or of as wide +application as these, there is no end of important problems yet to +be solved and from the solution of which we may look for similar +beneficial results. Applied entomology is often considered a sordid +pursuit, but it only becomes so when the object is sordid. When +pursued with unselfish enthusiasm born of the love of investigation +and the delight in benefiting our fellow men, it is inspiring, and +there are few pursuits more deservedly so, considering the vast +losses to our farmers from insect injury and the pressing need that +the distressed husbandman has for every aid that can be given him. +Our work is elevating in its sympathies for the struggles and +suffering of others. Our standard should be high—the pursuit +of knowledge for the advancement of agriculture. No official +entomologist should lower it by sordid aims.</p> + +<p>During the recent political campaign the farmer must have been +sorely puzzled to know whether his interests needed protection or +not. On the abstract question of tariff protection to his products +we, as entomologists, may no more agree than do the politicians or +than does the farmer himself. But ours is a case of protection from +injurious insects, and upon that there can nowhere be division of +opinion. It is our duty to see that he gets it with as little tax +for the means as possible.</p> + +<a id="Footnote_1c" name="Footnote_1c"></a><a href= +"#FNanchor_1c">[1]</a> + +<div class="note">Address of Dr. C.V. Riley at the annual meeting +of the Association of Economic Entomologists, Champaign, Ills., +November 11 to 14, 1890.</div> + +<hr /> +<h2><a id="iv_1" name="iv_1"></a>POTASH SALTS.<a id="FNanchor_1d" +name="FNanchor_1d"></a><a href="#Footnote_1d"><sup>1</sup></a></h2> + +<p>My attention was attracted to potash salts as an insecticide, by +the casual remark of an intelligent farmer, that washing his young +pear trees with a muriate of potash solution cleared them of +scales. The value of this substance for insecticide purposes, +should its powers be sufficient, struck me at once, and I began +investigation. It was unluckily too late in the season for field +experiments of the nature desired; but it is the uniform testimony +of farmers who have used either the muriate or the kainit in the +cornfields, that they have there no trouble with grubs or cut +worms. Mr. E.B. Voorhees, the senior chemist of the station, +assures me that on his father's farm the fields were badly +infested, and replanting cornhills killed by grubs or wire worms +was a recognized part of the programme. Since using the potash +salts, however, they have had absolutely no trouble, and even their +previously worst-infested fields show no further trace of injury. +The same testimony comes from others, and I feel safe in +recommending these salts, preferably kainit, to those who are +troubled with cut worms or wire worms in corn.</p> + +<h3>EXPERIMENTS.</h3> + +<p>A lot of wire worms (<i>Iulus</i> sp.) brought in from potato +hills were put into a tin can with about three inches of soil and +some potato cuttings, and the soil was thoroughly moistened with +kainit, one ounce to one pint of water. Next morning all the +specimens were dead. A check lot in another can, moistened with +water only, were healthy and lived for some days afterward.</p> + +<p>A number of cabbage maggots placed on the soil impregnated with +the solution died within twelve hours.</p> + +<p>To test its actual killing power, used the solution, one ounce +kainit to one pint water, to spray a rose bush badly infested with +plant lice. Effect, all the lice dead ten hours later; the younger +forms were dropping within an hour.</p> + +<p>Sprayed several heads of wheat with the solution, and within +three hours all the aphides infesting them were dead.</p> + +<p>Some experiments on hairy caterpillars resulted +unsatisfactorily, the hair serving as a perfect protection against +the spray, even from the atomizer.</p> + +<p>To test its effect on the foliage, sprayed some tender shoots of +rose and grape leaves, blossoms, and clusters of young fruit. No +bad effect observable 24 hours later. There was on some of the +leaves a fine glaze of salt crystals, and a decided salt taste was +manifest on all.</p> + +<p>Muriate of potash of the same strength was tested as follows: +Sprayed on some greenhouse camellias badly infested by mealy bugs, +it killed nearly all within three hours, and six hours later not a +living insect was found. The plants were entirely uninjured by the +application.</p> + +<p>Thoroughly sprayed some rose bushes badly infested with aphides, +and carried off some of the worst branches. On these the lice were +dead next morning; but on the bushes the effect was not so +satisfactory, most of the winged forms and many mature wingless +specimens were unaffected, while the terminal shoots and very young +leaves were drooping as though frosted. All, however, recovered +later.</p> + +<p>The same experiment repeated on other, hardier roses, resulted +similarly so far as the effect on the aphides was concerned, but +there was no injury to the plant.</p> + +<p>Used this same mixture on the caterpillars of <i>Orgyia +leucostigma</i> with unsatisfactory effect, and with the same +results used it on a number of other larvæ. Used on the rose +leaf roller, <i>Cacæcia rosaceana</i>, it was promptly +effective.</p> + +<p>Tested for injury to plants, it injured the foliage and flowers +of wisteria, the younger leaves of maple and grape, and the finer +kinds of roses.</p> + +<p>From these few experiments kainit seems preferable to the +muriate, as acting more effectively on insects and not injuriously +on plants. For general use on plants it is not to be recommended. +It is otherwise on underground species, where the soil will be +penetrated by the salts and where the moisture evaporates but +slowly, and the salt has a longer and better chance to act. The +best method of application would be a broadcasting in fertilizing +quantity before or during a rain, so as to carry the material into +the soil at once. In cornfields infested with grubs or wire worms, +the application should be made before planting. Where it is to be +used to reach root lice, it should be used when the injury is +beginning. When strawberry beds are infested by the white grub, the +application should be made when cultivating or before setting +out.</p> + +<p>The potash salts have a high value as fertilizers, and any +application made will act as a stimulant as well as insecticide, +thus enabling the plants to overcome the insect injury as well as +destroying the insect.</p> + +<p>In speaking on this subject in Salem county, I learned from +farmers present that those using potash were not troubled with the +corn root louse to any extent, and also that young peach trees have +been successfully grown in old lice-infested orchards, where +previously all died, by first treating the soil with kainit of +potash.</p> + +<a id="Footnote_1d" name="Footnote_1d"></a><a href= +"#FNanchor_1d">[1]</a> + +<div class="note">By John B. Smith, entomologist. Potash as an +insecticide is not entirely new, but has never been brought out +with the prominence I think it deserves.—<i>N.J. Ag. Col. +Exp. St., Bulletin 75.</i></div> + +<hr /> +<p><a id="vii_1" name="vii_1"></a>A meteorological station has been +built on Mont Blanc, at an elevation of 13,300 feet, under the +direction of M. Vallot. It required six weeks to deliver the +materials. The instruments are self-registering and are to be +visited in summer every fifteen days if possible, the instruments +being left to register between the visits. In the winter the +observatory will be entirely inaccessible. This is the highest +scientific station in Europe, but is 847 feet lower than the Pike's +Peak station in Colorado.</p> + +<hr /> +<h2><a id="v_1" name="v_1"></a>THE EXPENSE MARGIN IN LIFE +INSURANCE.</h2> + +<p>The principle of mutuality requires that the burden of expense +in life insurance should be borne by all the members equally; but, +even with the most careful adjustment, the allowance usually made +is considerably in excess of what is needed in the regular +companies doing business on the "level premium" plan.</p> + +<p>It is customary in these companies to add to the net premium a +percentage thereof to cover the expense account. This practice, +though in harmony with the "commission system," is so clearly +defective and so far removed from the spirit of life insurance +mathematics, that it scarcely deserves even this passing +notice.</p> + +<p>It is generally understood that these corporations combine the +functions of the savings bank and life insurance company, and it is +only by separating the two in our minds as far as possible that we +can obtain a clear conception of the laws that should govern the +apportionment of the expenses among the great variety of +policies.</p> + +<p>While it is a comparatively simple matter to state the amount of +either the insurance or savings bank element in a single policy, it +is by no means easy, as things go, to classify the company's actual +expenses on this basis.</p> + +<p>Fortunately, we can pretty accurately determine what these +amounts should be in any particular case.</p> + +<p>In the first place, there are institutions in our midst devoted +solely to receiving and conserving small sums of money; doing, in +fact, exactly what our insurance companies are undertaking to do +with the reserve and contributions thereto. These savings banks are +required by law to make returns to the State commissioner, from +whose official report we can get a very good idea of the expense +attendant on doing this business.</p> + +<p>Confining ourselves to the city banks, where the conditions more +nearly resemble those of the insurance companies, we find in +thirty-eight combined institutions for saving in the State of +Massachusetts a deposit in 1888 of $192,174,566, taken care of at +an aggregate cost of $455,387, or about 24-100 of one per cent.</p> + +<p>The same ratio carried out for all the savings banks in +Massachusetts gives a trifle over 25-100 of one per cent.; we may, +therefore, consider ¼ of one per cent. as expressing pretty +nearly the cost of receiving, paying out, and investing the savings +of the people.</p> + +<p>We must remember in this connection that in the popular +estimation, the savings bank is an important factor in the public +welfare, and in the towns and smaller cities there are often found +public spirited men willing to give their services to encourage +this mode of saving; but public sentiment has not yet given to life +insurance the place which it is destined, sooner or later, to +occupy by the side of the savings bank. Hence the services of able +managers can only be obtained by a liberal outlay of the corporate +funds. A satisfactory adjustment of the matter of expenses will, +perhaps, do more than anything else to bring about this recognition +on the part of the public.</p> + +<p>In the case of the savings bank it is safe to say that for +double the present outlay a liberal salary could be paid to all the +officers. Following the analogy, we are led to infer that if this +be the case in savings banks, then ½ of one per cent. of the +reserve should be an ample allowance for the special labor required +in the purely banking portion of the business.</p> + +<p>In this we have the concurrence of the late Elizur Wright. In an +essay on this subject he says:</p> + +<blockquote> +<p>"The expenses of the five largest savings banks in Boston, in +1869, did not exceed 4-10 of one per cent. on $28,000,000 deposited +in them. They certainly had twice as many transactions, in +proportion to the deposits, as any life insurance company could +have with the same amount of reserve, so that ½ of one per +cent. on the reserve seems to be ample for all working expenses +save those of maintaining the agencies and collecting the +premiums."</p> +</blockquote> + +<p>This need hardly be looked upon as an admission that it costs +twice as much to care for the funds of a life insurance company as +for those of a savings bank. A liberal expense allowance must be +made at the outset, seeing that an error in this particular cannot +easily be rectified after the policy is issued. The dividend, or, +to speak more correctly, the annual return of surplus, will correct +any overpayment on this account.</p> + +<p>There is another expense which seems inevitable. This is the +government tax on insurance companies, amounting in the aggregate +to nearly 1/3 of one per cent. on the reserve.</p> + +<p>When we consider that these institutions are intended to +encourage thrift and to relieve the community from the care of +numberless widows and orphans, it seems a clear violation of the +principles of political economy to levy a tax on this business; +still, whatever our opinion may be as to the justice or injustice +of the imposition, the tax is maintained and must be provided for. +Consequently a further allowance of ½ of one per cent. must +be added to the net premium to cover the same, making a total of 1 +per cent. of the reserve for banking expenses and taxes. +Considering this point as settled for the time being, let us +proceed to investigate the insurance expenses.</p> + +<p>Here, again, we are fortunate in being able to refer to the +official reports of a class of corporations doing nearly, if not +quite pure insurance.</p> + +<p>The assessment societies, outside of the fraternal and +benevolent, reporting in 1889 to the insurance commissioner of +Massachusetts, show outstanding risks amounting to $733,515,366. +Losses to the amount of $7,270,238 were paid during the year at a +cost for transacting the business of $2,403,053, which includes +among other items "agency expenses and commissions," which amount +to about $1,203,000, or 17 per cent. of the cost value of the +insurance actually done. It would seem as if an allowance of 20 per +cent. would be a liberal one in the case of the regular companies, +which surely have as good facilities for doing business as the +assessment societies.</p> + +<p>As far as insurance is concerned, there is less difference +between regular and co-operative companies than is generally +supposed. Regular companies assess each policy in advance for a +year's insurance at a time, while co-operative societies furnish +insurance only from one assessment to another. The difficulty in +the way of collecting the assessment in the latter case would seem +to be greater than in the former, owing to the more permanent +nature of the regular insurance contract.</p> + +<p>In compensating agents the assessment companies naturally pay in +proportion to the insurance obtained, inasmuch as there is no other +basis to go upon, but regular companies usually pay the agent a +percentage of the premium <i>which includes a considerable trust +fund</i> over and above the assessment for actual insurance. It is +easily seen that by the last method the agent's compensation +increases in proportion to the amount of savings bank business +forced upon the company.</p> + +<p>To realize how far we are from anything like a scientific, not +to say common sense basis for insurance expenses, we have but to +examine the following list, which gives the ratios between the +expenditures for general expenses in 1889, and those for the +extension of the business. For every $100 used in a general way, +the different companies spend for commissions and agency expenses: +$37, $66, $67, $78, $91, $106, $110, $113, $120, $140, $157, $161, +$173, $175, $186, $189, $200, $202, $222, $264, $311, $346.</p> + +<p>It will doubtless be said that I am taking a very advanced +position when I say that in the ideal life insurance scheme there +is no place for the commission system. Solicitors will be a +necessity only so long as they are in the field, but fifty years of +life insurance has taught our community its true value and, thanks +to the modern press, the institution it is no more likely to fall +into desuetude than is Christianity or the moral law.</p> + +<p>For the convenience of bringing the company to the individual, +the latter should be willing to pay a fee. The man who renders +another a service or puts his superior knowledge at another's +disposal should look to the party benefited for his remuneration. +Any compensation given for such service to a go-between by a mutual +company is paid by all, and the question arises, Is the advantage +to the company of sufficient importance to warrant the imposition +of this tax upon all its members promiscuously? The following, from +the Massachusetts Insurance Commissioner's Report for 1885, leaves +no doubt as to the convictions of the writer on this important +matter:</p> + +<blockquote> +<p>"The expensiveness of the life insurance policy is not because +the level net premium is too high, for the premium is absolutely +just, and the policy holder gets full value; but the complaint +justly applies to the excessive expense charge. A person who wants +insurance, life or fire or other, should be able to buy it at first +cost without paying tribute of profits to middlemen. To that +complexion the matter will finally be brought by the force of +intelligent opinion, whatever resistance may be opposed by persons +whose thrift lies in the perpetuation of the expensive system now +in fashion."</p> +</blockquote> + +<p>It requires but a slight degree of prophetic vision to predict +that in a very few years the companies in self defense will be +obliged to change their method of compensating agents.</p> + +<p>Several companies have already begun the reform by grading +commissions; granting a percentage proportional to the amount of +insurance likely to be done on the policy. Other companies have +simply reduced the amount of the commission rate, thus virtually +withdrawing from active competition.</p> + +<p>This will, in a certain degree, explain the wide variation in +the figures given above, where it is noticed that, in five +companies out of twenty-two, the total agency expenditures amount +to less than the general expenses, while in six cases the companies +spend more than double as much on the former as on the latter. In +either class we find representatives of the five largest companies +in the country.</p> + +<p>On applying the foregoing ratios to the business of the existing +companies we find that, calling the theoretical expenses $100, the +actual expenditures for 1889 were as follows: $112.67, $118.34, +$150.40, $194.48, $208.16, $208.53, $228.66, $235.89, $248.44, +$250.79, $258.33, $258.57, $265.14, $267.19, $267.92, $274.47, +$294.17, $314.96, $335.70, $377.94, $616.70.</p> + +<p>In this discouraging exhibit there is one ray of comfort. The +combined assets of the two companies heading the list amount to +over $100,000,000. There is no question as to their financial +standing, and both show a large increase in membership over the +previous year. I may also say here that it is a difficult matter to +get at the actual "cost of insurance" in the various companies. +Many of them, on their own acknowledgment, do not compute the +advance cost of carrying their "amount at risk," and others, for +reasons of their own, do not care to state the figures. In cases +where the correct figures were not obtainable, I have assumed the +cost to have been 1-1/3 per cent. of the mean amount at risk.</p> + +<p>If we should, in our comparison, omit the actual agency expenses +and commissions, the ratios would stand as follows:</p> + +<p>Where I would allow $100 the companies actually used: $43.17, +$55.90, $65.21, $77.21, $82.39, $88.34, $91.99. $91.98. $92.19, +$94.65, $97.15. $99.55. $99.11. $102.86, $109.35, $125.05, $133.03, +$141.92, $195.90, $207.06, $287.72.</p> + +<p>As might be supposed, the first two ratios are those companies +before alluded to. These companies might have doubled their +advertising account and expended $300,000 between them on agents' +salaries, and still have kept within my allowance.</p> + +<p>Admitting, for the present at least, the reasonableness of the +proposed allowance for the expenses of the banking and insurance +departments of the business, we have before us the problem how to +equitably adjust the burden among the great variety of +policies.</p> + +<p>In the first place, <i>there should be no policy in the company +that does not contribute its proportionate share of the expense +allowance during every year of its life</i>. I make a special point +of this, for at present the policies which have become paid up, +either by the payment of a single premium at the outset or by the +completion of a stipulated number of payments, contribute +practically nothing to the expense account after the premium +payments cease.</p> + +<p>The following plan, I think, complies with all the requirements +of the problem. By the proposed method every policy, at all stages +of its existence, contributes its exact share to the expense fund, +whatever its plan of payment may be.</p> + +<p>Let us, as an illustration, examine the case of a ten year +endowment policy, taken out at age 30, and consider it under three +aspects, first, as paid for in advance by a single payment, second, +as paid by five annual payments, and third, as paid for annually +throughout the term. I have used this short term endowment policy +simply for convenience, the rule applying equally to policies of +longer term or to the ordinary life policy, which is, in fact, an +endowment policy payable at death or age 100.<a id="FNanchor_1e" +name="FNanchor_1e"></a><a href="#Footnote_1e"><sup>1</sup></a></p> + +<p>Taking the case of the single premium endowment policy for +$1,000, we find that the following sums are required, each year to +provide for the care of the reserve and to pay the government fees +(1 per cent. of reserve):</p> + +<div class="ctr"> +<table border="0" width="50%" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="left" /> +<col align="center" /> +<col span="2" align="right" /> +<col align="center" /> +<col align="right" /></colgroup> + +<tr> +<td>1st</td> +<td>year</td> +<td>$6.9982</td> +<td>6th</td> +<td>year</td> +<td>$8.4136</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>7.2560</td> +<td>7th</td> +<td>"</td> +<td>8.7381</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>7.5258</td> +<td>8th</td> +<td>"</td> +<td>9.0781</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>7.8082</td> +<td>9th</td> +<td>"</td> +<td>9.4346</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>8.1039</td> +<td>10th</td> +<td>"</td> +<td>9.8086</td> +</tr> +</table> +</div> + +<p>The insurance expenses should be covered by the 20 per cent. +allowance given below:</p> + +<div class="ctr"> +<table border="0" width="50%" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="left" /> +<col align="center" /> +<col span="2" align="right" /> +<col align="center" /> +<col align="right" /></colgroup> + +<tr> +<td>1st</td> +<td>year</td> +<td>$ .4422</td> +<td>6th</td> +<td>year</td> +<td>$ .2566</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>.4100</td> +<td>7th</td> +<td>"</td> +<td>.2076</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>.3762</td> +<td>8th</td> +<td>"</td> +<td>.1556</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>.3402</td> +<td>9th</td> +<td>"</td> +<td>.0988</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>.2996</td> +<td>10th</td> +<td>"</td> +<td>.0344</td> +</tr> +</table> +</div> + +<p>Consequently the total contribution required from this policy +each year is:</p> + +<div class="ctr"> +<table width="50%" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="left" /> +<col align="center" /> +<col span="2" align="right" /> +<col align="center" /> +<col align="right" /></colgroup> + +<tr> +<td>1st</td> +<td>year</td> +<td>$7.4404</td> +<td>6th</td> +<td>year</td> +<td>$8.6702</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>7.6660</td> +<td>7th</td> +<td>"</td> +<td>8.9457</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>7.9020</td> +<td>8th</td> +<td>"</td> +<td>9.2337</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>8.1484</td> +<td>9th</td> +<td>"</td> +<td>9.5334</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>8.4034</td> +<td>10th</td> +<td>"</td> +<td>9.8430</td> +</tr> +</table> +</div> + +<p>The present value of all these contributions is found to be, at +4 per cent. interest, $71.6394; in other words, this sum paid at +the outset, provides a fund from which we may deduct the current +expenses of each year in advance, and by accumulating the balance +at the assumed rate of interest from year to year, we shall have +enough to pay the anticipated expenses, leaving nothing over.</p> + +<p>In the above case the sums in hand at the beginning of the year +are as follows:</p> + +<div class="ctr"> +<table width="50%" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="left" /> +<col align="center" /> +<col span="2" align="right" /> +<col align="center" /> +<col align="right" /></colgroup> + +<tr> +<td>1st</td> +<td>year</td> +<td>$71.3694</td> +<td>6th</td> +<td>year</td> +<td>$42.6981</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>66.7669</td> +<td>7th</td> +<td>"</td> +<td>35.3890</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>61.4650</td> +<td>8th</td> +<td>"</td> +<td>27.5009</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>55.7055</td> +<td>9th</td> +<td>"</td> +<td>18.9979</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>49.4594</td> +<td>10th</td> +<td>"</td> +<td>9.8430</td> +</tr> +</table> +</div> + +<p>We find a somewhat different condition existing during the first +years of a 5-year endowment policy. As there is more insurance and +less banking, the requirements are as follows:</p> + +<div class="ctr"> +<table align="center" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="right" /> +<col align="center" /> +<col align="right" span="4" /></colgroup> + +<tr> +<th></th> +<th></th> +<th>1 P. Ct.<br /> + on Reserve.</th> +<th>20 P. Ct.<br /> + on Cost.</th> +<th>Total.</th> +<th>Initial Fund.</th> +</tr> + +<tr> +<td>1st</td> +<td>year</td> +<td>$1.5038</td> +<td>$1.2572</td> +<td>$2.7610</td> +<td>$12.9769</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>3.0406</td> +<td>1.0216</td> +<td>4.0622</td> +<td>23.6015</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>4.6503</td> +<td>.7852</td> +<td>5.4355</td> +<td>33.2979</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>6.3367</td> +<td>.5378</td> +<td>6.8745</td> +<td>41.9538</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>8.1039</td> +<td>.2996</td> +<td>8.4035</td> +<td>49.4594</td> +</tr> + +<tr> +<td>6th</td> +<td>"</td> +<td>8.4136</td> +<td>.2566</td> +<td>8.6702</td> +<td>42.6981</td> +</tr> + +<tr> +<td>7th</td> +<td>"</td> +<td>8.7381</td> +<td>.2076</td> +<td>8.9257</td> +<td>35.3890</td> +</tr> + +<tr> +<td>8th</td> +<td>"</td> +<td>9.0781</td> +<td>.1556</td> +<td>9.2337</td> +<td>27.5009</td> +</tr> + +<tr> +<td>9th</td> +<td>"</td> +<td>9.4346</td> +<td>.0988</td> +<td>9.5334</td> +<td>18.9979</td> +</tr> + +<tr> +<td>10th</td> +<td>"</td> +<td>9.8086</td> +<td>.0344</td> +<td>9.8430</td> +<td>9.8430</td> +</tr> +</table> +</div> + +<p>As the premium payments extend over only five years, the expense +contributions must all be paid during that time and are most +conveniently made by a uniform addition to the net premium.</p> + +<p>The present value of the amounts in column 3 is $60.0819, and +the equivalent annuity for five years is $12.9769. This amount, +received for five consecutive years, will put the company in funds +to pay current expenses and leave a reserve of $42.6981 at the +beginning of the sixth year, which, as we have seen in the analysis +of the single-premium policy, is the sum required for future +expenses on the paid up basis.</p> + +<p>In like manner we find that the 10-year annuity equivalent to +the present value of the annual contributions in the case of an +annual-payment policy is $5.534, thus:</p> + +<div class="ctr"> +<table align="center" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="right" /> +<col align="center" /> +<col align="right" span="4" /></colgroup> + +<tr> +<th></th> +<th></th> +<th>1 P. Ct.<br /> + on Reserve.</th> +<th>20 P. Ct.<br /> + on Cost.</th> +<th>Total.</th> +<th>Initial Fund.</th> +</tr> + +<tr> +<td>1st</td> +<td>year</td> +<td>$.8234</td> +<td>$1.3514</td> +<td>$2.1748</td> +<td>$ 5.5340</td> +<td></td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>1.6473</td> +<td>1.2478</td> +<td>2.8951</td> +<td>9.0275</td> +<td></td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>2.5096</td> +<td>1.1388</td> +<td>3.6484</td> +<td>11.9116</td> +<td></td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>3.4124</td> +<td>1.0210</td> +<td>4.4334</td> +<td>14.1277</td> +<td></td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>4.3572</td> +<td>.8916</td> +<td>5.2488</td> +<td>15.6161</td> +<td></td> +</tr> + +<tr> +<td>6th</td> +<td>"</td> +<td>5.3479</td> +<td>.7534</td> +<td>6.1013</td> +<td>16.3160</td> +<td></td> +</tr> + +<tr> +<td>7th</td> +<td>"</td> +<td>6.3853</td> +<td>.5966</td> +<td>6.9819</td> +<td>16.1572</td> +<td></td> +</tr> + +<tr> +<td>8th</td> +<td>"</td> +<td>7.4726</td> +<td>.4270</td> +<td>7.8996</td> +<td>15.0763</td> +<td></td> +</tr> + +<tr> +<td>9th</td> +<td>"</td> +<td>8.6127</td> +<td>.2418</td> +<td>8.8545</td> +<td>12.9977</td> +<td></td> +</tr> + +<tr> +<td>10th</td> +<td>"</td> +<td>9.8086</td> +<td>.0344</td> +<td>9.8430</td> +<td>9.8430</td> +<td></td> +</tr> +</table> +</div> + +<p>The present value of the ten yearly expense items given in the +"total" column above is $46.6812, which is equal to a ten-year +annuity of $5.534. The several premiums stand now as follows:</p> + +<p class="ctr">ENDOWMENT: $1,000, AGE 30, PAYABLE AT DEATH OR +40</p> + +<div class="ctr"> +<table align="center" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="3"> +<col align="left" /> +<col align="right" span="3" /></colgroup> + +<tr> +<td></td> +<td>Net Prem.<a id="FNanchor_2e" name="FNanchor_2e"></a><a href= +"#Footnote_2e"><sup>2</sup></a></td> +<td>Margin.</td> +<td>Total.</td> +</tr> + +<tr> +<td>At single premium.</td> +<td>$687.228</td> +<td>$71.6394</td> +<td>$758.8674</td> +</tr> + +<tr> +<td>At five premiums.</td> +<td>150.615</td> +<td>12.9769</td> +<td>163.5939</td> +</tr> + +<tr> +<td>At annual premiums.</td> +<td>84.172</td> +<td>5.5340</td> +<td>89.7060</td> +</tr> +</table> +</div> + +<p>By the actuaries' rate we have, with the customary loading for +expense:</p> + +<blockquote> +<p>Single premium: $721.66 (loaded, $34.36). Five premiums, $188.70 +(loaded $37.78). Annual premium, $105.65 (loaded $21.11).</p> +</blockquote> + +<p>Admitting the correctness of the new method, we must conclude +that the present single premium is not sufficiently loaded to cover +its own expenses, while the annual payment policy pays more than +its just share. A prominent and thoroughly informed life insurance +president says in this connection: "Many of the policies, +particularly the short term endowments, are charged with too high a +percentage of expenses to prove a good investment at maturity or +profitable to the insured in case of surrender." This is not to be +wondered at when the applicant for a 10-year endowment policy sees +at a glance that he must pay, in the gross, more than is returned +unless he should die in the interim, in which case a plain "life" +or "term" policy would have answered the purpose. Under the new +system of assessing expenses one form is as desirable as another, +from the standpoint of the insured or the company.</p> + +<p>The new premium for the 10-year endowment policy, $89.71, +commends itself at once to the applicant, who can easily see that +his total outlay must fall short of the amount ultimately to be +realized, of course, disregarding interest and probable dividends +in both cases.</p> + +<p>In discounting the future expense contributions I have not taken +the chances of dying into account. Hence the expense reserve in any +instance applies only to that individual case, and, in the event of +death or surrender before the maturity of the policy, the amount of +the expense fund not used would naturally revert to the +insured.</p> + +<p>The scheme of expense assessment outlined above will doubtless +be pronounced impracticable by the majority of insurance men.</p> + +<p>Such a far reaching reform is too much to hope for, at least in +the immediate future.</p> + +<p>No well informed life insurance expert will deny that there are +opportunities for improvement in the business, but to graft new +methods on old companies is a hopeless undertaking.</p> + +<p>It is well, however, to have new methods well matured in advance +of the public demand, and I feel convinced that the ideas here set +forth are in the line of the reform which, before long, must be +instituted by the companies if they would retain the confidence and +patronage of the community.</p> + +<p>Doubtless many insurance presidents could tell of suggestions +which have impressed them favorably and which they would gladly +have adopted were it not for the injustice done thereby to older +members and the changes necessary to bring existing contracts into +conformity with the new system. Similar objections may be urged +against the ideas here advanced, and I must confess I hardly see a +way by which the present suggestions can be utilized by existing +companies. We can only hope that sooner or later some of the new +theories may be practically tested. Meanwhile the companies at +present in the field are doing a great work for the good of +humanity, even though their methods may be, in some particulars, +more practical than scientific.</p> + +<div class="ctr"> +<table summary="" width="100%"> +<tr> +<td align="left">Winchester, Mass.</td> +<td align="right">FRANK J. WILLS.</td> +</tr> +</table> +</div> + +<a id="Footnote_1e" name="Footnote_1e"></a><a href= +"#FNanchor_1e">[1]</a> + +<div class="note">The expense allowance on a plain life policy for +$1,000, taken at age 33, would be about $5.29; net premium (com. +ex. 4 per cent.), $18.04; total office premium, $23.33; present +rate $24.10.</div> + +<a id="Footnote_2e" name="Footnote_2e"></a><a href= +"#FNanchor_2e">[2]</a> + +<div class="note">Thirty American offices. Discount from middle of +year, Vx-½ or (M x 1.01961) / Dx.</div> + +<hr /> +<h2><a id="vii_2" name="vii_2"></a>THE FLOOD AT KARLSBAD.</h2> + +<p>During the flood which occurred in Germany and Bohemia, the last +week of November, Karlsbad was especially unfortunate; it suffered +such an inundation as had never before been known in the +"Sprudelstadt." On the evening of November 23, the Tepl was very +much swollen by the rain, which had continued for several days, but +it was supposed that there was no danger of a flood, as the bed of +the river had been put in proper condition. During the forenoon of +November 24, the water suddenly began to rise with such astonishing +rapidity that within half an hour all the lower streets were like +turbulent rivers and the Alte and Neue Wiese were transformed into +a lake. The stores on the Alte Wiese were under water to the roofs, +and the proprietors, who were trying to save their goods, were +surprised by the water and had to take refuge in the trees. They +were rescued by having ropes thrown to them, and during this work a +catastrophe occurred which was a great misfortune to all classes of +citizens. The beloved burgermeister of Karlsbad, Dr. Rudolf Knoll, +who had just recovered from a severe illness, was, with others, +directing the work from the balcony of one of the houses, when a +rope by which a man was being drawn through the water broke, and +the man was carried off by the waves. The fright and excitement of +the scene gave the burgermeister a shock which caused his instant +death, but the man who was in danger was brought safely out of the +water.</p> + +<p>The water was 9 ft. in Marienbaderstrasse, the Marktplatz, +Muhlbadgasse, the Sprudelgasse, Kreuzgasse, Kaiserstrasse, and +Egerstrasse, and flooded the quay, causing great destruction. All +places of business were flooded, the doors and iron shutters were +pushed in by the force of the water and the goods were carried away +or ruined.</p> + +<p>The house called "Zum Kaffeebaum" was undermined and part of it +fell to the ground; the same fate was feared for other buildings. +The Sophien and Curhaus bridges were carried away. Other bridges +were greatly damaged, and the masonry along the banks of the river +was partially destroyed. The Sprudelgasse was completely washed +out, and the condition of the Muhlbadgasse was almost as bad. The +fire department with its apparatus had great difficulty in saving +the inhabitants and guests, as there were very few boats or +pontoons at their command, and the soldiers (Pionniere) from Prague +and the firemen from the neighboring towns did not arrive until +evening. Fortunately the water began to fall in the night, and the +next day it had gone down so that it left its terrible work +visible. The Sprudel and the mineral springs were not injured, but, +on the other hand, the water pipes of the bathing establishments +and the gas pipes were completely destroyed.—<i>Illustrirte +Zeitung.</i></p> + +<hr /> +<h2><a id="ix_2" name="ix_2"></a>THEATRICAL WATER PLAYS.</h2> + +<p>In one of the plays at Hengler's Circus in London a water scene +is introduced, for which purpose the main ring is flooded with +water in a manner which is both striking and interesting.</p> + +<p class="ctr"><img src="./images/12-circus.png" alt= +"FLOODING A CIRCUS RING." title="CIRCUS RING" /><br /> + FLOODING A CIRCUS RING.</p> + +<p>The ring is entirely lined with stout macintosh sheeting, and +into this, from two large conduits. 23,000 gallons of water are +poured, the tank being filled to a depth of some 2 ft. in the +remarkably short time of 35 seconds. A steamboat and other small +craft are then launched and the adventures of the heroine then +proceed. She falls overboard, we believe, but is saved after +desperate and amusing struggles. Our engravings, which are from the +<i>Graphic</i>, illustrate the mode of filling the ring with water, +and the steamboat launch.</p> + +<p class="ctr"><img src="./images/12-boat.png" alt= +"A THEATRICAL STEAMBOAT." title="STEAMBOAT" /><br /> + A THEATRICAL STEAMBOAT.</p> + +<hr /> +<h2><a id="ix_1" name="ix_1"></a>SCIENCE IN THE THEATER.</h2> + +<p>In the pretty little hall of the Boulevard des Italiens, at +Paris, a striking exhibition of simulated hypnotism is given every +evening.</p> + +<p>This entertainment, which has met with much success, was devised +by Mr. Melies, director of the establishment, which was founded +many years ago by the celebrated prestidigitator whose popular name +(Robert Houdin) it still bears. This performance carries +instruction with it, for it shows how easily the most surprising +phenomena of the pathologic state can be imitated. To this effect, +several exhibitions are given every evening.</p> + +<p>Mr. Harmington, a convinced disciple of Mesmer, asks for a +subject, and finds one in the hall. A young artist named Marius +presents himself. Mr. Harmington makes him perform all sorts of +extravagant acts, accompanied with a continuous round of pantomimes +that are rendered the more striking by the supposed state of +somnipathy of the subject. At the moment at which Marius is +finishing his most extraordinary exercises, a policeman suddenly +breaks in upon the stage in order to execute the recent orders +relative to hypnotism. But he himself is subjugated by Mr. +Harmington and thrown down by the vibrations of which the +encephalus of this terrible magnetizer is the center. When the +curtain falls, the representative of authority is struggling +against the catalepsy that is overcoming him.</p> + +<p>All the phenomena of induced sleep are successively simulated +with much naturalness by Mr. Jules David, who plays the part of +Marius in this pleasing little performance.</p> + +<p>At a certain moment, after skillfully simulated passes made by +the magnetizer, Mr. David suddenly becomes as rigid as a stick of +wood, and falls in pivoting on his heels (Fig. 1). Did not Mr. +Harmington run to his assistance, he would inevitably crack his +skull upon the floor, but the magnetizer stands just behind him in +order to receive him in his arms. Then he lifts him, and places him +upon two chairs just as he would do with a simple board. He places +the head of the subject upon the seat of one of the chairs and the +heels upon that of the other. Mr. David then remains in a state of +perfect immobility. Not a muscle is seen to relax, and not a motion +betrays the persistence of life in him. The simulation is +perfect.</p> + +<p class="ctr"><a href="./images/13-fig1.png"><img src= +"./images/13-fig1_th.jpg" alt="FIG. 1.—CATALEPTIC RIGIDITY." +title="RIGIDITY" /></a><br clear="all" /> + FIG. 1.—CATALEPTIC RIGIDITY.</p> + +<p>In order to complete the astonishment of the spectators, Mr. +Harmington seats himself triumphantly upon the abdomen of the +subject and slowly raises his feet and holds them suspended in the +air to show that it is the subject only that supports him, without +the need of any other point of support than the two chairs (Fig. +2).</p> + +<p class="ctr"><a href="./images/13-fig2.png"><img src= +"./images/13-fig2_th.jpg" alt= +"FIG. 2.—EXPERIMENT ON THE SAME SUBJECT." title= +"EXPERIMENT" /></a><br clear="all" /> + FIG. 2.—EXPERIMENT ON THE SAME SUBJECT.</p> + +<p>Usually, there are plenty of persons ingenuous enough to think +that Mr. David is actually in a cataleptic sleep, one of the +characters of which is cadaveric rigidity.</p> + +<p>As Mr. David's neck is entirely bare, it is not possible to +suppose that the simulator of catalepsy wears an iron corset +concealed beneath his clothing. He has performed a feat of strength +and skill rendered easy by the exercise that he has given to the +muscles occupying the <i>colliciæ</i> of his vertebral +column. This part of the muscular system is greatly developed in +the weakest and least hardy persons. In fact, in order that man may +keep a vertical position and execute an infinite multitude of +motions in which stability is involved, nature has had to give him +a large number of different organs. The muscles of the back are +arranged upon several superposed layers, the vertebral column is +doubly recurved in order that it may have more strength, and, +finally, rachidion nerves issue from each vertebra in order to +regulate the contraction of each muscular fasciculus according to +the requirements of equilibrium. The trick is so easy that we have +seen youths belonging to the Ligue d'Education Physique immediately +imitate Mr. David after seeing him operate but once.</p> + +<p>For the sake of those who would like to perform it, we shall add +that Mr. David takes care to bend his body in the form of an arch +in such a way that the convexity shall be beneath. As Mr. +Harmington never fails to place himself in the center of the line +that joins Mr. David's head and heels, his weight is divided into +two parts, that is to say, 88 pounds on each side of the point of +support. The result is that the stress necessary is less than that +of a strong man of the Halle lifting a bag of wheat to his shoulder +or of an athlete supporting a human pyramid. The force of +contraction of the muscular fibers brought into play in this +experiment is much greater than is commonly believed. In his +lectures on physiology, Milne-Edwards cites some facts that prove +that it may exceed 600 pounds per square inch of section.</p> + +<p class="ctr"><a href="./images/13-fig3.png"><img src= +"./images/13-fig3_th.jpg" alt="FIG. 3.—THE PERFORATE ARM." +title="PERFORATE ARM" /></a><br clear="all" /> + FIG. 3.—THE PERFORATE ARM.</p> + +<p>The experiment on cadaveric rigidity is followed by others in +insensibility. Mr. David, without wincing, allows a poignard to be +thrust into his arm, which Mr. Harmington has previously +"cataleptized" (Fig. 3). This trick is performed by means of a +blade divided into two parts that are connected by a semicircle. +This process is well known to prestidigitators, but it might be +executed in a genuine manner. In fact, on replacing the poignard by +one of the gold needles used by physicians for acupuncture, it +would be possible to dispense with prestidigitation. Under such +conditions it is possible to transpierce a person's arm. The pain +is supportable, and consists in the sensation of a prick produced +in the passage of the needle through the skin. As for the muscular +flesh, that is of itself perfectly insensible. The needle, upon the +necessary antiseptic precautions being taken, may traverse the +veins and arteries with impunity, provided that it is not allowed +to remain long enough to bring about the formation of a clot of +coagulated blood (Fig. 4).</p> + +<p class="ctr"><img src="./images/13-fig4.png" alt= +"FIG. 4.—AN ARM TRANSPIERCED BY A NEEDLE." title= +"ARM PIERCED BY NEEDLE" /><br /> + FIG. 4.—AN ARM TRANSPIERCED BY A NEEDLE.</p> + +<p>We think it of interest to add that it is necessary that the +experiment be performed by a practitioner if one desires to +demonstrate upon himself a very curious physiological fact that has +been known from the remotest antiquity. It has been employed for +several thousand years in Chinese medicine, for opening a passage +for the bad spirits that produce diseases. For some years past a +much more serious use has been made of it in European medicine for +introducing electric currents into the interior of the organism. In +this case the perimeter of the needle is insulated, and the +electricity flows into the organism through the point. We have +several times had these operations performed upon ourselves, and +this permits us to assert that the above mentioned facts are +absolutely true.—<i>La Nature.</i></p> + +<hr /> +<h2><a id="xi_1" name="xi_1"></a>NEWER PHYSIOLOGY AND +PATHOLOGY.</h2> + +<h3>By Prof. SAMUEL BELL, M.D.</h3> + +<p>Physiology has for many decades been a science founded on +experiment, and pathology has been rapidly pressing forward in the +same direction. To read the accounts of how certain conclusions +have been arrived at in the laboratory, by ingenious devices and by +skillful manipulations, is as fascinating as any tale of +adventure.</p> + +<p>When the microscope began its work, how discouraging was the +vastness and complexity of the discoveries which it brought to +light; how many years has it been diligently used, and how +uncertain are we still about many of its revelations! But what a +happy conjecture of man, and as proper environment takes place we +may reach better results! Let me give an illustration:</p> + +<p>Some thirty years ago, Virchow began his studies and lectures +upon cellular pathology. The enthusiasm which he awakened spread +over the whole medical world. The wonderful attention to detail, +the broad philosophy which signalized his observations, were alike +remarkable. His class room was packed with students from every +country, who thought it no hardship to struggle for a seat at eight +o'clock in the morning. With his blackboard behind him and +specimens of pathology before him, and microscopes coursing upon +railway tracks around the tables which filled the room, he was the +embodiment of the teacher; his highest honor was as discoverer. The +life and importance of the cell, both in health and disease, it has +been his work to discover and to teach. The point of view from +which he has classified tumors is founded on this basis, and +remains the accepted method. The light which he cast upon the +nature of inflammation has not yet been obscured, and while other +phenomena appear, the multiplication of cells and nuclei and the +formation of connective tissue in the process of inflammation will +always call to mind his labors.</p> + +<p>To one of Virchow's pupils, Prof. Recklinghausen, we chiefly owe +our knowledge of the phenomena of diapedesis as a part of the +inflammatory activity. How incredible it seems that masses of +living matter can make their way through the walls of blood vessels +which do not rupture and which have no visible apertures!</p> + +<p>Virchow fixed his attention upon the forms and activities of the +cells, their multiplication and degradation, and how they build up +tissues, both healthy and morbid.</p> + +<p>To another matter with which, both literally and metaphorically, +the air is filled, we must also make allusion. The existence of +micro-organisms in countless numbers is no new fact, but the +influence they may exert over living tissues has only lately become +the subject of earnest attention. So long as they were not known to +have any practical bearing upon human welfare, they interested +almost nobody, but when, however, it was shown that putrefaction of +meat is due to the agency of the <i>bacterium termo</i>, and the +decomposition of albumen to the <i>bacillus subtilis</i>; when +anthrax in cattle and sheep was found to depend on the <i>bacillus +anthracis</i>, and that in human beings it caused malignant +pustules; when suppuration of wounds was found to be associated +with micrococci; and when it was announced that by a process of +inoculation cattle could be protected against anthrax, and that by +carbolic spray and other well known precautions the suppuration of +wounds could be prevented—all the world lent its ears and +investigation at once began.</p> + +<p>Because labors in bacteriology promised to be fruitful in +practical results, the workers speedily became innumerable, and we +are accumulating a wondrous store of facts. How long now is the +list of diseases in which germs make their appearance—in +pneumonia, in endocarditis, in erysipelas, in pyæmia, in +tuberculosis, and so on and so on. One of the most striking +illustrations is the gonococcus of gonorrhœa, whose presence +in and around gives to the pus cells their virulent properties, and +when transferred to the eye works such lamentable mischief. Without +their existence the inoculation of pus in the healthy eye is +harmless; pus bearing the gonococci excites the most intense +inflammation. Similar suppurative action in the cornea is often +caused by infection of cocci. The proof of causation may be found +in the fact that the most effective cure now practiced for such +suppuration is to sterilize them by the actual cautery. Rosenbach +says that he knows six distinct microbes which are capable of +exciting suppuration in man. Their activity may be productive of a +poison, or putrefactive alkaloid, which is absorbed.</p> + +<p>There are at present two prominent theories in regard to the +infections which produce disease. The first is based upon chemical +processes, the second upon the multiplication of living organisms. +The chemical theory maintains that after the infectious element has +been received into the body it acts as a ferment, and gives rise to +certain morbid processes, upon the principle of catalysis. The +theory of organisms, or the germ theory, maintains that the +infectious elements are living organisms, which, being received +into the system, are reproduced indefinitely, and excite morbid +processes which are characteristic of certain types of disease. +This latter theory so readily explains many of the facts connected +with the development and reproduction of infectious diseases, that +it has been unqualifiedly adopted by a large number of +investigators. The proofs of this theory had not, however, advanced +beyond the demonstrations of the presence of certain forms of +bacteria in the pathological changes of a very limited number of +infectious diseases, until February, 1882, when Koch announced his +discovery of the tubercle bacillus, since which time nearly every +disease has its supposed microbe, and the race is, indeed, swift in +which the would-be discoverers press forward with new germs for +public favor.</p> + +<p>The term bacteria or microbe refers to particles of matter, +microscopic in size, which belong to the vegetable kingdom, where +they are known as fungi. If we examine a drop of stagnant water +under the microscope, amplifying say four hundred diameters, we see +it loaded with minute bodies, some mere points, others slightly +elongated into rods, all actively in motion and in various +positions, a countless confusion. If evaporation now takes place, +all is still. If we now apply moisture, the dried-up granules will +show activity, as though they had not been disturbed.</p> + +<p>All these different organisms have become familiar to us under +the generic term bacteria, which is a very unfortunate application, +as it really applies to only a single class of fungi. Cohn calls +them schizomycetes, and makes the following classifications:</p> + +<div class="note"> +<p>1. <i>Sphero-bacteria</i>, or microbes.</p> + +<p>2. <i>Micro-bacteria</i>, or bacteria.</p> + +<p>3. <i>Desmo-bacteria</i>, or bacilli.</p> + +<p>4. <i>Spiroteria</i>, or spirillæ.</p> +</div> + +<p>The <i>spiro-bacteria</i>, or micrococci, are the simplest of +the fungi, and appear as minute organisms of spherical form. They +multiply by fission, a single coccus forming two, these two +producing four, and so on. They present a variety of appearances +under the microscope. From single isolated specimens (which under +the highest magnifying power present nothing beyond minute points) +you will observe them in pairs, again in fours, or in clusters of +hundreds (forming zoöglea) and still adhering together, +forming chains. When a given specimen is about to divide, it is +seen to elongate slightly, then a constriction is formed, which +deepens until complete fission ensues.</p> + +<p>Micrococci possess no visible structure. They consist of a +minute droplet of protoplasm (mycroprotein) surrounded by a +delicate cell membrane. Certain forms are embedded in a capsule +(diameter 0.0008 to 0.0001 millimeter).</p> + +<p>These little organisms, when observed in a fluid like blood, +sputum, etc., are found to present very active movements, although +provided with no organs of locomotion.</p> + +<p>This Brownian motion is possessed by almost every minute +particle of matter, organic and inorganic, and is not due to any +inherent power of the individual. They are almost omnipresent, +abounding in the air, the earth, the water, are always found in +millions where moist organic matter is undergoing decomposition, +and are associated with the processes of fermentation—in +fact, they are essential to it. The souring of milk succeeds the +multiplication of these germs. Certain varieties are pigmented, and +we observe colonies of chromogenic cocci multiplying upon slices of +boiled potato, eggs, etc., presenting all the colors of the +rainbow. All of these germs are not the cause of disease. Certain +species, however (termed pathogenic), are always associated with +certain diseased conditions.</p> + +<p>The <i>bacteria-termo</i>—micro-bacteria—are +slightly elongated, and inasmuch as they multiply by division, +frequently appear coupled together, linked in pairs, and in chains. +They are generally found in putrefying liquids, especially +infusions of vegetable matter. They possess mobility to a +remarkable degree. Observing a field of bacteria-termo under the +microscope, they may be seen actively engaged in twining and +twisting. A flagellum has been demonstrated as attached to one or +both extremities. This is too minute to be generally resolved, even +if it is a common appendage.</p> + +<p><i>Desmo-bacteria</i> (or bacilli) are rod-like organisms, +occurring of various lengths and different thicknesses. In a slide +of the bacillus of tuberculosis and anthrax, we notice at intervals +dots which represent the spores from which, as the rods break up, +future bacilli are developed.</p> + +<p>Then we have <i>spiro-bacteria,</i> the spirilla and the +spirochetæ; the former having short open spirals, the latter +long and closely wound spirals. The <i>spirillum, volutans</i> is +often found in drinking water, and in common with some other +specimens of this class is provided with flagellæ, sometimes +at both extremities, which furnish the means of rapid locomotion. +The spiro-bacteria multiply by spores, although little is at +present known of their life history. They frequently are attached +together at their extremities, forming zigzag chains.</p> + +<p>We have seen that bacteria differ greatly in appearance from the +elongated dot of the bacterium proper, to the elongated rod or +cylinder of the bacillus, and the long spirals of spiro-bacteria. +It is unfortunate that they are not sufficiently constant in habit +to always attach themselves to one or the other of these genera. +The micrococcus has a habit of elongating at times until it is +impossible to recognize him except as a bacterium; while bacilli, +again, break up until their particles exactly resemble +micrococci.</p> + +<p>Bacteria cannot exist without water; certain forms require +oxygen, while others thrive equally well without it; some thrive in +solution of simple salts, while others require albuminoid +material.</p> + +<p>Bacteriology, with its relation to the science of medicine, is +of importance to every investigating physician; it covers our +knowledge of the relation of these minute organisms to the +ætiology of disease. What has been gained as to practical +application in the treatment of disease? This question is not +infrequently asked in a sneering manner. We can, in reply, say that +the results are not all in the future. It is encouraging that +results have been attained which have had a very important +practical bearing, and that these complaints come generally from +individuals least acquainted with scientific investigations in +bacteriology.</p> + +<p>In the study of the relation of a given bacterium to a certain +disease, it becomes necessary to attend carefully to three +different operations: First, the organism supposed to cause the +disease must be found and isolated. Second, it must be cultivated +through several generations in order that absolute purity may be +secured. Lastly, the germ must be again introduced into a healthy +living being. If the preceding steps be carried out, and the +original disease be communicated by inoculation, and the germs be +again found in the diseased body, we have no alternative; we must +conclude that we have ascertained the cause of the disease. The +importance of being familiar with the ætiology of the disease +before we can expect to combat it with any well-grounded hope of +success is evident.</p> + +<p>If the sputum of a phthisical patient be submitted to the +skilled microscopist, he is nearly always able to demonstrate +bacilli, but this goes for very little. Because bacilli are found +in phthisis, it is no more certain that they are the cause of +phthisis than it is certain that cheese mites are the cause of +cheese. Well, suppose we were to inject sputum from a phthisical +person into the lower animal and tuberculosis follows, and then +announce to the profession that we have demonstrated the relation +of the cause and effect between bacilli and phthisis? Why we would +start such an uproar of objections as would speedily convince us +that there was much work yet in the domain of bacteriology.</p> + +<p>The scientific investigators would say you have injected with +the sputum into the blood of your unfortunate patient, pus, +morphological elements, and perhaps half a dozen other forms of +bacteria, any one of which is just as likely to produce the disease +as the bacillus you have selected.</p> + +<p>The first important step is, first isolate your bacillus. If I +were to take a glass plate, one side of which is coated with a +thick solution of peptonized gelatin, and allow the water to +collect, the gelatinous matter will become solid. If now, with a +wire dipped in some tuberculous matter, I draw a line along the +gelatin, I have deposited at intervals along this line, specimens +of tubercle bacilli. If this plate be now kept at a proper +temperature, after a few days, wherever the bacilli have been +caught, a grayish spot will appear, which, easily seen with the +naked eye, gradually spreads and becomes larger. These spots are +colonies containing thousands of bacilli. Let us return to our +gelatin plate.</p> + +<p>We find a spot which answers to the description of a colony of +tubercle bacilli. We now take a minute particle from this colony on +a wire and convey it to the surface of some hardened blood serum in +a test tube. We plug the tube so that no air germs may drop in, and +place it in an incubator at the proper temperature. After several +days, if no contamination be present, a colony of bacilli will +appear around the spot where we sowed the spores. Let us repeat the +process.</p> + +<p>Take a particle from this colony, and transfer it to another +tube. This is our second culture. This must be repeated until we +are satisfied that we have secured a <i>pure</i> culture. If this +be carried to the twenty-fifth generation, we may be assured that +there remains no pus, no ptomaines, nothing but the desired +bacilli.</p> + +<p>It is a proper material now for inoculation, and if we inoculate +some of the lower animals, for instance the monkey, we produce a +disease identical with phthisis pulmpnalis. Bacteria also afford +peculiar chemical reactions. For example, nitric acid will +discharge all the color from all bacilli artificially dyed with +anilin, except those of tubercle and anthrax. One species is +stained readily with a dye that leaves another unaltered. Thus we +are enabled in the laboratory to determine whether the bacilli +found in sputum, for example, are from tubercle or are the bacteria +of decomposition.</p> + +<p>From what I have said of the tubercle bacillus, it would seem +thoroughly demonstrated that it is the cause of tubercle in these +animals. But we must walk cautiously here. These are not human +beings, who know that like results would follow their inoculation. +The animals used by Koch are animals very subject to tubercle.</p> + +<p>We must, from the very nature of our environment, be constantly +inhaling these germs as we pass through the wards of our hospitals; +yes, they are floating in the air of our streets and dwellings. It +becomes necessary then for us to inquire: If bacteria cause +disease, in what manner do they produce it? The healthy organism is +always beset with a multitude of non-pathogenic bacteria. They +occupy the natural cavities, especially the alimentary canal. They +feed on the substances lying in their neighborhood, whether brought +into the body or secreted by the tissues. In so doing they set up +chemical changes in their substances. Where the organs are acting +normally these fungi work no mischief. The products of +decomposition thus set up are harmless, or are conveyed out of the +body before they begin to be active.</p> + +<p>If bacteria develop to an inordinate degree, if the contents of +organs are not frequently discharged, fermentative processes may be +set up, which result in disease. Bacteria must always multiply and +exist at the expense of the body which they infest, and the more +weakened the vital forces become, the more favorable is the soil +for their development.</p> + +<p>Septicæmia is caused by the absorption of the products of +putrefaction, induced before bacteria can multiply inside or +outside the body. Bacteria must find a congenial soil. The +so-called cholera bacillus must gain access to the intestinal tract +before it finds conditions suitable to colonization. It does not +seem to multiply in the stomach or in the blood, but once injected +into the duodenum develops with astonishing rapidity, and the +delicate epithelial cells of the villi become swollen, soften and +break down, exposing the mucosa.</p> + +<p>It has been shown that <i>bouillon</i> in which Loeffler's +diphtheria bacillus has grown, and which has been passed through +unglazed porcelain filters, shows the presence of a poison which is +capable of producing the same results upon inoculation as the pure +culture of the bacillus itself. Zarniko, working upon the same +organism, obtained a number of positive results that led him to +declare this bacillus is the cause of epidemic diphtheria, in spite +of many assertions to the contrary. Chantmesse and Widal record the +results of their work as to what will most easily and effectively +destroy the bacillus of diphtheria.</p> + +<p>The only three substances that actually checked and destroyed +its vitality were phenic acid (5 per cent.), camphor (20 per +cent.), olive oil (25 per cent.), in combination. For the last I +substitute glycerine, because this allows the mixture to penetrate +farther into the mucous membrane than oil, the latter favoring a +tendency to pass over the surface. This mixture when heated +separates into two layers, the upper one viscid and forming a sort +of "glycerol," the lower clear. The latter will completely +sterilize a thread dipped in a pure culture of the diphtheria +bacillus. Corrosive sublimate was not examined because in strong +enough doses it would be dangerous and in weaker ones it would be +useless.</p> + +<p>The facts obtained in regards to the streptococcus of erysipelas +are reported as follows: That both chemical and experimental +evidence teach the extreme ease of a renewed attack of the disease; +that it is possible to kill guinea pigs by an intoxication when +they are immune to an inoculation of the culture in ordinary +quantities. And this latter fact should warn experimenters trying +to obtain immunity in man by the inoculation of non-pathogenic +bacteria, because the same results may be reached.</p> + +<p>A new theory in regard to fevers and the relation of +micro-organisms is suggested by Roussy, viz.: That it is a +fermentation produced by a diastase or soluble ferment found in all +micro-organisms and cells, and which they use in attacking and +transforming matter, either inside their substance or without +it.</p> + +<p>The resemblance of the malaria parasite to that of recurrent +fever is noted in the work of Sacharoff. He states that there +exists in the blood of those suffering from recurrent fever a +hæmatozoon, which is most prominent after the fever has begun +to fall, when it is of enormous proportions, twenty or more +diameters of a red blood corpuscle, although smaller ones may still +be found. The parasite consists of a delicate amœboid body +containing a multitude of dark, round, uniform, sharply outlined, +movable granules. Besides these, the protoplasm contains a +generally grayish homogeneous nucleus as large as one or two red +blood corpuscles. The protoplasm sends out pseudopodia (with +granules), which sometimes separate and appear as small delicate +pieces of protoplasm. They vary in size, and are often swallowed by +the red blood corpuscles in which they grow, and finally develop +into the above mentioned amœboid bodies.</p> + +<p>Prof. J. Lewis Smith has made a great many autopsies of children +dead from cholera infantum, and almost invariably found the stomach +and liver in a comparatively healthy condition. Ganghen, who has +given this subject considerable study, denies the existence of any +specific germ in the summer diarrhea of infants, but claims to have +found three different germs in the intestines of children suffering +from cholera infantum, each producing a chemical poison which is +capable of producing vomiting, purging, and even death. A great +variety of germs are found in drinking water, and no doubt +countless numbers are taken into the digestive tract, and the +principal reason why pathological conditions do not occur more +frequently is on account of the germicidal qualities of the gastric +juice.</p> + +<p>The comma bacillus of Koch, and the typhoid fever germ of +Eberth, are especially destroyed in normal gastric juice. When the +germs are very numerous, they run the gauntlet of the stomach (as +the gastric juice is secreted only during digestion); and once in +the alkaline intestinal canal they are capable of setting up +disease, other conditions contributing—ill health, deranged +digestion, etc.</p> + +<p>Mittnam has made a study of bacteria beneath the nails, and +reports, after examining persons following different occupations, +having found numerous varieties of micro-organisms; which are +interesting from a scientific standpoint relative to the importance +of thoroughly cleansing the hands before undertaking any surgical +procedure. He found, out of twenty-five experiments, 78 varieties +of bacteria, of which 36 were classed as micrococci, 21 diplococci, +18 rods, 3 sarcinæ, and 1 yeast. Cooks, barbers, waiters, +etc., were examined.</p> + +<p>The blood, defibrinated and freshly drawn, has marked germicidal +action; for bacteria its action is decidedly deadly, even hours +after it has been drawn from the body. Especially were anti-germic +qualities noticed upon pathogenic bacteria. Buchner put the bacilli +of anthrax in a quantity of blood, and in two hours the number was +reduced from 4,800 to 56, and in three hours only 3 living bacteria +remained. Other bacteria were experimented upon in blood with +similar results, but the destruction of the organism from +putrefaction was much less marked, and on some varieties the blood +had little or no action.</p> + +<p>It is not the object of these remarks to even give a +<i>résumé</i> of the <i>status præsens</i> of +bacteriology, but simply to stimulate thought in that direction. +The claims of some of the ultra-bacteriologists may never be +realized, but enough has been accomplished to revolutionize the +treatment of certain diseases, and the observing student will do +well to keep his eye on the microbe, as it seems from the latest +investigations that its star is in the ascendant. And who can +prognosticate but that in the next decade an entire revolution in +the ætiology and treatment of many diseases may take +place?</p> + +<p>Detroit, Mich.</p> + +<hr /> +<h2><a id="xi_3" name="xi_3"></a>THE COMPOSITION OF KOCH'S +LYMPH.</h2> + +<h3>WHAT PROFESSOR KOCH SAYS IT IS, AND WHAT IT CAN DO.</h3> + +<h3>(By Cable to the <i>Medical Record</i>.)</h3> + +<h3>BERLIN, January 15, 1891.</h3> + +<p>The curiosity to know the composition of the famous lymph has +been gratified by the publication to-day of an article by Professor +Koch on the subject. In the following, as will be seen, he +reaffirms his original convictions and acknowledges the valuable +assistance he has received from those who have used his fluid, and +thus helped him in the accumulation of experience.</p> + +<p>Professor Koch says: Two months ago I published the results of +my experiments with the new remedy for tuberculosis, since which +time many physicians who received the preparation have been enabled +to become acquainted with its properties through their own +experiments. So far as I have been able to review the statements +published and the communications received by letter, my predictions +have been fully and completely confirmed. The general consensus of +opinion is that the remedy has a specific action upon tubercular +tissues, and is, therefore, applicable as a very delicate and sure +reagent for discovering latent and diagnosing doubtful tuberculous +processes. Regarding the curative effects of the remedy, most +reports agree that, despite the comparatively short duration of its +application, many patients have shown more or less pronounced +improvement. It has been affirmed that in not a few cases even a +cure has been established. Standing quite by itself is the +assertion that the remedy may not only be dangerous in cases which +have advanced too far—a fact which may forthwith be +conceded—but also that it actually promotes the tuberculous +process, being therefore injurious.</p> + +<p>During the past six weeks I myself have had opportunity to bring +together further experiences touching the curative effects and +diagnostic application of the remedy in the cases of about one +hundred and fifty sufferers from tuberculosis of the most varied +types in this city and in the Moabit Hospital.</p> + +<p>I can only say that everything I have latterly seen accords with +my previous observations. There has been nothing to modify in what +I before reported. As long as it was only a question of proving the +accuracy of my indications, it was needless for any one to know +what the remedy contained or whence it was derived. On the +contrary, subsequent testing would necessarily be more unbiased, +the less people knew of the remedy itself. Now, after sufficient +confirmatory testing, the importance of the remedy is proved, my +next task is to extend my study of the remedy beyond the field +where it has hitherto been applied, and if possible to apply the +principle underlying the discovery to other diseases.</p> + +<p>This task naturally demands a full knowledge of the remedy. I +therefore consider that the time has arrived when the requisite +indications in this direction shall be made. This is done in what +follows.</p> + +<p>Before going into the remedy itself, I deem it necessary for the +better understanding of its mode of operation to state briefly the +way by which I arrived at the discovery. If a healthy guinea pig be +inoculated with the pure cultivation of German Kultur of tubercle +bacilli, the wound caused by the inoculation mostly closes over +with a sticky matter, and appears in its early days to heal. Only +after ten to fourteen days a hard nodule presents itself, which, +soon breaking, forms an ulcerating sore, which continues until the +animal dies. Quite a different condition of things occurs when a +guinea pig already suffering from tuberculosis is inoculated. An +animal successfully inoculated from four to six weeks before is +best adapted for this purpose. In such an animal the small +indentation assumes the same sticky covering at the beginning, but +no nodules form. On the contrary, on the day following, or the +second day after the inoculation, the place where the lymph is +injected shows a strange change. It becomes hard and assumes a +darker coloring, which is not confined to the inoculation spot, but +spreads to the neighboring parts until it attains a diameter of +from 0.05 to 1 cm.</p> + +<p>In a few days it becomes more and more manifest that the skin +thus changed is necrotic, finally falling off, leaving a flat +ulceration which usually heals rapidly and permanently without any +involvement of the adjacent lymphatic glands. Thus the injected +tubercular bacilli quite differently affect the skin of a healthy +guinea pig from one affected with tuberculosis. This effect is not +exclusively produced with living tubercular bacilli, but is also +observed with the dead bacilli, the result being the same whether, +as I discovered by experiments at the outset, the bacilli are +killed by a somewhat prolonged application of a low temperature or +boiling heat or by means of certain chemicals. This peculiar fact I +followed up in all directions, and this further result was +obtained—that killed pure cultivations of tubercular bacilli, +after rinsing in water, might be injected in great quantities under +healthy guinea pig's skin without anything occurring beyond local +suppuration. Such injections belong to the simplest and surest +means of producing suppurations free from living bacteria.</p> + +<p>Tuberculous guinea pigs, on the other hand, are killed by the +injection of very small quantities of such diluted cultivations. In +fact, within six to forty-eight hours, according to the strength of +the dose, an injection which is not sufficient to produce the death +of the animal may cause extended necrosis to the skin in the +vicinity of the place of injection. If the dilution is still +further diluted until it is scarcely visibly clouded, the animals +inoculated remain alive and a noticeable improvement in their +condition soon supervenes. If the injections are continued at +intervals of from one to two days, the ulcerating inoculation wound +becomes smaller and finally scars over, which otherwise it never +does; the size of the swollen lymphatic glands is reduced, the body +becomes better nourished, and the morbid process ceases, unless it +has gone too far, in which case the animal perishes from +exhaustion. By this means the basis of a curative process against +tuberculosis was established.</p> + +<p>Against the practical application of such dilutions of dead +tubercle bacilli there presented itself the fact that the tubercle +bacilli are not absorbed at the inoculation points, nor do they +disappear in another way, but for a long time remain unchanged, and +engender greater or smaller suppurative foci. Anything, therefore, +intended to exercise a healing effect on the tuberculous process +must be a soluble substance which would be liberated to a certain +extent by the fluids of the body floating around the tubercle +bacilli, and be transferred in a fairly rapid manner to the juices +of the body; while the substance producing suppuration apparently +remains behind in the tubercular bacilli, or dissolves but very +slowly. The only important point was, therefore, to induce outside +the body the process going on inside, if possible, and to extract +from the tubercular bacilli alone the curative substance. This +demanded time and toil, until I finally succeeded, with the aid of +a forty to fifty per cent. solution of glycerine, in obtaining an +effective substance from the tubercular bacilli. With the fluid so +obtained I made further experiments on animals, and finally on +human beings. These fluids were given to other physicians to enable +them to repeat the experiments.</p> + +<p>The remedy which is used in the new treatment consists of a +glycerine extract, derived from the pure cultivation of tubercle +bacilli. Into the simple extract there naturally passes from the +tubercular bacilli, besides the effective substance, all the other +matter soluble in fifty per cent. glycerine.</p> + +<p>Consequently, it contains a certain quantity of mineral salts, +coloring substances, and other unknown extractive matters. Some of +these substances can be removed from it tolerably easily. The +effective substance is insoluble in absolute alcohol. It can be +precipitated by it, though not, indeed, in a pure condition, but +still combined with the other extractive matter. It is likewise +insoluble in alcohol. The coloring matter may also be removed, +rendering it possible to obtain from the extract a colorless, dry +substance containing the effective principle in a much more +concentrated form than the original glycerine solution. For +application in practice this purification of the glycerine extract +offers no advantage, because the substances so eliminated are +unessential for the human organism. The process of purification +would make the cost of the remedy unnecessarily high.</p> + +<p>Regarding the constitution of the more effective substances, +only surmises may for the present be expressed. It appears to me to +be derivative from albuminous bodies, having a close affinity to +them. It does not belong to the group of so-called toxalbumins, +because it bears high temperatures, and in the dialyzer goes easily +and quickly through the membrane. The proportion of the substance +in the extract to all appearance is very small. It is estimated at +fractions of one per cent., which, if correct, we should have to do +with a matter whose effects upon organisms attacked with +tuberculosis go far beyond what is known to us of the strongest +drugs.</p> + +<p>Regarding the manner in which the specific action of the remedy +on tuberculous tissue is to be represented, various hypotheses may +naturally be put forward. Without wishing to affirm that my view +affords the best explanation, I represent the process myself in the +following manner:</p> + +<p>The tubercle bacilli produced when growing in living tissues, +the same as in artificial cultivations, contain substances which +variously and notably unfavorably influence living elements in +their vicinity. Among these is a substance which in a certain +degree of concentration kills or so alters living protoplasm that +it passes into a condition that Weigert describes as coagulation +necrosis. In tissue thus become necrotic the bacillus finds such +unfavorable conditions of nourishment that it can grow no more and +sometimes dies.</p> + +<p>This explains the remarkable phenomenon that in organs newly +attacked with tuberculosis, for instance in guinea pigs' spleen and +liver, which then are covered with gray nodules, numbers of bacilli +are found, whereas they are rare or wholly absent when the +enormously enlarged spleen consists almost entirely of whitish +substance in a condition of coagulation necrosis, such as is often +found in cases of natural death in tuberculous guinea pigs. The +single bacillus cannot, therefore, induce necrosis at a great +distance, for as soon as necrosis attains a certain extension the +growth of the bacillus subsides, and therewith the production of +the necrotizing substance. A kind of reciprocal compensation thus +occurs, causing the vegetation of isolated bacilli to remain so +extraordinarily restricted, as, for instance, in lupus and +scrofulous glands.</p> + +<p>In such cases the necrosis generally extends only to a part of +the cells, which then, with further growth, assume the peculiar +form of riesen zelle, or giant cells. Thus, in this interpretation, +follow first the explanation Weigert gives of the production of +giant cells.</p> + +<p>If now one increased artificially in the vicinity of the +bacillus the amount of necrotizing substance in the tissue, the +necrosis would spread a greater distance. The conditions of +nourishment for the bacillus would thereby become more unfavorable +than usual.</p> + +<p>In the first place the tissue which had become necrotic over a +large extent would decay and detach itself, and where such were +possible would carry off the inclosed bacilli and eject them +outwardly, so far disturbing their vegetation that they would much +more speedily be killed than under ordinary circumstances.</p> + +<p>It is just in looking at such changes that the effect of the +remedy appears to consist. It contains a certain quantity of +necrotizing substance, a correspondingly large dose of which +injures certain tissue elements even in a healthy person, and +perhaps the white blood corpuscles or adjacent cells, thereby +producing fever and a complication of symptoms, whereas with +tuberculous patients a much smaller quantity suffices to induce at +certain places, namely, where tubercle bacilli are vegetating and +have already impregnated the adjacent region with the same +necrotizing matter, more or less extensive necrosis of the cells, +with the phenomena in the whole organism which result from and are +connected with it.</p> + +<p>For the present, at least, it is impossible to explain the +specific influence which the remedy, in accurately defined doses, +exercises upon tuberculous tissue, and the possibility of +increasing the doses with such remarkable rapidity, and the +remedial effects which have unquestionably been produced under not +too favorable circumstances.</p> + +<p>Of the consumptive patients whom he described as temporarily +cured, two have been returned to the Moabit Hospital for further +observation.</p> + +<p>No bacilli have appeared in their sputum for the past three +months, and their phthisical symptoms have gradually and completely +disappeared.</p> + +<hr /> +<h2><a id="ii_1" name="ii_1"></a>CAN WE SEPARATE ANIMALS FROM +PLANTS?</h2> + +<h3>By ANDREW WILSON.</h3> + +<p>One of the plainest points connected with the study of living +things is the power we apparently possess of separating animals +from plants. So self-evident appears this power that the popular +notion scoffs at the idea of science modestly disclaiming its +ability to separate the one group of living beings from the other. +Is there any danger of confusing a bird with the tree amid the +foliage of which it builds its nest, or of mistaking a cow for the +grass it eats? These queries are, of course, answerable in one way +only. Unfortunately (for the querists), however, they do not +include or comprehend the whole difficulty. They merely assert, +what is perfectly true, that we are able, without trouble, to mark +off the higher animals from the higher plants. What science +inquires is, whether we are able to separate <i>all</i> animals +from <i>all</i> plants, and to fix a definite boundary line, so as +to say that all the organisms on the one side of the line are +assuredly animals, while all the others on the opposite side of the +line may be declared to be truly plants. It is exactly this task +which science declares to be among the impossibilities of +knowledge. Away down in the depths of existence and among the +groundlings of life the identity of living things becomes of a +nature which is worse than confusing, and which renders it a futile +task to attempt to separate the two worlds of life. The +hopelessness of the task, indeed, has struck some observers so +forcibly that they have proposed to constitute a third +kingdom—the <i>Regnum Protisticum</i>—between the +animal and the plant worlds, for the reception of the host of +doubtful organisms. This third kingdom would resemble the casual +ward of a workhouse, in that it would receive the waifs and strays +of life which could not find a refuge anywhere else.</p> + +<p>A very slight incursion into biological fields may serve to show +forth the difficulties of naturalists when the task of separating +animals from plants is mooted for discussion. To begin with, if we +suppose our popular disbeliever to assert that animals and plants +are always to be distinguished by shape and form, it is easy enough +to show him that here, as elsewhere, appearances are deceptive. +What are we to say of a sponge, or a sea anemone, of corals, of +zoophytes growing rooted from oyster shells, of sea squirts, and of +sea mats? These, each and all of them, are true animals, but they +are so plant-like that, as a matter of fact, they are often +mistaken by seaside visitors for plants. This last remark holds +especially true of the zoophytes and the sea mats. Then, on the +other hand, we can point to hundreds of lower plants, from the +yeast plant onward, which show none of the ordinary features of +plant life at all. They possess neither roots, stems, branches, +leaves, nor flowers, so that on this first count of the indictment +the naturalist gains the day.</p> + +<p>Power of movement, to which the popular doubter is certain to +appeal, is an equally baseless ground of separation. For all the +animals I have above named are rooted and fixed, while many true +plants of lower grade are never rooted at all. The yeast plant, the +<i>Algæ</i> that swarm in our ponds, and the diatoms that +crowd the waters, exemplify plants that are as free as animals; and +many of them, besides, in their young state especially (e.g., the +seaweeds), swim about freely in the water as if they were roving +animalcules. On the second count, also, science gains the day; +power of motion is no legitimate ground at all for distinguishing +one living being as an animal, while absence of movement is +similarly no reason for assuming that the fixed organism must of +necessity be a plant. Then comes the microscopic evidence. What can +this wonder glass do in the way of drawing boundary lines betwixt +the living worlds? The reply again is disappointing to the doubter; +for the microscope teaches us that the tissues of animals and +plants are built upon kindred lines. We meet with cells and fibers +in both. The cell is in each case the primitive expression of the +whole organism. Beyond cells and fibers we see the wonderful living +substance, <i>protoplasm</i>, which is alike to our senses in the +two kingdoms, although, indeed, differing much here and there in +the results of its work. On purely microscopic grounds, we cannot +separate animals from plants. There is no justification for rigidly +assuming that this is a plant or that an animal on account of +anything the microscope can disclose. A still more important point +in connection with this protoplasm question consists in the fact +that as we go backward to the beginnings of life, both in animals +and plants, we seem to approach nearer and nearer to an identity of +substance which baffles the microscope with all its powers of +discernment. Every animal and every plant begins existence as a +mere speck of this living jelly. The germ of each is a protoplasm +particle, which, whatever traces of structure it may exhibit, is +practically unrecognizable as being definitely animal or plant in +respect of its nature. Later on, as we know, the egg or germ shows +traces of structure in the case of the higher animals and plants; +while even lowly forms of life exhibit more or less characteristic +phases when they reach their adult stage. But, of life's +beginnings, the microscope is as futile as a kind scientific +touchstone for distinguishing animals from plants as is power of +movement, or shape, or form.</p> + +<p>A fourth point of appeal in the matter is found within the +domain of the chemist. Chemistry, with its subtile powers of +analysis, with its many-sided possibilities of discovering the +composition of things, and with its ability to analyze for us even +the light of the far distant stars, only complicates the +difficulties of the biologist. For, while of old it was assumed +that a particular element, nitrogen, was peculiar to animals, and +that carbon was an element peculiar to plants, we now know that +both elements are found in animals, just as both occur in plants. +The chemistry of living things, moreover, when it did grow to +become a staple part of science, revealed other and greater +anomalies than these. It showed that certain substances which were +supposed to be peculiar to plants, and to be made and manufactured +by them alone, were also found in animals. Chlorophyl is the green +coloring matter of plants, and is, of course, a typical product of +the vegetable world; yet it is made by such animals as the hydra of +the brooks and ponds, and by many animalcules and some worms. +Starch is surely a typical plant product, yet it is undoubtedly +manufactured, or at least stored up, by animals—a work +illustrated by the liver of man himself, which occasionally +produces sugar out of its starch.</p> + +<p>Again, there is a substance called <i>cellulose</i>, found well +nigh universally in plants. Of this substance, which is akin to +starch, the walls or envelopes of the cells of plant tissues are +composed. Yet we find those curious animals, the sea squirts, found +on rocks and stones at low-water mark, manufacturing cellulose to +form part and parcel of the outer covering of their sac-like +bodies. Here it is as if the animal, like a dishonest manufacturer, +had infringed the patent rights of the plant. On the fourth count, +then—that of chemical composition—the verdict is that +nothing that chemistry can teach us may serve definitely, clearly, +and exactly to set a boundary line or to erect a partition wall +between the two worlds of life. There yet remains for us to +consider a fifth head—that of the food.</p> + +<p>In the matter of the feeding of the two great living worlds we +might perchance light upon some adequate grounds for making up the +one kingdom from the other. What the consideration of form, +movement, chemical composition, and microscopic structure could not +effect for us in this way, it might be supposed the investigation +of the diet of animals and plants would render clear. Our hopes of +distinguishing the one group from the other by reference to the +food on which animals and plants subsist are, however, dashed to +the ground; and the diet question leaves us, therefore, when it has +been discussed, in the same quandary as before.</p> + +<p>Nevertheless, it is an interesting story, this of the nutrition +of animals and plants. A large amount of scientific information is +to be gleaned from such a study, which may very well be commenced +by our having regard to the matters on which a <i>green</i> plant +feeds. I emphasize the word "green," because it so happens that +when a plant has no chlorophyl (as green color is named in the +plant world) its feeding is of diverse kind to that which a green +plant exhibits. The mushroom or other fungus may be taken as an +illustration of a plant which represents the non-green race, while +every common plant, from a bit of grass to an oak tree, exemplifies +the green-bearing order of the vegetable tribes.</p> + +<p>Suppose we were to invite a green plant to dinner, the +<i>menu</i> would have to be very differently arranged from that +which would satisfy a human or other animal guest. The soup would +be represented for the plant's delectation by water, the fish by +minerals, the joint by carbonic acid gas, and the dessert by +ammonia. On these four items a green plant feeds, out of them it +builds up its living frame. Note that its diet is of inorganic or +non-living matter. It derives its sustenance from soil and air, yet +out of these lifeless matters the green plant elaborates and +manufactures its living matter, or protoplasm. It is a more +wonderful organism than the animal, for while the latter can only +make new protoplasm when living matter is included in its food +supply, the green plant, by the exercise of its vital chemistry, +can transform that which is not living into that which is +life-possessing.</p> + +<p>The green plant in other words, raises non-living into living +matter, while the animal can only transform living matters into its +like. This is why the plant is called a constructive organism, +while the animal is, contrariwise, named a destructive one. The +result of the plant's existence is to build up, that of the +animal's life is to break down its substance, as the result of its +work, into non-living matter. The animal's body is, in fact, +breaking down into the very things on which the green plant feeds. +We ourselves are perpetually dissipating our substance in our acts +of life and work into the carbonic acid, water, ammonia, and +minerals on which plants feed. We "die daily" in as true a sense as +that in which the apostle used the term. And out of the debris of +the animal frame the green plant builds up leaf and flower, stein +and branch, and all the other tokens of its beauty and its +life.</p> + +<p>If, then, an animal can only live upon living matter—that +is to say on the bodies of other animals or of plants—with +water, minerals and oxygen gas from the air thrown in to boot, we +might be tempted to hold that in such distinctive ways and works we +had at last found a means of separating animals from plants. +Unfortunately, this view may be legitimately disputed and rendered +null and void, on two grounds. First of all, the mushrooms and +their friends and neighbors, all true plants, do not feed as do the +green tribes. And secondly, many of the green plants themselves can +be shown to have taken very kindly to an animal mode of diet.</p> + +<p>A mushroom, thus, because it has no green color, lives upon +water, oxygen, minerals, and organic matter. You can only grow +mushrooms where there is plenty of animal matter in a state of +decay, and as for the oxygen, they habitually inhale that gas as if +they were animals. Non-green plants thus want a most characteristic +action of their green neighbors. For the latter in daylight take in +the carbonic acid gas, which is composed of carbon and oxygen. +Under the combined influence of the green color and the light, they +split up the gas into its two elements, retaining the carbon for +food and allowing the oxygen to escape to the atmosphere. Alas! +however, in the dark our green plant becomes essentially like an +animal as regards its gas food, for then it is an absorber of +oxygen, while it gives off carbonic acid. If to take in carbonic +acid and to give out oxygen be held to be a feature characteristic +of a plant, it is one, as has been well said, which disappears with +the daylight in green plants, and which is not witnessed at all in +plants that have no green color.</p> + +<p>So far, we have seen that not even the food of plants and +animals can separate the one kingdom of life from the other. The +mushroom bars the way and the green plant's curious behavior by +night and by day respectively, in the matter of its gas food, once +more assimilates animal life and plant life in a remarkable manner. +Still more interesting is the fact, already noticed, that even +among the green tribes there are to be found many and various +lapses from the stated rules of their feeding. Thus what are we to +say of the parasitic mistletoe, which, while it has grown leaves of +its own, and can, therefore, obtain so much carbon food from the +air on its own account, nevertheless drinks up the sap of the oak +or apple which forms its host, and thus illustrates the spectacle +of a green plant feeding like an animal, on living matter? Or, what +may we think of such plants as the sundew, the Venus' fly trap, the +pitcher plants, the side saddle plants, the butterworts and +bladderworts, and others of their kind, which not only capture +insects, often by ingenious and complex lures, but also digest the +animal food thus captured? A sundew thus spreads out its lure in +the shape of its leaf studded with sensitive tentacles, each capped +by a glistening drop of gummy secretion. Entangled in this +secretion, the fly is further fixed to the leaf by the tentacles +which bend over it and inclose it in their fold. Then is poured out +upon the insect's body a digestive acid fluid, and the substance of +the dissolved and digested animal is duly absorbed by the plant. So +also the Venus' fly trap captures insects by means of its leaf, +which closes upon the prey when certain sensitive hairs have given +the signal that the animal has been trapped. Within the leaf the +insect is duly digested as before, and its substance applied to the +nutrition of the plant. Such plants, moreover, cannot flourish +perfectly unless duly supplied with their animal food. Such +illustrations of exceptions to the rule of green plant feeding +simply have the effect of abolishing the distinctions which the +diet question might be supposed to raise between animals and +plants. We may return to the sundews and other insect catchers; +meanwhile, I have said enough to show that to the question, "Can we +separate animals from plants?" a very decided negative reply must +be given. Life everywhere exhibits too many points of contact to +admit of any boundary line being drawn between the two great groups +which make up the sum total of organic +existence.—<i>Illustrated London News.</i></p> + +<hr /> +<h2><a id="xii_2" name="xii_2"></a>THE RECOVERY OF SILVER AND GOLD +FROM PLATING AND GILDING SOLUTIONS.</h2> + +<p>In view of the rapid development and extension of the methods of +electro-plating with silver and gold, and of the large amount of +spent liquors containing silver or gold thus produced, it has long +been desirable to find methods by which these metals can be +recovered from the spent liquors. The processes hitherto adopted +generally necessitate the tedious and unpleasant evaporation of the +cyanide liquors, or else involve a series of chemical operations +which are somewhat difficult to carry out, so that actually the +used-up baths are sold to some firm which undertakes this recovery +as a particular branch of its business.</p> + +<p>A process invented by Stockmuir and Fleischmann, and worked out +by them in the chemical laboratory of the Bavarian Industrial +Museum, is, however, exceedingly simple, and is employed in many +establishments.</p> + +<p>In order to remove silver from a potassium cyanide silver +solution, it is only necessary to allow a clean piece of plate zinc +to remain in the liquid for two days; even better results are +obtained by the use of iron conjointly with the zinc. In the first +case, the silver often adheres firmly to the zinc, while in the +second it always separates out as a powder. It is then only +necessary to wash the precipitated powder, which usually contains +copper (since spent silver solutions always contain copper), dry +it, and then dissolve it in hot concentrated sulphuric acid, water +being added, and the dissolved silver precipitated by strips of +copper. The silver thus obtained is perfectly pure. If the amount +of copper present is only small, it can usually be removed by +fusing the precipitated powder with a little niter and borax.</p> + +<p>In this way a spent silver bath was found to contain per +liter</p> + +<div class="ctr"> +<table border="0" cellpadding="4" cellspacing="0" summary=""> +<colgroup span="2"> +<col align="left" /> +<col align="right" /> +<col align="center" /></colgroup> + +<tr> +<td>1st experiment</td> +<td>1.5706</td> +<td>grms.</td> +</tr> + +<tr> +<td>2d experiment</td> +<td>1.5694</td> +<td>"</td> +</tr> + +<tr> +<td></td> +<td>———</td> +</tr> + +<tr> +<td>Mean</td> +<td>1.5700</td> +<td>"</td> +</tr> +</table> +</div> + +<p>The presence of silver could not be qualitatively ascertained in +the residual liquor.</p> + +<p>Although sheet zinc, or zinc and iron sheets, serve so well for +the precipitation of silver, they cannot be employed for the +recovery of gold. The latter separates out in such a case very +incompletely and as a firmly adhering lustrous film in the zinc. On +the other hand, finely divided zinc, the so-called zinc dust, is an +excellent substance to employ for precipitating gold quantitatively +and in the form of powder from spent cyanide liquors. When zinc +dust is added to a spent gold bath and the liquid periodically +stirred or shaken, all the gold is precipitated in two or three +days. The amount of zinc to be added naturally depends on the +quantity of gold present. Freshly prepared gold baths for gilding +in the cold contain on the average 3.5 grms. gold per liter, while +those used for the hot process contain 10.75 grms. To precipitate +all the gold in the original bath, 1.74 grms. or 0.37-0.5 grms. +zinc dust would be necessary, and, of course, a much smaller +quantity would be sufficient for the spent liquors. Since the +precipitation takes place more rapidly when an excess of zinc dust +is present, it is generally advisable to add ¼ or at the +most ½ kilo, of zinc dust to every 100 liters of +solution.</p> + +<p>The precipitated gold, which contains zinc dust and usually +silver and copper, is washed, freed from zinc by hydrochloric acid, +and then from silver and copper by nitric acid and thus obtained +pure.</p> + +<p>A spent bath treated in this way gave the following amounts of +gold per liter:</p> + +<div class="ctr"> +<table border="0" cellpadding="4" cellspacing="0" summary=""> +<colgroup span="2" align="left"></colgroup> + +<tr> +<td>1st experiment</td> +<td>0.2626</td> +</tr> + +<tr> +<td>2d experiment</td> +<td>0.2634</td> +</tr> + +<tr> +<td>Mean</td> +<td>0.2630 grms.</td> +</tr> +</table> +</div> + +<p>The presence of gold in the residual cyanide solution could not +be qualitatively detected. The potassium cyanide of the solutions +obtained by this process should be converted into ferrocyanide by +heating with ferrous sulphate and milk of lime, since this +substance is not poisonous and can therefore be got rid of without +danger. It would, however, be more economical and, considering the +large amount of cyanide present, more profitable to work it up into +Prussian blue.</p> + +<hr /> +<h3>A new Catalogue of Valuable Papers</h3> + +<p>Contained in SCIENTIFIC AMERICAN SUPPLEMENT during the past ten +years, sent <i>free of charge</i> to any address. MUNN & CO., +361 Broadway, New York.</p> + +<hr /> +<h3>THE SCIENTIFIC AMERICAN</h3> + +<h2>Architects and Builders Edition</h2> + +<p class="ctr"><b>$2.50 a Year. Single Copies, 25 cts.</b></p> + +<p>This is a Special Edition of the SCIENTIFIC AMERICAN, issued +monthly—on the first day of the month. Each number contains +about forty large quarto pages, equal to about two hundred ordinary +book pages, forming, practically, a large and splendid <b>Magazine +of Architecture</b>, richly adorned with <i>elegant platen in +colors</i> and with fine engravings, illustrating the most +interesting examples of modern Architectural Construction and +allied subjects.</p> + +<p>A special feature is the presentation in each number of a +variety of the latest and best plans for private residences, city +and country, including those of very moderate cost as well as the +more expensive. Drawings in perspective and in color are given, +together with full Plans, Specifications, Costs, Bills of Estimate, +and Sheets of Details.</p> + +<p>No other building paper contains so many plans, details, and +specifications regularly presented as the SCIENTIFIC AMERICAN. +Hundreds of dwellings have already been erected on the various +plans we have issued during the past year, and many others are in +process of construction.</p> + +<p>Architects, Builders, and Owners will find this work valuable in +furnishing fresh and useful suggestions. All who contemplate +building or improving homes, or erecting structures of any kind, +have before them in this work an almost <i>endless series of the +latest and best examples</i> from which to make selections, thus +saving time and money.</p> + +<p>Many other subjects, including Sewerage, Piping, Lighting, +Warming, Ventilating, Decorating, Laying out of Grounds, etc., are +illustrated. An extensive Compendium of Manufacturers' +Announcements is also given, in which the most reliable and +approved Building Materials, Goods, Machines, Tools, and Appliances +are described and illustrated, with addresses of the makers, +etc.</p> + +<p>The fullness, richness, cheapness, and convenience of this work +have won for it the <b>Largest Circulation</b> of any Architectural +publication in the world.</p> + +<p>A Catalogue of valuable books on Architecture, Building, +Carpentry, Masonry, Heating, Warming, Lighting, Ventilation, and +all branches of industry pertaining to the art of Building, is +supplied free of charge, sent to any address.</p> + +<p class="ctr"><b>MUNN & CO., Publishers,</b></p> + +<p class="ctr"><b>361 Broadway, New York.</b></p> + +<hr /> +<h3>Building Plans and Specifications.</h3> + +<p>In connection with the publication of the BUILDING EDITION of +the SCIENTIFIC AMERICAN, Messrs. Munn & Co. furnish plans and +specifications for buildings of every kind, including Churches, +Schools, Stores, Dwellings, Carriage Houses, Barns, etc.</p> + +<p>In this work they are assisted by able and experienced +architects. Full plans, details, and specifications for the various +buildings illustrated in this paper can be supplied.</p> + +<p>Those who contemplate building, or who wish to alter, improve, +extend, or add to existing buildings, whether wings, porches, bay +windows, or attic rooms, are invited to communicate with the +undersigned. Our work extends to all parts of the country. +Estimates, plans, and drawings promptly prepared. Terms moderate. +Address</p> + +<p class="ctr"><b>MUNN & CO., 361 BROADWAY, NEW YORK.</b></p> + +<hr /> +<h3>Scientific American Supplement.</h3> + +<p class="ctr"><b>PUBLISHED WEEKLY.</b></p> + +<p class="ctr"><b>Terms of Subscription, $5 a year.</b></p> + +<p>Sent by mail, postage prepaid, to subscribers in any part of the +United States or Canada. Six dollars a year, sent, prepaid, to any +foreign country.</p> + +<p>All the back numbers of THE SUPPLEMENT, from the commencement, +January 1, 1876, can be had. Price, 10 cents each.</p> + +<p>All the back volumes of THE SUPPLEMENT can likewise be supplied. +Two volumes are issued yearly. Price of each volume, $2.50 stitched +in paper, or $3.50 bound in stiff covers.</p> + +<p>COMBINED RATES.—One copy of SCIENTIFIC AMERICAN and one +copy of SCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, +$7.00.</p> + +<p>A liberal discount to booksellers, news agents, and +canvassers.</p> + +<p class="ctr"><b>MUNN & CO., Publishers</b>,</p> + +<p class="ctr"><b>361 Broadway, New York, N.Y.</b></p> + +<hr /> +<h2>Useful Engineering Books</h2> + +<p>Manufacturers, Agriculturists, Chemists, Engineers, Mechanics, +Builders, men of leisure, and professional men, of all classes, +need good books in the line of their respective callings. Our post +office department permits the transmission of books through the +mails at very small cost. A comprehensive catalogue of useful books +by different authors, on more than fifty different subjects, has +recently been published, for free circulation, at the office of +this paper. Subjects classified with names of author. Persons +desiring a copy have only to ask for it, and it will be mailed to +them. Address, MUNN & CO., 361 Broadway, New York.</p> + +<hr /> +<h2>PATENTS.</h2> + +<p>In connection with the <b>Scientific American</b>, Messrs. MUNN +& Co. are solicitors of American and Foreign Patents, have had +42 years' experience, and now have the largest establishment in the +world. Patents are obtained on the best terms.</p> + +<p>A special notice is made in the <b>Scientific American</b> of +all inventions patented through this Agency, with the name and +residence of the Patentee. By the immense circulation thus given, +public attention is directed to the merits of the new patent, and +sales or introduction often easily effected.</p> + +<p>Any person who has made a new discovery or invention can +ascertain, free of charge, whether a patent can probably be +obtained, by writing to MUNN & Co. We also send free our Hand +Book about the Patent Laws, Patents, Caveats, Trade Marks, their +costs and how procured. Address</p> + +<p class="ctr"><b>MUNN & Co.</b>,</p> + +<p class="ctr"><b>361 Broadway, New York.</b></p> + +<p class="ctr"><b>Branch Office, 622 and 624 F St., Washington, +D.C.</b></p> + +<div>*** END OF THE PROJECT GUTENBERG EBOOK 14009 ***</div> +</body> +</html> + diff --git a/14009-h/images/1-boat.png b/14009-h/images/1-boat.png Binary files differnew file mode 100644 index 0000000..deded01 --- /dev/null +++ b/14009-h/images/1-boat.png diff --git a/14009-h/images/1-boat_th.jpg b/14009-h/images/1-boat_th.jpg Binary files differnew file mode 100644 index 0000000..10893af --- /dev/null +++ b/14009-h/images/1-boat_th.jpg diff --git a/14009-h/images/12-boat.png b/14009-h/images/12-boat.png Binary files differnew file mode 100644 index 0000000..e68fa7d --- /dev/null +++ b/14009-h/images/12-boat.png diff --git a/14009-h/images/12-circus.png b/14009-h/images/12-circus.png Binary files differnew file mode 100644 index 0000000..125adab --- /dev/null +++ b/14009-h/images/12-circus.png diff --git a/14009-h/images/13-fig1.png b/14009-h/images/13-fig1.png Binary files differnew file mode 100644 index 0000000..8cc66b2 --- /dev/null +++ b/14009-h/images/13-fig1.png diff --git a/14009-h/images/13-fig1_th.jpg b/14009-h/images/13-fig1_th.jpg Binary files differnew file mode 100644 index 0000000..61c8693 --- /dev/null +++ b/14009-h/images/13-fig1_th.jpg diff --git a/14009-h/images/13-fig2.png b/14009-h/images/13-fig2.png Binary files differnew file mode 100644 index 0000000..a16fb0b --- /dev/null +++ b/14009-h/images/13-fig2.png diff --git a/14009-h/images/13-fig2_th.jpg b/14009-h/images/13-fig2_th.jpg Binary files differnew file mode 100644 index 0000000..4b9a6fb --- /dev/null +++ b/14009-h/images/13-fig2_th.jpg diff --git a/14009-h/images/13-fig3.png b/14009-h/images/13-fig3.png Binary files differnew file mode 100644 index 0000000..43a81f5 --- /dev/null +++ b/14009-h/images/13-fig3.png diff --git a/14009-h/images/13-fig3_th.jpg b/14009-h/images/13-fig3_th.jpg Binary files differnew file mode 100644 index 0000000..873b4d3 --- /dev/null +++ b/14009-h/images/13-fig3_th.jpg diff --git a/14009-h/images/13-fig4.png b/14009-h/images/13-fig4.png Binary files differnew file mode 100644 index 0000000..88dfc8d --- /dev/null +++ b/14009-h/images/13-fig4.png diff --git a/14009-h/images/2-fig1.png b/14009-h/images/2-fig1.png Binary files differnew file mode 100644 index 0000000..a7ca8a3 --- /dev/null +++ b/14009-h/images/2-fig1.png diff --git a/14009-h/images/2-fig2.png b/14009-h/images/2-fig2.png Binary files differnew file mode 100644 index 0000000..7d92ebd --- /dev/null +++ b/14009-h/images/2-fig2.png diff --git a/14009-h/images/2-fig3.png b/14009-h/images/2-fig3.png Binary files differnew file mode 100644 index 0000000..45df230 --- /dev/null +++ b/14009-h/images/2-fig3.png diff --git a/14009-h/images/2-fig4.png b/14009-h/images/2-fig4.png Binary files differnew file mode 100644 index 0000000..ff5a00a --- /dev/null +++ b/14009-h/images/2-fig4.png diff --git a/14009-h/images/2-fig5.png b/14009-h/images/2-fig5.png Binary files differnew file mode 100644 index 0000000..3d607ce --- /dev/null +++ b/14009-h/images/2-fig5.png diff --git a/14009-h/images/2-fig6.png b/14009-h/images/2-fig6.png Binary files differnew file mode 100644 index 0000000..64f7f12 --- /dev/null +++ b/14009-h/images/2-fig6.png diff --git a/14009-h/images/3-station.png b/14009-h/images/3-station.png Binary files differnew file mode 100644 index 0000000..74d6f2a --- /dev/null +++ b/14009-h/images/3-station.png diff --git a/14009-h/images/3-station_th.jpg b/14009-h/images/3-station_th.jpg Binary files differnew file mode 100644 index 0000000..8a5c04f --- /dev/null +++ b/14009-h/images/3-station_th.jpg diff --git a/14009-h/images/4-fig1.png b/14009-h/images/4-fig1.png Binary files differnew file mode 100644 index 0000000..4f73033 --- /dev/null +++ b/14009-h/images/4-fig1.png diff --git a/14009-h/images/4-fig2.png b/14009-h/images/4-fig2.png Binary files differnew file mode 100644 index 0000000..58cf06f --- /dev/null +++ b/14009-h/images/4-fig2.png diff --git a/14009-h/images/4-water.png b/14009-h/images/4-water.png Binary files differnew file mode 100644 index 0000000..fc69d95 --- /dev/null +++ b/14009-h/images/4-water.png diff --git a/14009-h/images/4-water_th.jpg b/14009-h/images/4-water_th.jpg Binary files differnew file mode 100644 index 0000000..9b69dc4 --- /dev/null +++ b/14009-h/images/4-water_th.jpg diff --git a/14009-h/images/5-goodyear.png b/14009-h/images/5-goodyear.png Binary files differnew file mode 100644 index 0000000..8777de8 --- /dev/null +++ b/14009-h/images/5-goodyear.png diff --git a/14009-h/images/5-goodyear_th.jpg b/14009-h/images/5-goodyear_th.jpg Binary files differnew file mode 100644 index 0000000..56e64fc --- /dev/null +++ b/14009-h/images/5-goodyear_th.jpg diff --git a/14009-h/images/6-fig51.png b/14009-h/images/6-fig51.png Binary files differnew file mode 100644 index 0000000..6de4505 --- /dev/null +++ b/14009-h/images/6-fig51.png diff --git a/14009-h/images/6-fig52.png b/14009-h/images/6-fig52.png Binary files differnew file mode 100644 index 0000000..6d68e0d --- /dev/null +++ b/14009-h/images/6-fig52.png diff --git a/14009-h/images/7-fig53.png b/14009-h/images/7-fig53.png Binary files differnew file mode 100644 index 0000000..57661cd --- /dev/null +++ b/14009-h/images/7-fig53.png diff --git a/14009-h/images/7-fig54.png b/14009-h/images/7-fig54.png Binary files differnew file mode 100644 index 0000000..5942700 --- /dev/null +++ b/14009-h/images/7-fig54.png diff --git a/14009-h/images/8-fig55.png b/14009-h/images/8-fig55.png Binary files differnew file mode 100644 index 0000000..7c049d8 --- /dev/null +++ b/14009-h/images/8-fig55.png diff --git a/14009-h/images/8-fig56.png b/14009-h/images/8-fig56.png Binary files differnew file mode 100644 index 0000000..21d718a --- /dev/null +++ b/14009-h/images/8-fig56.png diff --git a/14009-h/images/8-scope.png b/14009-h/images/8-scope.png Binary files differnew file mode 100644 index 0000000..40546bb --- /dev/null +++ b/14009-h/images/8-scope.png diff --git a/14009-h/images/8-scope_th.jpg b/14009-h/images/8-scope_th.jpg Binary files differnew file mode 100644 index 0000000..c981d04 --- /dev/null +++ b/14009-h/images/8-scope_th.jpg diff --git a/14009-h/images/8-target.png b/14009-h/images/8-target.png Binary files differnew file mode 100644 index 0000000..b6629cb --- /dev/null +++ b/14009-h/images/8-target.png diff --git a/14009-h/images/8-target_th.jpg b/14009-h/images/8-target_th.jpg Binary files differnew file mode 100644 index 0000000..a303149 --- /dev/null +++ b/14009-h/images/8-target_th.jpg diff --git a/14009-h/images/title.png b/14009-h/images/title.png Binary files differnew file mode 100644 index 0000000..0a7a0c2 --- /dev/null +++ b/14009-h/images/title.png diff --git a/14009-h/images/title_th.jpg b/14009-h/images/title_th.jpg Binary files differnew file mode 100644 index 0000000..2c5acda --- /dev/null +++ b/14009-h/images/title_th.jpg diff --git a/LICENSE.txt b/LICENSE.txt new file mode 100644 index 0000000..6312041 --- /dev/null +++ b/LICENSE.txt @@ -0,0 +1,11 @@ +This eBook, including all associated images, markup, improvements, +metadata, and any other content or labor, has been confirmed to be +in the PUBLIC DOMAIN IN THE UNITED STATES. + +Procedures for determining public domain status are described in +the "Copyright How-To" at https://www.gutenberg.org. + +No investigation has been made concerning possible copyrights in +jurisdictions other than the United States. Anyone seeking to utilize +this eBook outside of the United States should confirm copyright +status under the laws that apply to them. diff --git a/README.md b/README.md new file mode 100644 index 0000000..ef6d550 --- /dev/null +++ b/README.md @@ -0,0 +1,2 @@ +Project Gutenberg (https://www.gutenberg.org) public repository for +eBook #14009 (https://www.gutenberg.org/ebooks/14009) diff --git a/old/14009-8.txt b/old/14009-8.txt new file mode 100644 index 0000000..145dba6 --- /dev/null +++ b/old/14009-8.txt @@ -0,0 +1,5136 @@ +The Project Gutenberg EBook of Scientific American Supplement, No. 787, +January 31, 1891, by Various + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Scientific American Supplement, No. 787, January 31, 1891 + +Author: Various + +Release Date: November 10, 2004 [EBook #14009] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + + + + +Produced by Victoria Woosley, Don Kretz, Juliet Sutherland, Charles +Franks and the PG Distributed Proofreading Team + + + + + +[Illustration] + + + + +SCIENTIFIC AMERICAN SUPPLEMENT NO. 787 + + + + +NEW YORK, January 31, 1891 + +Scientific American Supplement. Vol. XXXI., No. 787. + +Scientific American established 1845 + +Scientific American Supplement, $5 a year. + +Scientific American and Supplement, $7 a year. + + * * * * * + + + + +TABLE OF CONTENTS. + + +I. BIOGRAPHY.--CHARLES GOODYEAR.--The life and discoveries of + the inventor of vulcanized India rubber, with portrait.--1 + illustration + +II. BIOLOGY.--Can we Separate Animals from Plants?--By ANDREW + WILSON.--A debated point well discussed.--The bases on which + distinctions must be drawn + +III. ELECTRICITY.--A New Electric Ballistic Target.--A target + for investigations of the velocity of projectiles, now in use at + the United States Military Academy, West Point, N.Y.--1 + illustration. + + Electric Erygmascope.--An electric lighting apparatus for + examining earth strata in bore holes for geologists' and + prospectors' use.--1 illustration + + The Electro-Magnet.--By Prof. SILVANUS THOMPSON.--Continuation + of this exhaustive treatise, giving further details on special + points of construction.--1 illustrations + +IV. ENTOMOLOGY.--Potash Salts.--The use of potash salts as + insecticides, with accounts of experiments + + The Outlook for Applied Entomology.--By Dr. C.V. RILEY, U.S. + entomologist.--The conclusion of Prof. Riley's lecture, treating + of the branch of entomology with which his name is so honorably + associated + +V. INSURANCE.--The Expense Margin in Life Insurance.--Elaborate + review of the necessary expenses of conducting the insurance of + lives, with tables and calculations + +VI. MATHEMATICS.--The Trisection of Any Angle.--By FREDERIC R. + HONEY, Ph.B.--A very ingenious demonstration of this problem, + based on the properties of conjugate hyperbolas + +VII. METEOROLOGY.--Note on the Mt. Blanc Meteorological Station + + The Flood at Karlsbad.--Account of the recent flood and of its + destructive effects.--1 illustration + +VIII. MECHANICAL ENGINEERING.--Station for Testing Agricultural + Machines.--A proposed establishment for applying dynamometer + tests to agricultural machines.--1 illustration + + Steam Engine Valves.--By THOMAS HAWLEY.--A review of modern + slide valve practice, the lap, cut-off, and other points.--6 + illustrations + +IX. MISCELLANEOUS.--Science in the Theater.--Curious examples of + stage effect in fictitious mesmerizing and hypnotizing.--4 + illustrations + + Theatrical Water Plays.--Recent episodes in real water plays at + Hengler's Circus, London.--2 illustrations + +X. NAVAL ENGINEERING.--The French Ironclad War Ship Colbert.--An + armored wood and iron ship, with central battery.--1 + illustration + +XI. PHYSIOLOGY AND HYGIENE.--Newer Physiology and Pathology.--By + Prof. SAMUEL BELL. M.D.--An excellent presentation of modern + practice in the light of bacteriology + + Test Card Hints.--How to test the eyes for selecting eyeglasses + and spectacles + + The Composition of Koch's Lymph.--What Prof. Koch says it is and + what it can do.--The cabled account of the disclosure so long + waited for + +XII. TECHNOLOGY.--Firing Points of Various Explosives.--The + leading explosives, with the temperature of their exploding + points tabulated + + The Recovery of Gold and Silver from Plating and Gilding + Solutions--A paper of interest to silver and gold platers, as + well as photographers + + Water Softening and Purifying Apparatus.--An apparatus for + treatment of sewage, etc., chemically and by deposition.--1 + illustration + + * * * * * + + + + +THE FRENCH IRONCLAD WAR SHIP COLBERT. + + +The central battery ironclad Colbert is one of the ten ships of the +French navy that constitute the group ranking next in importance to +the squadron of great turret ships, of which the Formidable is the +largest. The group consists of six types, as follows: + + 1. The Ocean type; three vessels; the Marengo, Ocean, and Suffren. + 2. The Friedland type, of which no others are built. + 3. The Richelieu type, of which no others are built. + 4. The Colbert type, of which there are two; the Colbert and the + Trident. + 5. The Redoubtable type, of which no others are built. + 6. The Devastation type, of which no others are built. + +[Illustration: THE FRENCH IRONCLAD WAR SHIP COLBERT.] + +The Colbert was launched at Brest in 1875, and her sister ship, the +Trident, in 1876. Both are of iron and wood, and the following are the +principal dimensions of the Colbert, which apply very closely to the +Trident: She is 321 ft. 6 in. long, 59 ft. 6 in. beam, and 29 ft. 6 +in. draught aft. Her displacement is 8,457 tons, her indicated horse +power is 4,652, and her speed 14.4 knots. She has coal carrying +capacity for 700 tons, and her crew numbers 706. The thickness of her +armor belt is 8.66 in., that protecting the central battery is 6.29 +in. thick, which is also the thickness of the transverse armored +bulkheads, while the deck is 0.43 in. in thickness. The armament of +the Colbert consists of eight 10.63 in. guns, two 9.45 in., six 5.51 +in., two quick firing guns, and fourteen revolving and machine +guns.--_Engineering._ + + * * * * * + +A compound locomotive, built by the Rhode Island Locomotive Works, has +been tried on the Union Elevated Railroad, Brooklyn, N.Y. The engine +can be run either single or compound. The economy in fuel was 37.7 per +cent, and in water 23.8 per cent, over a simple engine which was +tested at the same time. The smoothness of running and the stillness +and comparative absence of cinders was fully demonstrated. + + * * * * * + + + + +STEAM ENGINE VALVES. + +[Footnote: Lecture delivered at Wells Memorial Institute, Boston, in +the Lowell Free Course for Engineers. From report in the _Boston +Journal of Commerce_.] + +By THOMAS HAWLEY. + +RIDING CUT-OFF VALVES--PECULIARITIES AND MERITS OF THE DIFFERENT +STYLES. + + +In considering the slide valve in its simple form with or without lap, +we find there are certain limitations to its use as a valve that would +give the best results. The limitation of most importance is that its +construction will not allow of the proper cut off to obtain all the +benefits of expansion without hindering the perfect action of the +valve in other particulars. At this economical cut off the opening of +the steam port is very little and very narrow, and although this is +attempted to be overcome by exceedingly wide ports, sixteen inches in +width in many cases in locomotive work, this great width adds largely +to the unbalanced area of the valve. The exhausting functions of the +valve are materially changed at the short cut off, and when much lap +is added to overcome this defect, there usually takes place a choking +of the exhaust port. You might inquire, why not make the port wider, +but this would increase the minimum amount of load on the valve, and +this must not be overlooked. Then the cut off is a fixed one, and we +can govern only by throttling the pressure we have raised in the +boiler or by using a cut off governor and the consequent wastes of an +enormous clearance space. You will observe, therefore, that the plain +slide valve engine gives the most general satisfaction at about +two-thirds cut off and a very low economic result. The best of such +engines will require forty-five to fifty pounds of steam per horse +power per hour, and to generate this, assuming an evaporation of nine +pounds of water to a pound of coal, would require between five and six +pounds of coal per horse power per hour. And the only feature that the +valve has specially to commend it is its extreme simplicity and the +very little mechanism required to operate it. + +Yet this is of considerable importance, and in consideration of some +special features at its latest cut off, the attempt has been many +times made to take advantage of these features. For instance, at 90° +advance, the valve opens very rapidly indeed and fully satisfies our +requirements of a perfect valve. This is one good point, and in this +position also the exhaust and compression can be regulated very +closely and as desired without much lap, and as the opening of the +exhaust port comes with the eccentric at its most rapid movement the +release is very quick and as we would have it. This is only possible +at the most uneconomic position of the valve as regards cut off. + +The aim of many engineers has been to take advantage of these matters +by using the valve with 90° angular advance of eccentric ahead of +crank, for the admission, release, and compression of the steam, and +provide another means of cutting off, besides the one already referred +to, viz., cutting off the supply of steam to the chest, and overcome +the objection in this one of large clearance spaces. This is done by +means of riding cut off valves, often called expansion valves, of +which, perhaps, the most widely known types in this vicinity are the +Kendall & Roberts engine and the Buckeye. The former is used in the +simplest form of riding cut off, while the Buckeye has many peculiar +features that engineers, I find, are too prone to overlook in a casual +examination of the engine. In these uses of the slide valve, too, +means are suggested and carried out of practically balancing the +valve. + +The origin of the riding cut off is most generally attributed to +Gonzenbach. His arrangement had two steam chests, the lower one +provided with the ordinary slide valve of late cut off, and steam was +cut off from this steam chest by the expansion valve covering the +ports connecting with the upper steam chest. This had the old +disadvantage that all the steam in the lower chest expanded with that +in the cylinder, at a consequent considerable loss. This was further +improved by causing the riding cut off to be upon the top of the main +valve, instead of its chest, and resulted in a considerable reduction +of the clearance space. + +This is the simplest form, and is shown in Fig. 1. The steam is +supplied by a passage through the main valve which operates exactly as +an ordinary slide valve would. That is, the inside edges of the steam +passage are the same as the ordinary valve, the additional piece on +each end, if I may so term it, being merely to provide a passage for +the steam which can be closed, instead of allowing the steam to pass +the edge. The eccentric of the main valve is fastened to the shaft to +give the proper amount of lead, and the desired release and +compression, and the expansion valve is operated by a separate +eccentric fastened in line with or 180° ahead of the crank. When the +piston, therefore, commences to move from the crank end to open the +port, D, the expansion valve is forced by its eccentric in the +opposite direction, and is closing the steam port and would have +closed it before the piston reached quarter stroke, thus allowing the +steam then in the cylinder to do work by expansion. The eccentric +operating this expansion valve may be set to close this steam port at +any point in the stroke that is desired, the closing occurring when +the expansion valve has covered the steam port. Continuing the +movements of the valves, the two would move together until one or the +other reached its dead center, when the movements would be in opposite +directions. + +[Illustration: FIG. 1.] + +There are three ways of effecting the cut off in such engines, the +main valve meanwhile being undisturbed, its eccentric fastened +securely so as not to disturb the points of lead, release, and +compression. All that is required is to cause the edge of the +expansion valve to cover the steam port earlier in the stroke, and +this can be done, first, by increasing the angular advance of the cut +off eccentric; second, by adding lap to the cut off valve; and third +by changing the throw of the eccentric. In all these instances the +riding valve is caused to reach the edge of the steam port earlier in +the stroke. We will take first, as the simplest, those methods by +which the lap of the cut off valve is increased. + +It will be noted that there is but one edge of this valve that is +required to do any work, and that is to close the valve. The +eccentrics are so placed that the passage in the main valve is opened +long before the main valve itself is ready to admit steam to the +cylinder, so that only the outer edges are the ones to be considered, +and it will be readily seen that the two valves traveling in opposite +directions, any lap added to the working edge of the cut off valve +will cause it to reach the edge and therefore close the port earlier +than it would if there was less lap. And we might carry it to the +extreme that we could add lap enough that the steam passage would not +be opened at all. + +In Fig. 2 is shown the method by which this is accomplished, in what +is called Meyer's valve, and such as is used in the Kendall & Roberts +engine. We have only one point to look after, the cut off, so we can +add all the lap we wish without disturbing anything else. In this +engine the lap is changed by hand by means of a little hand wheel on a +stem that extends out of the rear of the steam chest. The valve is in +two sections, and when it is desired to cut off earlier, the hand +wheel is turned in such a direction that the right and left hand +screws controlling the cut off valve move one valve portion back and +the other forward, which would, if they were one valve and they should +be so considered, have the effect of lengthening them, or adding lap +to them. The result would be that the riding valve would reach the +edge of the steam port earlier in the stroke, bringing about an +earlier cut off. If the cut off is desired to be later, the hand wheel +is so turned that the right and left hand screws will bring the valve +sections nearer together, thus practically taking off lap. Now this +may be done by hand or it may be done by the action of a governor. + +[Illustration: FIG. 2.] + +In the latter case the governor at each change of load turns the right +and left hand screws to add or take away lap, as the load demands an +earlier or later cut off; in other cases the governor moves a rack in +mesh with a gear by which the valve sections are brought closer +together or are separated. The difficulty with the case where the hand +wheel is turned by hand is that the cut off is fixed where you leave +it, and governing can only be at the throttle. For this reason +anywhere near full boiler pressure would not be obtained in the +cylinder of the engine. If the load was a constant one, and the cut +off could be fixed at about one-third, causing the throttle to open +its widest, very good results would be obtained, but there is no +margin left for governing. + +If the load should increase at such a time the governor could not +control it under these conditions, and it would lead to a decrease in +speed unless the lap was again changed to give a later cut off. On +this account the general practice soon becomes to leave the cut off at +the later point and give range to the throttle, and we come back once +more to the plain slide valve cutting off at half stroke, and the only +gain there is, is in a quick port opening and quick cut off. But these +matters are more than offset by the wire drawing between the steam +pipe and chest, through the throttle, and the fact that there is added +to the friction of the engine the friction of this additional slide +valve and a considerable liability to have a leaky valve. + +In the case where the governor changes the position of the cut off +valve a greater decree of economy would result. In this engine, of +which the Lambertville engine is a type, the main valve is a long D +slide, with multiple ports at the ends through which the steam enters +the cylinders. It is operated from an eccentric on the crank shaft in +the usual manner. The cut off valve is also operated from the motion +on an eccentric fixed upon the crank shaft. The rod or stem of the cut +off valve passes through the main valve rod and slide. Upon the outer +end of the cut off valve rod are tappets fastened to engage with +tappets on the eccentric valve rod. Connection between the cut off +eccentric, therefore, and the cut off valve is only by means of the +engagement of these tappets. The eccentric rod is fastened to a rocker +arm having motion swinging about a pin or bearing in the governor +slide, which may be raised or lowered by a cam operated by the +governor. The cut off slide is of cylindrical shape and incloses a +spring and dash pot with disks attached by means of which the valve is +closed. The motion for operating the valves is relatively in the same +direction, the cut off eccentric having the greatest throw and greater +angular advance to cause it to open earlier and quickly before the +main valve is ready to admit steam. The cut off eccentric rod swinging +the rocker arm, the tappets thereon engage with those upon the cut off +valve rod and open the passages to the main valve, and in their +movement compress the spring in the main valve. According as the speed +of the engine, the rock arm will be raised or lowered so that the +tappets upon the eccentric rod may keep in engagement a shorter or +longer time before they disengage, thus allowing the spring that has +been compressed by the movement of the cut off valve to close that +valve quickly and the supply of steam to the engine, the cut off valve +traveling with the main valve for the balance of the stroke. This +device will give a remarkably quick opening and a quick cut off, but +in view of the fact that the governor has so much to do, its delicacy +is impaired and a quick response to the demands of the load changing +not so likely to occur. The cut off cannot be as quick as in some +other engines, because the valves are moving in opposite directions, +and while this fact would help, so far as shortening the distance to +be traveled before cut off, the resistance of the valves to travel in +opposite directions, or rather the tendency of the valve to travel +with the main valve, hinders its rapid action. + +[Illustration: FIG. 3.] + +This is one great objection to the rack and gear operated by the +governor, that two flat valves riding upon each other and sliding in +opposite directions at times require a considerable amount of force to +move them, and as only a slight change in load is required by the +load, the governor cannot handle the work as delicately as it should. +It is too much for the governor to do well. To overcome this +difficulty the Ryder cut-off, shown in Fig. 3, was made by the +Delamater people, of New York. The main slide valve is hollowed in the +back and the ports cut diagonally across the valve to form almost a +letter V. The expansion valve is V-shaped, and circular to fit its +circular-seat. The valve rod of the expansion valve has a sector upon +it and operated by a gear upon the governor stem, which rotates the +valve rod, and the edge of the valve rod is brought farther over the +steam port, thus practically adding lap to the valve. Little movement +is found necessary to make the ordinary change in cut-off, and it is +found to be much easier to move the riding valve across the valve than +in a direction directly opposite. It would require considerable force +to move the upper valve by the governor faster than the lower, or in a +direction opposite to that in which it is moving, but very little +force applied sideways at the same time it is moving forward will give +it a sideways motion. In this device the governor has only to exert +this side pressure and therefore has less to do than if it were called +upon to move the upper valve directly against the movement of the +lower. + +Something similar is the valve of the Woodbury engine, of Rochester, +N.Y. The cut-off valve is cylindrical, covering diagonal ports +directly opposite, and is caused to be rotated by the action of the +governor that operates a rack in mesh with a segment. Very little +movement will effect a considerable change in the lappage of the +valve, the valve turning about one-quarter a revolution for the +extremes of cut off. The cut off valve rod works through a bracket and +its end terminates in a ball in a socket on the end of the eccentric +rod. In this case the governor has not as much to do as in other +instances. + +[Illustration: FIG. 4.] + +Still another method of effecting this change in cut off, but hardly +by increasing the lap of the valve, is shown in the next drawing, Fig. +4. The cut off valve is held upon the main valve by the pressure of +steam upon its back and rides with it until it comes in contact with +the cut off wedge-shaped blocks, when its motion is arrested, and the +main valve continuing its movement the steam port is closed by the +main valve passing beneath the cut off valve. Thus the main valve +travels and carries the cut off valve upon its back again until the +cut off valve strikes the wedge on the other end and the cut off is +effected. The relative positions of the blocks are determined by the +governor, that will raise or lower them so that the cut off valve will +engage with them earlier or later as desired. This device was designed +specially as an inexpensive method of changing the common slide valve +into an automatic cut off. The cut off would not be as quick as in +other cases we have cited, depending here upon the movement of the +lower valve alone, and that, too, is in its slowest movement; whereas +in the other cases, the edges approaching each other, by the differing +movement of the valves the cut off is very rapid, provided the +distance to travel is not long. In this device considerable noise must +result by the cut off valve striking the cut off blocks, and a +considerable amount of leakage is likely to occur past this valve. + +But there is one great objection in the valve gears thus far cited, +that the travel of the expansion valve upon the main valve is +variable. I have in mind the case of a Kendall & Roberts engine, which +had been run for a long time at no better economy than would be +obtained from a plain slide valve engine, and when it was attempted to +get an earlier cut off by separating the two cut off valves, they had +worn so much in their old place on the valve that shoulders were found +sufficient to cause a disagreeable noise and a leaky valve. This is +very apt to occur, not only where the valve is run for a long time on +one seat, but in cases of variation of the travel of the expansion +valve. The result is that a change will bring about a leaky valve, +something that every engineer abhors. + +The construction of the Buckeye engine, which is also of this type, is +such that the travel of the valve on the back of the main valve is +always the same, no matter what the cut off may be. Then this engine +makes use of our second proposition as a means of effecting the cut +off, viz., by advancing the eccentric. You will readily observe that +anything that will cause the cut off valve to reach a certain point +earlier in the stroke will bring about an earlier cut off as it +hastens everything all around. This is the plan pursued in the +Buckeye, in which the governor, of the shaft type, turns the eccentric +forward or back according as the load demands. Then, in addition, the +valve is balanced partially, the attempt not being made to produce an +absolutely balanced valve, on the ground that there should be friction +enough to keep the surfaces bright and to prevent leakage. The most +perfect valve will, of course, be entirely balanced under all +conditions of pressure so as to move with perfect ease. With the +riding cut off valve in connection with the plain slide valve, this is +not accomplished, and it does not matter whether it is partially +unbalanced to prevent leakage or not, the fact that it is not entirely +balanced prevents it reaching the ideal valve. + +[Illustration: Fig. 5] + +This valve, Fig. 5, differs from the others also in this particular, +that the exhaust takes place at the end of the valve instead of under +the arch. Two eccentrics are used, the one for the main valve being +fastened to the shaft and the other riding loosely upon it and +connected to the fly wheel governor, by which it may be turned forward +or back as the load requires. The three points of lead, or admission +and exhaust and compression, are fixed and independent of the changes +and cut off. The motion of the main eccentric is given to a rocker +arm, the pivot of which is at the bottom, and from the upper end the +valve rod transfers the motion to the valve without reversing the +motion, as is done sometimes in the slide valve to overcome the +effects of the angularity of the connecting rod. The action of the +rocker arm, therefore, so far as the main valve in the Buckeye is +concerned, is no different than that which would occur if no rocker +arm intervened. The motion of the cut off eccentric, through its +eccentric rod, is given to a rocker rocking in a bearing in the center +of the main rocker arm (see Fig. 6). The motion of this eccentric is +reversed, so far as the cut off valve is concerned, and when the cut +off eccentric is moving forward, the cut off valve is being pushed +back. The main valve rod is hollow, and the cut off valve rod passes +through it. + +[Illustration: Fig. 6] + +The cut off eccentric can be placed in any position to cause it to cut +off as desired, and by drawing the valve forward, by increasing the +angular advance of the eccentric, the cut off valve is caused to reach +and cover the steam passage in the main valve earlier in the stroke. +Instead of being ahead of the crank, the main eccentric in this +arrangement follows the crank, on account of the exhaust and steam +edges being exactly opposite from those in the ordinary slide. What is +the steam edge of the common slide is in this the exhaust edge, and +what is the exhaust edge in the common valve is the steam edge in this +one. The valve, therefore, must be moved in the opposite direction +from what is ordinarily the case, the main eccentric being not 90 deg. +behind the crank. It has a rapid and full opening just the same, for +it is at this point behind the crank, or ahead of it, that the +eccentric gives to the valve its quickest movement, or between the +eccentric dead centers. The cut off eccentric is considerably ahead of +the main eccentric, and about even with the crank. If it was not for +the reversal of motion of the cut off valve through the rocker arm +this eccentric would be about in line with the crank, but on the other +end. The movement of the cut off valve, therefore, at the time of port +opening is very little, being about on its dead center, passing which, +it immediately commences to close. + +The object of the peculiar construction of the rocker arm, and the +pivot for the cut off rocker being placed thereon, is to provide equal +travel on the back of the main valve, no matter what the cut off. I +have already explained, in connection with the slide valve, that +advancing the eccentric does not change the movement of the valve on +its seat, but simply its relation to the movement of the piston. You +will see that this is unchanged as using the main valve as a seat or +any other seat. If the main valve was to remain stationary, and only +the cut off valve to be operated by its eccentric, the movement of +this cut off valve on a certain plane would be the same for all +positions of the eccentric. + +Moving the main slide does not affect the matter in any way, for it +moves at the same time the pivot of the cut off, and while the cut off +seat has assumed a different position with reference to the engine, it +is still as though stationary so far as the cut off valve is +concerned. This is the object of this peculiar construction, and not, +as some engineers suppose, simply to make an odd way of doing things. +And the object of it all is to give at all cut offs the same amount of +travel, so that there might be no unequal wear to bring about a leak, +to prevent which a perfect balancing has been sacrificed. + +Referring to the valve and this engine as to how it will satisfy our +requirements of a perfect valve gear, we find that the first +requirement of a rapid and full opening is met, in that the opening +occurs when the main eccentric is moving very rapidly, yet not its +fastest, and while this opening will be very satisfactory, it is not +so rapid an opening as is obtained in some other forms of valves and +valve gears, but this could be overcome very readily by increasing the +lead a trifle, and in my experience with these engines I find that the +practice is very general by engineers and by builders themselves to +give them a considerable amount of lead. As to the second requirement, +the maintenance of initial pressure until cut off, giving a straight +steam line, cards from this engine will not be found to show that the +engine satisfies this requirement, and for this reason, that the +cut-off valve commences to close the port immediately after the piston +commences to move. The cut off eccentric you will remember is set to +move with the crank or very nearly so, and the lighter the load, the +greater will this fact appear. For the lightest loads the governor +places the eccentric in advance of the crank, so that the cut off +valve will commence to close the port before steam is admitted by the +main valve to the engine. Now, the later the cut off, the less will +this wire drawing appear at first, and the shorter the cut off, the +amount of wire drawing increases sensibly. The operation of the valve, +therefore, in this particular, cannot be considered as meeting our +requirement that the port shall be held open full width until ready to +be closed. Many men claim for this engine that the closing occurs when +the cut off eccentric is moving its fastest. This is a fact, and if we +consider the point of cut off only to be the point of absolute cut +off, the cut off must be instantaneous, for there is an instantaneous +point where the cut off is final only to be considered. The reasoning +applied here would hold good also to a less extent on the slide valve, +but is not the point of absolute cut off. We want to note how long it +is from the time the valve commences to close at all until finally +closed, and, as I have shown you, this is considerable in this engine. + +Referring to the point of cut off finally, it is determined upon by a +governor of the fly wheel type. The eccentric is loose about the +shaft, and arms projecting therefrom are connected by other arms to +the extremity of an arm upon which is mounted a weight, and which is +attached to the spokes of the fly wheel, or special governor wheel in +this case, and which is fastened to the crank shaft. As the speed +increases through throwing off a portion of the load the governor +weights fly out, and this movement is transferred through the lever +connections to the eccentric, causing it to be turned ahead, and the +manner hastening the movement of the cut off valve on its seat and +causing it to reach and cover the edge of the steam port earlier in +the stroke. This engine was the pioneer in governors of this +character, the advantage being, in addition to its necessity for the +work of turning the eccentric ahead or back, that the liability of the +engine to run away, as very often happens from the breaking of the +governor belt or a similar cause, was not possible. + +The cut off valve has a travel considerably beyond the edge of the +steam passage after the valve is closed, and this has one advantage, +that the valve is less liable to leak, and to this must be added the +loss from the friction of this moving valve, and moving too in +opposition to the main valve. In our perfect valve, as we outlined it, +the valve does not move after the port is closed. The exhausting +functions of the valve are very good, giving a quick opening and a +full opening, because this opening occurs when the eccentric is moving +its fastest. The engine also possesses a distinct advantage in having +remarkably small clearance spaces. The length of the steam passage is +very small in comparison with any form of engine, and having but two +ports instead of four, as in the Corliss and four valve type. + +In these there must be included in the clearance, that to the exhaust +port as well as the steam port, adding a considerable amount where the +piston comes close to the head. As the engines leave the maker's hand +the engines are provided with a considerable amount of lap to give +plenty of compression, but are, of course, capable of having more +added to increase compression, or some planed off to decrease it. + +One of the peculiar things about this engine is the failure to realize +anywhere near boiler pressure, noticeable in every case that has come +under my notice. The considerable lead gives it for an instant, but it +soon falls away, indicating the steam chest pressure only by a peak at +the junction of the admission and steam lines. This is probably due to +the fact that the cut off valve commences closing the steam passage so +soon after steam is admitted, and in this particular does not satisfy +the requirements of a perfect valve. There is this about the engine, +that above all others of this type there has come under my notice +fewer engines of this type with a maladjustment of valves from +tampering by incompetent engineers. + + * * * * * + + + + +FIRING POINTS OF VARIOUS EXPLOSIVES. + + +An apparatus, devised by Horsley, was used, which consisted of an iron +stand with a ring support holding a hemispherical iron vessel, in +which paraffin or tin was put. Above this was another movable support, +from which a thermometer was suspended and so adjusted that its bulb +was immersed in molten material in the iron vessel. A thin copper +cartridge case, 5/8 in. in diameter and 1-5/16 in. long, was suspended +over the bath by means of a triangle, so that the end of the case was +1 in. below the surface of the liquid. On beginning the experiment the +material in the bath was heated to just above the melting point, the +thermometer was inserted in it, and a minute quantity of the explosive +was placed in the bottom of the cartridge case. The temperature marked +by the thermometer was noted as the _initial temperature_, the +cartridge case containing the explosive was inserted in the bath, and +the temperature quickly raised until the explosive flashed off or +exploded, when the temperature marked by the thermometer was again +noted as the _firing point_. The tables given show the results of +about six experiments with each explosive. The initial temperatures +range from 65° to 280° C. in some cases, but as the firing points +remained fairly constant, only the extremes of the latter are quoted +in the following table: + + + --------------------------------+----------------------- + Description of Explosive. | Firing Point in ° C. + --------------------------------+----------------------- + Compressed military gun-cotton. | 186 - 201 + Air-dried military gun-cotton. | 179 - 186 + " " " | 186 - 189 + " " " | 137 - 139 + " " " | 154 - 161 + Gun-cotton dried at 65° C. | 136 - 141 + Air-dried collodion gun-cotton. | 186 - 191 + " " " | 197 - 199 + " " " | 193 - 195 + Air-dried gun-cotton. | 192 - 197 + " " | 194 - 199 + Hydro-nitrocellulose. | 201 - 213 + Nitroglycerin. | 203 - 205 + Kieselghur dynamite. No. 1. | 197 - 200 + Explosive gelatin. | 203 - 209 + Explosive gelatin, camphorated. | 174 - 182 + Mercury fulminate. | 175 - 181 + Gunpowder. | 278 - 287 + Hill's picric powder. | 273 - 283 + " " " | 273 - 290 + Forcite, No. 1. | 184 - 200 + Atlas powder, 75 per cent. | 175 - 185 + Emmensite, No. 1. | 167 - 184 + Emmensite, No. 2. | 165 - 177 + Emmensite, No. 5. | 205 - 217 + --------------------------------+----------------------- + _--C.E. Munroe, J. Amer. Chem. Soc._ + + + * * * * * + + + + +STATION FOR TESTING AGRICULTURAL MACHINES. + + +The minister of agriculture has recently established a special +laboratory for testing agricultural _materiel_. This establishment, +which is as yet but little known, is destined to render the greatest +services to manufacturers and cultivators. + +In fact, agriculture now has recourse to physics and mechanics as well +as to chemistry. Now, although there were agricultural laboratories +whose mission it was to fix the choice of the cultivator upon such or +such a seed or fertilizer, there was no official establishment +designed to inform him as to the value of machines, the models of +which are often very numerous. _Chemical_ advice was to be had, but +_mechanical_ advice was wanting. It is such a want that has just been +supplied. Upon the report presented by Mr. Tisserand, director of +agriculture, a ministerial decree of the 24th of January, 1888, +ordered the establishment of an experimental station. Mr. Ringelmann, +professor of rural engineering at the school of Grignon, was put in +charge of the installation of it, and was appointed its director. He +immediately began to look around for a site, and on the 17th of +December, 1888, the Municipal Council of Paris, taking into +consideration the value of such an establishment to the city's +industries, decided that a plot of ground of an area of 3,309 square +meters, situated on Jenner Street, should be put at the disposal of +the minister of agriculture for fifteen years for the establishment +thereon of a trial station. This land, bordering on a very wide street +and easy of access, opposite the municipal buildings, offers, through +its area, its situation, and its neigborhood, indisputable advantages. +A fence 70 meters in extent surrounds the station. An iron gate opens +upon a paved path that ends at the station. + +The year 1889 was devoted to the installation, and the station is now +in full operation. The tests that can be made here are many, and +concern all kinds of apparatus, even those connected with the electric +lighting that the agriculturist may employ to facilitate his +exploitation. However, the tests that are oftenest made are (1) of +rotary apparatus, such as mills, thrashing machines, etc.; (2) of +traction machines, such as wagons, carts, plows, etc.; and (3) of +lifting apparatus. It is possible, also, to make experiments on the +resistance of materials. + +The experimental hall contains a 7 horse power gas motor, dynamometers +with automatic registering apparatus, counters, balances, etc. A small +machine shop contains a lathe, a forge, a drilling machine, etc. The +main shaft is 12 meters in length and is 7 centimeters in diameter. It +is supported at a distance of one meter from the floor by four pillow +blocks, and is formed of three sections united by movable coupling +boxes. Out of these 12 meters, 9 are in the hall and 3 extend beyond +the hall to an annex, 14 meters in length and 4 in width, in which +tests are made of machines whose operation creates dust. When the +machines to be tested require more than the power of seven horses that +the motor gives, the persons interested furnish a movable engine, +which, placed under the annex, actuates the driving shaft. Alongside +of the main building there is a ring for experimenting upon machines +actuated by a horse whim. There will soon be erected in the center of +the grounds an 18 meter tower for experiments on pumps. Platforms +spaced 5 meters apart, a crane at the top, and some gauging apparatus +will complete this hydraulic installation. + +The equipment of the hall is very complete, and is fitted for all +kinds of experiments. + +[Illustration: STATION FOR TESTING AGRICULTURAL MACHINES--DYNAMOMETER + FOR TESTING ROTARY MACHINES.] + +The tests of rotary machines are made by means of a dynamometer (see +figure). Two fast pulleys and one loose pulley are interposed between +the machine to be tested and the motor. The pulley connected with the +motor carries along the one connected with the machine, through the +intermedium of spring plates, whose strength varies with the nature of +the apparatus to be tested. The greater or less elongation of these +plates gives the tangential stress exerted by the driving pulley to +carry along the pulley that actuates the machine to be tested. This +elongation is registered by means of a pencil connected with the +spring plates, and which draws a diagram upon a sheet of paper. At the +same time, a special totalizer gives the stress in kilogrammeters. +Besides, the pulley shaft actuates a revolution counter, and a clock +measures the time employed in the experiment. In order to obtain a +simultaneous starting and stopping point for all these apparatus, they +are connected electrically, and, through the maneuver of a commutator, +are all controlled at once. The electric current is furnished by two +series of bichromate batteries. + +The tests of traction machines are effected by means of a +three-wheeled vehicle carrying a dynamometer. The front wheel is +capable of turning freely in the horizontal plane, and the dynamometer +is mounted upon a frame provided with a screw that permits of +regulating its position according to the slope of the ground. The +method of suspension of the dynamometer allows it to take +automatically the inclination of the line of traction without any +torsion of the plates. There are two models of this vehicle, one +designed to be drawn by a man, and the other by a horse. + +The station is provided, in addition, with registering pressure +gauges, a large double dynamometric indicator, a counter of +electricity, balances of precision, etc. + +An apparatus designed for measuring the rendering of presses is now in +course of construction. + +Although the station has been in operation only from the 1st of +January, twenty-five machines have already been presented to be +tested.--_Extract from Le Genie Civil_. + + * * * * * + + + + +WATER SOFTENING AND PURIFYING APPARATUS. + + +We have recently had brought under our notice a system of water and +sewage purification which appears to possess several substantial +advantages. Chief among these are simplicity in construction and +operation, economy in first cost and working and efficiency in action. +This system is the invention of Messrs. Slack & Brownlow, of Canning +Works, Upper Medlock Street, Manchester, and the apparatus adopted in +carrying it out is here illustrated. It consists of an iron +cylindrical tank having inside a series of plates arranged in a spiral +direction around a fixed center, and sloping downward at a +considerable angle outward. The water to be purified and softened +flows through the large inlet tube to the bottom, mixing on its way +with the necessary chemicals, and entering the apparatus at the +bottom, rises to the top, passing spirally round the whole +circumference, and depositing on the plates all solids and impurities. + +All that is needed in the way of attention, even when dealing with +sewage, or the most polluted waters, is stated to be the mixing in the +small tanks the necessary chemical reagents, at the commencement of +the working day; and at the close of the day the opening of the mud +cocks shown in our engraving, to remove the collected deposit upon the +plates. For the past six months this system has been in operation at a +dye works in Manchester, successfully purifying and softening the +foul waters of the river Medlock. It is stated that 84,000 gallons per +day can be easily purified by an apparatus 7 feet in diameter. The +chemicals used are chiefly lime, soda, and alumina, and the cost of +treatment is stated to vary from a farthing to twopence per 1,000 +gallons, according to the degree of impurity of the water or sewage +treated. + +The results of working at Manchester show that all the visible filth +is removed from the Medlock's inky waters, besides which the hardness +of the water is reduced to about 6° from a normal condition of about +30°. The effluent is fit for all the varied uses of a dye works, and +is stated to be perfectly capable of sustaining fish life. With +results such as these the system should have a promising future before +it in respect of sewage treatment, as well as the purification and +softening of water generally for industrial and manufacturing +purposes.--_Iron._ + +[Illustration: WATER SOFTENING AND PURIFYING APPARATUS.] + + * * * * * + + + + +THE TRISECTION OF ANY ANGLE. + +By FREDERIC R. HONEY, Ph.B., Yale University. + + +The following analysis shows that with the aid of an hyperbola any +arc, and therefore any angle, may be trisected. + +If the reader should not care to follow the analytical work, the +construction is described in the last paragraph--referring to Fig. II. + +Let a b c d (Fig. I.) be the arc subtending a given angle. Draw the +chord a d and bisect it at o. Through o draw e f perpendicular +to a d. + +We wish to find the locus of a point c whose distance from a given +straight line e f is one-half the distance from a given point d. + +In order to write the equation of this curve, refer it to the +co-ordinate axes a d (axis of X) and e f (axis of Y), intersecting +at the origin o. + + Let g c = x + +Therefore, from the definition c d = 2x + + Let o d = D + [Hence] h d = D-x + + Let c h = y + [Hence] (2x)² = y² + (D-x)² + or 4x² = y² + D²-2Dx + x² + [Hence] y²-3x² + D²-2Dx = o [I.] + +This is the equation of an hyperbola whose center is on the axis of +abscisses. In order to determine the position of the center, eliminate +the x term, and find the distance from the origin o to a new origin +o'. + + Let E = distance from o to o' + [Hence] x = x' + E + +Substituting this value of x in equation I. + + y²-3(x' + E)² + D²-2D(x' + E) = o + or y²-3x²-6Ex'-3E² + D²-2Dx'-2DE = o [II.] + +In this equation the x' terms should disappear. + + [Hence] -6Ex' - 2Dx' = o + [Hence] -E = - D/3 + +That is, the distance from the origin o to the new origin or the +center of the hyperbola o' is equal to one-third of the distance +from o to d; and the minus sign indicates that the measurement +should be laid off to the left of the origin o. Substituting this +value of E in equation II., and omitting accents-- + + We have + + y² - 3x² + 2Dx - D²/3 + D² - 2Dx + 2D²/3 = o + [Hence] y² - 3x² = - 4D²/3 + +[Illustration: Fig I] + +[Illustration: Fig II] + +This is the equation of an hyperbola referred to its center o' as +the origin of co-ordinates. To write it in the ordinary form, that is +in terms of the transverse and conjugate axes, multiply each term by +C, i.e., + __ + Let \/C = semi-transverse axis. + +[TEX: \sqrt{C} = \text{semi-transverse axis.}] + + Thus Cy² - 3Cx² = - 4CD²/3. [III.] + +When in this form the product of the coefficients of the x² and y² +terms should be equal to the remaining term. + +That is + + 3C² = - 4CD²/3. + [Hence] C = 4D²/9. + +And equation III. becomes: + + + 4D² 4D² 16D^{4} + ----- y² - ----- x² = - --------- + 9 3 27 + +[TEX: \frac{4D^2}{9} y^2 - \frac{4D^2}{3} x^2 = -\frac{16D^4}{27}] + ____ + / 4D² 2D + The semi-transverse axis = \/ ----- = ---- + 9 3 + +[TEX: \text{The semi-transverse axis} = \sqrt{\frac{4D^2}{9}} += \frac{2D}{3}] + ____ + / 4D² 2D + The semi-conjugate axis = \/ ----- = ----- + 3 ___ + \/ 3 + +[TEX: \text{The semi-conjugate axis} = \sqrt{\frac{4D^2}{3}} += \frac{2D}{\sqrt{3}}] + +Since the distance from the center of the curve to either focus is +equal to the square root of the sum of the squares of the semi-axes, +the distance from o' to either focus + + ____________ + /4D² 4D² 4D + = /\ /----- + ----- = ---- + \/ 9 3 3 + +[TEX: \sqrt{\frac{4D^2}{9} + \frac{4D^2}{3}} = \frac{4D}{3}] + +We can therefore make the following construction (Fig. II.) Draw a d +the chord of the arc a c d. Trisect a d at o' and k. Produce +d a to l, making a l = a o' = o' k = k d. With a k as a +transverse axis, and l and d as foci, construct the branch of the +hyperbola k c c' c", which will intersect all arcs having the common +chord a d at c, c', c", etc., making the arcs c d, c' d, c" +d, etc., respectively, equal to one-third of the arcs a c d, a c' d, +a c" d, etc. + + * * * * * + + + + +TEST CARD HINTS. + +By Dr. F. OGDEN STOUT. + + +I know it is the custom with a great many if not the majority of +opticians to fit a customer without knowing whether he has presbyopia, +hypermetropia, or any of the other errors of refraction. Their method +is first to try a convex, and if this does not improve, a concave, +etc., until the proper one is found. This, of course, amounts to the +same thing if the right glass is found. But in practice it will be +found both time saving and more satisfactory to first decide with what +error you have to deal. It is very simple, and, where you have no +other means of diagnosing (such as the ophthalmoscope), it does away +with the necessity of trying so many lenses before the proper one is +found. You should have a distance test card placed at a distance of +twenty feet from the person you are examining, and in a good light. + +A distance test card consists of letters of various sizes which it has +been found can be seen at certain distances by people with good +vision. Thus the largest letter is marked with a cc, meaning that this +should be seen at two hundred feet, and another line, XX, at twenty +feet, which is the proper distance for testing vision for distance, +for the reason that a normal eye is at rest when looking at any object +twenty feet from it or beyond, and the rays coming from it are +parallel and come to a focus on the retina. You must also have a near +vision test card with lines that should be seen by a normal eye from +ten to seventy-two inches, and a card of radiating lines for +astigmatism. With this preparation you are ready to proceed. To +illustrate, the first customer comes and tells you that up to six +months ago he had very good vision, but he finds now that, especially +at night, he has trouble in reading or writing, and that he finds he +can see better a little farther away. His head aches and eyes smart. +You will of course say that this is a very simple case. It must be old +sight (presbyopia). Probably it is if he is old enough (45), but you +must prove this for yourself, without asking his age, which is +embarrassing in the case of a lady. If you direct him to the distance +card twenty feet away, and find that he can see every one down to and +including the one marked XX, his vision is up to the standard for +distance, and you know that he can have no astigmatism worth +correcting, nor any near sight, as both of these affect vision for +distance, but he may have far sight or old sight or both combined. You +must find which it is. + +If, while he is still looking at the twenty-foot line, you place in +front of the eyes a weak convex and he tells you he sees just as well +with as without, it proves the existence of far-sight or +hypermetropia, and the strongest convex that still leaves vision as +good for distance as without any, corrects the manifest. But if the +weak convex blurs it, it shows that there is some defect in focusing, +if the near vision is below normal. You therefore know that you have a +case of old sight or presbyopia, requiring the weakest convex to +correct it, that will enable your customer to see the finest line on +the near card at the required distance. + +The next customer that comes to be fitted with glasses can only see +the line marked XL on the distance card at 20 feet or about one-half +of what he should see, which leads you to think that there is no far +sight, for vision for distance is good except in very high degrees of +this error. Nor can there be old-sight, for vision for distance is +good in old-sight until after the fifty-fifth year, but it can be near +sight (myopia) or astigmatism, or both. We next try the near card and +find that even the finest line can be seen clearly if held +sufficiently close to the eyes. We now know that this is a case of +near sight, and we must fit them with glasses for distance. The +weakest concave that will enable him to see the line that should be +seen on the distance card at 20 feet is the proper one to give him for +use.--_The Optician._ + + * * * * * + + + + +CHARLES GOODYEAR. + + +CHARLES GOODYEAR was born in New Haven, December 29, 1800. He was the +son of Amasa Goodyear, and the eldest among six children. His father +was quite proud of being a descendant of Stephen Goodyear, one of the +founders of the colony of New Haven in 1638. + +Amasa Goodyear owned a little farm on the neck of land in New Haven +which is now known as Oyster Point, and it was here that Charles spent +the earliest years of his life. When, however, he was quite young, his +father secured an interest in a patent for the manufacture of ivory +buttons, and looking for a convenient location for a small mill, +settled at Naugatuck, Conn., where he made use of the valuable water +power that is there. Aside from his manufacturing, the elder Goodyear +ran a farm, and between the two lines of industry kept young Charles +pretty busy. + +In 1816, Charles left his home and went to Philadelphia to learn the +hardware business. He worked at this very industriously until he was +twenty-one years old, and then, returning to Connecticut, entered into +partnership with his father at the old stand in Naugatuck, where they +manufactured not only ivory and metal buttons, but a variety of +agricultural implements, which were just beginning to be appreciated +by the farmers. In August of 1824 he was united in marriage with +Clarissa Beecher, a woman of remarkable strength of character and +kindness of disposition, and one who in after years was of the +greatest assistance to the impulsive inventor. Two years later he +removed again to Philadelphia, and there opened a hardware store. His +specialties were the valuable agricultural implements that his firm +had been manufacturing, and after the first distrust of home made +goods had worn away--for all agricultural implements were imported +from England at that time--he found himself established at the head of +a successful business. + +This continued to increase until it seemed but a question of a few +years until he would be a very wealthy man. Between 1829 and 1830 he +suddenly broke down in health, being troubled with dyspepsia. At the +same time came the failure of a number of business houses that +seriously embarrassed his firm. They struggled on, however, for some +time, but were finally obliged to fail. The ten years that followed +this were full of the bitterest struggles and trials to Goodyear. +Under the law that then existed he was imprisoned time after time for +debts, even while he was trying to perfect inventions that should pay +off his indebtedness. + +Between the years 1831 and 1832 he began to hear about gum elastic and +very carefully examined every article that appeared in the newspapers +relative to this new material. The Roxbury Rubber Company, of Boston, +had been for some time experimenting with the gum, and believing that +they had found means for manufacturing goods from it, had a large +plant and were sending their goods all over the country. It was some +of their goods that first attracted his attention. Soon after this +Goodyear visited New York, and went at once to the store of the +Roxbury Rubber Company. While there, he examined with considerable +care some of their life preservers, and it struck him that the tube +used for inflation was not very perfect. He, therefore, on his return +to Philadelphia, made some tubes and brought them down to New York and +showed them to the manager of the Roxbury Rubber Company. + +This gentlemen was so pleased with the ingenuity that Goodyear had +shown in manufacturing these tubes, that he talked very freely with +him and confessed to him that the business was on the verge of ruin, +that the goods had to be tested for a year before they could tell +whether they were perfect or not, and to their surprise, thousands of +dollars worth of goods that they had supposed were all right were +coming back to them, the gum having rotted and made them so offensive +that it was necessary to bury them in the ground to get them out of +the way. + +Goodyear at once made up his mind to experiment on this gum and see if +he could not overcome its stickiness. + +He, therefore, returned to Philadelphia, and, as usual, met a +creditor, who had him arrested and thrown into prison. While there, he +tried his first experiments with India rubber. The gum was very cheap +then, and by heating it and working it in his hands, he managed to +incorporate in it a certain amount of magnesia which produced a +beautiful white compound and appeared to take away the stickiness. + +He therefore thought he had discovered the secret, and through the +kindness of friends was put in the way of further perfecting his +invention at a little place in New Haven. The first thing that he made +here was shoes, and he used his own house for grinding room, calender +room, and vulcanizing department, and his wife and children helped to +make up the goods. His compound at this time was India rubber, +lampblack, and magnesia, the whole dissolved in turpentine and spread +upon the flannel cloth which served as the lining for the shoes. It +was not long, however, before he discovered that the gum, even treated +this way, became sticky, and then those who had supplied the money for +the furtherance of these experiments, completely discouraged, made up +their minds that they could go no further, and so told the inventor. + +[Illustration: CHARLES GOODYEAR.] + +He, however, had no mind to stop here in his experiments, but, selling +his furniture and placing his family in a quiet boarding place, he +went to New York, and there, in an attic, helped by a friendly +druggist, continued his experiments. His next step in this line was to +compound the rubber with magnesia and then boil it in quicklime and +water. This appeared to really solve the problem, and he made some +beautiful goods. At once it was noised abroad that India rubber had +been so treated that it lost its stickiness, and he received medals +and testimonials and seemed on the high road to success, till one day +he noticed that a drop of weak acid, falling on the cloth, neutralized +the alkali, and immediately the rubber was soft again. To see this, +with his knowledge of what rubber should do, proved to him at once +that his process was not a successful one. He therefore continued +experimenting, and after preparing his mixtures in his attic in New +York, would walk three miles to the mill of a Mr. Pike, at Greenwich +village, and there try various experiments. + +In the line of these, he discovered that rubber, dipped in nitric +acid, formed a surface cure, and he made a great many goods with this +acid cure which were spoken of, and which even received a letter of +commendation from Andrew Jackson. + +The constant and varied experiments that Goodyear went through with +affected his health more or less, and at one time he came very near +being suffocated by gas generated in his laboratory. That he did not +die then everybody knows, but he was thrown then into a fever by the +accident and came very near losing his life. + +It was there that he formed an acquaintance with Dr. Bradshaw, who was +very much pleased with the samples of rubber goods that he saw in +Goodyear's room, and when the doctor went to Europe he took them with +him, where they attracted a great deal of attention, but beyond that +nothing was done about them. Now that he appeared to have success, he +found no difficulty in obtaining a partner, and together the two +gentlemen fitted up a factory and began to make clothing, life +preservers, rubber shoes, and a great variety of rubber goods. They +also had a large factory, with special machinery, built at Staten +Island, where he removed his family and again had a home of his own. +Just about this time, when everything looked bright, the great panic +of 1836-1837 came, and swept away the entire fortune of his associate +and left Goodyear without a cent, and no means of earning one. + +His next move was to go to Boston, where he became acquainted with J. +Haskins, of the Roxbury Rubber Company, and found in him a firm +friend, who loaned him money and stood by him when no one would have +anything to do with the visionary inventor. Mr. Chaffee was also +exceedingly kind and ever ready to lend a listening ear to his plans, +and to also assist him in a pecuniary way. It was about this time that +it occurred to Mr. Chaffee that much of the trouble that they had +experienced in working India rubber might come from the solvent that +was used. He therefore invented a huge machine for doing the mixing +by mechanical means. The goods that were made in this way were +beautiful to look at, and it appeared, as it had before, that all +difficulties were overcome. + +Goodyear discovered a new method for making rubber shoes and got a +patent on it, which he sold to the Providence Company, in Rhode +Island. + +The secret of making the rubber so that it would stand heat and cold +and acids, however, had not been discovered, and the goods were +constantly growing sticky and decomposing and being returned. + +In 1838 he, for the first time, met Nathaniel Hayward, who was then +running a factory in Woburn. Some time after this Goodyear himself +moved to Woburn, all the time continuing his experiments. He was very +much interested in Hayward's sulphur experiments for drying rubber, +but it appears that neither of them at that time appreciated the fact +that it needed heat to make the sulphur combine with the rubber and to +vulcanize it. + +The circumstances attending the discovery of his celebrated process is +thus described by Mr. Goodyear himself in his book, "Gum Elastic." It +will be observed that he makes use of the third person in all +references to himself: + + "In the summer of 1838 he became acquainted with Mr. Nathaniel + Hayward, of Woburn, Mass., who had been employed as the foreman of + the Eagle Company at Woburn, where he had made use of sulphur by + impregnating the solvent with it. It was through him that the + writer (Charles Goodyear, who makes use all through his book of + the third person) received the first knowledge of the use of + sulphur as a drier of gum elastic. + + "Mr. Hayward was left in possession of the factory which was + abandoned by the Eagle Company. Soon after this it was occupied by + the writer, who employed him for the purpose of manufacturing life + preservers and other articles by the acid gas process. At this + period he made many novel and useful applications of this + substance. Among other fancy articles he had newspapers printed on + the gum elastic drapery, and the improvement began to be highly + appreciated. He therefore now entered, as he thought, upon a + successful career for the future. A far different result awaited + him. + + "It was supposed by others as well as himself that a change was + wrought through the mass of the goods acted upon by the acid gas, + and that the whole body of the article was made better than the + native gum. The surface of the goods really was so, but owing to + the eventual decomposition of the goods beneath the surface, the + process was pronounced by the public a complete failure. Thus + instead of realizing the large fortune which by all acquainted + with his prospects was considered certain, his whole invention + would not bring him a week's living. + + "He was obliged for the want of means to discontinue + manufacturing, and Mr. Hayward left his employment. The inventor + now applied himself alone, with unabated ardor and diligence, to + detect the cause of his misfortune and if possible to retrieve the + lost reputation of his invention. On one occasion he made some + experiments to ascertain the effect of heat upon the same compound + that had decomposed in the articles previously manufactured, and + was surprised to find that the specimen, being carelessly brought + in contact with a hot stove, charred like leather. He endeavored + to call the attention of his brother as well as some other + individuals who were present, and who were acquainted with the + manufacture of gum elastic, to this effect as remarkable and + unlike any before known, since gum elastic always melted when + exposed to a high degree of heat. The occurrence did not at the + time appear to them to be worthy of notice. It was considered as + one of the frequent appeals that he was in the habit of making in + behalf of some new experiment. He, however, directly inferred that + if the process of charring could be stopped at the right point, it + might divest the gum of its native adhesiveness throughout, which + would make it better than the native gum. + + "He made another trial of heating a similar fabric, before an open + fire. The same effect, that of charring the gum, followed, but + there were further and very satisfactory indications of ultimate + success in producing the desired result, as upon the edge of the + charred portions of the fabric there appeared a line, or border, + that was not charred, but perfectly cured. + + "These facts have been stated precisely as they occurred in + reference to the acid gas, as well as the vulcanizing process. + + "The incidents attending the discovery of both have a strong + resemblance, so much so they may be considered parallel cases. It + being now known that the results of the vulcanizing process are + produced by means and in a manner which would not have been + anticipated from any reasoning on the subject, and that they have + not yet been satisfactorily accounted for, it has been sometimes + asked, how the inventor came to make the discovery? The answer has + already been given. It may be added that he was many years seeking + to accomplish this object, and that he allowed nothing to escape + his notice that related to the subject. Like the falling of an + apple, it was suggestive of an important fact to one whose mind + was previously prepared to draw an inference from any occurrence + which might favor the object of his research. While the inventor + admits that these discoveries were not the results of scientific + chemical investigations, _he is not willing to admit that they + were the result of what is commonly termed accident_; he claims + them to be the result of the closest application and observation. + + "The discoloring and charring of the specimens proved nothing and + discovered nothing of value, but quite the contrary, for in the + first instance, as stated in the acid gas improvement, the + specimen acted upon was thrown away as worthless and left for some + time; in the latter instance, the specimen that was charred was in + like manner disregarded by others. + + "It may, therefore, be considered as one of those cases where the + leading of the Creator providentially aids his creatures, by what + are termed 'accidents,' to attain those things which are not + attainable by the powers of reasoning he has conferred on them." + +Now that Goodyear was sure that he had the key to the intricate puzzle +that he had worked over for so many years, he began at once to tell +his friends about it and to try to secure capital, but they had +listened to their sorrow so many times that his efforts were futile. +For a number of years be struggled and experimented and worked along +in a small way, his family suffering with himself the pangs of the +extremest poverty. At last he went to New York and showed some of his +samples to William Ryder, who, with his brother Emory, at once +appreciated the value of the discovery and started in to +manufacturing. Even here Goodyear's bad luck seemed to follow him, for +the Ryder Bros. failed and it was impossible to continue the business. + +He had, however, started a small factory at Springfield, Mass., and +his brother-in-law, Mr. De Forest, who was a wealthy woolen +manufacturer, took Ryder's place, and the work of making the invention +practical was continued. In 1844 it was so far perfected that Goodyear +felt it safe to take out a patent. The factory at Springfield was run +by his brothers, Nelson and Henry. + +In 1843 Henry started one in Naugatuck, and in 1844 introduced +mechanical mixing in place of the mixture by the use of solvents. + +In the year 1852 Goodyear went to Europe, a trip that he had long +planned, and saw Hancock, then in the employ of Charles Macintosh & +Co. Hancock admitted in evidence that the first piece of vulcanized +rubber he ever saw came from America, but claimed to have reinvented +vulcanization and secured patents in Great Britain, but it is _a +remarkable fact_ that Charles Goodyear's French patent was the first +publication in Europe of this discovery. + +In 1852 a French company were licensed by Mr. Goodyear to make shoes, +and a great deal of interest was felt in the new business. In 1855 the +French emperor gave to Charles Goodyear the grand medal of honor and +decorated him with the cross of the legion of honor in recognition of +his services as a public benefactor, but the French courts +subsequently set aside his French patents on the ground of the +importation of vulcanized goods from America by licenses under the +United States patents. He died July 1, 1860, at the Fifth Avenue +Hotel, New York City.--_India Rubber World_. + + * * * * * + +[Continued from SUPPLEMENT, No. 786, page 12558.] + + + + +THE ELECTROMAGNET. + +[Footnote: Lectures delivered before the Society of Arts, London, +1890. From the Journal of the Society.] + +BY PROFESSOR SILVANUS P. THOMPSON, D. SC., B.A., M.I.E.E. + +III. + +RESEARCHES OF PROFESSOR HUGHES. + + +[Illustration: FIG. 51.--HUGHES' ELECTROMAGNET.] + +His object was to find out the best form of electromagnet, the best +distance between the poles, and the best form of armature for the +rapid work required in Hughes' printing telegraphs. One word about +Hughes' magnets. This diagram (Fig. 51) shows the form of the well +known Hughes' electromagnet. I feel almost ashamed to say those words +"well known," because on the Continent everybody knows what you mean +by a Hughes' electromagnet. In England scarcely anyone knows what you +mean. Englishmen do not even know that Professor Hughes has invented a +special form of electromagnet. Hughes' special form is this: A +permanent steel magnet, generally a compound one, having soft iron +pole pieces, and a couple of coils on the pole pieces only. As I have +to speak of Hughes' special contrivance among the mechanisms that will +occupy our attention later on, I only now refer to this magnet in one +particular. If you wish a magnet to work rapidly, you will secure the +most rapid action, not when the coils are distributed all along, but +when they are heaped up near, not necessarily entirely on, the poles. +Hughes made a number of researches to find out what the right length +and thickness of these pole pieces should be. It was found an +advantage not to use too thin pole pieces, otherwise the magnetism +from the permanent magnet did not pass through the iron without +considerable reluctance, being choked by insufficiency of section: +also not to use too thick pieces, otherwise they presented too much +surface for leakage across from one to the other. Eventually a +particular length was settled upon, in proportion about six times the +diameter, or rather longer. In the further researches that Hughes made +he used a magnet of shorter form, not shown here, more like those +employed in relays, and with an armature from 2 to 3 millimeters +thick, 1 centimeter wide and 5 centimeters long. The poles were turned +over at the top toward one another. Hughes tried whether there was any +advantage in making those poles approach one another, and whether +there was any advantage in having as long an armature as 5 +centimeters. He tried all the different kinds, and plotted out the +results of observations in curves, which could be compared and +studied. His object was to ascertain the conditions which would give +the strongest pull, not with a steady current, but with such currents +as were required for operating his printing telegraph instruments; +currents which lasted but one to twenty hundredths of a second. He +found it was decidedly an advantage to shorten the length of the +armature, so that it did not protrude far over the poles. In fact, he +got a sufficient magnetic circuit to secure all the attractive power +that he needed, without allowing as much chance of leakage as there +would have been had the armature extended a longer distance over the +poles. He also tried various forms of armature having very various +cross sections. + + +POSITION AND FORM OF ARMATURE. + +In one of Du Moncel's papers on electromagnets[1] you will also find a +discussion on armatures, and the best forms for working in different +positions. Among other things in Du Moncel you will find this paradox: +that whereas using a horseshoe magnet with fat poles, and a flat piece +of soft iron for armature, it sticks on far tighter when put on +edgeways; on the other hand, if you are going to work at a distance, +across air, the attraction is far greater when it is set flatways. I +explained the advantage of narrowing the surfaces of contact by the +law of traction, B², coming in. Why should we have for action at a +distance the greater advantage from placing the armature flatway to +the poles? It is simply that you thereby reduce the reluctance offered +by the air gap to the flow of the magnetic lines. Du Moncel also tried +the difference between round armatures and flat ones, and found that a +cylindrical armature was only attracted about half as strongly as a +prismatic armature having the same surface when at the same distance. +Let us examine this fact in the light of the magnetic circuit. The +poles are flat. You have at a certain distance away a round armature; +there is a certain distance between its nearest side and the polar +surfaces. If you have at the same distance away a flat armature having +the same surface, and, therefore, about the same tendency to leak, why +do you get a greater pull in this case than in that? I think it is +clear that if they are at the same distance away, giving the same +range of motion, there is a greater magnetic reluctance in the case of +the round armature, although there is the same periphery, because, +though the nearest part of the surface is at the prescribed distance, +the rest of the under surface is farther away; so that the gain found +in substituting an armature with a flat surface is a gain resulting +from the diminution in the resistance offered by the air gap. + +[Footnote 1: "La Lumiere Electrique," vol. ii.] + + +POLE PIECES ON HORSESHOE MAGNETS. + +Another of Du Moncel's researches[2] relates to the effect of polar +projections or shoes--movable pole pieces, if you like--upon a +horseshoe electromagnet. The core of this magnet was of round iron 4 +centimeters in diameter, and the parallel limbs were 10 centimeters +long and 6 centimeters apart. The shoes consisted of two flat pieces +of iron slotted out at one end, so that they could be slid along over +the poles and brought nearer together. The attraction exerted on a +flat armature across air gaps 2 millimeters thick was measured by +counterpoising. Exciting this electromagnet with a certain battery, it +was found that the attraction was greatest when the shoes were pushed +to about 15 millimeters, or about one-quarter of the interpolar +distance, apart. The numbers were as follows: + + Distance between + shoes. Attraction, + Millimeters. in grammes. + + 2 900 + 10 1,012 + 15 1,025 + 25 965 + 40 890 + 60 550 + +[Footnote 2: "La Lumiere Electrique," vol. iv., p. 129.] + +With a stronger battery the magnet without shoes had an attraction of +885 grammes, but with the shoes 15 millimeters apart, 1,195 grammes. +When one pole only was employed, the attraction, which was 88 grammes +without a shoe, was _diminished_ by adding a shoe to 39 grammes! + + +CONTRAST BETWEEN ELECTROMAGNETS AND PERMANENT MAGNETS. + +Now I want particularly to ask you to guard against the idea that all +these results obtained from electromagnets are equally applicable to +permanent magnets of steel; they are not, for this simple reason. With +an electromagnet, when you put the armature near, and make the +magnetic circuit better, you not only get more magnetic lines going +through that armature, but you get more magnetic lines going through +the whole of the iron. You get more magnetic lines round the bend when +you put an armature on to the poles, because you have a magnetic +circuit of less reluctance with the same external magnetizing power in +the coils acting around it. Therefore, in that case, you will have a +greater magnetic flux all the way round. The data obtained with the +electromagnet (Fig. 42), with the exploring coil, C, on the bend of +the core, where the armature was in contact, and when it was removed +are most significant. When the armature was present it multiplied the +total magnetic flow tenfold for weak currents and nearly threefold for +strong currents. But with a steel horseshoe, magnetized once for all, +the magnetic lines that flow around the bend of the steel are a fixed +quantity, and, however much you diminish the reluctance of the +magnetic circuit, you do not create or evoke any more. When the +armature is away the magnetic lines arch across, not at the ends of +the horseshoe only, but from its flanks; the whole of the magnetic +lines leaking somehow across the space. Where you have put the +armature on, these lines, instead of arching out into space as freely +as they did, pass for the most part along the steel limbs and through +the iron armature. You may still have a considerable amount of +leakage, but you have not made one line more go through the bent part. +You have absolutely the same number going through the bend with the +armature off as with the armature on. You do not add to the total +number by reducing the magnetic reluctance, because you are not +working under the influence of a constantly impressed magnetizing +force. By putting the armature on to a steel horseshoe magnet you +only _collect_ the magnetic lines, you do not _multiply_ them. This is +not a matter of conjecture. A group of my students have been making +experiments in the following way: They took this large steel horseshoe +magnet (Fig. 52), the length of which, from end to end, through the +steel, is 42½ inches. A light, narrow frame was constructed so that it +could be slipped on over the magnet, and on it were wound 30 turns of +fine wire, to serve as an exploring coil. The ends of this coil were +carried to a distant part of the laboratory, and connected to a +sensitive ballistic galvanometer. The mode of experimenting is as +follows: + +The coil is slipped on over the magnet (or over its armature) to any +desired position. The armature of the magnet is placed gently upon the +poles, and time enough is allowed to elapse for the galvanometer +needle to settle to zero. The armature is then suddenly detached. The +first swing measures the change, due to removing the armature, in the +number of magnetic lines that pass through the coil in the particular +position. + +[Illustration: FIG. 52.--EXPERIMENT WITH PERMANENT MAGNET.] + +I will roughly repeat the experiment before you: The spot of light on +the screen is reflected from my galvanometer at the far end of the +table. I place the exploring coil just over the pole, and slide on the +armature; then close the galvanometer circuit. Now I detach the +armature, and you observe the large swing. I shift the exploring coil, +right up to the bend; replace the armature; wait until the spot of +light is brought to rest at the zero of the scale. Now, on detaching +the armature, the movement of the spot of light is quite +imperceptible. In our careful laboratory experiments, the effect was +noticed inch by inch all along the magnet. The effect when the +exploring coil was over the bend was not as great as 1-3000th part of +the effect when the coil was hard up to the pole. We are, therefore, +justified in saying that the number of magnetic lines in a permanently +magnetized steel horseshoe magnet is not altered by the presence or +absence of the armature. + +You will have noticed that I always put on the armature gently. It +does not do to slam on the armature; every time you do so, you knock +some of the so-called permanent magnetism out of it. But you may pull +off the armature as suddenly as you like. It does the magnet good +rather than harm. There is a popular superstition that you ought never +to pull off the keeper of a magnet suddenly. On investigation, it is +found that the facts are just the other way. You may pull off the +keeper as suddenly as you like, but you should never slam it on. + +From these experimental results I pass to the special design of +electromagnets for special purposes. + + +ELECTROMAGNETS FOR MAXIMUM TRACTION. + +These have already been dealt with in the preceding lecture; the +characteristic feature of all the forms suitable for traction being +the compact magnetic circuit. + +Several times it has been proposed to increase the power of +electromagnets by constructing them with intermediate masses of iron +between the central core and the outside, between the layers of +windings. All these constructions are founded on fallacies. Such iron +is far better placed either right inside the coils or right outside +them, so that it may properly constitute a part of the magnetic +circuit. The constructions known as Camacho's and Cance's, and one +patented by Mr. S.A. Varley, in 1877, belonging to this delusive order +of ideas, are now entirely obsolete. + +Another construction which is periodically brought forward as a +novelty is the use of iron windings of wire or strip in place of +copper winding. The lower electric conductivity of iron, as compared +with copper, makes such a construction wasteful of exciting power. To +apply equal magnetizing power by means of an iron coil implies the +expenditure of about six times as many watts as need be expended if +the coil is of copper. + + +ELECTROMAGNETS FOR MAXIMUM RANGE OF ATTRACTION. + +We have already laid down the principle which will enable us to design +electromagnets to act at a distance. We want our magnet to project, as +it were, its force across the greatest length of air gap. Clearly, +then, such a magnet must have a very large magnetizing power, with +many ampere turns upon it, to be able to make the required number of +magnetic lines pass across the air resistance. Also it is clear that +the poles must not be too close together for its work, otherwise the +magnetic lines at one pole will be likely to curl round and take short +cuts to the other pole. There must be a wider width between the poles +than is desirable in electromagnets for traction. + + +ELECTROMAGNETS OF MINIMUM WEIGHT. + +In designing an apparatus to put on board a boat or a balloon, where +weight is a consideration of primary importance, there is again a +difference. There are three things that come into play--iron, copper, +and electric current. The current weighs nothing, therefore, if you +are going to sacrifice everything else to weight, you may have +comparatively little iron, but you must have enough copper to be able +to carry the electric current; and under such circumstances you must +not mind heating your wires nearly red hot to pass the biggest +possible current. Provide as little copper as you conveniently can, +sacrificing economy in that case to the attainment of your object; +but, of course, you must use fireproof material, such as asbestos, for +insulating, instead of cotton or silk. + + +A USEFUL GUIDING PRINCIPLE. + +In all cases of design there is one leading principle which will be +found of great assistance, namely, that a magnet always tends so to +act as though it tried to diminish the length of its magnetic circuit. +It tries to grow more compact. This is the reverse of that which holds +good with an electric current. The electric circuit always tries to +enlarge itself, so as to inclose as much space as possible, but the +magnetic circuit always tries to make itself as compact as possible. +Armatures are drawn in as near as can be, to close up the magnetic +circuit. Many two-pole electromagnets show a tendency to bend together +when the current is turned on. One form in particular, which was +devised by Ruhmkorff for the purpose of repeating Faraday's celebrated +experiment on the magnetic rotation of polarized light, is liable to +this defect. Indeed, this form of electromagnet is often designed very +badly, the yoke being too thin, both mechanically and magnetically, +for the purpose which it has to fulfill. + +Here is a small electric bell, constructed by Wagener, of Wiesbaden, +the construction of which illustrates this principle. The +electromagnet, a horseshoe, lies horizontally; its poles are provided +with protruding curved pins of brass. Through the armature are drilled +two holes, so that it can be hung upon the two brass pins; and when so +hung up it touches the ends of the iron cores just at one edge, being +held from more perfect contact by a spring. There is no complete gap, +therefore, in the magnetic circuit. When the current comes and applies +a magnetizing power, it finds the magnetic circuit already complete in +the sense that there are no absolute gaps. But the circuit can be +bettered by tilting the armature to bring it flat against the polar +ends, that being indeed the mode of motion. This is a most reliable +and sensitive pattern of bell. + +[Illustration: FIG. 53.--ELECTROMAGNETIC POP-GUN.] + +_Electromagnetic Pop-gun._--Here is another curious illustration of +the tendency to complete the magnetic circuit. Here is a tubular +electromagnet (Fig. 53), consisting of a small bobbin, the core of +which is an iron tube about two inches long. There is nothing very +unusual about it; it will stick on, as you see, to pieces of iron when +the current is turned on. It clearly is an ordinary electromagnet in +that respect. Now suppose I take a little round rod of iron, about an +inch long, and put it into the end of the tube, what will happen when +I turn on my current? In this apparatus as it stands, the magnetic +circuit consists of a short length of iron, and then all the rest is +air. The magnetic circuit will try to complete itself, not by +shortening the iron, but by _lengthening_ it; by pushing the piece of +iron out so as to afford more surface for leakage. That is exactly +what happens; for, as you see, when I turn on the current, the little +piece of iron shoots out and drops down. You see that little piece of +iron shoot out with considerable force. It becomes a sort of magnetic +popgun. This is an experiment which has been twice discovered. I found +it first described by Count Du Moncel, in the pages of _La Lumiere +Electrique_, under the name of the "pistolet electromagnetique;" and +Mr. Shelford Bidwell invented it independently. I am indebted to him +for the use of this apparatus. He gave an account of it to the +Physical Society, in 1885, but the reporter missed it, I suppose, as +there is no record in the society's proceedings. + + +ELECTROMAGNETS FOR USE WITH ALTERNATING CURRENTS. + +When you are designing electromagnets for use with alternating +currents, it is necessary to make a change in one respect, namely, you +must so laminate the iron that internal eddy currents shall not occur; +indeed, for all rapid-acting electromagnetic apparatus it is a good +rule that the iron must not be solid. It is not usual with telegraphic +instruments to laminate them by making up the core of bundles of iron +plates or wires, but they are often made with tubular cores, that is +to say, the cylindrical iron core is drilled with a hole down the +middle, and the tube so formed is slit with a saw cut to prevent the +circulation of currents in the substance of the tube. Now when +electromagnets are to be employed with rapidly alternating currents, +such as are used for electric lighting, the frequency of the +alternations being usually about 100 periods per second, slitting the +cores is insufficient to guard against eddy currents; nothing short of +completely laminating the cores is a satisfactory remedy. I have here, +thanks to the Brush Electric Engineering Company, an electromagnet of +the special form that is used in the Brush arc lamp when required for +the purpose of working in an alternating current circuit. It has two +bobbins that are screwed up against the top of an iron box at the head +of the lamp. The iron slab serves as a kind of yoke to carry the +magnetism across the top. There are no fixed cores In the bobbins, +which are entered by the ends of a pair of yoked plungers. Now in the +ordinary Brush lamp for use with a steady current, the plungers are +simply two round pieces of iron tapped into a common yoke; but for +alternate current working this construction must not be used, and +instead a U-shaped double plunger is used, made up of laminated iron, +riveted together. Of course it is no novelty to use a laminated core; +that device, first used by Joule, and then by Cowper, has been +repatented rather too often during the past fifty years to be +considered as a recent invention. + +The alternate rapid reversals of the magnetism in the magnetic field +of an electromagnet, when excited by alternating electric currents, +sets up eddy currents in every piece of undivided metal within range. +All frames, bobbin tubes, bobbin ends, and the like, must be most +carefully slit, otherwise they will overheat. If a domestic flat iron +is placed on the top of the poles of a properly laminated +electromagnet, supplied with alternating currents, the flat iron is +speedily heated up by the eddy currents that are generated internally +within it. The eddy currents set up by induction in neighboring masses +of metal, especially in good conducting metals such as copper, give +rise to many curious phenomena. For example, a copper disk or copper +ring placed over the pole of a straight electromagnet so excited is +violently repelled. These remarkable phenomena have been recently +investigated by Professor Elihu Thomson, with whose beautiful and +elaborate researches we have lately been made conversant in the pages +of the technical journals. He rightly attributes many of the repulsion +phenomena to the lag in phase of the alternating currents thus induced +in the conducting metal. The electromagnetic inertia, or +self-inductive property of the electric circuit, causes the currents +to rise and fall later in time than the electromotive forces by which +they are occasioned. In all such cases the impedance which the circuit +offers is made up of two things--resistance and inductance. Both these +causes tend to diminish the amount of current that flows, and the +inductance also tends to delay the flow. + + +ELECTROMAGNETS FOR QUICKEST ACTION. + +I have already mentioned Hughes' researches on the form of +electromagnet best adapted for rapid signaling. I have also +incidentally mentioned the fact that where rapidly varying currents +are employed, the strength of the electric current that a given +battery can yield is determined not so much by the resistance of the +electric circuit as by its electric inertia. It is not a very easy +task to explain precisely what happens to an electric circuit when the +current is turned on suddenly. The current does not suddenly rise to +its full value, being retarded by inertia. The ordinary law of Ohm in +its simple form no longer applies; one needs to apply that other law +which bears the name of the law of Helmholtz, the use of which is to +give us an expression, not for the final value of the current, but for +its value at any short time, t, after the current has been turned on. +The strength of the current after a lapse of a short time, t, cannot +be calculated by the simple process of taking the electromotive force +and dividing it by the resistance, as you would calculate steady +currents. + +In symbols, Helmholtz's law is: + + i_{t} = E/R ( 1 - e^{-(R/L)t} ) + +In this formula i_{t} means the strength of the current after the +lapse of a short time t; E is the electromotive force; R, the +resistance of the whole circuit; L, its coefficient of self-induction; +and _e_ the number 2.7183, which is the base of the Napierian +logarithms. Let us look at this formula; in its general form it +resembles Ohm's law, but with a new factor, namely, the expression +contained within the brackets. The factor is necessarily a fractional +quantity, for it consists of unity less a certain negative +exponential, which we will presently further consider. If the factor +within brackets is a quantity less than unity, that signifies that +i_{t} will be less than E ÷ R. Now the exponential of negative sign, +and with negative fractional index, is rather a troublesome thing to +deal with in a popular lecture. Our best way is to calculate some +values, and then plot it out as a curve. When once you have got it +into the form of a curve, you can begin to think about it, for the +curve gives you a mental picture of the facts that the long formula +expresses in the abstract. Accordingly we will take the following +case. Let E = 2 volts; R = 1 ohm; and let us take a relatively large +self-induction, so as to exaggerate the effect; say let L = 10 quads. +This gives us the following: + + ________________________________________ + | | | | + | t_{(sec.)} | e^{+(R/L)t} | i_{t} | + --------------+--------------+---------| + | 0 | 1 | 0 | + | 1 | 1.105 | 0.950 | + | 2 | 1.221 | 1.810 | + | 5 | 1.649 | 3.936 | + | 10 | 2.718 | 6.343 | + | 20 | 7.389 | 8.646 | + | 30 | 20.08 | 9.501 | + | 60 | 403.4 | 9.975 | + | 120 | 16200.0 | 9.999 | + ---------------------------------------- + +In this case the value of the steady current as calculated by Ohm's +law is 10 amperes, but Helmholtz's law shows us that with the great +self-induction which we have assumed to be present, the current, even +at the end of 30 seconds, has only risen up to within 5 percent. of +its final value; and only at the end of two minutes has practically +attained full strength. These values are set out in the highest curve +in Fig. 54, in which, however, the further supposition is made that +the number of spirals, S, in the coils of the electromagnet is 100, so +that when the current attains its full value of 10 amperes, the full +magnetizing power will be Si = 1000. It will be noticed that the +curve rises from zero at first steeply and nearly in a straight line, +then bends over, and then becomes nearly straight again, as it +gradually rises to its limiting value. The first part of the +curve--that relating to the strength of the current after _very small_ +interval of time--is the period within which the strength of the +current is governed by inertia (i.e., the self-induction) rather than +by resistance. In reality the current is not governed either by the +self-induction or by the resistance alone, but by the ratio of the +two. This ratio is sometimes called the "time constant" of the +circuit, for it represents _the time_ which the current takes in that +circuit to rise to a definite fraction of its final value. + + E = 10 + r = 1 + R = 100 + L = 10 + + Si + 1000 + _..------------------------------- + | . _ _--------- + | . .---- + | . .- 2 IN SERIES + | . .- + | - + | .: - : + | .: . : + 500 | . : __- -:--------------------------- + | . : _.- - : 2 IN PARALLEL + | . :. - : + | . / : - : + | . / - : + |. / - : : + |./. : : + |/_____:_____________:____________________________ t + 10 20 40 60 80 100 120 + + FIG. 54.--CURVES OF RISE OF CURRENTS. + +This definite fraction is the fraction (e - 1)/e; or in decimals, +0.634. All curves of rise of current are alike in general shape, they +differ only in scale, that is to say, they differ only in the height +to which they will ultimately rise, and in the time they will take to +attain this fraction of their final value. + +_Example (1)._--Suppose E = 10; R = 200 ohms; L = 8. The final value +of the current will be 0.025 amp. or 25 milliamperes. Then the time +constant will be 8 ÷ 400 = 1-50th sec. + +_Example (2)._--The P.O. Standard "A" relay has R = 400 ohms; L = +3.25. It works with 0.5 milliampere current, and therefore will work +with 5 Daniell cells through a line of 9,600 ohms. Under these +circumstances the time constant of the instrument on short circuit is +0.0081 sec. + +It will be noted that the time constant of a circuit can be reduced +either by diminishing the self-induction or by increasing the +resistance. In Fig. 54 the position of the time constant for the top +curve is shown by the vertical dotted line at 10 seconds. The current +will take 10 seconds to rise to 0.634 of its final value. This +retardation of the rise of current is simply due to the presence of +coils and electromagnets in the circuit; the current as it grows being +retarded because it has to create magnetic fields in these coils, and +so sets up opposing electromotive forces that prevent it from growing +all at once to its full strength. Many electricians, unacquainted with +Helmholtz's law, have been in the habit of accounting for this by +saying that there is a lag in the iron of the electromagnet cores. +They tell you that an iron core cannot be magnetized suddenly, that it +takes time to acquire its magnetism. They think it is one of the +properties of iron. But we know that the only true time lag in the +magnetization of iron, that which is properly termed "viscous +hysteresis," does not amount to any great percentage of the whole +amount of magnetization, takes comparatively a long time to show +itself, and cannot therefore be the cause of the retardation which we +are considering. There are also electricians who will tell you that +when magnetization is suddenly evoked in an iron bar, there are +induction currents set up in the iron which oppose and delay its +magnetization. That they oppose the magnetization is perfectly true, +but if you carefully laminate the iron so as to eliminate eddy +currents, you will find, strangely enough, that the magnetism rises +still more slowly to its final value. For by laminating the iron you +have virtually increased the self-inductive action, and increased the +time constant of the circuit, so that the currents rise more slowly +than before. The lag is not in the iron, but in the magnetizing +current, and the current being retarded, the magnetization is of +course retarded also. + + +CONNECTING COILS FOR QUICKEST ACTION. + +Now let us apply these most important though rather intricate +considerations to the practical problems of the quick working of the +electromagnet. Take the case of an electromagnet forming some part of +the receiving apparatus of a telegraph system in which it is desired +to secure very rapid working. Suppose the two coils that are wound +upon the horseshoe core are connected together in series. The +coefficient of self-induction for these two is four times as great as +that of either separately; coefficients of self-induction being +proportional to the square of the number of turns of wire that +surround a given core. Now if the two coils instead of being put in +series are put in parallel, the coefficient of self-induction will be +reduced to the same value as if there were only one coil, because half +the line current (which is practically unaltered) will go through each +coil. Hence the time constant of the circuit when the coils are in +parallel will be a quarter of that which it is when the coils are in +series; on the other hand, for a given line current, the final +magnetizing power of the two coils in parallel is only half what it +would be with the coil in series. The two lower curves in Fig. 54 +illustrate this, from which it is at once plain that the magnetizing +power for very brief currents is greater when the two coils are put in +parallel with one another than when they are joined in series. + +Now this circumstance has been known for some time to telegraph +engineers. It has been patented several times over. It has formed the +theme of scientific papers, which have been read both in France and in +England. The explanation generally given of the advantage of uniting +the coils in parallel is, I think, fallacious; namely that the "extra +currents" (i.e., currents due to self-induction) set up in the two +coils are induced in such directions as tend to help one another when +the coils are in series, and to neutralize one another when they are +in parallel. It is a fallacy, because in neither case do they +neutralize one another. Whichever way the current flows to make the +magnetism, it is opposed in the coils while the current is rising, +and helped in the coils while the current is falling, by the so-called +extra currents. If the current is rising in both coils at the same +moment, then, whether the coils are in series or in parallel, the +effect of self-induction is to retard the rise of the current. The +advantage of parallel grouping is simply that it reduces the time +constant. + + +BATTERY GROUPING FOR QUICKEST ACTION. + +One may consider the question of grouping the battery cells from the +same point of view. How does the need for rapid working, and the +question of time constant, affect the best mode of grouping the +battery cells? The amateur's rule, which tells you to so arrange your +battery that its internal resistance should be equal to the external +resistance, gives you a result wholly wrong for rapid working. The +supposed best arrangement will not give you (at the expense even of +economy) the best result that might be got out of the given number of +cells. Let us take an example and calculate it out, and place the +results graphically before our eyes in the form of curves. Suppose the +line and electromagnet have together a resistance of 6 ohms, and that +we have 24 small Daniell cells, each of electromotive force say 1 volt, +and of internal resistance 4 ohms. Also let the coefficient of +self-induction of the electromagnet and circuit be 6 quadrants. When +all the cells are in series, the resistance of the battery will be 96 +ohms, the total resistance of the circuit 102 ohms, and the full value +of the current 0.235 ampere. When all the cells are in parallel, the +resistance of the battery will be 0.133 ohm, the total resistance +6.133 ohms, and the full value of the current 0.162 ampere. According +to the amateur rule of grouping cells so that internal resistance +equals external, we must arrange the cells in 4 parallels, each having +6 cells in series, so that the internal resistance of the battery will +be 6 ohms, total resistance of circuit 12 ohms, full value of current +0.5 ampere. Now the corresponding time constants of the circuit in the +three cases (calculated by dividing the coefficient of self-induction +by the total resistance) will be respectively--in series, 0.06 sec.; +in parallel, 0.5 sec.; grouped for maximum steady current, 0.96 sec. +From these data we may now draw the three curves, as in Fig. 55, +wherein the abscissæ are the values of time in seconds and the +ordinates the current. The faint vertical dotted lines mark the time +constants in the three cases. It will be seen that when rapid working +is required the magnetizing current will rise, during short intervals +of time, more rapidly if all the cells are put in series than it will +do if the cells are grouped according to the amateur rule. + + | + 5| . + | . + | . + 4| MAXIMUM . + | OUTPUT \ . + | . + 3| . + | . : ALL IN SERIES + | _-------------------:------------------------------ + 2| .- - : + | - - : + | -: - : + 1| / : - : ALL IN PARALLEL + |. : . : _________-------- + |- :__ : ---------- + +-----------------------------:------------------------------- + 0 1 2 3 4 5 6 7 8 9 10 + +FIG. 55.--CURVES OF RISE OF CURRENT WITH DIFFERENT GROUPINGS OF BATTERY. + +When they are all put in series, so that the battery has a much +greater resistance than the rest of the circuit, the current rises +much more rapidly, because of the smallness of the time constant, +although it never attains the same ultimate maximum as when grouped in +the other way. That is to say, if there is self-induction as well as +resistance in the circuit, the amateur rule does not tell you the best +way of arranging the battery. There is another mode of regarding the +matter which is helpful. Self-induction, while the current is growing, +acts as if there were a sort of spurious addition to the resistance of +the circuit; and while the current is dying away it acts of course in +the other way, as if there were a subtraction from the resistance. +Therefore you ought to arrange the battery so that the internal +resistance is equal to the real resistance of the circuit, plus the +spurious resistance during that time. But how much is the spurious +resistance during that time? It is a resistance proportional to the +time that has elapsed since the current was turned on. So then it +comes to a question of the length of time for which you want to work +it. What fraction of a second do you require your signal to be given +in? What is the rate of the vibrator of your electric bell? Suppose +you have settled that point, and that the short time during which the +current is required to rise is called t; then the apparent resistance +at time t after the current is turned on is given by the formula: + + R_{t} = R × e^{(R/L)t} + ( e^{(R/L)t} - 1 ) + + +TIME CONSTANTS OF ELECTROMAGNETS. + +I may here refer to some determinations made by M. Vaschy,[1] +respecting the coefficients of self-induction of the electromagnets of +a number of pieces of telegraphic apparatus. Of these I must only +quote one result, which is very significant. It relates to the +electromagnet of a Morse receiver of the pattern habitually used on +the French telegraph lines. + + L, in quadrants. + Bobbins, separately, without iron cores. 0.233 and 0.265 + Bobbins, separately, with iron cores. 1.65 and 1.71 + Bobbins, with cores joined by yoke, + coils in series 6.37 + Bobbins, with armature resting on poles. 10.68 + +[Footnote 1: "Bulletin de la Societe Internationale des Electriciens," +1886.] + +It is interesting to note how the perfecting of the magnetic circuit +increases the self-induction. + +Thanks to the kindness of Mr. Preece, I have been furnished with some +most valuable information about the coefficients of self-induction, +and the resistance of the standard pattern of relays, and other +instruments which are used in the British postal telegraph service, +from which data one is able to say exactly what the time constants of +those instruments will be on a given circuit, and how long in their +case the current will take to rise to any given fraction of its final +value. Here let me refer to a very capital paper by Mr. Preece in an +old number of the "Journal of the Society of Telegraph Engineers," a +paper "On Shunts," in which he treats this question, not as perfectly +as it could now be treated with the fuller knowledge we have in 1890 +about the coefficients of self-induction, but in a very useful and +practical way. He showed most completely that the more perfect the +magnetic circuit is--though of course you are getting more magnetism +from your current--the more is that current retarded. Mr. Preece'e +mode of experiment was extremely simple. He observed the throw of the +galvanometer when the circuit which contained the battery and the +electromagnet was opened by a key which at the same moment connected +the electromagnet wires to the galvanometer. The throw of the +galvanometer was assumed to represent the extra current which flowed +out. Fig. 56 represents a few of the results of Mr. Preece's paper. + + +==========+ + |=| |=| |=| |=| |=| + \======= \======= =======/ ======= ======= + | | | | | | | | | | + | | | | | | | | | | + | | | |--| | | | | | + ======= ======= ======= /======= =======\ + |=| |=| |=| |=| |=| + + +===========+ +==========+ +===== ======+ + |=| |=| |=| |=| |=| |=| + ======= =======/ B\======= =======/A A\======= =======/B + | | | | | | | | | | | | + | | | | | | | | | | | | + | |--| | | | | | | | | | + ======= ======= A======= =======B =======B =======A + |=| |=| |=| |=| |=| |=| + +==========+ +==========+ +====== =====+ + + FIG. 56.--ELECTROMAGNETS OF RELAY, AND THEIR EFFECTS. + +Take from an ordinary relay a coil, with its iron core, half the +electromagnet, so to speak, without any yoke or armature. Connect it +up as described, and observe the throw given to the galvanometer. The +amount of throw obtained from the single coil was taken as unity, and +all others were compared with it. If you join up two such coils as +they are usually joined, in series, but without any iron yoke across +the cores, the throw was 17. Putting the iron yoke across the cores, +to constitute a horseshoe form, 496 was the throw; that is to say, the +tendency of this electromagnet to retard the current was 496 times as +great as that of the simple coil. But when an armature was put over +the top, the effect ran up to 2,238. By the mere device of putting the +coils in parallel, instead of in series, the 2,238 came down to 502, a +little less than the quarter value which would have been expected. +Lastly, when the armature and yoke were both of them split in the +middle, as is done in fact in all the standard patterns of the British +postal telegraph relays, the throw of the galvanometer was brought +down from 502 to 26. Relays so constructed will work excessively +rapidly. Mr. Preece states that with the old pattern of relay having +so much self-induction as to give a galvanometer throw of 1,688, the +speed of signaling was only from 50 to 60 words per minute, whereas, +with the standard relays constructed on the new plan, the speed of +signaling is from 400 to 450 words per minute. It is a very +interesting and beautiful result to arrive at from the experimental +study of these magnetic circuits. + + +SHORT CORES _versus_ LONG CORES. + +In considering the forms that are best for rapid action, it ought to +be mentioned that the effects of hysteresis in retarding changes in +the magnetization of iron cores are much more noticeable in the case +of nearly closed magnetic circuits than in short pieces. +Electromagnets with iron armatures in contact across their poles will +retain, after the current has been cut off, a very large part of their +magnetism, even if the cores be of the softest of iron. But so soon as +the armature is wrenched off, the magnetism disappears. An air gap in +a magnetic circuit always tends to hasten demagnetizing. A magnetic +circuit composed of a long air path and a short iron path demagnetizes +itself much more rapidly than one composed of a short air path and a +long iron path. In long pieces of iron the mutual action of the +various parts tends to keep in them any magnetization that they may +possess; hence they are less readily demagnetized. In short pieces, +where these mutual actions are feeble or almost absent, the +magnetization is less stable, and disappears almost instantly on the +cessation of the magnetizing force. Short bits and small spheres of +iron have no magnetic memory. Hence the cause of the commonly received +opinion among telegraph engineers that for rapid work electromagnets +must have short cores. As we have seen, the only reason for employing +long cores is to afford the requisite length for winding the wire +which is necessary for carrying the needful circulation of current to +force the magnetism across the air gaps. If, for the sake of rapidity +of action, length has to be sacrificed, then the coils must be heaped +up more thickly on the short cores. The electromagnets in American +patterns of telegraphic apparatus usually have shorter cores, and a +relatively greater thickness of winding upon them, than those of +European patterns. + + * * * * * + + + + +ELECTRIC ERYGMASCOPE. + + +The erygmascope is the name of an electric lighting apparatus designed +for the examination of the strata of earth traversed by boring +apparatus. + +It consists of a very powerful incandescent lamp inclosed in a +metallic cylinder. One of the two semi-cylindrical sides constitutes +the reflector, and the other, which is of thick glass, allows of the +passage of the luminous rays, which thus illuminate with great +brilliancy the strata of earth traversed by the instrument. The base, +which is inclined at an angle of 45°, is an elliptical mirror, and the +top, of straight section, is open in order to permit the observer +standing at the mouth of the well, and provided with a powerful +spyglass, to see in the mirror the image of the earth. The lamp is so +mounted that its upwardly emitted rays are intercepted. + +The whole apparatus is suspended from a long cable, formed of two +conducting wires, which winds around a windlass with metallic +journals which are electrically insulated. These journals communicate, +through the intermedium of two friction springs, with the conductors +on the one hand and, on the other, with the poles of an automatic and +portable battery. + +[Illustration: THE TROUVE ERYGMASCOPE.] + +This permits of lowering and raising the apparatus at will, without +derangement, and without its being necessary to interrupt the light +and the observation.--_Revue Industrielle._ + + * * * * * + + + + +A NEW ELECTRIC BALLISTIC TARGET. + + +The electrical target usually employed in determining velocities of +projectiles consists of a wooden frame on which is strung a copper +wire so as to make a continuous circuit arranged in parallel vertical +lines about one inch or one and one half inches apart. + +It frequently happens that a projectile will pass through this target +without breaking the circuit, either by squeezing between the wires or +because, when last repaired, the target was short-circuited unnoticed, +so that the cutting of the wires did not break the circuit. The repair +of this target takes considerable time. + + _______________________________________________________ + | { + | +-------------__ --------------__---------------- } + | | _ // \\ // \\ } { + | | |_| || C_{0} || A || || || A { } + | | P \\ // \\ // } { + | +------------- --------------- ---------------- } + | F { + |_______________________________________________________} + + Plan. + P C + =|= _________ + |===| ========= A A + ========| | S |========\_______/================= + |spring | | | + | | | | | + |S_ | __| |__ __| + ||| | | + ___________|||______________| |_____________________ + | + | Section. + H / + \+/ + | + | + | + | + | + | + _____+_____ + | | + | W | + | | + |___________| + + +Besides these objections to this target, another and more serious one +is the irregularity in the manner of breaking the circuit. It has been +proved that times required for a flat headed and an ogival headed +projectile to rupture the current are very different. + +To remedy these defects a new and very ingenious target has been +devised and used with great success at the United States Military +Academy at West Point. The top of the target is a wooden strip, F, on +the upper side of which are screwed strips of copper, A A, about 1/2 +in. wide, and 1/8 in. thick. The connection between two adjoining +strips is made by a copper cartridge, C, which is dropped in a hole in +the frame bored to receive it. This cartridge is the one used in the +Springfield rifle. Inside the cartridge is a spiral spring, S, which, +acting on the bottom of the hole and the head of the cartridge, tends +to make the latter spring up, and so break the circuit. + +To the hook, H, which is attached to the cartridge, is suspended, by +means of a string, the lead weight, W, thus drawing down the cartridge +and making the circuit between A and A'. All the weights being +suspended the current comes in through the post, P, passes along the +copper strips and out of the corresponding post on the other end. + +On firing the projectile cuts a string, and the spring at once causes +the cartridge to spring up, thus breaking the circuit. + +It is not possible for the projectile to squeeze between the strings +and not break the current, for in so doing the cartridge is tipped +slightly, which is sufficient, as it breaks the current on one side. + +This target is used in connection with the Boulenge chronograph. Two +targets are established at a known distance apart, say 50 ft., and the +time required for the projectile to pass over this distance is +determined by finding the difference in the time of cutting of the two +targets, by finding the difference in the time of falling of the two +rods, caused by the demagnetization of two electromagnets in the same +circuit with the targets. + +By means of a disjunctor both rods are dropped at the same time, the +shorter one releasing a knife blade which makes a cut on the longer +one. Now both rods are hung from the magnets again and the gun is +fired. + +The projectile passes through the first target, breaks the circuit, +demagnetizes the magnet of the longer rod, and it begins to fall. On +passing through the second target, the projectile causes the shorter +rod to fall. This releases the knife blade, and a second cut is made. +The time corresponding to the distance between these cuts is the time +the longer rod was falling before the second rod began to fall or the +time between the cutting of the two targets by the projectile. + +The distance between the cuts is measured, and the time corresponding +to it can easily be found. Then the velocity of the projectile is +equal to 50/t. + +To repair this target, strings are prepared in advance of suitable +length and looped at both ends, so that by placing the hook of the +cartridge in one loop and that of the weight in the other the repair +is quickly made. + +This target has been used on the West Point proving ground to +determine velocities over distances of 100 ft. interval to distances +of only 9 ft. interval, and has given most satisfactory results. + + * * * * * + +[Continued from SUPPLEMENT, No. 786, page 12566.] + + + + +THE OUTLOOK FOR APPLIED ENTOMOLOGY. + +[Footnote: Address of Dr. C.V. Riley at the annual meeting of the +Association of Economic Entomologists, Champaign, Ills., November 11 +to 14, 1890.] + +LEGISLATION. + + +The amount of legislation in different countries that has of late +years been deemed necessary or sufficiently important, in view of +injurious insects, is a striking evidence of the increased attention +paid to applied entomology; and while modern legislation of this kind +has been, on the whole, far more intelligent than similar efforts in +years gone by, many of the laws passed have nevertheless been unwise, +futile, and impracticable, and even unnecessarily oppressive to other +interests. The chief danger here is the intervention of politics or +political methods. Expert counsel should guide our legislators and the +steps taken should be thorough in order to be effective. We have had +of late years in Germany very good evidence of the excellent results +flowing from thorough methods, and the recent legislation in +Massachusetts against the gypsy moth (_Ocneria dispar_), which at one +time threatened to become farcical, has, fortunately, proved more than +usually successful; the commission appointed to deal with the subject +having worked with energy and followed competent advice. + + +PUBLICATION. + +On the question of publication of the results of our labors it is +perhaps premature to dwell at length. Each of the experiment stations +is publishing its own bulletins and reports quite independently of the +others, but after a uniform plan recommended by the association with +which we meet here; and with but one exception that has come to my +notice, another important recommendation of the same association--that +these publications shall be void of all personal matter--has been kept +in mind. The National Bureau of Experiment Stations at Washington is +doing what it can with the means at command to further the general +work by issuing the Experiment Station Record, devoted chiefly to +digests of the State station bulletins. There is a serious question in +my mind as to the utility of State digests by the national department +of results already published extensively by the different States and +distributed under government frank to all similar institutions and to +whomsoever is interested enough to ask for them. + +Such digests may or may not be intelligently made, and, even under the +most favorable circumstances, will hardly serve any other purpose than +helping to the reference to the original articles, and this could +undoubtedly be done more satisfactorily to the stations and to the +people at large by general and classified indices to all the State +documents, made as full as possible and issued at stated intervals. +Only a small proportion of the bulletins have been so far noticed by +digest in this record, with no particular rule, so far as I can see, +in the selection. In point of fact, those will be most apt to be +noticed whose authors can find time to themselves send or make for the +purpose their own abstracts. This is, perhaps, inevitable under +present arrangements. Complete and satisfactory digests of all, if +intelligent and critical, imply a far greater force than is at present +at Prof. Atwater's command. + +Under these circumstances, it would seem wiser to devote all the +energies of the bureau to digests of the similar literature of other +countries, which would be of immense advantage to our people and to +the different station workers. Judging from the recommendations and +resolutions of the general association, this is the view very +generally held, but except in chemistry and special industries like +that of beet sugar, very little of that kind of work has yet been +attempted. + +What is true of the station publications in general is equally true of +special publications. As entomologist of the department, I have been +urged to bring together, at stated intervals, digests of the +entomological publications of the different stations. Such digests to +be of any value, however, should also be critical, and it were a +thankless task for any one to be critic or censor even of that which +needs correction or criticism. Moreover, to do this work intelligently +would require increase of the divisional force, which at present is +more advantageously employed, for, as already intimated, I should have +great doubts of the utility of these digests. + +I believe, however, that the division should strive for such increase +of means as would justify the periodic publication, either +independently or as a part of the department record, of general and +classified indices to the entomological matter of the station +bulletins, and should work more and more toward giving results from +other parts of the world. This could, perhaps, best be done by titles +of subject and of author so spaced and printed on stout paper that +they could be cut and used in the ordinary card catalogue. The +recipient could cut and systematically place the titles as fast as +received. + +As to the character of the matter of the entomological bulletins, it +will inevitably be influenced by the needs and demands of the people +of the respective States, and while originality should be kept in +mind, there must needs be in the earlier years of the work much +restatement of what is already well known. That some results have been +published of work which reflects no particular credit upon our calling +is a mere incident of the new positions created. Yet we may expect +marked improvement from year to year in this direction, and without +being invidious, I would cite those of Prof. Gillette's on his +spraying experiments and on the plum curculio and plum gouger, as +models of what such bulletins should be. + +Although the resolution offered at our last meeting by Prof. Cook, to +the effect that purely descriptive matter should be excluded from the +station bulletins, met with no favor, but was laid on the table, by +the general association, I am in full sympathy with this position and +am strongly of the opinion that in the ordinary bulletins such purely +technical and descriptive matter should be reduced to the necessary +minimum consistent with clearness of statement and accuracy, and that +if it is desired, on the part of the station entomologists, to issue +technical and descriptive papers, a separate series of bulletins were +better instituted for this class of matter. + +Finally, for results which it is desired to promptly get before the +people, the agricultural press is at our disposal, and so far as the +entomological work of the department of agriculture is concerned, the +periodical bulletin, _Insect Life_, was established for this purpose. +Its columns are open to all station workers, and I would here appeal +to the members of the association to help make it, as far as possible, +national, by sending brief notes and digests of their work as it +progresses. Hitherto we have been unable to make as much effort in +this direction as we desired, but in future it is our hope to make the +bulletin, as far as possible, a national medium through which the +results of work done in all parts of the country may quickly be put on +record and distributed, not only to all parts of our own country, but +to all parts of the world. + +The rapid growth and development of the national department and the +multiplication of its divisions have necessitated special modes of +publication and rendered the annual report almost an anachronism so +far as it pretends to be what it at one time was--a pretty complete +report of the scientific and other work of the department. The +attempts which I have made through the proper authorities to get +Congress to order more pretentious monographic works in quarto volume +similar to those issued by other departments of the government have +not met with encouragement, and in this direction many of the stations +will, let us hope, be able to do better. + + +CO-OPERATION. + +Every other subject that might be considered on this occasion must be +subordinate to the one great question of co-operation. With the large +increase of actual workers in our favorite field, distributed all over +the country, the necessity for some co-operation and co-ordination +must be apparent to every one. Just how this should be brought about +or in what direction we may work toward it, will be for this +association in its deliberations to decide. Nor will I venture to +anticipate the deliberations and conclusions of the special committee +appointed to take the matter into consideration, beyond the statement +that there are many directions in which we can adopt plans for mutual +benefit. Take, for instance, the introduction and dissemination of +parasites. How much greater will be the chance of success in any +particular case if we have all the different station entomologists +interested in some specific plan to be carried out in co-operation +with the national department, which ought to have better facilities of +introducing specimens to foreign countries or to different sections of +our own country than any of the State stations. + +Let us suppose that the fruit growers of one section of the country, +comprising several States in area, need the benefit in their warfare +against any particularly injurious insect of such natural enemy or +enemies as are known to help the fruit growers of some other section. +There will certainly be much greater chances of success in the +carrying out of any scheme of introduction if all the workers in the +one section may be called upon through some central or national body +to help in the introduction and disposition of the desired material +into the other section. Or, take the case of the boll worm +investigation already alluded to. The chances of success would be much +greater if the entomologists in all the States interested were to give +some attention to such lepidopterous larvæ as are found to be affected +with contagious diseases and to follow out some specific plan of +cultivating and transmitting them to the party or parties with whom +the actual trials are intrusted. The argument applies with still +greater force to any international efforts. I need hardly multiply +instances. There is, it is true, nothing to prevent any individual +station entomologist from requesting co-operation of the other +stations, nor is there anything to prevent the national department +from doing likewise; but in all organization results are more apt to +flow from the power to direct rather than from mere liberty to request +or to plead. The station entomologist may be engrossed in some line of +research which he deems of more importance to the people of his State, +and may resent being called upon to divert his energies; and with no +central or national power to decide upon plans of co-operation for the +common weal, we are left to voluntary methods, mutually devised, and +it is here that this association can, it seems to me, most fully +justify its organization. And this brings me to the question of + + +THE DEPARTMENT AND THE STATIONS. + +Immediately connected with the question of co-operation is the +relation of the National Department of Agriculture and the State +experiment stations. The relation, instead of being vital and +authoritative, is, in reality, a subordinate one. Many persons +interested in the advancement of agriculture foresaw the advantage of +having experiment stations attached to the State agricultural colleges +founded under the Morrill act of 1862; but I think that in the minds +of most persons the establishment of these stations implied some such +connection with the national department as that outlined in an address +on Agricultural Advancement in the United States, which I had the +honor to deliver in 1879 before the National Agricultural Congress, at +Rochester, and in which the following language was used: + + "In the light of the past history of the German experimental + stations and their work, or of that in our own State of + Connecticut, the expediency of purchasing an experimental farm of + large dimensions in the vicinity of Washington is very + questionable. There can be no doubt, however, of the value of a + good experimental station there that shall have its branches in + every State of the Union. The results to flow from such stations + will not depend upon the number of acres at command, and it will + be far wiser and more economical for the commissioner to make each + agricultural college that accepted the government endowment + auxiliary to the national bureau, so that the experimental farm + that is now, or should be, connected with each of these + institutions might be at its service and under the general + management of the superintendent of the main station. There is + reason to believe that the directors of these colleges would + cheerfully have them constituted as experimental stations under + the direction of the department, and thus help to make it really + national--the head of a vast system that should ramify through all + parts of the land.... + + "With the different State agricultural colleges, and the State + agricultural societies, or boards, we have every advantage for + building up a national bureau of agriculture worthy of the country + and its vast productive interests, and on a thoroughly economical + basis, such as that of Prussia, for instance." + +In short, the view in mind was something in the nature of that which +has since been adopted by our neighbors of the North, where there is a +central or national station or farm at Ottawa and sub-stations or +branch farms at Nappan, Nova Scotia, Brandon, Manitoba, Indian Head, +N.W.T., and Agassiz, British Columbia, all under the able direction of +Mr. William Saunders, one of our esteemed fellow workers. It was my +privilege to be a good deal with Mr. Saunders when he was in Europe +studying the experience of other countries in this matter, and the +policy finally adopted in Canada as a result of his labors is an +eminently wise one, preventing some of the difficulties and dangers +which beset our plan, whether as between State and nation or college +and station. + +Under the present laws and with the vast influence which the +Association of Agricultural Colleges and Experiment Stations will +wield, both in Congress and in the different States, there is great +danger of transposition, in this agricultural body politic, of those +parts which in the animal body are denominated head and tail, and the +old saw to the effect that "the dog wags the tail because the tail +cannot wag the dog," will find another application. So far as the law +goes, the national department, which should hold a truly national +position toward State agricultural institutions depending on federal +support, can do little except by suggestion, whether in the line of +directing plans or in any way co-ordinating or controlling the work of +the different stations throughout the country. The men who influenced +and shaped the legislation which resulted in the Hatch bill were +careful that the department's function should be to indicate, not to +dictate; to advise and assist, not to govern or regulate. We have, +therefore, to depend on such relationships and such plans of +co-operation as will appear advantageous to all concerned, and these +can best be brought about through such associations as are now in +convention here. + +Without such plans there is great danger of such waste of energy and +means and duplication of results as will bring the work into popular +disfavor and invite disintegration, for already there is a growing +feeling that agricultural experiment is and will be subordinated to +the ordinary college work in the disposition of the federal +appropriations. + +What is true of the national department as a whole in its connection +with the State stations is true in a greater or less degree of the +different divisions of the department in connection with the different +specialists of the stations. With the multiplicity of workers in any +given direction in the different States, the necessity for national +work lessens. A favorite scheme of mine in the past, for instance (and +one I am glad to say fully indorsed by Prof. Willits), was to endeavor +to have a permanent agent located in every section of the country that +was sufficiently distinctive in its agricultural resources and +climate, or, as a yet further elaboration of the same plan, one in +each of the more important agricultural States. The necessity for such +State agents has been lessened, if not obviated, by the Hatch bill, +and the subsequent modifications looking to permanent appropriations +to the State stations or colleges, which give no central power at +Washington. The question then arises, What function shall the national +department perform? Its influence and field for usefulness have been +lessened rather than augmented in the lines of actual investigation in +very many directions. Many a State is already far better equipped both +as to valuable surrounding land, laboratory and library facilities, +more liberal salaries, and greater freedom from red tape, +administrative routine, and restrictions as to expenditures, than we +are at Washington; and, except as a directing agent and a useful +servant, I cannot see where the future growth of the department's +influence is to be outside of those federal functions which are +executive. Just what that directing influence is to be is the question +of the hour, not only in the broader but in the special sense. The +same question, in a narrower sense, had arisen in the case of the few +States which employed State entomologists. In the event, for instance, +of an outbreak of some injurious insect, or in the event of any +particular economic entomological question within the limits of the +State having such an officer, the United States entomologist would +naturally feel that any effort on his part would be unnecessary, or +might even be looked upon as an interference. He would feel that there +was always danger of mere duplication of observation or experiment, +except where appealed to for aid or co-operation. This is, perhaps, +true only of insects which are local or sectional, and is rather a +narrow view of the matter, but it is one brought home from experience, +and is certainly to be considered in our future plans. The favor with +which the museum work of the national division was viewed by you at +the meeting last November and the amount of material sent on for +determination would indicate that the building up of a grand national +reference collection will be most useful to the station workers. But +to do this satisfactorily we need your co-operation, and I appeal to +all entomologists to aid in this effort by sending duplicates of their +types to Washington, and thus more fully insuring against ultimate +loss thereof. + + +STATUS OF OUR SOCIETY. + +This train of thought brings up the question of the status of our +society with the station entomologists as represented by the committee +of the general association. Those of us who had desired a national +association for the various purposes for which such associations are +formed, felt, I believe, if I may speak for them, that the creation of +the different experimental stations rendered such an organization +feasible. Your organization at Toronto and the constitution adopted +and amended at the meeting at Washington all indicate that the chief +object was the advancement of our chosen work and that the strength of +the association would come from the experiment station entomologists. +There was then no other organization of the kind, nor any intimation +that such a one would be founded. Some of us therefore were surprised +to learn from the circular sent out by Prof. Forbes, its chairman, +that the committee appointed by the association of agricultural +colleges and experiment stations, and through which we had hoped to +communicate and co-operate with that association, was not in the +proper sense a committee, but a section which has prepared (and in +fact was required by the executive committee and the rules of the +superior body to prepare) a programme of papers and discussions for +the meeting to be held at the same time and place with our own. I +cannot but feel that this is in some respects a misfortune, and it +will devolve upon you to decide upon several questions of importance +that will materially affect our future existence. That there is not +room for two national organizations having the same objects in view +and meeting at the same time and place goes, I think, without saying; +and if the committee of the general association is to be anything more +than a committee in the proper sense of the word, or if it is to +assume with or without formal constitution the functions of our own +association, then our own must necessarily be crippled, and to do any +good at all must meet at a different time and a different place. A +committee or section, or whatever it may be called, of the general +association with which we meet, would preclude active membership of +any but those who come within the constitution of that body. Our +Canadian friends and many others who have identified themselves with +applied entomology, and do not belong to any of our State or +government institutions, would be debarred from active representation, +however liberal the association may have been in inviting such to +participate, without power to vote in its deliberations. Our own +association has, or should have, no such limitations. Some of us who +are entitled to membership in both bodies may feel indifferent as to +the course finally decided upon, and that it will not make any +difference whether we have an outside and independent organization, as +that of the association of official chemists, or whether we do, as did +the botanists and horticulturists, waive independence in favor of more +direct connection with the general association, provided there is some +way whereby the committees of the general association are given +sufficient latitude and time to properly present their papers and +deliberate; but there are others who feel more sensitive as to their +action and are more immediately influenced by the feelings of the main +body. I hope that whatever action be taken at this meeting, the +general good and the promotion of economic entomology will be kept in +mind and that no sectional or personal feeling will be allowed to +influence our deliberations. + + +SUGGESTION AND COMMENT. + +You will, I know, pardon me if, before concluding these remarks, I +venture to make a few comments which, though not altogether agreeable, +are made in all sincerity and in the hope of doing good. The question +as to how far purely technical and especially descriptive and +monographic work should be done by the different stations or by the +national department is one which I have already alluded to and upon +which we shall probably hold differing opinions, and which will be +settled according to the views of the authorities at the different +stations. Individually, I have ever felt that one ostensibly engaged +in applied entomology and paid by the State or national government to +the end that he may benefit the agricultural community can be true to +his trust only by largely overcoming the pleasure of entomological +work having no practical bearing. I would, therefore, draw the line at +descriptive work except where it is incidental to the economic work +and for the purpose of giving accuracy to the popular and economic +statements. This would make our work essentially biological, for all +biologic investigation would be justified, not only because the life +habits of any insect, once ascertained, throw light on those of +species which are closely related to it, but because we can never know +when a species at present harmless may subsequently prove harmful, and +have to be classed among the species injurious to agriculture. + +On the question of credit to their original sources of results already +on record, it is hardly necessary for me to advise, because good sense +and the consensus of opinion will in the end justify or condemn a +writer according as he prove just and conscientious in this regard. + +There is one principle that should guide every careful writer, viz., +that in any publications whatever, where facts or opinions are put +forth, it should always be made clear as to which are based upon the +author's personal experience and which are compiled or stated upon the +authority of others. We should have no patience with a very common +tendency to set forth facts, even those relating to the most common +and best known species, without the indications to which I have +referred. The tendency belittles our calling and is generally +misleading and confusing, especially for bibliographic work, and +cannot be too strongly deprecated. + +On this point there will hardly be any difference of opinion, but I +will allude to another question of credit upon which there prevails a +good deal of loose opinion and custom. It is the habit of using +illustrations of other authors without any indication of their +original source. + +This is an equally vicious custom and one to be condemned, though I +know that some have fallen into the habit, without appreciation of its +evil effect. It is, in my judgment, almost as blameworthy as to use +the language or the facts of another without citing the authority. + +Every member of this association who has due appreciation of the time +and labor and special knowledge required to produce a good and true +illustration of the transformations and chief characteristics of an +insect will appreciate this criticism. However pardonable in fugitive +newspaper articles in respect of cuts which, from repeated use, have +become common or which have no individuality, the habit inevitably +gives a certain spurious character to more serious and official +publications, for assumption of originality, whether intended or not, +goes with uncredited matter whether of text or figure. Nor is mere +acknowledgment of loan or purchase to the publisher, institution or +individual who may own the block or stone what I refer to. But that +acknowledgment to the author of the figure or the work in which it +first appears which is part of conscientious writing, and often a +valuable index as to the reliability of the figure. + +It were supererogation to point out to a body of this kind the value +of the most careful and thorough work in connection with life +histories and habits, often involving as it does much microscopic +study of structure. The officers of our institutions who control the +funds, and more or less fully our conduct, are apt to be somewhat +impatient and inappreciative of the time given to anatomic work, and +where it is given for the purpose of describing species and of +synopsizing or monographing higher groups, without reference to +agriculture, I am firmly of the belief that it diverts one from +economic work, but where pursued for a definite economic purpose it +cannot be too careful or too thorough and I know of no instances +better calculated to appeal to and modify the views of those inclined +to belittle such structural study than Phylloxera and Icerya. On the +careful comparison of the European and American specimens of +_Phylloxera vastatrix_, involving the most minute structures and +details, depended originally those important economic questions which +have resulted in legislation by many different nations and the +regeneration of the affected vineyards of Europe, of our own Pacific +coast, and of other parts of the world by the use of American +resistant stocks. In the case of _Icerya purchasi_ the possibilities +of success in checking it by its natural enemies hung at one time upon +a question of specific difference between it and the _Icerya sacchari_ +of Signoret--a question of minute structure which the descriptions +left unsettled and which could only be settled by the most careful +structural study and the comparison of the types, involving a trip to +Europe. + + +CONCLUSION. + +I have thus touched, gentlemen, upon a few of the many subjects that +crowd upon the mind for consideration on an occasion like this--a few +gleanings from a field which is passing rich in promise and +possibility. It is a field that some of us have cultivated for many +years and yet have only scratched the surface, and if I have ventured +to suggest or admonish, it is with the feeling that my own labors in +this field are ere long about to end and that I may not have another +occasion. + +At no time in the history of the world has there, I trow, been +gathered together such a body of devoted and capable workers in +applied entomology. It marks an era in our calling and, looking back +at the progress of the past fifteen years, we may well ponder the +possibilities of the next fifteen. They will be fruitful of grand +results in proportion as we persistently and combinedly pursue the yet +unsolved problems and are not tempted to the immediate presentation of +separate facts, which are so innumerable and so easily observed that +their very wealth becomes an element of weakness. Epoch-making +discoveries result only from this power of following up unswervingly +any given problem, or any fixed ideal. The kerosene emulsion, the +Cyclone nozzle, the history of _Phylloxera vastatrix_, of _Phorodon +humuli_, of _Vedalia cardinalis_, are illustrations in point, and +while we may not expect frequent results as striking or of as wide +application as these, there is no end of important problems yet to be +solved and from the solution of which we may look for similar +beneficial results. Applied entomology is often considered a sordid +pursuit, but it only becomes so when the object is sordid. When +pursued with unselfish enthusiasm born of the love of investigation +and the delight in benefiting our fellow men, it is inspiring, and +there are few pursuits more deservedly so, considering the vast losses +to our farmers from insect injury and the pressing need that the +distressed husbandman has for every aid that can be given him. Our +work is elevating in its sympathies for the struggles and suffering of +others. Our standard should be high--the pursuit of knowledge for the +advancement of agriculture. No official entomologist should lower it +by sordid aims. + +During the recent political campaign the farmer must have been sorely +puzzled to know whether his interests needed protection or not. On the +abstract question of tariff protection to his products we, as +entomologists, may no more agree than do the politicians or than does +the farmer himself. But ours is a case of protection from injurious +insects, and upon that there can nowhere be division of opinion. It is +our duty to see that he gets it with as little tax for the means as +possible. + + * * * * * + + + + +POTASH SALTS. + +[Footnote: By John B. Smith, entomologist. Potash as an insecticide is +not entirely new, but has never been brought out with the prominence I +think it deserves.--_N.J. Ag. Col. Exp. St., Bulletin 75._] + + +My attention was attracted to potash salts as an insecticide, by the +casual remark of an intelligent farmer, that washing his young pear +trees with a muriate of potash solution cleared them of scales. The +value of this substance for insecticide purposes, should its powers be +sufficient, struck me at once, and I began investigation. It was +unluckily too late in the season for field experiments of the nature +desired; but it is the uniform testimony of farmers who have used +either the muriate or the kainit in the cornfields, that they have +there no trouble with grubs or cut worms. Mr. E.B. Voorhees, the +senior chemist of the station, assures me that on his father's farm +the fields were badly infested, and replanting cornhills killed by +grubs or wire worms was a recognized part of the programme. Since +using the potash salts, however, they have had absolutely no trouble, +and even their previously worst-infested fields show no further trace +of injury. The same testimony comes from others, and I feel safe in +recommending these salts, preferably kainit, to those who are troubled +with cut worms or wire worms in corn. + + +EXPERIMENTS. + +A lot of wire worms (_Iulus_ sp.) brought in from potato hills were +put into a tin can with about three inches of soil and some potato +cuttings, and the soil was thoroughly moistened with kainit, one ounce +to one pint of water. Next morning all the specimens were dead. A +check lot in another can, moistened with water only, were healthy and +lived for some days afterward. + +A number of cabbage maggots placed on the soil impregnated with the +solution died within twelve hours. + +To test its actual killing power, used the solution, one ounce kainit +to one pint water, to spray a rose bush badly infested with plant +lice. Effect, all the lice dead ten hours later; the younger forms +were dropping within an hour. + +Sprayed several heads of wheat with the solution, and within three +hours all the aphides infesting them were dead. + +Some experiments on hairy caterpillars resulted unsatisfactorily, the +hair serving as a perfect protection against the spray, even from the +atomizer. + +To test its effect on the foliage, sprayed some tender shoots of rose +and grape leaves, blossoms, and clusters of young fruit. No bad effect +observable 24 hours later. There was on some of the leaves a fine +glaze of salt crystals, and a decided salt taste was manifest on all. + +Muriate of potash of the same strength was tested as follows: Sprayed +on some greenhouse camellias badly infested by mealy bugs, it killed +nearly all within three hours, and six hours later not a living insect +was found. The plants were entirely uninjured by the application. + +Thoroughly sprayed some rose bushes badly infested with aphides, and +carried off some of the worst branches. On these the lice were dead +next morning; but on the bushes the effect was not so satisfactory, +most of the winged forms and many mature wingless specimens were +unaffected, while the terminal shoots and very young leaves were +drooping as though frosted. All, however, recovered later. + +The same experiment repeated on other, hardier roses, resulted +similarly so far as the effect on the aphides was concerned, but there +was no injury to the plant. + +Used this same mixture on the caterpillars of _Orgyia leucostigma_ +with unsatisfactory effect, and with the same results used it on a +number of other larvæ. Used on the rose leaf roller, _Cacæcia +rosaceana_, it was promptly effective. + +Tested for injury to plants, it injured the foliage and flowers of +wisteria, the younger leaves of maple and grape, and the finer kinds +of roses. + +From these few experiments kainit seems preferable to the muriate, as +acting more effectively on insects and not injuriously on plants. For +general use on plants it is not to be recommended. It is otherwise on +underground species, where the soil will be penetrated by the salts +and where the moisture evaporates but slowly, and the salt has a +longer and better chance to act. The best method of application would +be a broadcasting in fertilizing quantity before or during a rain, so +as to carry the material into the soil at once. In cornfields infested +with grubs or wire worms, the application should be made before +planting. Where it is to be used to reach root lice, it should be used +when the injury is beginning. When strawberry beds are infested by the +white grub, the application should be made when cultivating or before +setting out. + +The potash salts have a high value as fertilizers, and any application +made will act as a stimulant as well as insecticide, thus enabling the +plants to overcome the insect injury as well as destroying the insect. + +In speaking on this subject in Salem county, I learned from farmers +present that those using potash were not troubled with the corn root +louse to any extent, and also that young peach trees have been +successfully grown in old lice-infested orchards, where previously all +died, by first treating the soil with kainit of potash. + + * * * * * + + +A meteorological station has been built on Mont Blanc, at an elevation +of 13,300 feet, under the direction of M. Vallot. It required six +weeks to deliver the materials. The instruments are self-registering +and are to be visited in summer every fifteen days if possible, the +instruments being left to register between the visits. In the winter +the observatory will be entirely inaccessible. This is the highest +scientific station in Europe, but is 847 feet lower than the Pike's +Peak station in Colorado. + + * * * * * + + + + +THE EXPENSE MARGIN IN LIFE INSURANCE. + + +The principle of mutuality requires that the burden of expense in life +insurance should be borne by all the members equally; but, even with +the most careful adjustment, the allowance usually made is +considerably in excess of what is needed in the regular companies +doing business on the "level premium" plan. + +It is customary in these companies to add to the net premium a +percentage thereof to cover the expense account. This practice, though +in harmony with the "commission system," is so clearly defective and +so far removed from the spirit of life insurance mathematics, that it +scarcely deserves even this passing notice. + +It is generally understood that these corporations combine the +functions of the savings bank and life insurance company, and it is +only by separating the two in our minds as far as possible that we can +obtain a clear conception of the laws that should govern the +apportionment of the expenses among the great variety of policies. + +While it is a comparatively simple matter to state the amount of +either the insurance or savings bank element in a single policy, it is +by no means easy, as things go, to classify the company's actual +expenses on this basis. + +Fortunately, we can pretty accurately determine what these amounts +should be in any particular case. + +In the first place, there are institutions in our midst devoted solely +to receiving and conserving small sums of money; doing, in fact, +exactly what our insurance companies are undertaking to do with the +reserve and contributions thereto. These savings banks are required by +law to make returns to the State commissioner, from whose official +report we can get a very good idea of the expense attendant on doing +this business. + +Confining ourselves to the city banks, where the conditions more +nearly resemble those of the insurance companies, we find in +thirty-eight combined institutions for saving in the State of +Massachusetts a deposit in 1888 of $192,174,566, taken care of at an +aggregate cost of $455,387, or about 24-100 of one per cent. + +The same ratio carried out for all the savings banks in Massachusetts +gives a trifle over 25-100 of one per cent.; we may, therefore, +consider ¼ of one per cent. as expressing pretty nearly the cost of +receiving, paying out, and investing the savings of the people. + +We must remember in this connection that in the popular estimation, +the savings bank is an important factor in the public welfare, and in +the towns and smaller cities there are often found public spirited men +willing to give their services to encourage this mode of saving; but +public sentiment has not yet given to life insurance the place which +it is destined, sooner or later, to occupy by the side of the savings +bank. Hence the services of able managers can only be obtained by a +liberal outlay of the corporate funds. A satisfactory adjustment of +the matter of expenses will, perhaps, do more than anything else to +bring about this recognition on the part of the public. + +In the case of the savings bank it is safe to say that for double the +present outlay a liberal salary could be paid to all the officers. +Following the analogy, we are led to infer that if this be the case in +savings banks, then ½ of one per cent. of the reserve should be an +ample allowance for the special labor required in the purely banking +portion of the business. + +In this we have the concurrence of the late Elizur Wright. In an essay +on this subject he says: + + "The expenses of the five largest savings banks in Boston, in + 1869, did not exceed 4-10 of one per cent. on $28,000,000 + deposited in them. They certainly had twice as many transactions, + in proportion to the deposits, as any life insurance company could + have with the same amount of reserve, so that ½ of one per cent. + on the reserve seems to be ample for all working expenses save + those of maintaining the agencies and collecting the premiums." + +This need hardly be looked upon as an admission that it costs twice as +much to care for the funds of a life insurance company as for those of +a savings bank. A liberal expense allowance must be made at the +outset, seeing that an error in this particular cannot easily be +rectified after the policy is issued. The dividend, or, to speak more +correctly, the annual return of surplus, will correct any overpayment +on this account. + +There is another expense which seems inevitable. This is the +government tax on insurance companies, amounting in the aggregate to +nearly 1/3 of one per cent. on the reserve. + +When we consider that these institutions are intended to encourage +thrift and to relieve the community from the care of numberless widows +and orphans, it seems a clear violation of the principles of political +economy to levy a tax on this business; still, whatever our opinion +may be as to the justice or injustice of the imposition, the tax is +maintained and must be provided for. Consequently a further allowance +of ½ of one per cent. must be added to the net premium to cover the +same, making a total of 1 per cent. of the reserve for banking +expenses and taxes. Considering this point as settled for the time +being, let us proceed to investigate the insurance expenses. + +Here, again, we are fortunate in being able to refer to the official +reports of a class of corporations doing nearly, if not quite pure +insurance. + +The assessment societies, outside of the fraternal and benevolent, +reporting in 1889 to the insurance commissioner of Massachusetts, show +outstanding risks amounting to $733,515,366. Losses to the amount of +$7,270,238 were paid during the year at a cost for transacting the +business of $2,403,053, which includes among other items "agency +expenses and commissions," which amount to about $1,203,000, or 17 per +cent. of the cost value of the insurance actually done. It would seem +as if an allowance of 20 per cent. would be a liberal one in the case +of the regular companies, which surely have as good facilities for +doing business as the assessment societies. + +As far as insurance is concerned, there is less difference between +regular and co-operative companies than is generally supposed. Regular +companies assess each policy in advance for a year's insurance at a +time, while co-operative societies furnish insurance only from one +assessment to another. The difficulty in the way of collecting the +assessment in the latter case would seem to be greater than in the +former, owing to the more permanent nature of the regular insurance +contract. + +In compensating agents the assessment companies naturally pay in +proportion to the insurance obtained, inasmuch as there is no other +basis to go upon, but regular companies usually pay the agent a +percentage of the premium _which includes a considerable trust fund_ +over and above the assessment for actual insurance. It is easily seen +that by the last method the agent's compensation increases in +proportion to the amount of savings bank business forced upon the +company. + +To realize how far we are from anything like a scientific, not to say +common sense basis for insurance expenses, we have but to examine the +following list, which gives the ratios between the expenditures for +general expenses in 1889, and those for the extension of the business. +For every $100 used in a general way, the different companies spend +for commissions and agency expenses: $37, $66, $67, $78, $91, $106, +$110, $113, $120, $140, $157, $161, $173, $175, $186, $189, $200, +$202, $222, $264, $311, $346. + +It will doubtless be said that I am taking a very advanced position +when I say that in the ideal life insurance scheme there is no place +for the commission system. Solicitors will be a necessity only so long +as they are in the field, but fifty years of life insurance has taught +our community its true value and, thanks to the modern press, the +institution it is no more likely to fall into desuetude than is +Christianity or the moral law. + +For the convenience of bringing the company to the individual, the +latter should be willing to pay a fee. The man who renders another a +service or puts his superior knowledge at another's disposal should +look to the party benefited for his remuneration. Any compensation +given for such service to a go-between by a mutual company is paid by +all, and the question arises, Is the advantage to the company of +sufficient importance to warrant the imposition of this tax upon all +its members promiscuously? The following, from the Massachusetts +Insurance Commissioner's Report for 1885, leaves no doubt as to the +convictions of the writer on this important matter: + + "The expensiveness of the life insurance policy is not because the + level net premium is too high, for the premium is absolutely just, + and the policy holder gets full value; but the complaint justly + applies to the excessive expense charge. A person who wants + insurance, life or fire or other, should be able to buy it at + first cost without paying tribute of profits to middlemen. To that + complexion the matter will finally be brought by the force of + intelligent opinion, whatever resistance may be opposed by persons + whose thrift lies in the perpetuation of the expensive system now + in fashion." + +It requires but a slight degree of prophetic vision to predict that in +a very few years the companies in self defense will be obliged to +change their method of compensating agents. + +Several companies have already begun the reform by grading +commissions; granting a percentage proportional to the amount of +insurance likely to be done on the policy. Other companies have simply +reduced the amount of the commission rate, thus virtually withdrawing +from active competition. + +This will, in a certain degree, explain the wide variation in the +figures given above, where it is noticed that, in five companies out +of twenty-two, the total agency expenditures amount to less than the +general expenses, while in six cases the companies spend more than +double as much on the former as on the latter. In either class we find +representatives of the five largest companies in the country. + +On applying the foregoing ratios to the business of the existing +companies we find that, calling the theoretical expenses $100, the +actual expenditures for 1889 were as follows: $112.67, $118.34, +$150.40, $194.48, $208.16, $208.53, $228.66, $235.89, $248.44, +$250.79, $258.33, $258.57, $265.14, $267.19, $267.92, $274.47, +$294.17, $314.96, $335.70, $377.94, $616.70. + +In this discouraging exhibit there is one ray of comfort. The combined +assets of the two companies heading the list amount to over +$100,000,000. There is no question as to their financial standing, and +both show a large increase in membership over the previous year. I may +also say here that it is a difficult matter to get at the actual "cost +of insurance" in the various companies. Many of them, on their own +acknowledgment, do not compute the advance cost of carrying their +"amount at risk," and others, for reasons of their own, do not care to +state the figures. In cases where the correct figures were not +obtainable, I have assumed the cost to have been 1-1/3 per cent. of +the mean amount at risk. + +If we should, in our comparison, omit the actual agency expenses and +commissions, the ratios would stand as follows: + +Where I would allow $100 the companies actually used: $43.17, $55.90, +$65.21, $77.21, $82.39, $88.34, $91.99. $91.98. $92.19, $94.65, +$97.15. $99.55. $99.11. $102.86, $109.35, $125.05, $133.03, $141.92, +$195.90, $207.06, $287.72. + +As might be supposed, the first two ratios are those companies before +alluded to. These companies might have doubled their advertising +account and expended $300,000 between them on agents' salaries, and +still have kept within my allowance. + +Admitting, for the present at least, the reasonableness of the +proposed allowance for the expenses of the banking and insurance +departments of the business, we have before us the problem how to +equitably adjust the burden among the great variety of policies. + +In the first place, _there should be no policy in the company that +does not contribute its proportionate share of the expense allowance +during every year of its life_. I make a special point of this, for at +present the policies which have become paid up, either by the payment +of a single premium at the outset or by the completion of a stipulated +number of payments, contribute practically nothing to the expense +account after the premium payments cease. + +The following plan, I think, complies with all the requirements of the +problem. By the proposed method every policy, at all stages of its +existence, contributes its exact share to the expense fund, whatever +its plan of payment may be. + +Let us, as an illustration, examine the case of a ten year endowment +policy, taken out at age 30, and consider it under three aspects, +first, as paid for in advance by a single payment, second, as paid by +five annual payments, and third, as paid for annually throughout the +term. I have used this short term endowment policy simply for +convenience, the rule applying equally to policies of longer term or +to the ordinary life policy, which is, in fact, an endowment policy +payable at death or age 100.[1] + +[Footnote 1: The expense allowance on a plain life policy for $1,000, +taken at age 33, would be about $5.29; net premium (com. ex. 4 per +cent.), $18.04; total office premium, $23.33; present rate $24.10.] + +Taking the case of the single premium endowment policy for $1,000, we +find that the following sums are required, each year to provide for +the care of the reserve and to pay the government fees (1 per cent. of +reserve): + + 1st year $6.9982 | 6th year $8.4136 + 2d " 7.2560 | 7th " 8.7381 + 3d " 7.5258 | 8th " 9.0781 + 4th " 7.8082 | 9th " 9.4346 + 5th " 8.1039 | 10th " 9.8086 + +The insurance expenses should be covered by the 20 per cent. allowance +given below: + + 1st year $ .4422 | 6th year $ .2566 + 2d " .4100 | 7th " .2076 + 3d " .3762 | 8th " .1556 + 4th " .3402 | 9th " .0988 + 5th " .2996 | 10th " .0344 + +Consequently the total contribution required from this policy each +year is: + + 1st year $7.4404 | 6th year $8.6702 + 2d " 7.6660 | 7th " 8.9457 + 3d " 7.9020 | 8th " 9.2337 + 4th " 8.1484 | 9th " 9.5334 + 5th " 8.4034 | 10th " 9.8430 + +The present value of all these contributions is found to be, at 4 per +cent. interest, $71.6394; in other words, this sum paid at the outset, +provides a fund from which we may deduct the current expenses of each +year in advance, and by accumulating the balance at the assumed rate +of interest from year to year, we shall have enough to pay the +anticipated expenses, leaving nothing over. + +In the above case the sums in hand at the beginning of the year are as +follows: + + 1st year $71.3694 | 6th year $42.6981 + 2d " 66.7669 | 7th " 35.3890 + 3d " 61.4650 | 8th " 27.5009 + 4th " 55.7055 | 9th " 18.9979 + 5th " 49.4594 | 10th " 9.8430 + +We find a somewhat different condition existing during the first years +of a 5-year endowment policy. As there is more insurance and less +banking, the requirements are as follows: + + ------------+----------+-----------+--------+---------+ + | 1 P. Ct. | 20 P. Ct. | | | + | on | on | Total. | Initial | + | Reserve. | Cost. | | Fund. | + ------------+----------+-----------+--------+---------+ + 1st year | $1.5038 | $1.2572 |$2.7610 |$12.9769 | + 2d " | 3.0406 | 1.0216 | 4.0622 | 23.6015 | + 3d " | 4.6503 | .7852 | 5.4355 | 33.2979 | + 4th " | 6.3367 | .5378 | 6.8745 | 41.9538 | + 5th " | 8.1039 | .2996 | 8.4035 | 49.4594 | + 6th " | 8.4136 | .2566 | 8.6702 | 42.6981 | + 7th " | 8.7381 | .2076 | 8.9257 | 35.3890 | + 8th " | 9.0781 | .1556 | 9.2337 | 27.5009 | + 9th " | 9.4346 | .0988 | 9.5334 | 18.9979 | + 10th " | 9.8086 | .0344 | 9.8430 | 9.8430 | + ------------+----------+-----------+--------+---------+ + +As the premium payments extend over only five years, the expense +contributions must all be paid during that time and are most +conveniently made by a uniform addition to the net premium. + +The present value of the amounts in column 3 is $60.0819, and the +equivalent annuity for five years is $12.9769. This amount, received +for five consecutive years, will put the company in funds to pay +current expenses and leave a reserve of $42.6981 at the beginning of +the sixth year, which, as we have seen in the analysis of the +single-premium policy, is the sum required for future expenses on the +paid up basis. + +In like manner we find that the 10-year annuity equivalent to the +present value of the annual contributions in the case of an +annual-payment policy is $5.534, thus: + + ------------+----------+-----------+--------+---------+ + | 1 P. Ct. | 20 P. Ct. | | | + | on | on | Total. | Initial | + | Reserve. | Cost. | | Fund. | + ------------+----------+-----------+--------+---------+ + 1st year | $.8234 | $1.3514 |$2.1748 |$ 5.5340 | + 2d " | 1.6473 | 1.2478 | 2.8951 | 9.0275 | + 3d " | 2.5096 | 1.1388 | 3.6484 | 11.9116 | + 4th " | 3.4124 | 1.0210 | 4.4334 | 14.1277 | + 5th " | 4.3572 | .8916 | 5.2488 | 15.6161 | + 6th " | 5.3479 | .7534 | 6.1013 | 16.3160 | + 7th " | 6.3853 | .5966 | 6.9819 | 16.1572 | + 8th " | 7.4726 | .4270 | 7.8996 | 15.0763 | + 9th " | 8.6127 | .2418 | 8.8545 | 12.9977 | + 10th " | 9.8086 | .0344 | 9.8430 | 9.8430 | + ------------+----------+-----------+--------+---------+ + +The present value of the ten yearly expense items given in the "total" +column above is $46.6812, which is equal to a ten-year annuity of +$5.534. The several premiums stand now as follows: + + ENDOWMENT: $1,000, AGE 30, PAYABLE AT DEATH OR 40 + + Net Prem.[2] Margin. Total. + +At single premium. $687.228 $71.6394 $758.8674 +At five premiums. 150.615 12.9769 163.5939 +At annual premiums. 84.172 5.5340 89.7060 + +[Footnote 2: Thirty American offices. Discount from middle of year, +Vx-½ or (M x 1.01961) / Dx.] + +By the actuaries' rate we have, with the customary loading for +expense: + + Single premium: $721.66 (loaded, $34.36). Five premiums, $188.70 + (loaded $37.78). Annual premium, $105.65 (loaded $21.11). + +Admitting the correctness of the new method, we must conclude that the +present single premium is not sufficiently loaded to cover its own +expenses, while the annual payment policy pays more than its just +share. A prominent and thoroughly informed life insurance president +says in this connection: "Many of the policies, particularly the short +term endowments, are charged with too high a percentage of expenses to +prove a good investment at maturity or profitable to the insured in +case of surrender." This is not to be wondered at when the applicant +for a 10-year endowment policy sees at a glance that he must pay, in +the gross, more than is returned unless he should die in the interim, +in which case a plain "life" or "term" policy would have answered the +purpose. Under the new system of assessing expenses one form is as +desirable as another, from the standpoint of the insured or the +company. + +The new premium for the 10-year endowment policy, $89.71, commends +itself at once to the applicant, who can easily see that his total +outlay must fall short of the amount ultimately to be realized, of +course, disregarding interest and probable dividends in both cases. + +In discounting the future expense contributions I have not taken the +chances of dying into account. Hence the expense reserve in any +instance applies only to that individual case, and, in the event of +death or surrender before the maturity of the policy, the amount of +the expense fund not used would naturally revert to the insured. + +The scheme of expense assessment outlined above will doubtless be +pronounced impracticable by the majority of insurance men. + +Such a far reaching reform is too much to hope for, at least in the +immediate future. + +No well informed life insurance expert will deny that there are +opportunities for improvement in the business, but to graft new +methods on old companies is a hopeless undertaking. + +It is well, however, to have new methods well matured in advance of +the public demand, and I feel convinced that the ideas here set forth +are in the line of the reform which, before long, must be instituted +by the companies if they would retain the confidence and patronage of +the community. + +Doubtless many insurance presidents could tell of suggestions which +have impressed them favorably and which they would gladly have adopted +were it not for the injustice done thereby to older members and the +changes necessary to bring existing contracts into conformity with the +new system. Similar objections may be urged against the ideas here +advanced, and I must confess I hardly see a way by which the present +suggestions can be utilized by existing companies. We can only hope +that sooner or later some of the new theories may be practically +tested. Meanwhile the companies at present in the field are doing a +great work for the good of humanity, even though their methods may be, +in some particulars, more practical than scientific. + +Winchester, Mass. FRANK J. WILLS. + + * * * * * + + + + +THE FLOOD AT KARLSBAD. + + +During the flood which occurred in Germany and Bohemia, the last week +of November, Karlsbad was especially unfortunate; it suffered such an +inundation as had never before been known in the "Sprudelstadt." On +the evening of November 23, the Tepl was very much swollen by the +rain, which had continued for several days, but it was supposed that +there was no danger of a flood, as the bed of the river had been put +in proper condition. During the forenoon of November 24, the water +suddenly began to rise with such astonishing rapidity that within half +an hour all the lower streets were like turbulent rivers and the Alte +and Neue Wiese were transformed into a lake. The stores on the Alte +Wiese were under water to the roofs, and the proprietors, who were +trying to save their goods, were surprised by the water and had to +take refuge in the trees. They were rescued by having ropes thrown to +them, and during this work a catastrophe occurred which was a great +misfortune to all classes of citizens. The beloved burgermeister of +Karlsbad, Dr. Rudolf Knoll, who had just recovered from a severe +illness, was, with others, directing the work from the balcony of one +of the houses, when a rope by which a man was being drawn through the +water broke, and the man was carried off by the waves. The fright and +excitement of the scene gave the burgermeister a shock which caused +his instant death, but the man who was in danger was brought safely +out of the water. + +The water was 9 ft. in Marienbaderstrasse, the Marktplatz, +Muhlbadgasse, the Sprudelgasse, Kreuzgasse, Kaiserstrasse, and +Egerstrasse, and flooded the quay, causing great destruction. All +places of business were flooded, the doors and iron shutters were +pushed in by the force of the water and the goods were carried away or +ruined. + +The house called "Zum Kaffeebaum" was undermined and part of it fell +to the ground; the same fate was feared for other buildings. The +Sophien and Curhaus bridges were carried away. Other bridges were +greatly damaged, and the masonry along the banks of the river was +partially destroyed. The Sprudelgasse was completely washed out, and +the condition of the Muhlbadgasse was almost as bad. The fire +department with its apparatus had great difficulty in saving the +inhabitants and guests, as there were very few boats or pontoons at +their command, and the soldiers (Pionniere) from Prague and the +firemen from the neighboring towns did not arrive until evening. +Fortunately the water began to fall in the night, and the next day it +had gone down so that it left its terrible work visible. The Sprudel +and the mineral springs were not injured, but, on the other hand, the +water pipes of the bathing establishments and the gas pipes were +completely destroyed.--_Illustrirte Zeitung._ + + * * * * * + + + + +THEATRICAL WATER PLAYS. + + +In one of the plays at Hengler's Circus in London a water scene is +introduced, for which purpose the main ring is flooded with water in a +manner which is both striking and interesting. + +[Illustration: FLOODING A CIRCUS RING.] + +The ring is entirely lined with stout macintosh sheeting, and into +this, from two large conduits. 23,000 gallons of water are poured, the +tank being filled to a depth of some 2 ft. in the remarkably short +time of 35 seconds. A steamboat and other small craft are then +launched and the adventures of the heroine then proceed. She falls +overboard, we believe, but is saved after desperate and amusing +struggles. Our engravings, which are from the _Graphic_, illustrate +the mode of filling the ring with water, and the steamboat launch. + +[Illustration: A THEATRICAL STEAMBOAT.] + + * * * * * + + + + +SCIENCE IN THE THEATER. + + +In the pretty little hall of the Boulevard des Italiens, at Paris, a +striking exhibition of simulated hypnotism is given every evening. + +This entertainment, which has met with much success, was devised by +Mr. Melies, director of the establishment, which was founded many +years ago by the celebrated prestidigitator whose popular name (Robert +Houdin) it still bears. This performance carries instruction with it, +for it shows how easily the most surprising phenomena of the +pathologic state can be imitated. To this effect, several exhibitions +are given every evening. + +Mr. Harmington, a convinced disciple of Mesmer, asks for a subject, +and finds one in the hall. A young artist named Marius presents +himself. Mr. Harmington makes him perform all sorts of extravagant +acts, accompanied with a continuous round of pantomimes that are +rendered the more striking by the supposed state of somnipathy of the +subject. At the moment at which Marius is finishing his most +extraordinary exercises, a policeman suddenly breaks in upon the stage +in order to execute the recent orders relative to hypnotism. But he +himself is subjugated by Mr. Harmington and thrown down by the +vibrations of which the encephalus of this terrible magnetizer is the +center. When the curtain falls, the representative of authority is +struggling against the catalepsy that is overcoming him. + +All the phenomena of induced sleep are successively simulated with +much naturalness by Mr. Jules David, who plays the part of Marius in +this pleasing little performance. + +At a certain moment, after skillfully simulated passes made by the +magnetizer, Mr. David suddenly becomes as rigid as a stick of wood, +and falls in pivoting on his heels (Fig. 1). Did not Mr. Harmington +run to his assistance, he would inevitably crack his skull upon the +floor, but the magnetizer stands just behind him in order to receive +him in his arms. Then he lifts him, and places him upon two chairs +just as he would do with a simple board. He places the head of the +subject upon the seat of one of the chairs and the heels upon that of +the other. Mr. David then remains in a state of perfect immobility. +Not a muscle is seen to relax, and not a motion betrays the +persistence of life in him. The simulation is perfect. + +[Illustration: FIG. 1.--CATALEPTIC RIGIDITY.] + +In order to complete the astonishment of the spectators, Mr. +Harmington seats himself triumphantly upon the abdomen of the subject +and slowly raises his feet and holds them suspended in the air to show +that it is the subject only that supports him, without the need of +any other point of support than the two chairs (Fig. 2). + +[Illustration: FIG. 2.--EXPERIMENT ON THE SAME SUBJECT.] + +Usually, there are plenty of persons ingenuous enough to think that +Mr. David is actually in a cataleptic sleep, one of the characters of +which is cadaveric rigidity. + +As Mr. David's neck is entirely bare, it is not possible to suppose +that the simulator of catalepsy wears an iron corset concealed beneath +his clothing. He has performed a feat of strength and skill rendered +easy by the exercise that he has given to the muscles occupying the +_colliciæ_ of his vertebral column. This part of the muscular system +is greatly developed in the weakest and least hardy persons. In fact, +in order that man may keep a vertical position and execute an infinite +multitude of motions in which stability is involved, nature has had to +give him a large number of different organs. The muscles of the back +are arranged upon several superposed layers, the vertebral column is +doubly recurved in order that it may have more strength, and, finally, +rachidion nerves issue from each vertebra in order to regulate the +contraction of each muscular fasciculus according to the requirements +of equilibrium. The trick is so easy that we have seen youths +belonging to the Ligue d'Education Physique immediately imitate Mr. +David after seeing him operate but once. + +For the sake of those who would like to perform it, we shall add that +Mr. David takes care to bend his body in the form of an arch in such a +way that the convexity shall be beneath. As Mr. Harmington never fails +to place himself in the center of the line that joins Mr. David's head +and heels, his weight is divided into two parts, that is to say, 88 +pounds on each side of the point of support. The result is that the +stress necessary is less than that of a strong man of the Halle +lifting a bag of wheat to his shoulder or of an athlete supporting a +human pyramid. The force of contraction of the muscular fibers brought +into play in this experiment is much greater than is commonly +believed. In his lectures on physiology, Milne-Edwards cites some +facts that prove that it may exceed 600 pounds per square inch of +section. + +[Illustration: FIG. 3.--THE PERFORATE ARM.] + +The experiment on cadaveric rigidity is followed by others in +insensibility. Mr. David, without wincing, allows a poignard to be +thrust into his arm, which Mr. Harmington has previously +"cataleptized" (Fig. 3). This trick is performed by means of a blade +divided into two parts that are connected by a semicircle. This +process is well known to prestidigitators, but it might be executed in +a genuine manner. In fact, on replacing the poignard by one of the +gold needles used by physicians for acupuncture, it would be possible +to dispense with prestidigitation. Under such conditions it is +possible to transpierce a person's arm. The pain is supportable, and +consists in the sensation of a prick produced in the passage of the +needle through the skin. As for the muscular flesh, that is of itself +perfectly insensible. The needle, upon the necessary antiseptic +precautions being taken, may traverse the veins and arteries with +impunity, provided that it is not allowed to remain long enough to +bring about the formation of a clot of coagulated blood (Fig. 4). + +[Illustration: FIG. 4.--AN ARM TRANSPIERCED BY A NEEDLE.] + +We think it of interest to add that it is necessary that the +experiment be performed by a practitioner if one desires to +demonstrate upon himself a very curious physiological fact that has +been known from the remotest antiquity. It has been employed for +several thousand years in Chinese medicine, for opening a passage for +the bad spirits that produce diseases. For some years past a much more +serious use has been made of it in European medicine for introducing +electric currents into the interior of the organism. In this case the +perimeter of the needle is insulated, and the electricity flows into +the organism through the point. We have several times had these +operations performed upon ourselves, and this permits us to assert +that the above mentioned facts are absolutely true.--_La Nature._ + + * * * * * + + + + +NEWER PHYSIOLOGY AND PATHOLOGY. + +By Prof. SAMUEL BELL, M.D. + + +Physiology has for many decades been a science founded on experiment, +and pathology has been rapidly pressing forward in the same direction. +To read the accounts of how certain conclusions have been arrived at +in the laboratory, by ingenious devices and by skillful manipulations, +is as fascinating as any tale of adventure. + +When the microscope began its work, how discouraging was the vastness +and complexity of the discoveries which it brought to light; how many +years has it been diligently used, and how uncertain are we still +about many of its revelations! But what a happy conjecture of man, and +as proper environment takes place we may reach better results! Let me +give an illustration: + +Some thirty years ago, Virchow began his studies and lectures upon +cellular pathology. The enthusiasm which he awakened spread over the +whole medical world. The wonderful attention to detail, the broad +philosophy which signalized his observations, were alike remarkable. +His class room was packed with students from every country, who +thought it no hardship to struggle for a seat at eight o'clock in the +morning. With his blackboard behind him and specimens of pathology +before him, and microscopes coursing upon railway tracks around the +tables which filled the room, he was the embodiment of the teacher; +his highest honor was as discoverer. The life and importance of the +cell, both in health and disease, it has been his work to discover and +to teach. The point of view from which he has classified tumors is +founded on this basis, and remains the accepted method. The light +which he cast upon the nature of inflammation has not yet been +obscured, and while other phenomena appear, the multiplication of +cells and nuclei and the formation of connective tissue in the process +of inflammation will always call to mind his labors. + +To one of Virchow's pupils, Prof. Recklinghausen, we chiefly owe our +knowledge of the phenomena of diapedesis as a part of the inflammatory +activity. How incredible it seems that masses of living matter can +make their way through the walls of blood vessels which do not rupture +and which have no visible apertures! + +Virchow fixed his attention upon the forms and activities of the +cells, their multiplication and degradation, and how they build up +tissues, both healthy and morbid. + +To another matter with which, both literally and metaphorically, the +air is filled, we must also make allusion. The existence of +micro-organisms in countless numbers is no new fact, but the influence +they may exert over living tissues has only lately become the subject +of earnest attention. So long as they were not known to have any +practical bearing upon human welfare, they interested almost nobody, +but when, however, it was shown that putrefaction of meat is due to +the agency of the _bacterium termo_, and the decomposition of albumen +to the _bacillus subtilis_; when anthrax in cattle and sheep was found +to depend on the _bacillus anthracis_, and that in human beings it +caused malignant pustules; when suppuration of wounds was found to be +associated with micrococci; and when it was announced that by a +process of inoculation cattle could be protected against anthrax, and +that by carbolic spray and other well known precautions the +suppuration of wounds could be prevented--all the world lent its ears +and investigation at once began. + +Because labors in bacteriology promised to be fruitful in practical +results, the workers speedily became innumerable, and we are +accumulating a wondrous store of facts. How long now is the list of +diseases in which germs make their appearance--in pneumonia, in +endocarditis, in erysipelas, in pyæmia, in tuberculosis, and so on and +so on. One of the most striking illustrations is the gonococcus of +gonorrhoea, whose presence in and around gives to the pus cells +their virulent properties, and when transferred to the eye works such +lamentable mischief. Without their existence the inoculation of pus in +the healthy eye is harmless; pus bearing the gonococci excites the +most intense inflammation. Similar suppurative action in the cornea is +often caused by infection of cocci. The proof of causation may be +found in the fact that the most effective cure now practiced for such +suppuration is to sterilize them by the actual cautery. Rosenbach says +that he knows six distinct microbes which are capable of exciting +suppuration in man. Their activity may be productive of a poison, or +putrefactive alkaloid, which is absorbed. + +There are at present two prominent theories in regard to the +infections which produce disease. The first is based upon chemical +processes, the second upon the multiplication of living organisms. The +chemical theory maintains that after the infectious element has been +received into the body it acts as a ferment, and gives rise to certain +morbid processes, upon the principle of catalysis. The theory of +organisms, or the germ theory, maintains that the infectious elements +are living organisms, which, being received into the system, are +reproduced indefinitely, and excite morbid processes which are +characteristic of certain types of disease. This latter theory so +readily explains many of the facts connected with the development and +reproduction of infectious diseases, that it has been unqualifiedly +adopted by a large number of investigators. The proofs of this theory +had not, however, advanced beyond the demonstrations of the presence +of certain forms of bacteria in the pathological changes of a very +limited number of infectious diseases, until February, 1882, when Koch +announced his discovery of the tubercle bacillus, since which time +nearly every disease has its supposed microbe, and the race is, +indeed, swift in which the would-be discoverers press forward with new +germs for public favor. + +The term bacteria or microbe refers to particles of matter, +microscopic in size, which belong to the vegetable kingdom, where they +are known as fungi. If we examine a drop of stagnant water under the +microscope, amplifying say four hundred diameters, we see it loaded +with minute bodies, some mere points, others slightly elongated into +rods, all actively in motion and in various positions, a countless +confusion. If evaporation now takes place, all is still. If we now +apply moisture, the dried-up granules will show activity, as though +they had not been disturbed. + +All these different organisms have become familiar to us under the +generic term bacteria, which is a very unfortunate application, as it +really applies to only a single class of fungi. Cohn calls them +schizomycetes, and makes the following classifications: + + 1. _Sphero-bacteria_, or microbes. + 2. _Micro-bacteria_, or bacteria. + 3. _Desmo-bacteria_, or bacilli. + 4. _Spiroteria_, or spirillæ. + +The _spiro-bacteria_, or micrococci, are the simplest of the fungi, +and appear as minute organisms of spherical form. They multiply by +fission, a single coccus forming two, these two producing four, and so +on. They present a variety of appearances under the microscope. From +single isolated specimens (which under the highest magnifying power +present nothing beyond minute points) you will observe them in pairs, +again in fours, or in clusters of hundreds (forming zoöglea) and still +adhering together, forming chains. When a given specimen is about to +divide, it is seen to elongate slightly, then a constriction is +formed, which deepens until complete fission ensues. + +Micrococci possess no visible structure. They consist of a minute +droplet of protoplasm (mycroprotein) surrounded by a delicate cell +membrane. Certain forms are embedded in a capsule (diameter 0.0008 to +0.0001 millimeter). + +These little organisms, when observed in a fluid like blood, sputum, +etc., are found to present very active movements, although provided +with no organs of locomotion. + +This Brownian motion is possessed by almost every minute particle of +matter, organic and inorganic, and is not due to any inherent power of +the individual. They are almost omnipresent, abounding in the air, the +earth, the water, are always found in millions where moist organic +matter is undergoing decomposition, and are associated with the +processes of fermentation--in fact, they are essential to it. The +souring of milk succeeds the multiplication of these germs. Certain +varieties are pigmented, and we observe colonies of chromogenic cocci +multiplying upon slices of boiled potato, eggs, etc., presenting all +the colors of the rainbow. All of these germs are not the cause of +disease. Certain species, however (termed pathogenic), are always +associated with certain diseased conditions. + +The _bacteria-termo_--micro-bacteria--are slightly elongated, and +inasmuch as they multiply by division, frequently appear coupled +together, linked in pairs, and in chains. They are generally found in +putrefying liquids, especially infusions of vegetable matter. They +possess mobility to a remarkable degree. Observing a field of +bacteria-termo under the microscope, they may be seen actively engaged +in twining and twisting. A flagellum has been demonstrated as attached +to one or both extremities. This is too minute to be generally +resolved, even if it is a common appendage. + +_Desmo-bacteria_ (or bacilli) are rod-like organisms, occurring of +various lengths and different thicknesses. In a slide of the bacillus +of tuberculosis and anthrax, we notice at intervals dots which +represent the spores from which, as the rods break up, future bacilli +are developed. + +Then we have _spiro-bacteria,_ the spirilla and the spirochetæ; the +former having short open spirals, the latter long and closely wound +spirals. The _spirillum, volutans_ is often found in drinking water, +and in common with some other specimens of this class is provided with +flagellæ, sometimes at both extremities, which furnish the means of +rapid locomotion. The spiro-bacteria multiply by spores, although +little is at present known of their life history. They frequently are +attached together at their extremities, forming zigzag chains. + +We have seen that bacteria differ greatly in appearance from the +elongated dot of the bacterium proper, to the elongated rod or +cylinder of the bacillus, and the long spirals of spiro-bacteria. It +is unfortunate that they are not sufficiently constant in habit to +always attach themselves to one or the other of these genera. The +micrococcus has a habit of elongating at times until it is impossible +to recognize him except as a bacterium; while bacilli, again, break up +until their particles exactly resemble micrococci. + +Bacteria cannot exist without water; certain forms require oxygen, +while others thrive equally well without it; some thrive in solution +of simple salts, while others require albuminoid material. + +Bacteriology, with its relation to the science of medicine, is of +importance to every investigating physician; it covers our knowledge +of the relation of these minute organisms to the ætiology of disease. +What has been gained as to practical application in the treatment of +disease? This question is not infrequently asked in a sneering manner. +We can, in reply, say that the results are not all in the future. It +is encouraging that results have been attained which have had a very +important practical bearing, and that these complaints come generally +from individuals least acquainted with scientific investigations in +bacteriology. + +In the study of the relation of a given bacterium to a certain +disease, it becomes necessary to attend carefully to three different +operations: First, the organism supposed to cause the disease must be +found and isolated. Second, it must be cultivated through several +generations in order that absolute purity may be secured. Lastly, the +germ must be again introduced into a healthy living being. If the +preceding steps be carried out, and the original disease be +communicated by inoculation, and the germs be again found in the +diseased body, we have no alternative; we must conclude that we have +ascertained the cause of the disease. The importance of being familiar +with the ætiology of the disease before we can expect to combat it +with any well-grounded hope of success is evident. + +If the sputum of a phthisical patient be submitted to the skilled +microscopist, he is nearly always able to demonstrate bacilli, but +this goes for very little. Because bacilli are found in phthisis, it +is no more certain that they are the cause of phthisis than it is +certain that cheese mites are the cause of cheese. Well, suppose we +were to inject sputum from a phthisical person into the lower animal +and tuberculosis follows, and then announce to the profession that we +have demonstrated the relation of the cause and effect between bacilli +and phthisis? Why we would start such an uproar of objections as would +speedily convince us that there was much work yet in the domain of +bacteriology. + +The scientific investigators would say you have injected with the +sputum into the blood of your unfortunate patient, pus, morphological +elements, and perhaps half a dozen other forms of bacteria, any one of +which is just as likely to produce the disease as the bacillus you +have selected. + +The first important step is, first isolate your bacillus. If I were to +take a glass plate, one side of which is coated with a thick solution +of peptonized gelatin, and allow the water to collect, the gelatinous +matter will become solid. If now, with a wire dipped in some +tuberculous matter, I draw a line along the gelatin, I have deposited +at intervals along this line, specimens of tubercle bacilli. If this +plate be now kept at a proper temperature, after a few days, wherever +the bacilli have been caught, a grayish spot will appear, which, +easily seen with the naked eye, gradually spreads and becomes larger. +These spots are colonies containing thousands of bacilli. Let us +return to our gelatin plate. + +We find a spot which answers to the description of a colony of +tubercle bacilli. We now take a minute particle from this colony on a +wire and convey it to the surface of some hardened blood serum in a +test tube. We plug the tube so that no air germs may drop in, and +place it in an incubator at the proper temperature. After several +days, if no contamination be present, a colony of bacilli will appear +around the spot where we sowed the spores. Let us repeat the process. + +Take a particle from this colony, and transfer it to another tube. +This is our second culture. This must be repeated until we are +satisfied that we have secured a _pure_ culture. If this be carried to +the twenty-fifth generation, we may be assured that there remains no +pus, no ptomaines, nothing but the desired bacilli. + +It is a proper material now for inoculation, and if we inoculate some +of the lower animals, for instance the monkey, we produce a disease +identical with phthisis pulmpnalis. Bacteria also afford peculiar +chemical reactions. For example, nitric acid will discharge all the +color from all bacilli artificially dyed with anilin, except those of +tubercle and anthrax. One species is stained readily with a dye that +leaves another unaltered. Thus we are enabled in the laboratory to +determine whether the bacilli found in sputum, for example, are from +tubercle or are the bacteria of decomposition. + +From what I have said of the tubercle bacillus, it would seem +thoroughly demonstrated that it is the cause of tubercle in these +animals. But we must walk cautiously here. These are not human beings, +who know that like results would follow their inoculation. The animals +used by Koch are animals very subject to tubercle. + +We must, from the very nature of our environment, be constantly +inhaling these germs as we pass through the wards of our hospitals; +yes, they are floating in the air of our streets and dwellings. It +becomes necessary then for us to inquire: If bacteria cause disease, +in what manner do they produce it? The healthy organism is always +beset with a multitude of non-pathogenic bacteria. They occupy the +natural cavities, especially the alimentary canal. They feed on the +substances lying in their neighborhood, whether brought into the body +or secreted by the tissues. In so doing they set up chemical changes +in their substances. Where the organs are acting normally these fungi +work no mischief. The products of decomposition thus set up are +harmless, or are conveyed out of the body before they begin to be +active. + +If bacteria develop to an inordinate degree, if the contents of organs +are not frequently discharged, fermentative processes may be set up, +which result in disease. Bacteria must always multiply and exist at +the expense of the body which they infest, and the more weakened the +vital forces become, the more favorable is the soil for their +development. + +Septicæmia is caused by the absorption of the products of +putrefaction, induced before bacteria can multiply inside or outside +the body. Bacteria must find a congenial soil. The so-called cholera +bacillus must gain access to the intestinal tract before it finds +conditions suitable to colonization. It does not seem to multiply in +the stomach or in the blood, but once injected into the duodenum +develops with astonishing rapidity, and the delicate epithelial cells +of the villi become swollen, soften and break down, exposing the +mucosa. + +It has been shown that _bouillon_ in which Loeffler's diphtheria +bacillus has grown, and which has been passed through unglazed +porcelain filters, shows the presence of a poison which is capable of +producing the same results upon inoculation as the pure culture of the +bacillus itself. Zarniko, working upon the same organism, obtained a +number of positive results that led him to declare this bacillus is +the cause of epidemic diphtheria, in spite of many assertions to the +contrary. Chantmesse and Widal record the results of their work as to +what will most easily and effectively destroy the bacillus of +diphtheria. + +The only three substances that actually checked and destroyed its +vitality were phenic acid (5 per cent.), camphor (20 per cent.), olive +oil (25 per cent.), in combination. For the last I substitute +glycerine, because this allows the mixture to penetrate farther into +the mucous membrane than oil, the latter favoring a tendency to pass +over the surface. This mixture when heated separates into two layers, +the upper one viscid and forming a sort of "glycerol," the lower +clear. The latter will completely sterilize a thread dipped in a pure +culture of the diphtheria bacillus. Corrosive sublimate was not +examined because in strong enough doses it would be dangerous and in +weaker ones it would be useless. + +The facts obtained in regards to the streptococcus of erysipelas are +reported as follows: That both chemical and experimental evidence +teach the extreme ease of a renewed attack of the disease; that it is +possible to kill guinea pigs by an intoxication when they are immune +to an inoculation of the culture in ordinary quantities. And this +latter fact should warn experimenters trying to obtain immunity in man +by the inoculation of non-pathogenic bacteria, because the same +results may be reached. + +A new theory in regard to fevers and the relation of micro-organisms +is suggested by Roussy, viz.: That it is a fermentation produced by a +diastase or soluble ferment found in all micro-organisms and cells, +and which they use in attacking and transforming matter, either inside +their substance or without it. + +The resemblance of the malaria parasite to that of recurrent fever is +noted in the work of Sacharoff. He states that there exists in the +blood of those suffering from recurrent fever a hæmatozoon, which is +most prominent after the fever has begun to fall, when it is of +enormous proportions, twenty or more diameters of a red blood +corpuscle, although smaller ones may still be found. The parasite +consists of a delicate amoeboid body containing a multitude of dark, +round, uniform, sharply outlined, movable granules. Besides these, the +protoplasm contains a generally grayish homogeneous nucleus as large +as one or two red blood corpuscles. The protoplasm sends out +pseudopodia (with granules), which sometimes separate and appear as +small delicate pieces of protoplasm. They vary in size, and are often +swallowed by the red blood corpuscles in which they grow, and finally +develop into the above mentioned amoeboid bodies. + +Prof. J. Lewis Smith has made a great many autopsies of children dead +from cholera infantum, and almost invariably found the stomach and +liver in a comparatively healthy condition. Ganghen, who has given +this subject considerable study, denies the existence of any specific +germ in the summer diarrhea of infants, but claims to have found three +different germs in the intestines of children suffering from cholera +infantum, each producing a chemical poison which is capable of +producing vomiting, purging, and even death. A great variety of germs +are found in drinking water, and no doubt countless numbers are taken +into the digestive tract, and the principal reason why pathological +conditions do not occur more frequently is on account of the +germicidal qualities of the gastric juice. + +The comma bacillus of Koch, and the typhoid fever germ of Eberth, are +especially destroyed in normal gastric juice. When the germs are very +numerous, they run the gauntlet of the stomach (as the gastric juice +is secreted only during digestion); and once in the alkaline +intestinal canal they are capable of setting up disease, other +conditions contributing--ill health, deranged digestion, etc. + +Mittnam has made a study of bacteria beneath the nails, and reports, +after examining persons following different occupations, having found +numerous varieties of micro-organisms; which are interesting from a +scientific standpoint relative to the importance of thoroughly +cleansing the hands before undertaking any surgical procedure. He +found, out of twenty-five experiments, 78 varieties of bacteria, of +which 36 were classed as micrococci, 21 diplococci, 18 rods, 3 +sarcinæ, and 1 yeast. Cooks, barbers, waiters, etc., were examined. + +The blood, defibrinated and freshly drawn, has marked germicidal +action; for bacteria its action is decidedly deadly, even hours after +it has been drawn from the body. Especially were anti-germic qualities +noticed upon pathogenic bacteria. Buchner put the bacilli of anthrax +in a quantity of blood, and in two hours the number was reduced from +4,800 to 56, and in three hours only 3 living bacteria remained. Other +bacteria were experimented upon in blood with similar results, but the +destruction of the organism from putrefaction was much less marked, +and on some varieties the blood had little or no action. + +It is not the object of these remarks to even give a _résumé_ of the +_status præsens_ of bacteriology, but simply to stimulate thought in +that direction. The claims of some of the ultra-bacteriologists may +never be realized, but enough has been accomplished to revolutionize +the treatment of certain diseases, and the observing student will do +well to keep his eye on the microbe, as it seems from the latest +investigations that its star is in the ascendant. And who can +prognosticate but that in the next decade an entire revolution in the +ætiology and treatment of many diseases may take place? + +Detroit, Mich. + + * * * * * + + + + +THE COMPOSITION OF KOCH'S LYMPH. + +WHAT PROFESSOR KOCH SAYS IT IS, AND WHAT IT CAN DO. + +(By Cable to the _Medical Record_.) + +BERLIN, January 15, 1891. + + +The curiosity to know the composition of the famous lymph has been +gratified by the publication to-day of an article by Professor Koch on +the subject. In the following, as will be seen, he reaffirms his +original convictions and acknowledges the valuable assistance he has +received from those who have used his fluid, and thus helped him in +the accumulation of experience. + +Professor Koch says: Two months ago I published the results of my +experiments with the new remedy for tuberculosis, since which time +many physicians who received the preparation have been enabled to +become acquainted with its properties through their own experiments. +So far as I have been able to review the statements published and the +communications received by letter, my predictions have been fully and +completely confirmed. The general consensus of opinion is that the +remedy has a specific action upon tubercular tissues, and is, +therefore, applicable as a very delicate and sure reagent for +discovering latent and diagnosing doubtful tuberculous processes. +Regarding the curative effects of the remedy, most reports agree that, +despite the comparatively short duration of its application, many +patients have shown more or less pronounced improvement. It has been +affirmed that in not a few cases even a cure has been established. +Standing quite by itself is the assertion that the remedy may not only +be dangerous in cases which have advanced too far--a fact which may +forthwith be conceded--but also that it actually promotes the +tuberculous process, being therefore injurious. + +During the past six weeks I myself have had opportunity to bring +together further experiences touching the curative effects and +diagnostic application of the remedy in the cases of about one hundred +and fifty sufferers from tuberculosis of the most varied types in this +city and in the Moabit Hospital. + +I can only say that everything I have latterly seen accords with my +previous observations. There has been nothing to modify in what I +before reported. As long as it was only a question of proving the +accuracy of my indications, it was needless for any one to know what +the remedy contained or whence it was derived. On the contrary, +subsequent testing would necessarily be more unbiased, the less people +knew of the remedy itself. Now, after sufficient confirmatory testing, +the importance of the remedy is proved, my next task is to extend my +study of the remedy beyond the field where it has hitherto been +applied, and if possible to apply the principle underlying the +discovery to other diseases. + +This task naturally demands a full knowledge of the remedy. I +therefore consider that the time has arrived when the requisite +indications in this direction shall be made. This is done in what +follows. + +Before going into the remedy itself, I deem it necessary for the +better understanding of its mode of operation to state briefly the way +by which I arrived at the discovery. If a healthy guinea pig be +inoculated with the pure cultivation of German Kultur of tubercle +bacilli, the wound caused by the inoculation mostly closes over with a +sticky matter, and appears in its early days to heal. Only after ten +to fourteen days a hard nodule presents itself, which, soon breaking, +forms an ulcerating sore, which continues until the animal dies. Quite +a different condition of things occurs when a guinea pig already +suffering from tuberculosis is inoculated. An animal successfully +inoculated from four to six weeks before is best adapted for this +purpose. In such an animal the small indentation assumes the same +sticky covering at the beginning, but no nodules form. On the +contrary, on the day following, or the second day after the +inoculation, the place where the lymph is injected shows a strange +change. It becomes hard and assumes a darker coloring, which is not +confined to the inoculation spot, but spreads to the neighboring parts +until it attains a diameter of from 0.05 to 1 cm. + +In a few days it becomes more and more manifest that the skin thus +changed is necrotic, finally falling off, leaving a flat ulceration +which usually heals rapidly and permanently without any involvement of +the adjacent lymphatic glands. Thus the injected tubercular bacilli +quite differently affect the skin of a healthy guinea pig from one +affected with tuberculosis. This effect is not exclusively produced +with living tubercular bacilli, but is also observed with the dead +bacilli, the result being the same whether, as I discovered by +experiments at the outset, the bacilli are killed by a somewhat +prolonged application of a low temperature or boiling heat or by means +of certain chemicals. This peculiar fact I followed up in all +directions, and this further result was obtained--that killed pure +cultivations of tubercular bacilli, after rinsing in water, might be +injected in great quantities under healthy guinea pig's skin without +anything occurring beyond local suppuration. Such injections belong to +the simplest and surest means of producing suppurations free from +living bacteria. + +Tuberculous guinea pigs, on the other hand, are killed by the +injection of very small quantities of such diluted cultivations. In +fact, within six to forty-eight hours, according to the strength of +the dose, an injection which is not sufficient to produce the death of +the animal may cause extended necrosis to the skin in the vicinity of +the place of injection. If the dilution is still further diluted until +it is scarcely visibly clouded, the animals inoculated remain alive +and a noticeable improvement in their condition soon supervenes. If +the injections are continued at intervals of from one to two days, the +ulcerating inoculation wound becomes smaller and finally scars over, +which otherwise it never does; the size of the swollen lymphatic +glands is reduced, the body becomes better nourished, and the morbid +process ceases, unless it has gone too far, in which case the animal +perishes from exhaustion. By this means the basis of a curative +process against tuberculosis was established. + +Against the practical application of such dilutions of dead tubercle +bacilli there presented itself the fact that the tubercle bacilli are +not absorbed at the inoculation points, nor do they disappear in +another way, but for a long time remain unchanged, and engender +greater or smaller suppurative foci. Anything, therefore, intended to +exercise a healing effect on the tuberculous process must be a soluble +substance which would be liberated to a certain extent by the fluids +of the body floating around the tubercle bacilli, and be transferred +in a fairly rapid manner to the juices of the body; while the +substance producing suppuration apparently remains behind in the +tubercular bacilli, or dissolves but very slowly. The only important +point was, therefore, to induce outside the body the process going on +inside, if possible, and to extract from the tubercular bacilli alone +the curative substance. This demanded time and toil, until I finally +succeeded, with the aid of a forty to fifty per cent. solution of +glycerine, in obtaining an effective substance from the tubercular +bacilli. With the fluid so obtained I made further experiments on +animals, and finally on human beings. These fluids were given to other +physicians to enable them to repeat the experiments. + +The remedy which is used in the new treatment consists of a glycerine +extract, derived from the pure cultivation of tubercle bacilli. Into +the simple extract there naturally passes from the tubercular bacilli, +besides the effective substance, all the other matter soluble in fifty +per cent. glycerine. + +Consequently, it contains a certain quantity of mineral salts, +coloring substances, and other unknown extractive matters. Some of +these substances can be removed from it tolerably easily. The +effective substance is insoluble in absolute alcohol. It can be +precipitated by it, though not, indeed, in a pure condition, but still +combined with the other extractive matter. It is likewise insoluble in +alcohol. The coloring matter may also be removed, rendering it +possible to obtain from the extract a colorless, dry substance +containing the effective principle in a much more concentrated form +than the original glycerine solution. For application in practice this +purification of the glycerine extract offers no advantage, because the +substances so eliminated are unessential for the human organism. The +process of purification would make the cost of the remedy +unnecessarily high. + +Regarding the constitution of the more effective substances, only +surmises may for the present be expressed. It appears to me to be +derivative from albuminous bodies, having a close affinity to them. It +does not belong to the group of so-called toxalbumins, because it +bears high temperatures, and in the dialyzer goes easily and quickly +through the membrane. The proportion of the substance in the extract +to all appearance is very small. It is estimated at fractions of one +per cent., which, if correct, we should have to do with a matter whose +effects upon organisms attacked with tuberculosis go far beyond what +is known to us of the strongest drugs. + +Regarding the manner in which the specific action of the remedy on +tuberculous tissue is to be represented, various hypotheses may +naturally be put forward. Without wishing to affirm that my view +affords the best explanation, I represent the process myself in the +following manner: + +The tubercle bacilli produced when growing in living tissues, the same +as in artificial cultivations, contain substances which variously and +notably unfavorably influence living elements in their vicinity. Among +these is a substance which in a certain degree of concentration kills +or so alters living protoplasm that it passes into a condition that +Weigert describes as coagulation necrosis. In tissue thus become +necrotic the bacillus finds such unfavorable conditions of nourishment +that it can grow no more and sometimes dies. + +This explains the remarkable phenomenon that in organs newly attacked +with tuberculosis, for instance in guinea pigs' spleen and liver, +which then are covered with gray nodules, numbers of bacilli are +found, whereas they are rare or wholly absent when the enormously +enlarged spleen consists almost entirely of whitish substance in a +condition of coagulation necrosis, such as is often found in cases of +natural death in tuberculous guinea pigs. The single bacillus cannot, +therefore, induce necrosis at a great distance, for as soon as +necrosis attains a certain extension the growth of the bacillus +subsides, and therewith the production of the necrotizing substance. A +kind of reciprocal compensation thus occurs, causing the vegetation of +isolated bacilli to remain so extraordinarily restricted, as, for +instance, in lupus and scrofulous glands. + +In such cases the necrosis generally extends only to a part of the +cells, which then, with further growth, assume the peculiar form of +riesen zelle, or giant cells. Thus, in this interpretation, follow +first the explanation Weigert gives of the production of giant cells. + +If now one increased artificially in the vicinity of the bacillus the +amount of necrotizing substance in the tissue, the necrosis would +spread a greater distance. The conditions of nourishment for the +bacillus would thereby become more unfavorable than usual. + +In the first place the tissue which had become necrotic over a large +extent would decay and detach itself, and where such were possible +would carry off the inclosed bacilli and eject them outwardly, so far +disturbing their vegetation that they would much more speedily be +killed than under ordinary circumstances. + +It is just in looking at such changes that the effect of the remedy +appears to consist. It contains a certain quantity of necrotizing +substance, a correspondingly large dose of which injures certain +tissue elements even in a healthy person, and perhaps the white blood +corpuscles or adjacent cells, thereby producing fever and a +complication of symptoms, whereas with tuberculous patients a much +smaller quantity suffices to induce at certain places, namely, where +tubercle bacilli are vegetating and have already impregnated the +adjacent region with the same necrotizing matter, more or less +extensive necrosis of the cells, with the phenomena in the whole +organism which result from and are connected with it. + +For the present, at least, it is impossible to explain the specific +influence which the remedy, in accurately defined doses, exercises +upon tuberculous tissue, and the possibility of increasing the doses +with such remarkable rapidity, and the remedial effects which have +unquestionably been produced under not too favorable circumstances. + +Of the consumptive patients whom he described as temporarily cured, +two have been returned to the Moabit Hospital for further observation. + +No bacilli have appeared in their sputum for the past three months, +and their phthisical symptoms have gradually and completely +disappeared. + + * * * * * + + + + +CAN WE SEPARATE ANIMALS FROM PLANTS? + +By ANDREW WILSON. + + +One of the plainest points connected with the study of living things +is the power we apparently possess of separating animals from plants. +So self-evident appears this power that the popular notion scoffs at +the idea of science modestly disclaiming its ability to separate the +one group of living beings from the other. Is there any danger of +confusing a bird with the tree amid the foliage of which it builds its +nest, or of mistaking a cow for the grass it eats? These queries are, +of course, answerable in one way only. Unfortunately (for the +querists), however, they do not include or comprehend the whole +difficulty. They merely assert, what is perfectly true, that we are +able, without trouble, to mark off the higher animals from the higher +plants. What science inquires is, whether we are able to separate +_all_ animals from _all_ plants, and to fix a definite boundary line, +so as to say that all the organisms on the one side of the line are +assuredly animals, while all the others on the opposite side of the +line may be declared to be truly plants. It is exactly this task which +science declares to be among the impossibilities of knowledge. Away +down in the depths of existence and among the groundlings of life the +identity of living things becomes of a nature which is worse than +confusing, and which renders it a futile task to attempt to separate +the two worlds of life. The hopelessness of the task, indeed, has +struck some observers so forcibly that they have proposed to +constitute a third kingdom--the _Regnum Protisticum_--between the +animal and the plant worlds, for the reception of the host of doubtful +organisms. This third kingdom would resemble the casual ward of a +workhouse, in that it would receive the waifs and strays of life which +could not find a refuge anywhere else. + +A very slight incursion into biological fields may serve to show forth +the difficulties of naturalists when the task of separating animals +from plants is mooted for discussion. To begin with, if we suppose our +popular disbeliever to assert that animals and plants are always to be +distinguished by shape and form, it is easy enough to show him that +here, as elsewhere, appearances are deceptive. What are we to say of a +sponge, or a sea anemone, of corals, of zoophytes growing rooted from +oyster shells, of sea squirts, and of sea mats? These, each and all of +them, are true animals, but they are so plant-like that, as a matter +of fact, they are often mistaken by seaside visitors for plants. This +last remark holds especially true of the zoophytes and the sea mats. +Then, on the other hand, we can point to hundreds of lower plants, +from the yeast plant onward, which show none of the ordinary features +of plant life at all. They possess neither roots, stems, branches, +leaves, nor flowers, so that on this first count of the indictment the +naturalist gains the day. + +Power of movement, to which the popular doubter is certain to appeal, +is an equally baseless ground of separation. For all the animals I +have above named are rooted and fixed, while many true plants of lower +grade are never rooted at all. The yeast plant, the _Algæ_ that swarm +in our ponds, and the diatoms that crowd the waters, exemplify plants +that are as free as animals; and many of them, besides, in their young +state especially (e.g., the seaweeds), swim about freely in the water +as if they were roving animalcules. On the second count, also, science +gains the day; power of motion is no legitimate ground at all for +distinguishing one living being as an animal, while absence of +movement is similarly no reason for assuming that the fixed organism +must of necessity be a plant. Then comes the microscopic evidence. +What can this wonder glass do in the way of drawing boundary lines +betwixt the living worlds? The reply again is disappointing to the +doubter; for the microscope teaches us that the tissues of animals and +plants are built upon kindred lines. We meet with cells and fibers in +both. The cell is in each case the primitive expression of the whole +organism. Beyond cells and fibers we see the wonderful living +substance, _protoplasm_, which is alike to our senses in the two +kingdoms, although, indeed, differing much here and there in the +results of its work. On purely microscopic grounds, we cannot separate +animals from plants. There is no justification for rigidly assuming +that this is a plant or that an animal on account of anything the +microscope can disclose. A still more important point in connection +with this protoplasm question consists in the fact that as we go +backward to the beginnings of life, both in animals and plants, we +seem to approach nearer and nearer to an identity of substance which +baffles the microscope with all its powers of discernment. Every +animal and every plant begins existence as a mere speck of this living +jelly. The germ of each is a protoplasm particle, which, whatever +traces of structure it may exhibit, is practically unrecognizable as +being definitely animal or plant in respect of its nature. Later on, +as we know, the egg or germ shows traces of structure in the case of +the higher animals and plants; while even lowly forms of life exhibit +more or less characteristic phases when they reach their adult stage. +But, of life's beginnings, the microscope is as futile as a kind +scientific touchstone for distinguishing animals from plants as is +power of movement, or shape, or form. + +A fourth point of appeal in the matter is found within the domain of +the chemist. Chemistry, with its subtile powers of analysis, with its +many-sided possibilities of discovering the composition of things, and +with its ability to analyze for us even the light of the far distant +stars, only complicates the difficulties of the biologist. For, while +of old it was assumed that a particular element, nitrogen, was +peculiar to animals, and that carbon was an element peculiar to +plants, we now know that both elements are found in animals, just as +both occur in plants. The chemistry of living things, moreover, when +it did grow to become a staple part of science, revealed other and +greater anomalies than these. It showed that certain substances which +were supposed to be peculiar to plants, and to be made and +manufactured by them alone, were also found in animals. Chlorophyl is +the green coloring matter of plants, and is, of course, a typical +product of the vegetable world; yet it is made by such animals as the +hydra of the brooks and ponds, and by many animalcules and some worms. +Starch is surely a typical plant product, yet it is undoubtedly +manufactured, or at least stored up, by animals--a work illustrated by +the liver of man himself, which occasionally produces sugar out of its +starch. + +Again, there is a substance called _cellulose_, found well nigh +universally in plants. Of this substance, which is akin to starch, the +walls or envelopes of the cells of plant tissues are composed. Yet we +find those curious animals, the sea squirts, found on rocks and stones +at low-water mark, manufacturing cellulose to form part and parcel of +the outer covering of their sac-like bodies. Here it is as if the +animal, like a dishonest manufacturer, had infringed the patent rights +of the plant. On the fourth count, then--that of chemical +composition--the verdict is that nothing that chemistry can teach us +may serve definitely, clearly, and exactly to set a boundary line or +to erect a partition wall between the two worlds of life. There yet +remains for us to consider a fifth head--that of the food. + +In the matter of the feeding of the two great living worlds we might +perchance light upon some adequate grounds for making up the one +kingdom from the other. What the consideration of form, movement, +chemical composition, and microscopic structure could not effect for +us in this way, it might be supposed the investigation of the diet of +animals and plants would render clear. Our hopes of distinguishing the +one group from the other by reference to the food on which animals and +plants subsist are, however, dashed to the ground; and the diet +question leaves us, therefore, when it has been discussed, in the same +quandary as before. + +Nevertheless, it is an interesting story, this of the nutrition of +animals and plants. A large amount of scientific information is to be +gleaned from such a study, which may very well be commenced by our +having regard to the matters on which a _green_ plant feeds. I +emphasize the word "green," because it so happens that when a plant +has no chlorophyl (as green color is named in the plant world) its +feeding is of diverse kind to that which a green plant exhibits. The +mushroom or other fungus may be taken as an illustration of a plant +which represents the non-green race, while every common plant, from a +bit of grass to an oak tree, exemplifies the green-bearing order of +the vegetable tribes. + +Suppose we were to invite a green plant to dinner, the _menu_ would +have to be very differently arranged from that which would satisfy a +human or other animal guest. The soup would be represented for the +plant's delectation by water, the fish by minerals, the joint by +carbonic acid gas, and the dessert by ammonia. On these four items a +green plant feeds, out of them it builds up its living frame. Note +that its diet is of inorganic or non-living matter. It derives its +sustenance from soil and air, yet out of these lifeless matters the +green plant elaborates and manufactures its living matter, or +protoplasm. It is a more wonderful organism than the animal, for while +the latter can only make new protoplasm when living matter is included +in its food supply, the green plant, by the exercise of its vital +chemistry, can transform that which is not living into that which is +life-possessing. + +The green plant in other words, raises non-living into living matter, +while the animal can only transform living matters into its like. This +is why the plant is called a constructive organism, while the animal +is, contrariwise, named a destructive one. The result of the plant's +existence is to build up, that of the animal's life is to break down +its substance, as the result of its work, into non-living matter. The +animal's body is, in fact, breaking down into the very things on which +the green plant feeds. We ourselves are perpetually dissipating our +substance in our acts of life and work into the carbonic acid, water, +ammonia, and minerals on which plants feed. We "die daily" in as true +a sense as that in which the apostle used the term. And out of the +debris of the animal frame the green plant builds up leaf and flower, +stein and branch, and all the other tokens of its beauty and its life. + +If, then, an animal can only live upon living matter--that is to say +on the bodies of other animals or of plants--with water, minerals and +oxygen gas from the air thrown in to boot, we might be tempted to hold +that in such distinctive ways and works we had at last found a means +of separating animals from plants. Unfortunately, this view may be +legitimately disputed and rendered null and void, on two grounds. +First of all, the mushrooms and their friends and neighbors, all true +plants, do not feed as do the green tribes. And secondly, many of the +green plants themselves can be shown to have taken very kindly to an +animal mode of diet. + +A mushroom, thus, because it has no green color, lives upon water, +oxygen, minerals, and organic matter. You can only grow mushrooms +where there is plenty of animal matter in a state of decay, and as for +the oxygen, they habitually inhale that gas as if they were animals. +Non-green plants thus want a most characteristic action of their green +neighbors. For the latter in daylight take in the carbonic acid gas, +which is composed of carbon and oxygen. Under the combined influence +of the green color and the light, they split up the gas into its two +elements, retaining the carbon for food and allowing the oxygen to +escape to the atmosphere. Alas! however, in the dark our green plant +becomes essentially like an animal as regards its gas food, for then +it is an absorber of oxygen, while it gives off carbonic acid. If to +take in carbonic acid and to give out oxygen be held to be a feature +characteristic of a plant, it is one, as has been well said, which +disappears with the daylight in green plants, and which is not +witnessed at all in plants that have no green color. + +So far, we have seen that not even the food of plants and animals can +separate the one kingdom of life from the other. The mushroom bars the +way and the green plant's curious behavior by night and by day +respectively, in the matter of its gas food, once more assimilates +animal life and plant life in a remarkable manner. Still more +interesting is the fact, already noticed, that even among the green +tribes there are to be found many and various lapses from the stated +rules of their feeding. Thus what are we to say of the parasitic +mistletoe, which, while it has grown leaves of its own, and can, +therefore, obtain so much carbon food from the air on its own account, +nevertheless drinks up the sap of the oak or apple which forms its +host, and thus illustrates the spectacle of a green plant feeding like +an animal, on living matter? Or, what may we think of such plants as +the sundew, the Venus' fly trap, the pitcher plants, the side saddle +plants, the butterworts and bladderworts, and others of their kind, +which not only capture insects, often by ingenious and complex lures, +but also digest the animal food thus captured? A sundew thus spreads +out its lure in the shape of its leaf studded with sensitive +tentacles, each capped by a glistening drop of gummy secretion. +Entangled in this secretion, the fly is further fixed to the leaf by +the tentacles which bend over it and inclose it in their fold. Then is +poured out upon the insect's body a digestive acid fluid, and the +substance of the dissolved and digested animal is duly absorbed by the +plant. So also the Venus' fly trap captures insects by means of its +leaf, which closes upon the prey when certain sensitive hairs have +given the signal that the animal has been trapped. Within the leaf the +insect is duly digested as before, and its substance applied to the +nutrition of the plant. Such plants, moreover, cannot flourish +perfectly unless duly supplied with their animal food. Such +illustrations of exceptions to the rule of green plant feeding simply +have the effect of abolishing the distinctions which the diet question +might be supposed to raise between animals and plants. We may return +to the sundews and other insect catchers; meanwhile, I have said +enough to show that to the question, "Can we separate animals from +plants?" a very decided negative reply must be given. Life everywhere +exhibits too many points of contact to admit of any boundary line +being drawn between the two great groups which make up the sum total +of organic existence.--_Illustrated London News._ + + * * * * * + + + + +THE RECOVERY OF SILVER AND GOLD FROM PLATING AND GILDING SOLUTIONS. + + +In view of the rapid development and extension of the methods of +electro-plating with silver and gold, and of the large amount of spent +liquors containing silver or gold thus produced, it has long been +desirable to find methods by which these metals can be recovered from +the spent liquors. The processes hitherto adopted generally +necessitate the tedious and unpleasant evaporation of the cyanide +liquors, or else involve a series of chemical operations which are +somewhat difficult to carry out, so that actually the used-up baths +are sold to some firm which undertakes this recovery as a particular +branch of its business. + +A process invented by Stockmuir and Fleischmann, and worked out by +them in the chemical laboratory of the Bavarian Industrial Museum, is, +however, exceedingly simple, and is employed in many establishments. + +In order to remove silver from a potassium cyanide silver solution, it +is only necessary to allow a clean piece of plate zinc to remain in +the liquid for two days; even better results are obtained by the use +of iron conjointly with the zinc. In the first case, the silver often +adheres firmly to the zinc, while in the second it always separates +out as a powder. It is then only necessary to wash the precipitated +powder, which usually contains copper (since spent silver solutions +always contain copper), dry it, and then dissolve it in hot +concentrated sulphuric acid, water being added, and the dissolved +silver precipitated by strips of copper. The silver thus obtained is +perfectly pure. If the amount of copper present is only small, it can +usually be removed by fusing the precipitated powder with a little +niter and borax. + +In this way a spent silver bath was found to contain per liter + + 1st experiment 1.5706 grms. + 2d " 1.5694 " + ------ + Mean 1.5700 " + +The presence of silver could not be qualitatively ascertained in the +residual liquor. + +Although sheet zinc, or zinc and iron sheets, serve so well for the +precipitation of silver, they cannot be employed for the recovery of +gold. The latter separates out in such a case very incompletely and as +a firmly adhering lustrous film in the zinc. On the other hand, finely +divided zinc, the so-called zinc dust, is an excellent substance to +employ for precipitating gold quantitatively and in the form of powder +from spent cyanide liquors. When zinc dust is added to a spent gold +bath and the liquid periodically stirred or shaken, all the gold is +precipitated in two or three days. The amount of zinc to be added +naturally depends on the quantity of gold present. Freshly prepared +gold baths for gilding in the cold contain on the average 3.5 grms. +gold per liter, while those used for the hot process contain 10.75 +grms. To precipitate all the gold in the original bath, 1.74 grms. or +0.37-0.5 grms. zinc dust would be necessary, and, of course, a much +smaller quantity would be sufficient for the spent liquors. Since the +precipitation takes place more rapidly when an excess of zinc dust is +present, it is generally advisable to add ¼ or at the most ½ kilo, of +zinc dust to every 100 liters of solution. + +The precipitated gold, which contains zinc dust and usually silver and +copper, is washed, freed from zinc by hydrochloric acid, and then from +silver and copper by nitric acid and thus obtained pure. + +A spent bath treated in this way gave the following amounts of gold +per liter: + + 1st experiment 0.2626 + 2d " 0.2634 + Mean 0.2630 grms. + +The presence of gold in the residual cyanide solution could not be +qualitatively detected. The potassium cyanide of the solutions +obtained by this process should be converted into ferrocyanide by +heating with ferrous sulphate and milk of lime, since this substance +is not poisonous and can therefore be got rid of without danger. It +would, however, be more economical and, considering the large amount +of cyanide present, more profitable to work it up into Prussian blue. + + * * * * * + + +A NEW CATALOGUE OF VALUABLE PAPERS + +Contained in SCIENTIFIC AMERICAN SUPPLEMENT during the past ten years, +sent _free of charge_ to any address. MUNN & CO., 361 Broadway, New +York. + + * * * * * + + +THE SCIENTIFIC AMERICAN + +ARCHITECTS AND BUILDERS EDITION + +$2.50 A YEAR. SINGLE COPIES, 25 CTS. + +This is a Special Edition of the SCIENTIFIC AMERICAN, issued +monthly--on the first day of the month. Each number contains about +forty large quarto pages, equal to about two hundred ordinary book +pages, forming, practically, a large and splendid Magazine of +Architecture, richly adorned with _elegant platen in colors_ and with +fine engravings, illustrating the most interesting examples of modern +Architectural Construction and allied subjects. + +A special feature is the presentation in each number of a variety of +the latest and best plans for private residences, city and country, +including those of very moderate cost as well as the more expensive. +Drawings in perspective and in color are given, together with full +Plans, Specifications, Costs, Bills of Estimate, and Sheets of +Details. + +No other building paper contains so many plans, details, and +specifications regularly presented as the SCIENTIFIC AMERICAN. +Hundreds of dwellings have already been erected on the various plans +we have issued during the past year, and many others are in process of +construction. + +Architects, Builders, and Owners will find this work valuable in +furnishing fresh and useful suggestions. All who contemplate building +or improving homes, or erecting structures of any kind, have before +them in this work an almost _endless series of the latest and best +examples_ from which to make selections, thus saving time and money. + +Many other subjects, including Sewerage, Piping, Lighting, Warming, +Ventilating, Decorating, Laying out of Grounds, etc., are illustrated. +An extensive Compendium of Manufacturers' Announcements is also given, +in which the most reliable and approved Building Materials, Goods, +Machines, Tools, and Appliances are described and illustrated, with +addresses of the makers, etc. + +The fullness, richness, cheapness, and convenience of this work have +won for it the Largest Circulation of any Architectural publication in +the world. + +A Catalogue of valuable books on Architecture, Building, Carpentry, +Masonry, Heating, Warming, Lighting, Ventilation, and all branches of +industry pertaining to the art of Building, is supplied free of +charge, sent to any address. + +MUNN & CO., Publishers, + +361 Broadway, New York. + + * * * * * + + +BUILDING PLANS AND SPECIFICATIONS. + +In connection with the publication of the BUILDING EDITION of the +SCIENTIFIC AMERICAN, Messrs. Munn & Co. furnish plans and +specifications for buildings of every kind, including Churches, +Schools, Stores, Dwellings, Carriage Houses, Barns, etc. + +In this work they are assisted by able and experienced architects. +Full plans, details, and specifications for the various buildings +illustrated in this paper can be supplied. + +Those who contemplate building, or who wish to alter, improve, extend, +or add to existing buildings, whether wings, porches, bay windows, or +attic rooms, are invited to communicate with the undersigned. Our work +extends to all parts of the country. Estimates, plans, and drawings +promptly prepared. Terms moderate. Address + +MUNN & CO., 361 BROADWAY, NEW YORK. + + * * * * * + + +SCIENTIFIC AMERICAN SUPPLEMENT. + +PUBLISHED WEEKLY. + +Terms of Subscription, $5 a year. + +Sent by mail, postage prepaid, to subscribers in any part of the +United States or Canada. Six dollars a year, sent, prepaid, to any +foreign country. + +All the back numbers of THE SUPPLEMENT, from the commencement, January +1, 1876, can be had. Price, 10 cents each. + +All the back volumes of THE SUPPLEMENT can likewise be supplied. Two +volumes are issued yearly. Price of each volume, $2.50 stitched in +paper, or $3.50 bound in stiff covers. + +COMBINED RATES.--One copy of SCIENTIFIC AMERICAN and one copy of +SCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, $7.00. + +A liberal discount to booksellers, news agents, and canvassers. + +MUNN & CO., Publishers, +361 Broadway, New York, N.Y. + + * * * * * + + +USEFUL ENGINEERING BOOKS + +Manufacturers, Agriculturists, Chemists, Engineers, Mechanics, +Builders, men of leisure, and professional men, of all classes, need +good books in the line of their respective callings. Our post office +department permits the transmission of books through the mails at very +small cost. A comprehensive catalogue of useful books by different +authors, on more than fifty different subjects, has recently been +published, for free circulation, at the office of this paper. Subjects +classified with names of author. Persons desiring a copy have only to +ask for it, and it will be mailed to them. Address, MUNN & CO., 361 +Broadway, New York. + + * * * * * + + +PATENTS. + +In connection with the Scientific American, Messrs. MUNN & Co. are +solicitors of American and Foreign Patents, have had 42 years' +experience, and now have the largest establishment in the world. +Patents are obtained on the best terms. + +A special notice is made in the Scientific American of all inventions +patented through this Agency, with the name and residence of the +Patentee. By the immense circulation thus given, public attention is +directed to the merits of the new patent, and sales or introduction +often easily effected. + +Any person who has made a new discovery or invention can ascertain, +free of charge, whether a patent can probably be obtained, by writing +to MUNN & Co. We also send free our Hand Book about the Patent Laws, +Patents, Caveats, Trade Marks, their costs and how procured. Address + +MUNN & Co., + 361 Broadway, New York. +Branch Office, 622 and 624 F St., Washington, D.C. + + + + + + + +End of the Project Gutenberg EBook of Scientific American Supplement, No. +787, January 31, 1891, by Various + +*** END OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + +***** This file should be named 14009-8.txt or 14009-8.zip ***** +This and all associated files of various formats will be found in: + https://www.gutenberg.org/1/4/0/0/14009/ + +Produced by Victoria Woosley, Don Kretz, Juliet Sutherland, Charles +Franks and the PG Distributed Proofreading Team + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. Special rules, +set forth in the General Terms of Use part of this license, apply to +copying and distributing Project Gutenberg-tm electronic works to +protect the PROJECT GUTENBERG-tm concept and trademark. Project +Gutenberg is a registered trademark, and may not be used if you +charge for the eBooks, unless you receive specific permission. If you +do not charge anything for copies of this eBook, complying with the +rules is very easy. You may use this eBook for nearly any purpose +such as creation of derivative works, reports, performances and +research. They may be modified and printed and given away--you may do +practically ANYTHING with public domain eBooks. Redistribution is +subject to the trademark license, especially commercial +redistribution. + + + +*** START: FULL LICENSE *** + +THE FULL PROJECT GUTENBERG LICENSE +PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK + +To protect the Project Gutenberg-tm mission of promoting the free +distribution of electronic works, by using or distributing this work +(or any other work associated in any way with the phrase "Project +Gutenberg"), you agree to comply with all the terms of the Full Project +Gutenberg-tm License (available with this file or online at +https://gutenberg.org/license). + + +Section 1. General Terms of Use and Redistributing Project Gutenberg-tm +electronic works + +1.A. By reading or using any part of this Project Gutenberg-tm +electronic work, you indicate that you have read, understand, agree to +and accept all the terms of this license and intellectual property +(trademark/copyright) agreement. If you do not agree to abide by all +the terms of this agreement, you must cease using and return or destroy +all copies of Project Gutenberg-tm electronic works in your possession. +If you paid a fee for obtaining a copy of or access to a Project +Gutenberg-tm electronic work and you do not agree to be bound by the +terms of this agreement, you may obtain a refund from the person or +entity to whom you paid the fee as set forth in paragraph 1.E.8. + +1.B. "Project Gutenberg" is a registered trademark. It may only be +used on or associated in any way with an electronic work by people who +agree to be bound by the terms of this agreement. There are a few +things that you can do with most Project Gutenberg-tm electronic works +even without complying with the full terms of this agreement. See +paragraph 1.C below. There are a lot of things you can do with Project +Gutenberg-tm electronic works if you follow the terms of this agreement +and help preserve free future access to Project Gutenberg-tm electronic +works. See paragraph 1.E below. + +1.C. The Project Gutenberg Literary Archive Foundation ("the Foundation" +or PGLAF), owns a compilation copyright in the collection of Project +Gutenberg-tm electronic works. Nearly all the individual works in the +collection are in the public domain in the United States. If an +individual work is in the public domain in the United States and you are +located in the United States, we do not claim a right to prevent you from +copying, distributing, performing, displaying or creating derivative +works based on the work as long as all references to Project Gutenberg +are removed. Of course, we hope that you will support the Project +Gutenberg-tm mission of promoting free access to electronic works by +freely sharing Project Gutenberg-tm works in compliance with the terms of +this agreement for keeping the Project Gutenberg-tm name associated with +the work. You can easily comply with the terms of this agreement by +keeping this work in the same format with its attached full Project +Gutenberg-tm License when you share it without charge with others. + +1.D. The copyright laws of the place where you are located also govern +what you can do with this work. Copyright laws in most countries are in +a constant state of change. If you are outside the United States, check +the laws of your country in addition to the terms of this agreement +before downloading, copying, displaying, performing, distributing or +creating derivative works based on this work or any other Project +Gutenberg-tm work. The Foundation makes no representations concerning +the copyright status of any work in any country outside the United +States. + +1.E. Unless you have removed all references to Project Gutenberg: + +1.E.1. The following sentence, with active links to, or other immediate +access to, the full Project Gutenberg-tm License must appear prominently +whenever any copy of a Project Gutenberg-tm work (any work on which the +phrase "Project Gutenberg" appears, or with which the phrase "Project +Gutenberg" is associated) is accessed, displayed, performed, viewed, +copied or distributed: + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + +1.E.2. If an individual Project Gutenberg-tm electronic work is derived +from the public domain (does not contain a notice indicating that it is +posted with permission of the copyright holder), the work can be copied +and distributed to anyone in the United States without paying any fees +or charges. If you are redistributing or providing access to a work +with the phrase "Project Gutenberg" associated with or appearing on the +work, you must comply either with the requirements of paragraphs 1.E.1 +through 1.E.7 or obtain permission for the use of the work and the +Project Gutenberg-tm trademark as set forth in paragraphs 1.E.8 or +1.E.9. + +1.E.3. If an individual Project Gutenberg-tm electronic work is posted +with the permission of the copyright holder, your use and distribution +must comply with both paragraphs 1.E.1 through 1.E.7 and any additional +terms imposed by the copyright holder. Additional terms will be linked +to the Project Gutenberg-tm License for all works posted with the +permission of the copyright holder found at the beginning of this work. + +1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm +License terms from this work, or any files containing a part of this +work or any other work associated with Project Gutenberg-tm. + +1.E.5. Do not copy, display, perform, distribute or redistribute this +electronic work, or any part of this electronic work, without +prominently displaying the sentence set forth in paragraph 1.E.1 with +active links or immediate access to the full terms of the Project +Gutenberg-tm License. + +1.E.6. You may convert to and distribute this work in any binary, +compressed, marked up, nonproprietary or proprietary form, including any +word processing or hypertext form. However, if you provide access to or +distribute copies of a Project Gutenberg-tm work in a format other than +"Plain Vanilla ASCII" or other format used in the official version +posted on the official Project Gutenberg-tm web site (www.gutenberg.org), +you must, at no additional cost, fee or expense to the user, provide a +copy, a means of exporting a copy, or a means of obtaining a copy upon +request, of the work in its original "Plain Vanilla ASCII" or other +form. Any alternate format must include the full Project Gutenberg-tm +License as specified in paragraph 1.E.1. + +1.E.7. Do not charge a fee for access to, viewing, displaying, +performing, copying or distributing any Project Gutenberg-tm works +unless you comply with paragraph 1.E.8 or 1.E.9. + +1.E.8. You may charge a reasonable fee for copies of or providing +access to or distributing Project Gutenberg-tm electronic works provided +that + +- You pay a royalty fee of 20% of the gross profits you derive from + the use of Project Gutenberg-tm works calculated using the method + you already use to calculate your applicable taxes. The fee is + owed to the owner of the Project Gutenberg-tm trademark, but he + has agreed to donate royalties under this paragraph to the + Project Gutenberg Literary Archive Foundation. Royalty payments + must be paid within 60 days following each date on which you + prepare (or are legally required to prepare) your periodic tax + returns. Royalty payments should be clearly marked as such and + sent to the Project Gutenberg Literary Archive Foundation at the + address specified in Section 4, "Information about donations to + the Project Gutenberg Literary Archive Foundation." + +- You provide a full refund of any money paid by a user who notifies + you in writing (or by e-mail) within 30 days of receipt that s/he + does not agree to the terms of the full Project Gutenberg-tm + License. You must require such a user to return or + destroy all copies of the works possessed in a physical medium + and discontinue all use of and all access to other copies of + Project Gutenberg-tm works. + +- You provide, in accordance with paragraph 1.F.3, a full refund of any + money paid for a work or a replacement copy, if a defect in the + electronic work is discovered and reported to you within 90 days + of receipt of the work. + +- You comply with all other terms of this agreement for free + distribution of Project Gutenberg-tm works. + +1.E.9. If you wish to charge a fee or distribute a Project Gutenberg-tm +electronic work or group of works on different terms than are set +forth in this agreement, you must obtain permission in writing from +both the Project Gutenberg Literary Archive Foundation and Michael +Hart, the owner of the Project Gutenberg-tm trademark. Contact the +Foundation as set forth in Section 3 below. + +1.F. + +1.F.1. Project Gutenberg volunteers and employees expend considerable +effort to identify, do copyright research on, transcribe and proofread +public domain works in creating the Project Gutenberg-tm +collection. Despite these efforts, Project Gutenberg-tm electronic +works, and the medium on which they may be stored, may contain +"Defects," such as, but not limited to, incomplete, inaccurate or +corrupt data, transcription errors, a copyright or other intellectual +property infringement, a defective or damaged disk or other medium, a +computer virus, or computer codes that damage or cannot be read by +your equipment. + +1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right +of Replacement or Refund" described in paragraph 1.F.3, the Project +Gutenberg Literary Archive Foundation, the owner of the Project +Gutenberg-tm trademark, and any other party distributing a Project +Gutenberg-tm electronic work under this agreement, disclaim all +liability to you for damages, costs and expenses, including legal +fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT +LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE +PROVIDED IN PARAGRAPH F3. YOU AGREE THAT THE FOUNDATION, THE +TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE +LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR +INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH +DAMAGE. + +1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a +defect in this electronic work within 90 days of receiving it, you can +receive a refund of the money (if any) you paid for it by sending a +written explanation to the person you received the work from. If you +received the work on a physical medium, you must return the medium with +your written explanation. The person or entity that provided you with +the defective work may elect to provide a replacement copy in lieu of a +refund. If you received the work electronically, the person or entity +providing it to you may choose to give you a second opportunity to +receive the work electronically in lieu of a refund. If the second copy +is also defective, you may demand a refund in writing without further +opportunities to fix the problem. + +1.F.4. Except for the limited right of replacement or refund set forth +in paragraph 1.F.3, this work is provided to you 'AS-IS' WITH NO OTHER +WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO +WARRANTIES OF MERCHANTIBILITY OR FITNESS FOR ANY PURPOSE. + +1.F.5. Some states do not allow disclaimers of certain implied +warranties or the exclusion or limitation of certain types of damages. +If any disclaimer or limitation set forth in this agreement violates the +law of the state applicable to this agreement, the agreement shall be +interpreted to make the maximum disclaimer or limitation permitted by +the applicable state law. The invalidity or unenforceability of any +provision of this agreement shall not void the remaining provisions. + +1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the +trademark owner, any agent or employee of the Foundation, anyone +providing copies of Project Gutenberg-tm electronic works in accordance +with this agreement, and any volunteers associated with the production, +promotion and distribution of Project Gutenberg-tm electronic works, +harmless from all liability, costs and expenses, including legal fees, +that arise directly or indirectly from any of the following which you do +or cause to occur: (a) distribution of this or any Project Gutenberg-tm +work, (b) alteration, modification, or additions or deletions to any +Project Gutenberg-tm work, and (c) any Defect you cause. + + +Section 2. Information about the Mission of Project Gutenberg-tm + +Project Gutenberg-tm is synonymous with the free distribution of +electronic works in formats readable by the widest variety of computers +including obsolete, old, middle-aged and new computers. It exists +because of the efforts of hundreds of volunteers and donations from +people in all walks of life. + +Volunteers and financial support to provide volunteers with the +assistance they need, is critical to reaching Project Gutenberg-tm's +goals and ensuring that the Project Gutenberg-tm collection will +remain freely available for generations to come. In 2001, the Project +Gutenberg Literary Archive Foundation was created to provide a secure +and permanent future for Project Gutenberg-tm and future generations. +To learn more about the Project Gutenberg Literary Archive Foundation +and how your efforts and donations can help, see Sections 3 and 4 +and the Foundation web page at https://www.pglaf.org. + + +Section 3. Information about the Project Gutenberg Literary Archive +Foundation + +The Project Gutenberg Literary Archive Foundation is a non profit +501(c)(3) educational corporation organized under the laws of the +state of Mississippi and granted tax exempt status by the Internal +Revenue Service. The Foundation's EIN or federal tax identification +number is 64-6221541. Its 501(c)(3) letter is posted at +https://pglaf.org/fundraising. Contributions to the Project Gutenberg +Literary Archive Foundation are tax deductible to the full extent +permitted by U.S. federal laws and your state's laws. + +The Foundation's principal office is located at 4557 Melan Dr. S. +Fairbanks, AK, 99712., but its volunteers and employees are scattered +throughout numerous locations. Its business office is located at +809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887, email +business@pglaf.org. Email contact links and up to date contact +information can be found at the Foundation's web site and official +page at https://pglaf.org + +For additional contact information: + Dr. Gregory B. Newby + Chief Executive and Director + gbnewby@pglaf.org + + +Section 4. Information about Donations to the Project Gutenberg +Literary Archive Foundation + +Project Gutenberg-tm depends upon and cannot survive without wide +spread public support and donations to carry out its mission of +increasing the number of public domain and licensed works that can be +freely distributed in machine readable form accessible by the widest +array of equipment including outdated equipment. Many small donations +($1 to $5,000) are particularly important to maintaining tax exempt +status with the IRS. + +The Foundation is committed to complying with the laws regulating +charities and charitable donations in all 50 states of the United +States. Compliance requirements are not uniform and it takes a +considerable effort, much paperwork and many fees to meet and keep up +with these requirements. We do not solicit donations in locations +where we have not received written confirmation of compliance. To +SEND DONATIONS or determine the status of compliance for any +particular state visit https://pglaf.org + +While we cannot and do not solicit contributions from states where we +have not met the solicitation requirements, we know of no prohibition +against accepting unsolicited donations from donors in such states who +approach us with offers to donate. + +International donations are gratefully accepted, but we cannot make +any statements concerning tax treatment of donations received from +outside the United States. U.S. laws alone swamp our small staff. + +Please check the Project Gutenberg Web pages for current donation +methods and addresses. Donations are accepted in a number of other +ways including including checks, online payments and credit card +donations. To donate, please visit: https://pglaf.org/donate + + +Section 5. General Information About Project Gutenberg-tm electronic +works. + +Professor Michael S. Hart was the originator of the Project Gutenberg-tm +concept of a library of electronic works that could be freely shared +with anyone. For thirty years, he produced and distributed Project +Gutenberg-tm eBooks with only a loose network of volunteer support. + + +Project Gutenberg-tm eBooks are often created from several printed +editions, all of which are confirmed as Public Domain in the U.S. +unless a copyright notice is included. Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + https://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. diff --git a/old/14009-8.zip b/old/14009-8.zip Binary files differnew file mode 100644 index 0000000..fbe4b03 --- /dev/null +++ b/old/14009-8.zip diff --git a/old/14009-h.zip b/old/14009-h.zip Binary files differnew file mode 100644 index 0000000..02ffc9e --- /dev/null +++ b/old/14009-h.zip diff --git a/old/14009-h/14009-h.htm b/old/14009-h/14009-h.htm new file mode 100644 index 0000000..cf20f5c --- /dev/null +++ b/old/14009-h/14009-h.htm @@ -0,0 +1,6092 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" +"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"> +<head> +<meta name="generator" content= +"HTML Tidy for Linux/x86 (vers 1st November 2002), see www.w3.org" /> +<meta http-equiv="Content-Type" content= +"text/html; charset=ISO-8859-1" /> +<title>The Project Gutenberg eBook of Scientific American +Supplement, January 31, 1891</title> +<style type="text/css"> + /*<![CDATA[*/ +<!-- + body { margin-left: 15%; margin-right: 15%; background-color: white} + img { border: 0;} + h1,h2,h3 { text-align: center;} + .note { margin-left: 2em; margin-right: 2em; margin-bottom: 1em;} + .ind { margin-left: 10%; margin-right: 10%;} + hr { text-align: center; width: 50%;} + .ctr { text-align: center;} +--> + /*]]>*/ + +</style> +</head> +<body> + + +<pre> + +The Project Gutenberg EBook of Scientific American Supplement, No. 787, +January 31, 1891, by Various + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Scientific American Supplement, No. 787, January 31, 1891 + +Author: Various + +Release Date: November 10, 2004 [EBook #14009] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + + + + +Produced by Victoria Woosley, Don Kretz, Juliet Sutherland, Charles +Franks and the PG Distributed Proofreading Team + + + + + + +</pre> + +<p class="ctr"><a href="./images/title.png"><img src= +"./images/title_th.jpg" alt="" /></a></p> + +<h1>SCIENTIFIC AMERICAN SUPPLEMENT NO. 787</h1> + +<h2>NEW YORK, January 31, 1891</h2> + +<h4>Scientific American Supplement. Vol. XXXI., No. 787.</h4> + +<h4>Scientific American established 1845</h4> + +<h4>Scientific American Supplement, $5 a year.</h4> + +<h4>Scientific American and Supplement, $7 a year.</h4> + +<hr /> +<table summary="Contents" border="0" cellspacing="5"> +<tr> +<th colspan="2">TABLE OF CONTENTS.</th> +</tr> + +<tr> +<td valign="top">I.</td> +<td><a href="#i_1">BIOGRAPHY.—CHARLES GOODYEAR.—The +life and discoveries of the inventor of vulcanized India rubber, +with portrait.—1 illustration</a></td> +</tr> + +<tr> +<td valign="top">II.</td> +<td><a href="#ii_1">BIOLOGY.—Can we Separate Animals from +Plants?—By ANDREW WILSON.—A debated point well +discussed.—The bases on which distinctions must be +drawn</a></td> +</tr> + +<tr> +<td valign="top">III.</td> +<td><a href="#iii_1">ELECTRICITY.—A New Electric Ballistic +Target.—A target for investigations of the velocity of +projectiles, now in use at the United States Military Academy, West +Point, N. Y.—1 illustration.</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#iii_2">Electric Erygmascope.—An electric +lighting apparatus for examining earth strata in bore holes for +geologists' and prospectors' use.—1 illustration</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#iii_3">The Electro-Magnet.—By Prof. SILVANUS +THOMPSON.—Continuation of this exhaustive treatise, giving +further details on special points of construction.—1 +illustrations</a></td> +</tr> + +<tr> +<td valign="top">IV.</td> +<td><a href="#iv_1">ENTOMOLOGY.—Potash Salts.—The use +of potash salts as insecticides, with accounts of +experiments</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#iv_2">The Outlook for Applied Entomology.—By +Dr. C.V. RILEY, U.S. entomologist.—The conclusion of Prof. +Riley's lecture, treating of the branch of entomology with which +his name is so honorably associated</a></td> +</tr> + +<tr> +<td valign="top">V.</td> +<td><a href="#v_1">INSURANCE.—The Expense Margin in Life +Insurance.—Elaborate review of the necessary expenses of +conducting the insurance of lives, with tables and +calculations</a></td> +</tr> + +<tr> +<td valign="top">VI.</td> +<td><a href="#vi_1">MATHEMATICS.—The Trisection of Any +Angle.—By FREDERIC R. HONEY, Ph.B.—A very ingenious +demonstration of this problem, based on the properties of conjugate +hyperbolas</a></td> +</tr> + +<tr> +<td valign="top">VII.</td> +<td><a href="#vii_1">METEOROLOGY.—Note on the Mt. Blanc +Meteorological Station</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#vii_2">The Flood at Karlsbad.—Account of the +recent flood and of its destructive effects.—1 +illustration</a></td> +</tr> + +<tr> +<td valign="top">VIII.</td> +<td><a href="#viii_1">MECHANICAL ENGINEERING.—Station for +Testing Agricultural Machines.—A proposed establishment for +applying dynamometer tests to agricultural machines.—1 +illustration</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#viii_2">Steam Engine Valves.—By THOMAS +HAWLEY.—A review of modern slide valve practice, the lap, +cut-off, and other points.—6 illustrations</a></td> +</tr> + +<tr> +<td valign="top">IX.</td> +<td><a href="#ix_1">MISCELLANEOUS.—Science in the +Theater.—Curious examples of stage effect in fictitious +mesmerizing and hypnotizing.—4 illustrations</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#ix_2">Theatrical Water Plays.—Recent episodes +in real water plays at Hengler's Circus, London.—2 +illustrations</a></td> +</tr> + +<tr> +<td valign="top">X.</td> +<td><a href="#x_1">NAVAL ENGINEERING.—The French Ironclad War Ship +Colbert.—An armored wood and iron ship, with central +battery.—1 illustration</a></td> +</tr> + +<tr> +<td valign="top">XI.</td> +<td><a href="#xi_1">PHYSIOLOGY AND HYGIENE.—Newer Physiology +and Pathology.—By Prof. SAMUEL BELL. M.D.—An excellent +presentation of modern practice in the light of +bacteriology</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#xi_2">Test Card Hints.—How to test the eyes for +selecting eyeglasses and spectacles</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#xi_3">The Composition of Koch's Lymph.—What +Prof. Koch says it is and what it can do.—The cabled account +of the disclosure so long waited for</a></td> +</tr> + +<tr> +<td valign="top">XII.</td> +<td><a href="#xii_1">TECHNOLOGY.—Firing Points of Various +Explosives.—The leading explosives, with the temperature of +their exploding points tabulated</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#xii_2">The Recovery of Gold and Silver from Plating +and Gilding Solutions—A paper of interest to silver and gold +platers, as well as photographers</a></td> +</tr> + +<tr> +<td></td> +<td><a href="#xii_3">Water Softening and Purifying +Apparatus.—An apparatus for treatment of sewage, etc., +chemically and by deposition.—1 illustration</a></td> +</tr> +</table> + +<hr /> +<h2><a id="x_1" name="x_1"></a>THE FRENCH IRONCLAD WAR SHIP +COLBERT.</h2> + +<p class="ctr"><a href="./images/1-boat.png"><img src= +"./images/1-boat_th.jpg" alt= +"THE FRENCH IRONCLAD WAR SHIP COLBERT." title= +"IRONCLAD" /></a><br /> + THE FRENCH IRONCLAD WAR SHIP COLBERT.</p> + +<p>The central battery ironclad Colbert is one of the ten ships of +the French navy that constitute the group ranking next in +importance to the squadron of great turret ships, of which the +Formidable is the largest. The group consists of six types, as +follows:</p> + +<div class="note"> +<p>1. The Ocean type; three vessels; the Marengo, Ocean, and +Suffren.</p> + +<p>2. The Friedland type, of which no others are built.</p> + +<p>3. The Richelieu type, of which no others are built.</p> + +<p>4. The Colbert type, of which there are two; the Colbert and the +Trident.</p> + +<p>5. The Redoubtable type, of which no others are built.</p> + +<p>6. The Devastation type, of which no others are built.</p> +</div> + +<p>The Colbert was launched at Brest in 1875, and her sister ship, +the Trident, in 1876. Both are of iron and wood, and the following +are the principal dimensions of the Colbert, which apply very +closely to the Trident: She is 321 ft. 6 in. long, 59 ft. 6 in. +beam, and 29 ft. 6 in. draught aft. Her displacement is 8,457 tons, +her indicated horse power is 4,652, and her speed 14.4 knots. She +has coal carrying capacity for 700 tons, and her crew numbers 706. +The thickness of her armor belt is 8.66 in., that protecting the +central battery is 6.29 in. thick, which is also the thickness of +the transverse armored bulkheads, while the deck is 0.43 in. in +thickness. The armament of the Colbert consists of eight 10.63 in. +guns, two 9.45 in., six 5.51 in., two quick firing guns, and +fourteen revolving and machine guns.—<i>Engineering.</i></p> + +<hr /> +<p>A compound locomotive, built by the Rhode Island Locomotive +Works, has been tried on the Union Elevated Railroad, Brooklyn, +N.Y. The engine can be run either single or compound. The economy +in fuel was 37.7 per cent, and in water 23.8 per cent, over a +simple engine which was tested at the same time. The smoothness of +running and the stillness and comparative absence of cinders was +fully demonstrated.</p> + +<hr /> +<h2><a id="viii_2" name="viii_2"></a>STEAM ENGINE VALVES.<a id= +"FNanchor_1a" name="FNanchor_1a"></a><a href= +"#Footnote_1a"><sup>1</sup></a></h2> + +<h3>By THOMAS HAWLEY.</h3> + +<h3>RIDING CUT-OFF VALVES—PECULIARITIES AND MERITS OF THE +DIFFERENT STYLES.</h3> + +<p>In considering the slide valve in its simple form with or +without lap, we find there are certain limitations to its use as a +valve that would give the best results. The limitation of most +importance is that its construction will not allow of the proper +cut off to obtain all the benefits of expansion without hindering +the perfect action of the valve in other particulars. At this +economical cut off the opening of the steam port is very little and +very narrow, and although this is attempted to be overcome by +exceedingly wide ports, sixteen inches in width in many cases in +locomotive work, this great width adds largely to the unbalanced +area of the valve. The exhausting functions of the valve are +materially changed at the short cut off, and when much lap is added +to overcome this defect, there usually takes place a choking of the +exhaust port. You might inquire, why not make the port wider, but +this would increase the minimum amount of load on the valve, and +this must not be overlooked. Then the cut off is a fixed one, and +we can govern only by throttling the pressure we have raised in the +boiler or by using a cut off governor and the consequent wastes of +an enormous clearance space. You will observe, therefore, that the +plain slide valve engine gives the most general satisfaction at +about two-thirds cut off and a very low economic result. The best +of such engines will require forty-five to fifty pounds of steam +per horse power per hour, and to generate this, assuming an +evaporation of nine pounds of water to a pound of coal, would +require between five and six pounds of coal per horse power per +hour. And the only feature that the valve has specially to commend +it is its extreme simplicity and the very little mechanism required +to operate it.</p> + +<p>Yet this is of considerable importance, and in consideration of +some special features at its latest cut off, the attempt has been +many times made to take advantage of these features. For instance, +at 90° advance, the valve opens very rapidly indeed and fully +satisfies our requirements of a perfect valve. This is one good +point, and in this position also the exhaust and compression can be +regulated very closely and as desired without much lap, and as the +opening of the exhaust port comes with the eccentric at its most +rapid movement the release is very quick and as we would have it. +This is only possible at the most uneconomic position of the valve +as regards cut off.</p> + +<p>The aim of many engineers has been to take advantage of these +matters by using the valve with 90° angular advance of +eccentric ahead of crank, for the admission, release, and +compression of the steam, and provide another means of cutting off, +besides the one already referred to, viz., cutting off the supply +of steam to the chest, and overcome the objection in this one of +large clearance spaces. This is done by means of riding cut off +valves, often called expansion valves, of which, perhaps, the most +widely known types in this vicinity are the Kendall & Roberts +engine and the Buckeye. The former is used in the simplest form of +riding cut off, while the Buckeye has many peculiar features that +engineers, I find, are too prone to overlook in a casual +examination of the engine. In these uses of the slide valve, too, +means are suggested and carried out of practically balancing the +valve.</p> + +<p>The origin of the riding cut off is most generally attributed to +Gonzenbach. His arrangement had two steam chests, the lower one +provided with the ordinary slide valve of late cut off, and steam +was cut off from this steam chest by the expansion valve covering +the ports connecting with the upper steam chest. This had the old +disadvantage that all the steam in the lower chest expanded with +that in the cylinder, at a consequent considerable loss. This was +further improved by causing the riding cut off to be upon the top +of the main valve, instead of its chest, and resulted in a +considerable reduction of the clearance space.</p> + +<p>This is the simplest form, and is shown in Fig. 1. The steam is +supplied by a passage through the main valve which operates exactly +as an ordinary slide valve would. That is, the inside edges of the +steam passage are the same as the ordinary valve, the additional +piece on each end, if I may so term it, being merely to provide a +passage for the steam which can be closed, instead of allowing the +steam to pass the edge. The eccentric of the main valve is fastened +to the shaft to give the proper amount of lead, and the desired +release and compression, and the expansion valve is operated by a +separate eccentric fastened in line with or 180° ahead of the +crank. When the piston, therefore, commences to move from the crank +end to open the port, D, the expansion valve is forced by its +eccentric in the opposite direction, and is closing the steam port +and would have closed it before the piston reached quarter stroke, +thus allowing the steam then in the cylinder to do work by +expansion. The eccentric operating this expansion valve may be set +to close this steam port at any point in the stroke that is +desired, the closing occurring when the expansion valve has covered +the steam port. Continuing the movements of the valves, the two +would move together until one or the other reached its dead center, +when the movements would be in opposite directions.</p> + +<p class="ctr"><img src="./images/2-fig1.png" alt="FIG. 1." title= +"FIG. 1" /><br /> + FIG. 1</p> + +<p>There are three ways of effecting the cut off in such engines, +the main valve meanwhile being undisturbed, its eccentric fastened +securely so as not to disturb the points of lead, release, and +compression. All that is required is to cause the edge of the +expansion valve to cover the steam port earlier in the stroke, and +this can be done, first, by increasing the angular advance of the +cut off eccentric; second, by adding lap to the cut off valve; and +third by changing the throw of the eccentric. In all these +instances the riding valve is caused to reach the edge of the steam +port earlier in the stroke. We will take first, as the simplest, +those methods by which the lap of the cut off valve is +increased.</p> + +<p>It will be noted that there is but one edge of this valve that +is required to do any work, and that is to close the valve. The +eccentrics are so placed that the passage in the main valve is +opened long before the main valve itself is ready to admit steam to +the cylinder, so that only the outer edges are the ones to be +considered, and it will be readily seen that the two valves +traveling in opposite directions, any lap added to the working edge +of the cut off valve will cause it to reach the edge and therefore +close the port earlier than it would if there was less lap. And we +might carry it to the extreme that we could add lap enough that the +steam passage would not be opened at all.</p> + +<p>In Fig. 2 is shown the method by which this is accomplished, in +what is called Meyer's valve, and such as is used in the Kendall +& Roberts engine. We have only one point to look after, the cut +off, so we can add all the lap we wish without disturbing anything +else. In this engine the lap is changed by hand by means of a +little hand wheel on a stem that extends out of the rear of the +steam chest. The valve is in two sections, and when it is desired +to cut off earlier, the hand wheel is turned in such a direction +that the right and left hand screws controlling the cut off valve +move one valve portion back and the other forward, which would, if +they were one valve and they should be so considered, have the +effect of lengthening them, or adding lap to them. The result would +be that the riding valve would reach the edge of the steam port +earlier in the stroke, bringing about an earlier cut off. If the +cut off is desired to be later, the hand wheel is so turned that +the right and left hand screws will bring the valve sections nearer +together, thus practically taking off lap. Now this may be done by +hand or it may be done by the action of a governor.</p> + +<p class="ctr"><img src="./images/2-fig2.png" alt="FIG. 2." title= +"FIG. 2" /><br /> + FIG. 2</p> + +<p>In the latter case the governor at each change of load turns the +right and left hand screws to add or take away lap, as the load +demands an earlier or later cut off; in other cases the governor +moves a rack in mesh with a gear by which the valve sections are +brought closer together or are separated. The difficulty with the +case where the hand wheel is turned by hand is that the cut off is +fixed where you leave it, and governing can only be at the +throttle. For this reason anywhere near full boiler pressure would +not be obtained in the cylinder of the engine. If the load was a +constant one, and the cut off could be fixed at about one-third, +causing the throttle to open its widest, very good results would be +obtained, but there is no margin left for governing.</p> + +<p>If the load should increase at such a time the governor could +not control it under these conditions, and it would lead to a +decrease in speed unless the lap was again changed to give a later +cut off. On this account the general practice soon becomes to leave +the cut off at the later point and give range to the throttle, and +we come back once more to the plain slide valve cutting off at half +stroke, and the only gain there is, is in a quick port opening and +quick cut off. But these matters are more than offset by the wire +drawing between the steam pipe and chest, through the throttle, and +the fact that there is added to the friction of the engine the +friction of this additional slide valve and a considerable +liability to have a leaky valve.</p> + +<p>In the case where the governor changes the position of the cut +off valve a greater decree of economy would result. In this engine, +of which the Lambertville engine is a type, the main valve is a +long D slide, with multiple ports at the ends through which the +steam enters the cylinders. It is operated from an eccentric on the +crank shaft in the usual manner. The cut off valve is also operated +from the motion on an eccentric fixed upon the crank shaft. The rod +or stem of the cut off valve passes through the main valve rod and +slide. Upon the outer end of the cut off valve rod are tappets +fastened to engage with tappets on the eccentric valve rod. +Connection between the cut off eccentric, therefore, and the cut +off valve is only by means of the engagement of these tappets. The +eccentric rod is fastened to a rocker arm having motion swinging +about a pin or bearing in the governor slide, which may be raised +or lowered by a cam operated by the governor. The cut off slide is +of cylindrical shape and incloses a spring and dash pot with disks +attached by means of which the valve is closed. The motion for +operating the valves is relatively in the same direction, the cut +off eccentric having the greatest throw and greater angular advance +to cause it to open earlier and quickly before the main valve is +ready to admit steam. The cut off eccentric rod swinging the rocker +arm, the tappets thereon engage with those upon the cut off valve +rod and open the passages to the main valve, and in their movement +compress the spring in the main valve. According as the speed of +the engine, the rock arm will be raised or lowered so that the +tappets upon the eccentric rod may keep in engagement a shorter or +longer time before they disengage, thus allowing the spring that +has been compressed by the movement of the cut off valve to close +that valve quickly and the supply of steam to the engine, the cut +off valve traveling with the main valve for the balance of the +stroke. This device will give a remarkably quick opening and a +quick cut off, but in view of the fact that the governor has so +much to do, its delicacy is impaired and a quick response to the +demands of the load changing not so likely to occur. The cut off +cannot be as quick as in some other engines, because the valves are +moving in opposite directions, and while this fact would help, so +far as shortening the distance to be traveled before cut off, the +resistance of the valves to travel in opposite directions, or +rather the tendency of the valve to travel with the main valve, +hinders its rapid action.</p> + +<p class="ctr"><img src="./images/2-fig3.png" alt="FIG. 3." title= +"FIG. 3" /><br /> + FIG. 3</p> + +<p>This is one great objection to the rack and gear operated by the +governor, that two flat valves riding upon each other and sliding +in opposite directions at times require a considerable amount of +force to move them, and as only a slight change in load is required +by the load, the governor cannot handle the work as delicately as +it should. It is too much for the governor to do well. To overcome +this difficulty the Ryder cut-off, shown in Fig. 3, was made by the +Delamater people, of New York. The main slide valve is hollowed in +the back and the ports cut diagonally across the valve to form +almost a letter V. The expansion valve is V-shaped, and circular to +fit its circular-seat. The valve rod of the expansion valve has a +sector upon it and operated by a gear upon the governor stem, which +rotates the valve rod, and the edge of the valve rod is brought +farther over the steam port, thus practically adding lap to the +valve. Little movement is found necessary to make the ordinary +change in cut-off, and it is found to be much easier to move the +riding valve across the valve than in a direction directly +opposite. It would require considerable force to move the upper +valve by the governor faster than the lower, or in a direction +opposite to that in which it is moving, but very little force +applied sideways at the same time it is moving forward will give it +a sideways motion. In this device the governor has only to exert +this side pressure and therefore has less to do than if it were +called upon to move the upper valve directly against the movement +of the lower.</p> + +<p>Something similar is the valve of the Woodbury engine, of +Rochester, N.Y. The cut-off valve is cylindrical, covering diagonal +ports directly opposite, and is caused to be rotated by the action +of the governor that operates a rack in mesh with a segment. Very +little movement will effect a considerable change in the lappage of +the valve, the valve turning about one-quarter a revolution for the +extremes of cut off. The cut off valve rod works through a bracket +and its end terminates in a ball in a socket on the end of the +eccentric rod. In this case the governor has not as much to do as +in other instances.</p> + +<p class="ctr"><img src="./images/2-fig4.png" alt="FIG. 4." title= +"FIG. 4" /><br /> + FIG. 4</p> + +<p>Still another method of effecting this change in cut off, but +hardly by increasing the lap of the valve, is shown in the next +drawing, Fig. 4. The cut off valve is held upon the main valve by +the pressure of steam upon its back and rides with it until it +comes in contact with the cut off wedge-shaped blocks, when its +motion is arrested, and the main valve continuing its movement the +steam port is closed by the main valve passing beneath the cut off +valve. Thus the main valve travels and carries the cut off valve +upon its back again until the cut off valve strikes the wedge on +the other end and the cut off is effected. The relative positions +of the blocks are determined by the governor, that will raise or +lower them so that the cut off valve will engage with them earlier +or later as desired. This device was designed specially as an +inexpensive method of changing the common slide valve into an +automatic cut off. The cut off would not be as quick as in other +cases we have cited, depending here upon the movement of the lower +valve alone, and that, too, is in its slowest movement; whereas in +the other cases, the edges approaching each other, by the differing +movement of the valves the cut off is very rapid, provided the +distance to travel is not long. In this device considerable noise +must result by the cut off valve striking the cut off blocks, and a +considerable amount of leakage is likely to occur past this +valve.</p> + +<p>But there is one great objection in the valve gears thus far +cited, that the travel of the expansion valve upon the main valve +is variable. I have in mind the case of a Kendall & Roberts +engine, which had been run for a long time at no better economy +than would be obtained from a plain slide valve engine, and when it +was attempted to get an earlier cut off by separating the two cut +off valves, they had worn so much in their old place on the valve +that shoulders were found sufficient to cause a disagreeable noise +and a leaky valve. This is very apt to occur, not only where the +valve is run for a long time on one seat, but in cases of variation +of the travel of the expansion valve. The result is that a change +will bring about a leaky valve, something that every engineer +abhors.</p> + +<p>The construction of the Buckeye engine, which is also of this +type, is such that the travel of the valve on the back of the main +valve is always the same, no matter what the cut off may be. Then +this engine makes use of our second proposition as a means of +effecting the cut off, viz., by advancing the eccentric. You will +readily observe that anything that will cause the cut off valve to +reach a certain point earlier in the stroke will bring about an +earlier cut off as it hastens everything all around. This is the +plan pursued in the Buckeye, in which the governor, of the shaft +type, turns the eccentric forward or back according as the load +demands. Then, in addition, the valve is balanced partially, the +attempt not being made to produce an absolutely balanced valve, on +the ground that there should be friction enough to keep the +surfaces bright and to prevent leakage. The most perfect valve +will, of course, be entirely balanced under all conditions of +pressure so as to move with perfect ease. With the riding cut off +valve in connection with the plain slide valve, this is not +accomplished, and it does not matter whether it is partially +unbalanced to prevent leakage or not, the fact that it is not +entirely balanced prevents it reaching the ideal valve.</p> + +<p class="ctr"><img src="./images/2-fig5.png" alt="FIG. 5." title= +"FIG. 5" /><br /> + FIG. 5</p> + +<p>This valve, Fig. 5, differs from the others also in this +particular, that the exhaust takes place at the end of the valve +instead of under the arch. Two eccentrics are used, the one for the +main valve being fastened to the shaft and the other riding loosely +upon it and connected to the fly wheel governor, by which it may be +turned forward or back as the load requires. The three points of +lead, or admission and exhaust and compression, are fixed and +independent of the changes and cut off. The motion of the main +eccentric is given to a rocker arm, the pivot of which is at the +bottom, and from the upper end the valve rod transfers the motion +to the valve without reversing the motion, as is done sometimes in +the slide valve to overcome the effects of the angularity of the +connecting rod. The action of the rocker arm, therefore, so far as +the main valve in the Buckeye is concerned, is no different than +that which would occur if no rocker arm intervened. The motion of +the cut off eccentric, through its eccentric rod, is given to a +rocker rocking in a bearing in the center of the main rocker arm +(see Fig. 6). The motion of this eccentric is reversed, so far as +the cut off valve is concerned, and when the cut off eccentric is +moving forward, the cut off valve is being pushed back. The main +valve rod is hollow, and the cut off valve rod passes through +it.</p> + +<p class="ctr"><img src="./images/2-fig6.png" alt="FIG. 6." title= +"FIG. 6" /><br /> + FIG. 6</p> + +<p>The cut off eccentric can be placed in any position to cause it +to cut off as desired, and by drawing the valve forward, by +increasing the angular advance of the eccentric, the cut off valve +is caused to reach and cover the steam passage in the main valve +earlier in the stroke. Instead of being ahead of the crank, the +main eccentric in this arrangement follows the crank, on account of +the exhaust and steam edges being exactly opposite from those in +the ordinary slide. What is the steam edge of the common slide is +in this the exhaust edge, and what is the exhaust edge in the +common valve is the steam edge in this one. The valve, therefore, +must be moved in the opposite direction from what is ordinarily the +case, the main eccentric being not 90 deg. behind the crank. It has +a rapid and full opening just the same, for it is at this point +behind the crank, or ahead of it, that the eccentric gives to the +valve its quickest movement, or between the eccentric dead centers. +The cut off eccentric is considerably ahead of the main eccentric, +and about even with the crank. If it was not for the reversal of +motion of the cut off valve through the rocker arm this eccentric +would be about in line with the crank, but on the other end. The +movement of the cut off valve, therefore, at the time of port +opening is very little, being about on its dead center, passing +which, it immediately commences to close.</p> + +<p>The object of the peculiar construction of the rocker arm, and +the pivot for the cut off rocker being placed thereon, is to +provide equal travel on the back of the main valve, no matter what +the cut off. I have already explained, in connection with the slide +valve, that advancing the eccentric does not change the movement of +the valve on its seat, but simply its relation to the movement of +the piston. You will see that this is unchanged as using the main +valve as a seat or any other seat. If the main valve was to remain +stationary, and only the cut off valve to be operated by its +eccentric, the movement of this cut off valve on a certain plane +would be the same for all positions of the eccentric.</p> + +<p>Moving the main slide does not affect the matter in any way, for +it moves at the same time the pivot of the cut off, and while the +cut off seat has assumed a different position with reference to the +engine, it is still as though stationary so far as the cut off +valve is concerned. This is the object of this peculiar +construction, and not, as some engineers suppose, simply to make an +odd way of doing things. And the object of it all is to give at all +cut offs the same amount of travel, so that there might be no +unequal wear to bring about a leak, to prevent which a perfect +balancing has been sacrificed.</p> + +<p>Referring to the valve and this engine as to how it will satisfy +our requirements of a perfect valve gear, we find that the first +requirement of a rapid and full opening is met, in that the opening +occurs when the main eccentric is moving very rapidly, yet not its +fastest, and while this opening will be very satisfactory, it is +not so rapid an opening as is obtained in some other forms of +valves and valve gears, but this could be overcome very readily by +increasing the lead a trifle, and in my experience with these +engines I find that the practice is very general by engineers and +by builders themselves to give them a considerable amount of lead. +As to the second requirement, the maintenance of initial pressure +until cut off, giving a straight steam line, cards from this engine +will not be found to show that the engine satisfies this +requirement, and for this reason, that the cut-off valve commences +to close the port immediately after the piston commences to move. +The cut off eccentric you will remember is set to move with the +crank or very nearly so, and the lighter the load, the greater will +this fact appear. For the lightest loads the governor places the +eccentric in advance of the crank, so that the cut off valve will +commence to close the port before steam is admitted by the main +valve to the engine. Now, the later the cut off, the less will this +wire drawing appear at first, and the shorter the cut off, the +amount of wire drawing increases sensibly. The operation of the +valve, therefore, in this particular, cannot be considered as +meeting our requirement that the port shall be held open full width +until ready to be closed. Many men claim for this engine that the +closing occurs when the cut off eccentric is moving its fastest. +This is a fact, and if we consider the point of cut off only to be +the point of absolute cut off, the cut off must be instantaneous, +for there is an instantaneous point where the cut off is final only +to be considered. The reasoning applied here would hold good also +to a less extent on the slide valve, but is not the point of +absolute cut off. We want to note how long it is from the time the +valve commences to close at all until finally closed, and, as I +have shown you, this is considerable in this engine.</p> + +<p>Referring to the point of cut off finally, it is determined upon +by a governor of the fly wheel type. The eccentric is loose about +the shaft, and arms projecting therefrom are connected by other +arms to the extremity of an arm upon which is mounted a weight, and +which is attached to the spokes of the fly wheel, or special +governor wheel in this case, and which is fastened to the crank +shaft. As the speed increases through throwing off a portion of the +load the governor weights fly out, and this movement is transferred +through the lever connections to the eccentric, causing it to be +turned ahead, and the manner hastening the movement of the cut off +valve on its seat and causing it to reach and cover the edge of the +steam port earlier in the stroke. This engine was the pioneer in +governors of this character, the advantage being, in addition to +its necessity for the work of turning the eccentric ahead or back, +that the liability of the engine to run away, as very often happens +from the breaking of the governor belt or a similar cause, was not +possible.</p> + +<p>The cut off valve has a travel considerably beyond the edge of +the steam passage after the valve is closed, and this has one +advantage, that the valve is less liable to leak, and to this must +be added the loss from the friction of this moving valve, and +moving too in opposition to the main valve. In our perfect valve, +as we outlined it, the valve does not move after the port is +closed. The exhausting functions of the valve are very good, giving +a quick opening and a full opening, because this opening occurs +when the eccentric is moving its fastest. The engine also possesses +a distinct advantage in having remarkably small clearance spaces. +The length of the steam passage is very small in comparison with +any form of engine, and having but two ports instead of four, as in +the Corliss and four valve type.</p> + +<p>In these there must be included in the clearance, that to the +exhaust port as well as the steam port, adding a considerable +amount where the piston comes close to the head. As the engines +leave the maker's hand the engines are provided with a considerable +amount of lap to give plenty of compression, but are, of course, +capable of having more added to increase compression, or some +planed off to decrease it.</p> + +<p>One of the peculiar things about this engine is the failure to +realize anywhere near boiler pressure, noticeable in every case +that has come under my notice. The considerable lead gives it for +an instant, but it soon falls away, indicating the steam chest +pressure only by a peak at the junction of the admission and steam +lines. This is probably due to the fact that the cut off valve +commences closing the steam passage so soon after steam is +admitted, and in this particular does not satisfy the requirements +of a perfect valve. There is this about the engine, that above all +others of this type there has come under my notice fewer engines of +this type with a maladjustment of valves from tampering by +incompetent engineers.</p> + +<a id="Footnote_1a" name="Footnote_1a"></a><a href= +"#FNanchor_1a">[1]</a> + +<div class="note">Lecture delivered at Wells Memorial Institute, +Boston, in the Lowell Free Course for Engineers. From report in the +<i>Boston Journal of Commerce</i>.</div> + +<hr /> +<h2><a id="xii_1" name="xii_1"></a>FIRING POINTS OF VARIOUS +EXPLOSIVES.</h2> + +<p>An apparatus, devised by Horsley, was used, which consisted of +an iron stand with a ring support holding a hemispherical iron +vessel, in which paraffin or tin was put. Above this was another +movable support, from which a thermometer was suspended and so +adjusted that its bulb was immersed in molten material in the iron +vessel. A thin copper cartridge case, 5/8 in. in diameter and +1-5/16 in. long, was suspended over the bath by means of a +triangle, so that the end of the case was 1 in. below the surface +of the liquid. On beginning the experiment the material in the bath +was heated to just above the melting point, the thermometer was +inserted in it, and a minute quantity of the explosive was placed +in the bottom of the cartridge case. The temperature marked by the +thermometer was noted as the <i>initial temperature</i>, the +cartridge case containing the explosive was inserted in the bath, +and the temperature quickly raised until the explosive flashed off +or exploded, when the temperature marked by the thermometer was +again noted as the <i>firing point</i>. The tables given show the +results of about six experiments with each explosive. The initial +temperatures range from 65° to 280° C. in some cases, but +as the firing points remained fairly constant, only the extremes of +the latter are quoted in the following table:</p> + +<div class="ctr"> +<table border="1" cellspacing="3" summary= +"EXPLOSIVE AND FIRING POINT"> +<colgroup span="2"> +<col align="left" /> +<col align="center" /></colgroup> + +<tr> +<th>Description of Explosive.</th> +<th>Firing Point in ° C.</th> +</tr> + +<tr> +<td>Compressed military gun-cotton.</td> +<td>186 - 201</td> +</tr> + +<tr> +<td>Air-dried military gun-cotton.</td> +<td>179 - 186</td> +</tr> + +<tr> +<td align="center">"</td> +<td>186 - 189</td> +</tr> + +<tr> +<td align="center">"</td> +<td>137 - 139</td> +</tr> + +<tr> +<td align="center">"</td> +<td>154 - 161</td> +</tr> + +<tr> +<td>Gun-cotton dried at 65° C.</td> +<td>136 - 141</td> +</tr> + +<tr> +<td>Air-dried collodion gun-cotton.</td> +<td>186 - 191</td> +</tr> + +<tr> +<td align="center">"</td> +<td>197 - 199</td> +</tr> + +<tr> +<td align="center">"</td> +<td>193 - 195</td> +</tr> + +<tr> +<td>Air-dried gun-cotton.</td> +<td>192 - 197</td> +</tr> + +<tr> +<td align="center">"</td> +<td>194 - 199</td> +</tr> + +<tr> +<td>Hydro-nitrocellulose.</td> +<td>201 - 213</td> +</tr> + +<tr> +<td>Nitroglycerin.</td> +<td>203 - 205</td> +</tr> + +<tr> +<td>Kieselghur dynamite. No. 1.</td> +<td>197 - 200</td> +</tr> + +<tr> +<td>Explosive gelatin.</td> +<td>203 - 209</td> +</tr> + +<tr> +<td>Explosive gelatin, camphorated.</td> +<td>174 - 182</td> +</tr> + +<tr> +<td>Mercury fulminate.</td> +<td>175 - 181</td> +</tr> + +<tr> +<td>Gunpowder.</td> +<td>278 - 287</td> +</tr> + +<tr> +<td>Hill's picric powder.</td> +<td>273 - 283</td> +</tr> + +<tr> +<td align="center">"</td> +<td>273 - 290</td> +</tr> + +<tr> +<td>Forcite, No. 1.</td> +<td>184 - 200</td> +</tr> + +<tr> +<td>Atlas powder, 75 per cent.</td> +<td>175 - 185</td> +</tr> + +<tr> +<td>Emmensite, No. 1.</td> +<td>167 - 184</td> +</tr> + +<tr> +<td>Emmensite, No. 2.</td> +<td>165 - 177</td> +</tr> + +<tr> +<td>Emmensite, No. 5.</td> +<td>205 - 217</td> +</tr> +</table> +</div> + +<p class="ctr"><i>—C.E. Munroe, J. Amer. Chem. Soc.</i></p> + +<hr /> +<h2><a id="viii_1" name="viii_1"></a>STATION FOR TESTING +AGRICULTURAL MACHINES.</h2> + +<p>The minister of agriculture has recently established a special +laboratory for testing agricultural <i>materiel</i>. This +establishment, which is as yet but little known, is destined to +render the greatest services to manufacturers and cultivators.</p> + +<p>In fact, agriculture now has recourse to physics and mechanics +as well as to chemistry. Now, although there were agricultural +laboratories whose mission it was to fix the choice of the +cultivator upon such or such a seed or fertilizer, there was no +official establishment designed to inform him as to the value of +machines, the models of which are often very numerous. +<i>Chemical</i> advice was to be had, but <i>mechanical</i> advice +was wanting. It is such a want that has just been supplied. Upon +the report presented by Mr. Tisserand, director of agriculture, a +ministerial decree of the 24th of January, 1888, ordered the +establishment of an experimental station. Mr. Ringelmann, professor +of rural engineering at the school of Grignon, was put in charge of +the installation of it, and was appointed its director. He +immediately began to look around for a site, and on the 17th of +December, 1888, the Municipal Council of Paris, taking into +consideration the value of such an establishment to the city's +industries, decided that a plot of ground of an area of 3,309 +square meters, situated on Jenner Street, should be put at the +disposal of the minister of agriculture for fifteen years for the +establishment thereon of a trial station. This land, bordering on a +very wide street and easy of access, opposite the municipal +buildings, offers, through its area, its situation, and its +neigborhood, indisputable advantages. A fence 70 meters in extent +surrounds the station. An iron gate opens upon a paved path that +ends at the station.</p> + +<p>The year 1889 was devoted to the installation, and the station +is now in full operation. The tests that can be made here are many, +and concern all kinds of apparatus, even those connected with the +electric lighting that the agriculturist may employ to facilitate +his exploitation. However, the tests that are oftenest made are (1) +of rotary apparatus, such as mills, thrashing machines, etc.; (2) +of traction machines, such as wagons, carts, plows, etc.; and (3) +of lifting apparatus. It is possible, also, to make experiments on +the resistance of materials.</p> + +<p>The experimental hall contains a 7 horse power gas motor, +dynamometers with automatic registering apparatus, counters, +balances, etc. A small machine shop contains a lathe, a forge, a +drilling machine, etc. The main shaft is 12 meters in length and is +7 centimeters in diameter. It is supported at a distance of one +meter from the floor by four pillow blocks, and is formed of three +sections united by movable coupling boxes. Out of these 12 meters, +9 are in the hall and 3 extend beyond the hall to an annex, 14 +meters in length and 4 in width, in which tests are made of +machines whose operation creates dust. When the machines to be +tested require more than the power of seven horses that the motor +gives, the persons interested furnish a movable engine, which, +placed under the annex, actuates the driving shaft. Alongside of +the main building there is a ring for experimenting upon machines +actuated by a horse whim. There will soon be erected in the center +of the grounds an 18 meter tower for experiments on pumps. +Platforms spaced 5 meters apart, a crane at the top, and some +gauging apparatus will complete this hydraulic installation.</p> + +<p>The equipment of the hall is very complete, and is fitted for +all kinds of experiments.</p> + +<p class="ctr"><a href="./images/3-station.png"><img src= +"./images/3-station_th.jpg" alt= +"STATION FOR TESTING AGRICULTURAL MACHINES" title= +"TESTING STATION" /></a> STATION FOR TESTING AGRICULTURAL +MACHINES—DYNAMOMETER FOR TESTING ROTARY MACHINES.</p> + +<p>The tests of rotary machines are made by means of a dynamometer +(see figure). Two fast pulleys and one loose pulley are interposed +between the machine to be tested and the motor. The pulley +connected with the motor carries along the one connected with the +machine, through the intermedium of spring plates, whose strength +varies with the nature of the apparatus to be tested. The greater +or less elongation of these plates gives the tangential stress +exerted by the driving pulley to carry along the pulley that +actuates the machine to be tested. This elongation is registered by +means of a pencil connected with the spring plates, and which draws +a diagram upon a sheet of paper. At the same time, a special +totalizer gives the stress in kilogrammeters. Besides, the pulley +shaft actuates a revolution counter, and a clock measures the time +employed in the experiment. In order to obtain a simultaneous +starting and stopping point for all these apparatus, they are +connected electrically, and, through the maneuver of a commutator, +are all controlled at once. The electric current is furnished by +two series of bichromate batteries.</p> + +<p>The tests of traction machines are effected by means of a +three-wheeled vehicle carrying a dynamometer. The front wheel is +capable of turning freely in the horizontal plane, and the +dynamometer is mounted upon a frame provided with a screw that +permits of regulating its position according to the slope of the +ground. The method of suspension of the dynamometer allows it to +take automatically the inclination of the line of traction without +any torsion of the plates. There are two models of this vehicle, +one designed to be drawn by a man, and the other by a horse.</p> + +<p>The station is provided, in addition, with registering pressure +gauges, a large double dynamometric indicator, a counter of +electricity, balances of precision, etc.</p> + +<p>An apparatus designed for measuring the rendering of presses is +now in course of construction.</p> + +<p>Although the station has been in operation only from the 1st of +January, twenty-five machines have already been presented to be +tested.—<i>Extract from Le Genie Civil</i>.</p> + +<hr /> +<h2><a id="xii_3" name="xii_3"></a>WATER SOFTENING AND PURIFYING +APPARATUS.</h2> + +<p>We have recently had brought under our notice a system of water +and sewage purification which appears to possess several +substantial advantages. Chief among these are simplicity in +construction and operation, economy in first cost and working and +efficiency in action. This system is the invention of Messrs. Slack +& Brownlow, of Canning Works, Upper Medlock Street, Manchester, +and the apparatus adopted in carrying it out is here illustrated. +It consists of an iron cylindrical tank having inside a series of +plates arranged in a spiral direction around a fixed center, and +sloping downward at a considerable angle outward. The water to be +purified and softened flows through the large inlet tube to the +bottom, mixing on its way with the necessary chemicals, and +entering the apparatus at the bottom, rises to the top, passing +spirally round the whole circumference, and depositing on the +plates all solids and impurities.</p> + +<p>All that is needed in the way of attention, even when dealing +with sewage, or the most polluted waters, is stated to be the +mixing in the small tanks the necessary chemical reagents, at the +commencement of the working day; and at the close of the day the +opening of the mud cocks shown in our engraving, to remove the +collected deposit upon the plates. For the past six months this +system has been in operation at a dye works in Manchester, +successfully purifying and softening the foul waters of the river +Medlock. It is stated that 84,000 gallons per day can be easily +purified by an apparatus 7 feet in diameter. The chemicals used are +chiefly lime, soda, and alumina, and the cost of treatment is +stated to vary from a farthing to twopence per 1,000 gallons, +according to the degree of impurity of the water or sewage +treated.</p> + +<p>The results of working at Manchester show that all the visible +filth is removed from the Medlock's inky waters, besides which the +hardness of the water is reduced to about 6° from a normal +condition of about 30°. The effluent is fit for all the varied +uses of a dye works, and is stated to be perfectly capable of +sustaining fish life. With results such as these the system should +have a promising future before it in respect of sewage treatment, +as well as the purification and softening of water generally for +industrial and manufacturing purposes.—<i>Iron.</i></p> + +<p class="ctr"><a href="./images/4-water.png"><img src= +"./images/4-water_th.jpg" alt= +"WATER SOFTENING AND PURIFYING APPARATUS" title= +"WATER SOFTENER" /></a><br clear="all" /> + WATER SOFTENING AND PURIFYING APPARATUS.</p> + +<hr /> +<h2><a id="vi_1" name="vi_1"></a>THE TRISECTION OF ANY ANGLE.</h2> + +<h3>By FREDERIC R. HONEY, Ph.B., Yale University.</h3> + +<p>The following analysis shows that with the aid of an hyperbola +any arc, and therefore any angle, may be trisected.</p> + +<p>If the reader should not care to follow the analytical work, the +construction is described in the last paragraph—referring to +Fig. II.</p> + +<p>Let <i>a b c d</i> (Fig. I.) be the arc subtending a given +angle. Draw the chord <i>a d</i> and bisect it at <i>o</i>. Through +<i>o</i> draw <i>e f</i> perpendicular to <i>a d</i>.</p> + +<p class="ctr"><img src="./images/4-fig1.png" alt="FIG 1." title= +"" /></p> + +<p>We wish to find the locus of a point <i>c</i> whose distance +from a given straight line <i>e f</i> is one-half the distance from +a given point <i>d</i>.</p> + +<p>In order to write the equation of this curve, refer it to the +co-ordinate axes <i>a d</i> (axis of X) and <i>e f</i> (axis of Y), +intersecting at the origin <i>o</i>.</p> + +<div class="ctr"> +<p>Let g c = x</p> + +<p>Therefore, from the definition c d = 2x</p> + +<p>Let o d = D</p> + +<p>[Hence] h d = D-x</p> + +<p>Let c h = y</p> + +<p>[Hence] (2x)² = y² + (D-x)²</p> + +<p>or 4x² = y² + D²-2Dx + x²</p> + +<p>[Hence] y²-3x² + D²-2Dx = o [I.]</p> +</div> + +<p>This is the equation of an hyperbola whose center is on the axis +of abscisses. In order to determine the position of the center, +eliminate the x term, and find the distance from the origin o to a +new origin o'.</p> + +<div class="ctr"> +<p>Let E = distance from o to o'</p> + +<p>[Hence] x = x' + E</p> +</div> + +<p>Substituting this value of x in equation I.</p> + +<div class="ctr"> +<p>y²-3(x' + E)² + D²-2D(x' + E) = o</p> + +<p>or y²-3x²-6Ex'-3E² + D²-2Dx'-2DE = o +[II.]</p> +</div> + +<p>In this equation the <i>x'</i> terms should disappear.</p> + +<div class="ctr"> +<p>[Hence] -6Ex' - 2Dx' = o</p> + +<p>[Hence] -E = - D/3</p> +</div> + +<p>That is, the distance from the origin <i>o</i> to the new origin +or the center of the hyperbola <i>o'</i> is equal to one-third of +the distance from <i>o</i> to <i>d</i>; and the minus sign +indicates that the measurement should be laid off to the left of +the origin <i>o</i>. Substituting this value of E in equation II., +and omitting accents—</p> + +<p>We have</p> + +<div class="ctr"> +<p>y² - 3x² + 2Dx - D²/3 + D² - 2Dx + +2D²/3 = o</p> + +<p>[Hence] y² - 3x² = - 4D²/3</p> +</div> + +<p>This is the equation of an hyperbola referred to its center +<i>o'</i> as the origin of co-ordinates. To write it in the +ordinary form, that is in terms of the transverse and conjugate +axes, multiply each term by C, i.e.,</p> + +<div class="ctr"> +<p>Let √<span style="text-decoration: overline;">C</span> = +semi-transverse axis.</p> + +<p>Thus Cy² - 3Cx² = - 4CD² / 3. [III.]</p> +</div> + +<p>When in this form the product of the coefficients of the +<i>x²</i> and <i>y²</i> terms should be equal to the +remaining term.</p> + +<p>That is</p> + +<div class="ctr"> +<p>3C² = - 4CD² / 3.</p> + +<p>[Hence] C = 4D² / 9.</p> +</div> + +<p>And equation III. becomes:</p> + +<p class="ctr">(4D² / 9) y² - (4D² / 3) x² = +16D<sup>4</sup> / 27</p> + +<p class="ctr">The semi-transverse axis = √<span style= +"text-decoration: overline;">4D² /9</span> = 2D / 3</p> + +<p class="ctr">The semi-conjugate axis = √<span style= +"text-decoration: overline;">4D² / 3</span> = 2D / +√<span style="text-decoration: overline;">3</span></p> + +<p>Since the distance from the center of the curve to either focus +is equal to the square root of the sum of the squares of the +semi-axes, the distance from <i>o</i>' to either focus</p> + +<p class="ctr">= √<span style= +"text-decoration: overline;">4D²/9 + 4D²/ 3</span> = 4D / +3</p> + +<p class="ctr"><img src="./images/4-fig2.png" alt="FIG. 2." title= +"" /></p> + +<p>We can therefore make the following construction (Fig. II.) Draw +<i>a d</i> the chord of the arc <i>a c d</i>. Trisect <i>a d</i> at +<i>o'</i> and <i>k</i>. Produce <i>d a</i> to <i>l</i>, making <i>a +l</i> = <i>a o'</i> = <i>o' k</i> = <i>k d</i>. With <i>a k</i> as +a transverse axis, and <i>l</i> and <i>d</i> as foci, construct the +branch of the hyperbola <i>k c c' c"</i>, which will intersect all +arcs having the common chord <i>a d</i> at <i>c, c', c"</i>, etc., +making the arcs <i>c d</i>, <i>c' d</i>, <i>c" d</i>, etc., +respectively, equal to one-third of the arcs <i>a c d</i>, <i>a c' +d</i>, <i>a c" d</i>, etc.</p> + +<hr /> +<h2><a id="xi_2" name="xi_2"></a>TEST CARD HINTS.</h2> + +<h3>By Dr. F. OGDEN STOUT.</h3> + +<p>I know it is the custom with a great many if not the majority of +opticians to fit a customer without knowing whether he has +presbyopia, hypermetropia, or any of the other errors of +refraction. Their method is first to try a convex, and if this does +not improve, a concave, etc., until the proper one is found. This, +of course, amounts to the same thing if the right glass is found. +But in practice it will be found both time saving and more +satisfactory to first decide with what error you have to deal. It +is very simple, and, where you have no other means of diagnosing +(such as the ophthalmoscope), it does away with the necessity of +trying so many lenses before the proper one is found. You should +have a distance test card placed at a distance of twenty feet from +the person you are examining, and in a good light.</p> + +<p>A distance test card consists of letters of various sizes which +it has been found can be seen at certain distances by people with +good vision. Thus the largest letter is marked with a cc, meaning +that this should be seen at two hundred feet, and another line, XX, +at twenty feet, which is the proper distance for testing vision for +distance, for the reason that a normal eye is at rest when looking +at any object twenty feet from it or beyond, and the rays coming +from it are parallel and come to a focus on the retina. You must +also have a near vision test card with lines that should be seen by +a normal eye from ten to seventy-two inches, and a card of +radiating lines for astigmatism. With this preparation you are +ready to proceed. To illustrate, the first customer comes and tells +you that up to six months ago he had very good vision, but he finds +now that, especially at night, he has trouble in reading or +writing, and that he finds he can see better a little farther away. +His head aches and eyes smart. You will of course say that this is +a very simple case. It must be old sight (presbyopia). Probably it +is if he is old enough (45), but you must prove this for yourself, +without asking his age, which is embarrassing in the case of a +lady. If you direct him to the distance card twenty feet away, and +find that he can see every one down to and including the one marked +XX, his vision is up to the standard for distance, and you know +that he can have no astigmatism worth correcting, nor any near +sight, as both of these affect vision for distance, but he may have +far sight or old sight or both combined. You must find which it +is.</p> + +<p>If, while he is still looking at the twenty-foot line, you place +in front of the eyes a weak convex and he tells you he sees just as +well with as without, it proves the existence of far-sight or +hypermetropia, and the strongest convex that still leaves vision as +good for distance as without any, corrects the manifest. But if the +weak convex blurs it, it shows that there is some defect in +focusing, if the near vision is below normal. You therefore know +that you have a case of old sight or presbyopia, requiring the +weakest convex to correct it, that will enable your customer to see +the finest line on the near card at the required distance.</p> + +<p>The next customer that comes to be fitted with glasses can only +see the line marked XL on the distance card at 20 feet or about +one-half of what he should see, which leads you to think that there +is no far sight, for vision for distance is good except in very +high degrees of this error. Nor can there be old-sight, for vision +for distance is good in old-sight until after the fifty-fifth year, +but it can be near sight (myopia) or astigmatism, or both. We next +try the near card and find that even the finest line can be seen +clearly if held sufficiently close to the eyes. We now know that +this is a case of near sight, and we must fit them with glasses for +distance. The weakest concave that will enable him to see the line +that should be seen on the distance card at 20 feet is the proper +one to give him for use.—<i>The Optician.</i></p> + +<hr /> +<h2><a id="i_1" name="i_1"></a>CHARLES GOODYEAR.</h2> + +<p>CHARLES GOODYEAR was born in New Haven, December 29, 1800. He +was the son of Amasa Goodyear, and the eldest among six children. +His father was quite proud of being a descendant of Stephen +Goodyear, one of the founders of the colony of New Haven in +1638.</p> + +<p>Amasa Goodyear owned a little farm on the neck of land in New +Haven which is now known as Oyster Point, and it was here that +Charles spent the earliest years of his life. When, however, he was +quite young, his father secured an interest in a patent for the +manufacture of ivory buttons, and looking for a convenient location +for a small mill, settled at Naugatuck, Conn., where he made use of +the valuable water power that is there. Aside from his +manufacturing, the elder Goodyear ran a farm, and between the two +lines of industry kept young Charles pretty busy.</p> + +<p>In 1816, Charles left his home and went to Philadelphia to learn +the hardware business. He worked at this very industriously until +he was twenty-one years old, and then, returning to Connecticut, +entered into partnership with his father at the old stand in +Naugatuck, where they manufactured not only ivory and metal +buttons, but a variety of agricultural implements, which were just +beginning to be appreciated by the farmers. In August of 1824 he +was united in marriage with Clarissa Beecher, a woman of remarkable +strength of character and kindness of disposition, and one who in +after years was of the greatest assistance to the impulsive +inventor. Two years later he removed again to Philadelphia, and +there opened a hardware store. His specialties were the valuable +agricultural implements that his firm had been manufacturing, and +after the first distrust of home made goods had worn away—for +all agricultural implements were imported from England at that +time—he found himself established at the head of a successful +business.</p> + +<p>This continued to increase until it seemed but a question of a +few years until he would be a very wealthy man. Between 1829 and +1830 he suddenly broke down in health, being troubled with +dyspepsia. At the same time came the failure of a number of +business houses that seriously embarrassed his firm. They struggled +on, however, for some time, but were finally obliged to fail. The +ten years that followed this were full of the bitterest struggles +and trials to Goodyear. Under the law that then existed he was +imprisoned time after time for debts, even while he was trying to +perfect inventions that should pay off his indebtedness.</p> + +<p>Between the years 1831 and 1832 he began to hear about gum +elastic and very carefully examined every article that appeared in +the newspapers relative to this new material. The Roxbury Rubber +Company, of Boston, had been for some time experimenting with the +gum, and believing that they had found means for manufacturing +goods from it, had a large plant and were sending their goods all +over the country. It was some of their goods that first attracted +his attention. Soon after this Goodyear visited New York, and went +at once to the store of the Roxbury Rubber Company. While there, he +examined with considerable care some of their life preservers, and +it struck him that the tube used for inflation was not very +perfect. He, therefore, on his return to Philadelphia, made some +tubes and brought them down to New York and showed them to the +manager of the Roxbury Rubber Company.</p> + +<p>This gentlemen was so pleased with the ingenuity that Goodyear +had shown in manufacturing these tubes, that he talked very freely +with him and confessed to him that the business was on the verge of +ruin, that the goods had to be tested for a year before they could +tell whether they were perfect or not, and to their surprise, +thousands of dollars worth of goods that they had supposed were all +right were coming back to them, the gum having rotted and made them +so offensive that it was necessary to bury them in the ground to +get them out of the way.</p> + +<p>Goodyear at once made up his mind to experiment on this gum and +see if he could not overcome its stickiness.</p> + +<p>He, therefore, returned to Philadelphia, and, as usual, met a +creditor, who had him arrested and thrown into prison. While there, +he tried his first experiments with India rubber. The gum was very +cheap then, and by heating it and working it in his hands, he +managed to incorporate in it a certain amount of magnesia which +produced a beautiful white compound and appeared to take away the +stickiness.</p> + +<p>He therefore thought he had discovered the secret, and through +the kindness of friends was put in the way of further perfecting +his invention at a little place in New Haven. The first thing that +he made here was shoes, and he used his own house for grinding +room, calender room, and vulcanizing department, and his wife and +children helped to make up the goods. His compound at this time was +India rubber, lampblack, and magnesia, the whole dissolved in +turpentine and spread upon the flannel cloth which served as the +lining for the shoes. It was not long, however, before he +discovered that the gum, even treated this way, became sticky, and +then those who had supplied the money for the furtherance of these +experiments, completely discouraged, made up their minds that they +could go no further, and so told the inventor.</p> + +<p class="ctr"><a href="./images/5-goodyear.png"><img src= +"./images/5-goodyear_th.jpg" alt="CHARLES GOODYEAR." title= +"GOODYEAR" /></a><br clear="all" /> + CHARLES GOODYEAR.</p> + +<p>He, however, had no mind to stop here in his experiments, but, +selling his furniture and placing his family in a quiet boarding +place, he went to New York, and there, in an attic, helped by a +friendly druggist, continued his experiments. His next step in this +line was to compound the rubber with magnesia and then boil it in +quicklime and water. This appeared to really solve the problem, and +he made some beautiful goods. At once it was noised abroad that +India rubber had been so treated that it lost its stickiness, and +he received medals and testimonials and seemed on the high road to +success, till one day he noticed that a drop of weak acid, falling +on the cloth, neutralized the alkali, and immediately the rubber +was soft again. To see this, with his knowledge of what rubber +should do, proved to him at once that his process was not a +successful one. He therefore continued experimenting, and after +preparing his mixtures in his attic in New York, would walk three +miles to the mill of a Mr. Pike, at Greenwich village, and there +try various experiments.</p> + +<p>In the line of these, he discovered that rubber, dipped in +nitric acid, formed a surface cure, and he made a great many goods +with this acid cure which were spoken of, and which even received a +letter of commendation from Andrew Jackson.</p> + +<p>The constant and varied experiments that Goodyear went through +with affected his health more or less, and at one time he came very +near being suffocated by gas generated in his laboratory. That he +did not die then everybody knows, but he was thrown then into a +fever by the accident and came very near losing his life.</p> + +<p>It was there that he formed an acquaintance with Dr. Bradshaw, +who was very much pleased with the samples of rubber goods that he +saw in Goodyear's room, and when the doctor went to Europe he took +them with him, where they attracted a great deal of attention, but +beyond that nothing was done about them. Now that he appeared to +have success, he found no difficulty in obtaining a partner, and +together the two gentlemen fitted up a factory and began to make +clothing, life preservers, rubber shoes, and a great variety of +rubber goods. They also had a large factory, with special +machinery, built at Staten Island, where he removed his family and +again had a home of his own. Just about this time, when everything +looked bright, the great panic of 1836-1837 came, and swept away +the entire fortune of his associate and left Goodyear without a +cent, and no means of earning one.</p> + +<p>His next move was to go to Boston, where he became acquainted +with J. Haskins, of the Roxbury Rubber Company, and found in him a +firm friend, who loaned him money and stood by him when no one +would have anything to do with the visionary inventor. Mr. Chaffee +was also exceedingly kind and ever ready to lend a listening ear to +his plans, and to also assist him in a pecuniary way. It was about +this time that it occurred to Mr. Chaffee that much of the trouble +that they had experienced in working India rubber might come from +the solvent that was used. He therefore invented a huge machine for +doing the mixing by mechanical means. The goods that were made in +this way were beautiful to look at, and it appeared, as it had +before, that all difficulties were overcome.</p> + +<p>Goodyear discovered a new method for making rubber shoes and got +a patent on it, which he sold to the Providence Company, in Rhode +Island.</p> + +<p>The secret of making the rubber so that it would stand heat and +cold and acids, however, had not been discovered, and the goods +were constantly growing sticky and decomposing and being +returned.</p> + +<p>In 1838 he, for the first time, met Nathaniel Hayward, who was +then running a factory in Woburn. Some time after this Goodyear +himself moved to Woburn, all the time continuing his experiments. +He was very much interested in Hayward's sulphur experiments for +drying rubber, but it appears that neither of them at that time +appreciated the fact that it needed heat to make the sulphur +combine with the rubber and to vulcanize it.</p> + +<p>The circumstances attending the discovery of his celebrated +process is thus described by Mr. Goodyear himself in his book, "Gum +Elastic." It will be observed that he makes use of the third person +in all references to himself:</p> + +<blockquote> +<p>"In the summer of 1838 he became acquainted with Mr. Nathaniel +Hayward, of Woburn, Mass., who had been employed as the foreman of +the Eagle Company at Woburn, where he had made use of sulphur by +impregnating the solvent with it. It was through him that the +writer (Charles Goodyear, who makes use all through his book of the +third person) received the first knowledge of the use of sulphur as +a drier of gum elastic.</p> + +<p>"Mr. Hayward was left in possession of the factory which was +abandoned by the Eagle Company. Soon after this it was occupied by +the writer, who employed him for the purpose of manufacturing life +preservers and other articles by the acid gas process. At this +period he made many novel and useful applications of this +substance. Among other fancy articles he had newspapers printed on +the gum elastic drapery, and the improvement began to be highly +appreciated. He therefore now entered, as he thought, upon a +successful career for the future. A far different result awaited +him.</p> + +<p>"It was supposed by others as well as himself that a change was +wrought through the mass of the goods acted upon by the acid gas, +and that the whole body of the article was made better than the +native gum. The surface of the goods really was so, but owing to +the eventual decomposition of the goods beneath the surface, the +process was pronounced by the public a complete failure. Thus +instead of realizing the large fortune which by all acquainted with +his prospects was considered certain, his whole invention would not +bring him a week's living.</p> + +<p>"He was obliged for the want of means to discontinue +manufacturing, and Mr. Hayward left his employment. The inventor +now applied himself alone, with unabated ardor and diligence, to +detect the cause of his misfortune and if possible to retrieve the +lost reputation of his invention. On one occasion he made some +experiments to ascertain the effect of heat upon the same compound +that had decomposed in the articles previously manufactured, and +was surprised to find that the specimen, being carelessly brought +in contact with a hot stove, charred like leather. He endeavored to +call the attention of his brother as well as some other individuals +who were present, and who were acquainted with the manufacture of +gum elastic, to this effect as remarkable and unlike any before +known, since gum elastic always melted when exposed to a high +degree of heat. The occurrence did not at the time appear to them +to be worthy of notice. It was considered as one of the frequent +appeals that he was in the habit of making in behalf of some new +experiment. He, however, directly inferred that if the process of +charring could be stopped at the right point, it might divest the +gum of its native adhesiveness throughout, which would make it +better than the native gum.</p> + +<p>"He made another trial of heating a similar fabric, before an +open fire. The same effect, that of charring the gum, followed, but +there were further and very satisfactory indications of ultimate +success in producing the desired result, as upon the edge of the +charred portions of the fabric there appeared a line, or border, +that was not charred, but perfectly cured.</p> + +<p>"These facts have been stated precisely as they occurred in +reference to the acid gas, as well as the vulcanizing process.</p> + +<p>"The incidents attending the discovery of both have a strong +resemblance, so much so they may be considered parallel cases. It +being now known that the results of the vulcanizing process are +produced by means and in a manner which would not have been +anticipated from any reasoning on the subject, and that they have +not yet been satisfactorily accounted for, it has been sometimes +asked, how the inventor came to make the discovery? The answer has +already been given. It may be added that he was many years seeking +to accomplish this object, and that he allowed nothing to escape +his notice that related to the subject. Like the falling of an +apple, it was suggestive of an important fact to one whose mind was +previously prepared to draw an inference from any occurrence which +might favor the object of his research. While the inventor admits +that these discoveries were not the results of scientific chemical +investigations, <i>he is not willing to admit that they were the +result of what is commonly termed accident</i>; he claims them to +be the result of the closest application and observation.</p> + +<p>"The discoloring and charring of the specimens proved nothing +and discovered nothing of value, but quite the contrary, for in the +first instance, as stated in the acid gas improvement, the specimen +acted upon was thrown away as worthless and left for some time; in +the latter instance, the specimen that was charred was in like +manner disregarded by others.</p> + +<p>"It may, therefore, be considered as one of those cases where +the leading of the Creator providentially aids his creatures, by +what are termed 'accidents,' to attain those things which are not +attainable by the powers of reasoning he has conferred on +them."</p> +</blockquote> + +<p>Now that Goodyear was sure that he had the key to the intricate +puzzle that he had worked over for so many years, he began at once +to tell his friends about it and to try to secure capital, but they +had listened to their sorrow so many times that his efforts were +futile. For a number of years be struggled and experimented and +worked along in a small way, his family suffering with himself the +pangs of the extremest poverty. At last he went to New York and +showed some of his samples to William Ryder, who, with his brother +Emory, at once appreciated the value of the discovery and started +in to manufacturing. Even here Goodyear's bad luck seemed to follow +him, for the Ryder Bros. failed and it was impossible to continue +the business.</p> + +<p>He had, however, started a small factory at Springfield, Mass., +and his brother-in-law, Mr. De Forest, who was a wealthy woolen +manufacturer, took Ryder's place, and the work of making the +invention practical was continued. In 1844 it was so far perfected +that Goodyear felt it safe to take out a patent. The factory at +Springfield was run by his brothers, Nelson and Henry.</p> + +<p>In 1843 Henry started one in Naugatuck, and in 1844 introduced +mechanical mixing in place of the mixture by the use of +solvents.</p> + +<p>In the year 1852 Goodyear went to Europe, a trip that he had +long planned, and saw Hancock, then in the employ of Charles +Macintosh & Co. Hancock admitted in evidence that the first +piece of vulcanized rubber he ever saw came from America, but +claimed to have reinvented vulcanization and secured patents in +Great Britain, but it is <i>a remarkable fact</i> that Charles +Goodyear's French patent was the first publication in Europe of +this discovery.</p> + +<p>In 1852 a French company were licensed by Mr. Goodyear to make +shoes, and a great deal of interest was felt in the new business. +In 1855 the French emperor gave to Charles Goodyear the grand medal +of honor and decorated him with the cross of the legion of honor in +recognition of his services as a public benefactor, but the French +courts subsequently set aside his French patents on the ground of +the importation of vulcanized goods from America by licenses under +the United States patents. He died July 1, 1860, at the Fifth +Avenue Hotel, New York City.—<i>India Rubber World</i>.</p> + +<hr /> +<p class="ctr">[Continued from SUPPLEMENT, No. 786, page +12558.]</p> + +<h2><a id="iii_3" name="iii_3"></a>THE ELECTROMAGNET.<a id= +"FNanchor_1b" name="FNanchor_1b"></a><a href= +"#Footnote_1b"><sup>1</sup></a></h2> + +<h3>By Professor SILVANUS P. THOMPSON, D.Sc., B.A., M.I.E.E.</h3> + +<h3>III.</h3> + +<h3>RESEARCHES OF PROFESSOR HUGHES.</h3> + +<p class="ctr"><img src="./images/6-fig51.png" alt= +"FIG. 51.—HUGHES' ELECTROMAGNET." title="FIG. 51" /><br /> + FIG. 51.—HUGHES' ELECTROMAGNET.</p> + +<p>His object was to find out the best form of electromagnet, the +best distance between the poles, and the best form of armature for +the rapid work required in Hughes' printing telegraphs. One word +about Hughes' magnets. This diagram (Fig. 51) shows the form of the +well known Hughes' electromagnet. I feel almost ashamed to say +those words "well known," because on the Continent everybody knows +what you mean by a Hughes' electromagnet. In England scarcely +anyone knows what you mean. Englishmen do not even know that +Professor Hughes has invented a special form of electromagnet. +Hughes' special form is this: A permanent steel magnet, generally a +compound one, having soft iron pole pieces, and a couple of coils +on the pole pieces only. As I have to speak of Hughes' special +contrivance among the mechanisms that will occupy our attention +later on, I only now refer to this magnet in one particular. If you +wish a magnet to work rapidly, you will secure the most rapid +action, not when the coils are distributed all along, but when they +are heaped up near, not necessarily entirely on, the poles. Hughes +made a number of researches to find out what the right length and +thickness of these pole pieces should be. It was found an advantage +not to use too thin pole pieces, otherwise the magnetism from the +permanent magnet did not pass through the iron without considerable +reluctance, being choked by insufficiency of section: also not to +use too thick pieces, otherwise they presented too much surface for +leakage across from one to the other. Eventually a particular +length was settled upon, in proportion about six times the +diameter, or rather longer. In the further researches that Hughes +made he used a magnet of shorter form, not shown here, more like +those employed in relays, and with an armature from 2 to 3 +millimeters thick, 1 centimeter wide and 5 centimeters long. The +poles were turned over at the top toward one another. Hughes tried +whether there was any advantage in making those poles approach one +another, and whether there was any advantage in having as long an +armature as 5 centimeters. He tried all the different kinds, and +plotted out the results of observations in curves, which could be +compared and studied. His object was to ascertain the conditions +which would give the strongest pull, not with a steady current, but +with such currents as were required for operating his printing +telegraph instruments; currents which lasted but one to twenty +hundredths of a second. He found it was decidedly an advantage to +shorten the length of the armature, so that it did not protrude far +over the poles. In fact, he got a sufficient magnetic circuit to +secure all the attractive power that he needed, without allowing as +much chance of leakage as there would have been had the armature +extended a longer distance over the poles. He also tried various +forms of armature having very various cross sections.</p> + +<h3>POSITION AND FORM OF ARMATURE.</h3> + +<p>In one of Du Moncel's papers on electromagnets<a id= +"FNanchor_2b" name="FNanchor_2b"></a><a href= +"#Footnote_2b"><sup>2</sup></a> you will also find a discussion on +armatures, and the best forms for working in different positions. +Among other things in Du Moncel you will find this paradox: that +whereas using a horseshoe magnet with fat poles, and a flat piece +of soft iron for armature, it sticks on far tighter when put on +edgeways; on the other hand, if you are going to work at a +distance, across air, the attraction is far greater when it is set +flatways. I explained the advantage of narrowing the surfaces of +contact by the law of traction, <b>B²</b>, coming in. Why +should we have for action at a distance the greater advantage from +placing the armature flatway to the poles? It is simply that you +thereby reduce the reluctance offered by the air gap to the flow of +the magnetic lines. Du Moncel also tried the difference between +round armatures and flat ones, and found that a cylindrical +armature was only attracted about half as strongly as a prismatic +armature having the same surface when at the same distance. Let us +examine this fact in the light of the magnetic circuit. The poles +are flat. You have at a certain distance away a round armature; +there is a certain distance between its nearest side and the polar +surfaces. If you have at the same distance away a flat armature +having the same surface, and, therefore, about the same tendency to +leak, why do you get a greater pull in this case than in that? I +think it is clear that if they are at the same distance away, +giving the same range of motion, there is a greater magnetic +reluctance in the case of the round armature, although there is the +same periphery, because, though the nearest part of the surface is +at the prescribed distance, the rest of the under surface is +farther away; so that the gain found in substituting an armature +with a flat surface is a gain resulting from the diminution in the +resistance offered by the air gap.</p> + +<h3>POLE PIECES ON HORSESHOE MAGNETS.</h3> + +<p>Another of Du Moncel's researches<a id="FNanchor_3b" name= +"FNanchor_3b"></a><a href="#Footnote_3b"><sup>3</sup></a> relates +to the effect of polar projections or shoes—movable pole +pieces, if you like—upon a horseshoe electromagnet. The core +of this magnet was of round iron 4 centimeters in diameter, and the +parallel limbs were 10 centimeters long and 6 centimeters apart. +The shoes consisted of two flat pieces of iron slotted out at one +end, so that they could be slid along over the poles and brought +nearer together. The attraction exerted on a flat armature across +air gaps 2 millimeters thick was measured by counterpoising. +Exciting this electromagnet with a certain battery, it was found +that the attraction was greatest when the shoes were pushed to +about 15 millimeters, or about one-quarter of the interpolar +distance, apart. The numbers were as follows:</p> + +<div class="ctr"> +<table width="40%" summary="DISTANCE AND ATTRACTION" border="0" +cellspacing="3"> +<colgroup span="2" align="right"></colgroup> + +<tr> +<th>Distance<br /> + between shoes.<br /> + Millimeters.</th> +<th align="center">Attraction,<br /> + in grammes.</th> +</tr> + +<tr> +<td>2</td> +<td>900</td> +</tr> + +<tr> +<td>10</td> +<td>1,012</td> +</tr> + +<tr> +<td>15</td> +<td>1,025</td> +</tr> + +<tr> +<td>25</td> +<td>965</td> +</tr> + +<tr> +<td>40</td> +<td>890</td> +</tr> + +<tr> +<td>60</td> +<td>550</td> +</tr> +</table> +</div> + +<p>With a stronger battery the magnet without shoes had an +attraction of 885 grammes, but with the shoes 15 millimeters apart, +1,195 grammes. When one pole only was employed, the attraction, +which was 88 grammes without a shoe, was <i>diminished</i> by +adding a shoe to 39 grammes!</p> + +<h3>CONTRAST BETWEEN ELECTROMAGNETS AND PERMANENT MAGNETS.</h3> + +<p>Now I want particularly to ask you to guard against the idea +that all these results obtained from electromagnets are equally +applicable to permanent magnets of steel; they are not, for this +simple reason. With an electromagnet, when you put the armature +near, and make the magnetic circuit better, you not only get more +magnetic lines going through that armature, but you get more +magnetic lines going through the whole of the iron. You get more +magnetic lines round the bend when you put an armature on to the +poles, because you have a magnetic circuit of less reluctance with +the same external magnetizing power in the coils acting around it. +Therefore, in that case, you will have a greater magnetic flux all +the way round. The data obtained with the electromagnet (Fig. 42), +with the exploring coil, C, on the bend of the core, where the +armature was in contact, and when it was removed are most +significant. When the armature was present it multiplied the total +magnetic flow tenfold for weak currents and nearly threefold for +strong currents. But with a steel horseshoe, magnetized once for +all, the magnetic lines that flow around the bend of the steel are +a fixed quantity, and, however much you diminish the reluctance of +the magnetic circuit, you do not create or evoke any more. When the +armature is away the magnetic lines arch across, not at the ends of +the horseshoe only, but from its flanks; the whole of the magnetic +lines leaking somehow across the space. Where you have put the +armature on, these lines, instead of arching out into space as +freely as they did, pass for the most part along the steel limbs +and through the iron armature. You may still have a considerable +amount of leakage, but you have not made one line more go through +the bent part. You have absolutely the same number going through +the bend with the armature off as with the armature on. You do not +add to the total number by reducing the magnetic reluctance, +because you are not working under the influence of a constantly +impressed magnetizing force. By putting the armature on to a steel +horseshoe magnet you only <i>collect</i> the magnetic lines, you do +not <i>multiply</i> them. This is not a matter of conjecture. A +group of my students have been making experiments in the following +way: They took this large steel horseshoe magnet (Fig. 52), the +length of which, from end to end, through the steel, is 42½ +inches. A light, narrow frame was constructed so that it could be +slipped on over the magnet, and on it were wound 30 turns of fine +wire, to serve as an exploring coil. The ends of this coil were +carried to a distant part of the laboratory, and connected to a +sensitive ballistic galvanometer. The mode of experimenting is as +follows:</p> + +<p>The coil is slipped on over the magnet (or over its armature) to +any desired position. The armature of the magnet is placed gently +upon the poles, and time enough is allowed to elapse for the +galvanometer needle to settle to zero. The armature is then +suddenly detached. The first swing measures the change, due to +removing the armature, in the number of magnetic lines that pass +through the coil in the particular position.</p> + +<p class="ctr"><img src="./images/6-fig52.png" alt= +"FIG. 52.—EXPERIMENT WITH PERMANENT MAGNET." title= +"FIG. 52" /><br /> + FIG. 52.—EXPERIMENT WITH PERMANENT MAGNET.</p> + +<p>I will roughly repeat the experiment before you: The spot of +light on the screen is reflected from my galvanometer at the far +end of the table. I place the exploring coil just over the pole, +and slide on the armature; then close the galvanometer circuit. Now +I detach the armature, and you observe the large swing. I shift the +exploring coil, right up to the bend; replace the armature; wait +until the spot of light is brought to rest at the zero of the +scale. Now, on detaching the armature, the movement of the spot of +light is quite imperceptible. In our careful laboratory +experiments, the effect was noticed inch by inch all along the +magnet. The effect when the exploring coil was over the bend was +not as great as 1-3000th part of the effect when the coil was hard +up to the pole. We are, therefore, justified in saying that the +number of magnetic lines in a permanently magnetized steel +horseshoe magnet is not altered by the presence or absence of the +armature.</p> + +<p>You will have noticed that I always put on the armature gently. +It does not do to slam on the armature; every time you do so, you +knock some of the so-called permanent magnetism out of it. But you +may pull off the armature as suddenly as you like. It does the +magnet good rather than harm. There is a popular superstition that +you ought never to pull off the keeper of a magnet suddenly. On +investigation, it is found that the facts are just the other way. +You may pull off the keeper as suddenly as you like, but you should +never slam it on.</p> + +<p>From these experimental results I pass to the special design of +electromagnets for special purposes.</p> + +<h3>ELECTROMAGNETS FOR MAXIMUM TRACTION.</h3> + +<p>These have already been dealt with in the preceding lecture; the +characteristic feature of all the forms suitable for traction being +the compact magnetic circuit.</p> + +<p>Several times it has been proposed to increase the power of +electromagnets by constructing them with intermediate masses of +iron between the central core and the outside, between the layers +of windings. All these constructions are founded on fallacies. Such +iron is far better placed either right inside the coils or right +outside them, so that it may properly constitute a part of the +magnetic circuit. The constructions known as Camacho's and Cance's, +and one patented by Mr. S.A. Varley, in 1877, belonging to this +delusive order of ideas, are now entirely obsolete.</p> + +<p>Another construction which is periodically brought forward as a +novelty is the use of iron windings of wire or strip in place of +copper winding. The lower electric conductivity of iron, as +compared with copper, makes such a construction wasteful of +exciting power. To apply equal magnetizing power by means of an +iron coil implies the expenditure of about six times as many watts +as need be expended if the coil is of copper.</p> + +<h3>ELECTROMAGNETS FOR MAXIMUM RANGE OF ATTRACTION.</h3> + +<p>We have already laid down the principle which will enable us to +design electromagnets to act at a distance. We want our magnet to +project, as it were, its force across the greatest length of air +gap. Clearly, then, such a magnet must have a very large +magnetizing power, with many ampere turns upon it, to be able to +make the required number of magnetic lines pass across the air +resistance. Also it is clear that the poles must not be too close +together for its work, otherwise the magnetic lines at one pole +will be likely to curl round and take short cuts to the other pole. +There must be a wider width between the poles than is desirable in +electromagnets for traction.</p> + +<h3>ELECTROMAGNETS OF MINIMUM WEIGHT.</h3> + +<p>In designing an apparatus to put on board a boat or a balloon, +where weight is a consideration of primary importance, there is +again a difference. There are three things that come into +play—iron, copper, and electric current. The current weighs +nothing, therefore, if you are going to sacrifice everything else +to weight, you may have comparatively little iron, but you must +have enough copper to be able to carry the electric current; and +under such circumstances you must not mind heating your wires +nearly red hot to pass the biggest possible current. Provide as +little copper as you conveniently can, sacrificing economy in that +case to the attainment of your object; but, of course, you must use +fireproof material, such as asbestos, for insulating, instead of +cotton or silk.</p> + +<h2>A USEFUL GUIDING PRINCIPLE.</h2> + +<p>In all cases of design there is one leading principle which will +be found of great assistance, namely, that a magnet always tends so +to act as though it tried to diminish the length of its magnetic +circuit. It tries to grow more compact. This is the reverse of that +which holds good with an electric current. The electric circuit +always tries to enlarge itself, so as to inclose as much space as +possible, but the magnetic circuit always tries to make itself as +compact as possible. Armatures are drawn in as near as can be, to +close up the magnetic circuit. Many two-pole electromagnets show a +tendency to bend together when the current is turned on. One form +in particular, which was devised by Ruhmkorff for the purpose of +repeating Faraday's celebrated experiment on the magnetic rotation +of polarized light, is liable to this defect. Indeed, this form of +electromagnet is often designed very badly, the yoke being too +thin, both mechanically and magnetically, for the purpose which it +has to fulfill.</p> + +<p>Here is a small electric bell, constructed by Wagener, of +Wiesbaden, the construction of which illustrates this principle. +The electromagnet, a horseshoe, lies horizontally; its poles are +provided with protruding curved pins of brass. Through the armature +are drilled two holes, so that it can be hung upon the two brass +pins; and when so hung up it touches the ends of the iron cores +just at one edge, being held from more perfect contact by a spring. +There is no complete gap, therefore, in the magnetic circuit. When +the current comes and applies a magnetizing power, it finds the +magnetic circuit already complete in the sense that there are no +absolute gaps. But the circuit can be bettered by tilting the +armature to bring it flat against the polar ends, that being indeed +the mode of motion. This is a most reliable and sensitive pattern +of bell.</p> + +<p class="ctr"><img src="./images/7-fig53.png" alt= +"FIG. 53.—ELECTROMAGNETIC POP-GUN." title="FIG. 53" /><br /> + FIG. 53.—ELECTROMAGNETIC POP-GUN.</p> + +<p><i>Electromagnetic Pop-gun.</i>—Here is another curious +illustration of the tendency to complete the magnetic circuit. Here +is a tubular electromagnet (Fig. 53), consisting of a small bobbin, +the core of which is an iron tube about two inches long. There is +nothing very unusual about it; it will stick on, as you see, to +pieces of iron when the current is turned on. It clearly is an +ordinary electromagnet in that respect. Now suppose I take a little +round rod of iron, about an inch long, and put it into the end of +the tube, what will happen when I turn on my current? In this +apparatus as it stands, the magnetic circuit consists of a short +length of iron, and then all the rest is air. The magnetic circuit +will try to complete itself, not by shortening the iron, but by +<i>lengthening</i> it; by pushing the piece of iron out so as to +afford more surface for leakage. That is exactly what happens; for, +as you see, when I turn on the current, the little piece of iron +shoots out and drops down. You see that little piece of iron shoot +out with considerable force. It becomes a sort of magnetic popgun. +This is an experiment which has been twice discovered. I found it +first described by Count Du Moncel, in the pages of <i>La Lumiere +Electrique</i>, under the name of the "pistolet electromagnetique;" +and Mr. Shelford Bidwell invented it independently. I am indebted +to him for the use of this apparatus. He gave an account of it to +the Physical Society, in 1885, but the reporter missed it, I +suppose, as there is no record in the society's proceedings.</p> + +<h3>ELECTROMAGNETS FOR USE WITH ALTERNATING CURRENTS.</h3> + +<p>When you are designing electromagnets for use with alternating +currents, it is necessary to make a change in one respect, namely, +you must so laminate the iron that internal eddy currents shall not +occur; indeed, for all rapid-acting electromagnetic apparatus it is +a good rule that the iron must not be solid. It is not usual with +telegraphic instruments to laminate them by making up the core of +bundles of iron plates or wires, but they are often made with +tubular cores, that is to say, the cylindrical iron core is drilled +with a hole down the middle, and the tube so formed is slit with a +saw cut to prevent the circulation of currents in the substance of +the tube. Now when electromagnets are to be employed with rapidly +alternating currents, such as are used for electric lighting, the +frequency of the alternations being usually about 100 periods per +second, slitting the cores is insufficient to guard against eddy +currents; nothing short of completely laminating the cores is a +satisfactory remedy. I have here, thanks to the Brush Electric +Engineering Company, an electromagnet of the special form that is +used in the Brush arc lamp when required for the purpose of working +in an alternating current circuit. It has two bobbins that are +screwed up against the top of an iron box at the head of the lamp. +The iron slab serves as a kind of yoke to carry the magnetism +across the top. There are no fixed cores In the bobbins, which are +entered by the ends of a pair of yoked plungers. Now in the +ordinary Brush lamp for use with a steady current, the plungers are +simply two round pieces of iron tapped into a common yoke; but for +alternate current working this construction must not be used, and +instead a <b>U</b>-shaped double plunger is used, made up of +laminated iron, riveted together. Of course it is no novelty to use +a laminated core; that device, first used by Joule, and then by +Cowper, has been repatented rather too often during the past fifty +years to be considered as a recent invention.</p> + +<p>The alternate rapid reversals of the magnetism in the magnetic +field of an electromagnet, when excited by alternating electric +currents, sets up eddy currents in every piece of undivided metal +within range. All frames, bobbin tubes, bobbin ends, and the like, +must be most carefully slit, otherwise they will overheat. If a +domestic flat iron is placed on the top of the poles of a properly +laminated electromagnet, supplied with alternating currents, the +flat iron is speedily heated up by the eddy currents that are +generated internally within it. The eddy currents set up by +induction in neighboring masses of metal, especially in good +conducting metals such as copper, give rise to many curious +phenomena. For example, a copper disk or copper ring placed over +the pole of a straight electromagnet so excited is violently +repelled. These remarkable phenomena have been recently +investigated by Professor Elihu Thomson, with whose beautiful and +elaborate researches we have lately been made conversant in the +pages of the technical journals. He rightly attributes many of the +repulsion phenomena to the lag in phase of the alternating currents +thus induced in the conducting metal. The electromagnetic inertia, +or self-inductive property of the electric circuit, causes the +currents to rise and fall later in time than the electromotive +forces by which they are occasioned. In all such cases the +impedance which the circuit offers is made up of two +things—resistance and inductance. Both these causes tend to +diminish the amount of current that flows, and the inductance also +tends to delay the flow.</p> + +<h3>ELECTROMAGNETS FOR QUICKEST ACTION.</h3> + +<p>I have already mentioned Hughes' researches on the form of +electromagnet best adapted for rapid signaling. I have also +incidentally mentioned the fact that where rapidly varying currents +are employed, the strength of the electric current that a given +battery can yield is determined not so much by the resistance of +the electric circuit as by its electric inertia. It is not a very +easy task to explain precisely what happens to an electric circuit +when the current is turned on suddenly. The current does not +suddenly rise to its full value, being retarded by inertia. The +ordinary law of Ohm in its simple form no longer applies; one needs +to apply that other law which bears the name of the law of +Helmholtz, the use of which is to give us an expression, not for +the final value of the current, but for its value at any short +time, t, after the current has been turned on. The strength of the +current after a lapse of a short time, t, cannot be calculated by +the simple process of taking the electromotive force and dividing +it by the resistance, as you would calculate steady currents.</p> + +<p>In symbols, Helmholtz's law is:</p> + +<p class="ctr">i<sub>t</sub> = E/R ( 1 - e<sup>- (R/L)t</sup> )</p> + +<p>In this formula <i>i<sub>t</sub></i> means the strength of the +current after the lapse of a short time <i>t</i>; E is the +electromotive force; R, the resistance of the whole circuit; L, its +coefficient of self-induction; and <i>e</i> the number 2.7183, +which is the base of the Napierian logarithms. Let us look at this +formula; in its general form it resembles Ohm's law, but with a new +factor, namely, the expression contained within the brackets. The +factor is necessarily a fractional quantity, for it consists of +unity less a certain negative exponential, which we will presently +further consider. If the factor within brackets is a quantity less +than unity, that signifies that <i>i<sub>t</sub></i> will be less +than E ÷ R. Now the exponential of negative sign, and with +negative fractional index, is rather a troublesome thing to deal +with in a popular lecture. Our best way is to calculate some +values, and then plot it out as a curve. When once you have got it +into the form of a curve, you can begin to think about it, for the +curve gives you a mental picture of the facts that the long formula +expresses in the abstract. Accordingly we will take the following +case. Let E = 2 volts; R = 1 ohm; and let us take a relatively +large self-induction, so as to exaggerate the effect; say let L = +10 quads. This gives us the following:</p> + +<div class="ctr"> +<table border="0" width="40%" cellspacing="5" summary=""> +<colgroup span="3" align="right"></colgroup> + +<tr> +<th>t<sub>(sec.)</sub></th> +<th>e<sup>+(R/L)t</sup></th> +<th>i<sub>t</sub></th> +</tr> + +<tr> +<td>0</td> +<td>1</td> +<td>0</td> +<td></td> +</tr> + +<tr> +<td>1</td> +<td>1.105</td> +<td>0.950</td> +</tr> + +<tr> +<td>2</td> +<td>1.221</td> +<td>1.810</td> +</tr> + +<tr> +<td>5</td> +<td>1.649</td> +<td>3.936</td> +</tr> + +<tr> +<td>10</td> +<td>2.718</td> +<td>6.343</td> +</tr> + +<tr> +<td>20</td> +<td>7.389</td> +<td>8.646</td> +</tr> + +<tr> +<td>30</td> +<td>20.08</td> +<td>9.501</td> +</tr> + +<tr> +<td>60</td> +<td>403.4</td> +<td>9.975</td> +</tr> + +<tr> +<td>120</td> +<td>16200.0</td> +<td>9.999</td> +</tr> +</table> +</div> + +<p>In this case the value of the steady current as calculated by +Ohm's law is 10 amperes, but Helmholtz's law shows us that with the +great self-induction which we have assumed to be present, the +current, even at the end of 30 seconds, has only risen up to within +5 percent. of its final value; and only at the end of two minutes +has practically attained full strength. These values are set out in +the highest curve in Fig. 54, in which, however, the further +supposition is made that the number of spirals, S, in the coils of +the electromagnet is 100, so that when the current attains its full +value of 10 amperes, the full magnetizing power will be S<i>i</i> = +1000. It will be noticed that the curve rises from zero at first +steeply and nearly in a straight line, then bends over, and then +becomes nearly straight again, as it gradually rises to its +limiting value. The first part of the curve—that relating to +the strength of the current after <i>very small</i> interval of +time—is the period within which the strength of the current +is governed by inertia (i.e., the self-induction) rather than by +resistance. In reality the current is not governed either by the +self-induction or by the resistance alone, but by the ratio of the +two. This ratio is sometimes called the "time constant" of the +circuit, for it represents <i>the time</i> which the current takes +in that circuit to rise to a definite fraction of its final +value.</p> + +<p class="ctr"><img src="./images/7-fig54.png" alt= +"FIG. 54.—CURVES OF RISE OF CURRENTS." title="FIG. 54" /><br +clear="all" /> + FIG. 54.—CURVES OF RISE OF CURRENTS.</p> + +<p>This definite fraction is the fraction (e - 1)/e; or in +decimals, 0.634. All curves of rise of current are alike in general +shape, they differ only in scale, that is to say, they differ only +in the height to which they will ultimately rise, and in the time +they will take to attain this fraction of their final value.</p> + +<p><i>Example (1).</i>—Suppose E = 10; R = 200 ohms; L = 8. +The final value of the current will be 0.025 amp. or 25 +milliamperes. Then the time constant will be 8 ÷ 400 = +1-50th sec.</p> + +<p><i>Example (2).</i>—The P.O. Standard "A" relay has R = +400 ohms; L = 3.25. It works with 0.5 milliampere current, and +therefore will work with 5 Daniell cells through a line of 9,600 +ohms. Under these circumstances the time constant of the instrument +on short circuit is 0.0081 sec.</p> + +<p>It will be noted that the time constant of a circuit can be +reduced either by diminishing the self-induction or by increasing +the resistance. In Fig. 54 the position of the time constant for +the top curve is shown by the vertical dotted line at 10 seconds. +The current will take 10 seconds to rise to 0.634 of its final +value. This retardation of the rise of current is simply due to the +presence of coils and electromagnets in the circuit; the current as +it grows being retarded because it has to create magnetic fields in +these coils, and so sets up opposing electromotive forces that +prevent it from growing all at once to its full strength. Many +electricians, unacquainted with Helmholtz's law, have been in the +habit of accounting for this by saying that there is a lag in the +iron of the electromagnet cores. They tell you that an iron core +cannot be magnetized suddenly, that it takes time to acquire its +magnetism. They think it is one of the properties of iron. But we +know that the only true time lag in the magnetization of iron, that +which is properly termed "viscous hysteresis," does not amount to +any great percentage of the whole amount of magnetization, takes +comparatively a long time to show itself, and cannot therefore be +the cause of the retardation which we are considering. There are +also electricians who will tell you that when magnetization is +suddenly evoked in an iron bar, there are induction currents set up +in the iron which oppose and delay its magnetization. That they +oppose the magnetization is perfectly true, but if you carefully +laminate the iron so as to eliminate eddy currents, you will find, +strangely enough, that the magnetism rises still more slowly to its +final value. For by laminating the iron you have virtually +increased the self-inductive action, and increased the time +constant of the circuit, so that the currents rise more slowly than +before. The lag is not in the iron, but in the magnetizing current, +and the current being retarded, the magnetization is of course +retarded also.</p> + +<h3>CONNECTING COILS FOR QUICKEST ACTION.</h3> + +<p>Now let us apply these most important though rather intricate +considerations to the practical problems of the quick working of +the electromagnet. Take the case of an electromagnet forming some +part of the receiving apparatus of a telegraph system in which it +is desired to secure very rapid working. Suppose the two coils that +are wound upon the horseshoe core are connected together in series. +The coefficient of self-induction for these two is four times as +great as that of either separately; coefficients of self-induction +being proportional to the square of the number of turns of wire +that surround a given core. Now if the two coils instead of being +put in series are put in parallel, the coefficient of +self-induction will be reduced to the same value as if there were +only one coil, because half the line current (which is practically +unaltered) will go through each coil. Hence the time constant of +the circuit when the coils are in parallel will be a quarter of +that which it is when the coils are in series; on the other hand, +for a given line current, the final magnetizing power of the two +coils in parallel is only half what it would be with the coil in +series. The two lower curves in Fig. 54 illustrate this, from which +it is at once plain that the magnetizing power for very brief +currents is greater when the two coils are put in parallel with one +another than when they are joined in series.</p> + +<p>Now this circumstance has been known for some time to telegraph +engineers. It has been patented several times over. It has formed +the theme of scientific papers, which have been read both in France +and in England. The explanation generally given of the advantage of +uniting the coils in parallel is, I think, fallacious; namely that +the "extra currents" (i.e., currents due to self-induction) set up +in the two coils are induced in such directions as tend to help one +another when the coils are in series, and to neutralize one another +when they are in parallel. It is a fallacy, because in neither case +do they neutralize one another. Whichever way the current flows to +make the magnetism, it is opposed in the coils while the current is +rising, and helped in the coils while the current is falling, by +the so-called extra currents. If the current is rising in both +coils at the same moment, then, whether the coils are in series or +in parallel, the effect of self-induction is to retard the rise of +the current. The advantage of parallel grouping is simply that it +reduces the time constant.</p> + +<h3>BATTERY GROUPING FOR QUICKEST ACTION.</h3> + +<p>One may consider the question of grouping the battery cells from +the same point of view. How does the need for rapid working, and +the question of time constant, affect the best mode of grouping the +battery cells? The amateur's rule, which tells you to so arrange +your battery that its internal resistance should be equal to the +external resistance, gives you a result wholly wrong for rapid +working. The supposed best arrangement will not give you (at the +expense even of economy) the best result that might be got out of +the given number of cells. Let us take an example and calculate it +out, and place the results graphically before our eyes in the form +of curves. Suppose the line and electromagnet have together a +resistance of 6 ohms, and that we have 24 small Daniell cells, each +of electromotive force say 1 volt, and of internal resistance 4 +ohms. Also let the coefficient of self-induction of the +electromagnet and circuit be 6 quadrants. When all the cells are in +series, the resistance of the battery will be 96 ohms, the total +resistance of the circuit 102 ohms, and the full value of the +current 0.235 ampere. When all the cells are in parallel, the +resistance of the battery will be 0.133 ohm, the total resistance +6.133 ohms, and the full value of the current 0.162 ampere. +According to the amateur rule of grouping cells so that internal +resistance equals external, we must arrange the cells in 4 +parallels, each having 6 cells in series, so that the internal +resistance of the battery will be 6 ohms, total resistance of +circuit 12 ohms, full value of current 0.5 ampere. Now the +corresponding time constants of the circuit in the three cases +(calculated by dividing the coefficient of self-induction by the +total resistance) will be respectively—in series, 0.06 sec.; +in parallel, 0.5 sec.; grouped for maximum steady current, 0.96 +sec. From these data we may now draw the three curves, as in Fig. +55, wherein the abscissæ are the values of time in seconds +and the ordinates the current. The faint vertical dotted lines mark +the time constants in the three cases. It will be seen that when +rapid working is required the magnetizing current will rise, during +short intervals of time, more rapidly if all the cells are put in +series than it will do if the cells are grouped according to the +amateur rule.</p> + +<p class="ctr"><img src="./images/8-fig55.png" alt= +"FIG. 55.—CURVES OF RISE OF CURRENT WITH DIFFERENT GROUPINGS OF BATTERY." + title="FIG. 55" /><br /> + FIG. 55.—CURVES OF RISE OF CURRENT WITH DIFFERENT GROUPINGS +OF BATTERY.</p> + +<p>When they are all put in series, so that the battery has a much +greater resistance than the rest of the circuit, the current rises +much more rapidly, because of the smallness of the time constant, +although it never attains the same ultimate maximum as when grouped +in the other way. That is to say, if there is self-induction as +well as resistance in the circuit, the amateur rule does not tell +you the best way of arranging the battery. There is another mode of +regarding the matter which is helpful. Self-induction, while the +current is growing, acts as if there were a sort of spurious +addition to the resistance of the circuit; and while the current is +dying away it acts of course in the other way, as if there were a +subtraction from the resistance. Therefore you ought to arrange the +battery so that the internal resistance is equal to the real +resistance of the circuit, plus the spurious resistance during that +time. But how much is the spurious resistance during that time? It +is a resistance proportional to the time that has elapsed since the +current was turned on. So then it comes to a question of the length +of time for which you want to work it. What fraction of a second do +you require your signal to be given in? What is the rate of the +vibrator of your electric bell? Suppose you have settled that +point, and that the short time during which the current is required +to rise is called t; then the apparent resistance at time t after +the current is turned on is given by the formula:</p> + +<p class="ctr">R<sub>t</sub> = R × e<sup>(R/L)t</sup> + ( +e<sup>(R/L)t</sup> - 1 )</p> + +<h3>TIME CONSTANTS OF ELECTROMAGNETS.</h3> + +<p>I may here refer to some determinations made by M. Vaschy,<a id= +"FNanchor_4b" name="FNanchor_4b"></a><a href= +"#Footnote_4b"><sup>4</sup></a> respecting the coefficients of +self-induction of the electromagnets of a number of pieces of +telegraphic apparatus. Of these I must only quote one result, which +is very significant. It relates to the electromagnet of a Morse +receiver of the pattern habitually used on the French telegraph +lines.</p> + +<div class="ctr"> +<table align="center" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="2"> +<col align="left" /> +<col span="2" align="right" /></colgroup> + +<tr> +<td></td> +<td colspan="2">L, in quadrants.</td> +</tr> + +<tr> +<td>Bobbins, separately, without iron cores.</td> +<td>0.233</td> +<td>and 0.265</td> +</tr> + +<tr> +<td>Bobbins, separately, with iron cores.</td> +<td>1.65</td> +<td>and 1.71</td> +</tr> + +<tr> +<td>Bobbins, with cores joined by yoke, coils in series</td> +<td>6.37</td> +</tr> + +<tr> +<td>Bobbins, with armature resting on poles.</td> +<td>10.68</td> +</tr> +</table> +</div> + +<p>It is interesting to note how the perfecting of the magnetic +circuit increases the self-induction.</p> + +<p>Thanks to the kindness of Mr. Preece, I have been furnished with +some most valuable information about the coefficients of +self-induction, and the resistance of the standard pattern of +relays, and other instruments which are used in the British postal +telegraph service, from which data one is able to say exactly what +the time constants of those instruments will be on a given circuit, +and how long in their case the current will take to rise to any +given fraction of its final value. Here let me refer to a very +capital paper by Mr. Preece in an old number of the "Journal of the +Society of Telegraph Engineers," a paper "On Shunts," in which he +treats this question, not as perfectly as it could now be treated +with the fuller knowledge we have in 1890 about the coefficients of +self-induction, but in a very useful and practical way. He showed +most completely that the more perfect the magnetic circuit +is—though of course you are getting more magnetism from your +current—the more is that current retarded. Mr. Preece'e mode +of experiment was extremely simple. He observed the throw of the +galvanometer when the circuit which contained the battery and the +electromagnet was opened by a key which at the same moment +connected the electromagnet wires to the galvanometer. The throw of +the galvanometer was assumed to represent the extra current which +flowed out. Fig. 56 represents a few of the results of Mr. Preece's +paper.</p> + +<p class="ctr"><img src="./images/8-fig56.png" alt= +" FIG. 56.—ELECTROMAGNETS OF RELAY, AND THEIR EFFECTS." +title="FIG. 56" /><br /> + FIG. 56.—ELECTROMAGNETS OF RELAY, AND THEIR EFFECTS.</p> + +<p>Take from an ordinary relay a coil, with its iron core, half the +electromagnet, so to speak, without any yoke or armature. Connect +it up as described, and observe the throw given to the +galvanometer. The amount of throw obtained from the single coil was +taken as unity, and all others were compared with it. If you join +up two such coils as they are usually joined, in series, but +without any iron yoke across the cores, the throw was 17. Putting +the iron yoke across the cores, to constitute a horseshoe form, 496 +was the throw; that is to say, the tendency of this electromagnet +to retard the current was 496 times as great as that of the simple +coil. But when an armature was put over the top, the effect ran up +to 2,238. By the mere device of putting the coils in parallel, +instead of in series, the 2,238 came down to 502, a little less +than the quarter value which would have been expected. Lastly, when +the armature and yoke were both of them split in the middle, as is +done in fact in all the standard patterns of the British postal +telegraph relays, the throw of the galvanometer was brought down +from 502 to 26. Relays so constructed will work excessively +rapidly. Mr. Preece states that with the old pattern of relay +having so much self-induction as to give a galvanometer throw of +1,688, the speed of signaling was only from 50 to 60 words per +minute, whereas, with the standard relays constructed on the new +plan, the speed of signaling is from 400 to 450 words per minute. +It is a very interesting and beautiful result to arrive at from the +experimental study of these magnetic circuits.</p> + +<h3>SHORT CORES <i>versus</i> LONG CORES.</h3> + +<p>In considering the forms that are best for rapid action, it +ought to be mentioned that the effects of hysteresis in retarding +changes in the magnetization of iron cores are much more noticeable +in the case of nearly closed magnetic circuits than in short +pieces. Electromagnets with iron armatures in contact across their +poles will retain, after the current has been cut off, a very large +part of their magnetism, even if the cores be of the softest of +iron. But so soon as the armature is wrenched off, the magnetism +disappears. An air gap in a magnetic circuit always tends to hasten +demagnetizing. A magnetic circuit composed of a long air path and a +short iron path demagnetizes itself much more rapidly than one +composed of a short air path and a long iron path. In long pieces +of iron the mutual action of the various parts tends to keep in +them any magnetization that they may possess; hence they are less +readily demagnetized. In short pieces, where these mutual actions +are feeble or almost absent, the magnetization is less stable, and +disappears almost instantly on the cessation of the magnetizing +force. Short bits and small spheres of iron have no magnetic +memory. Hence the cause of the commonly received opinion among +telegraph engineers that for rapid work electromagnets must have +short cores. As we have seen, the only reason for employing long +cores is to afford the requisite length for winding the wire which +is necessary for carrying the needful circulation of current to +force the magnetism across the air gaps. If, for the sake of +rapidity of action, length has to be sacrificed, then the coils +must be heaped up more thickly on the short cores. The +electromagnets in American patterns of telegraphic apparatus +usually have shorter cores, and a relatively greater thickness of +winding upon them, than those of European patterns.</p> + +<a id="Footnote_1b" name="Footnote_1b"></a><a href= +"#FNanchor_1b">[1]</a> + +<div class="note">Lectures delivered before the Society of Arts, +London, 1890. From the Journal of the Society.</div> + +<a id="Footnote_2b" name="Footnote_2b"></a><a href= +"#FNanchor_2b">[2]</a> + +<div class="note">"La Lumiere Electrique," vol. ii.</div> + +<a id="Footnote_3b" name="Footnote_3b"></a><a href= +"#FNanchor_3b">[3]</a> + +<div class="note">"La Lumiere Electrique," vol. iv., p. 129.</div> + +<a id="Footnote_4b" name="Footnote_4b"></a><a href= +"#FNanchor_1c">[1]</a> + +<div class="note">"Bulletin de la Societe Internationale des +Electriciens," 1886.</div> + +<hr /> +<h2><a id="iii_2" name="iii_2"></a>ELECTRIC ERYGMASCOPE.</h2> + +<p>The erygmascope is the name of an electric lighting apparatus +designed for the examination of the strata of earth traversed by +boring apparatus.</p> + +<p>It consists of a very powerful incandescent lamp inclosed in a +metallic cylinder. One of the two semi-cylindrical sides +constitutes the reflector, and the other, which is of thick glass, +allows of the passage of the luminous rays, which thus illuminate +with great brilliancy the strata of earth traversed by the +instrument. The base, which is inclined at an angle of 45°, is +an elliptical mirror, and the top, of straight section, is open in +order to permit the observer standing at the mouth of the well, and +provided with a powerful spyglass, to see in the mirror the image +of the earth. The lamp is so mounted that its upwardly emitted rays +are intercepted.</p> + +<p>The whole apparatus is suspended from a long cable, formed of +two conducting wires, which winds around a windlass with metallic +journals which are electrically insulated. These journals +communicate, through the intermedium of two friction springs, with +the conductors on the one hand and, on the other, with the poles of +an automatic and portable battery.</p> + +<p class="ctr"><a href="./images/8-scope.png"><img src= +"./images/8-scope_th.jpg" alt="THE TROUVE ERYGMASCOPE." title= +"ERYGMASCOPE" /></a><br clear="all" /> + THE TROUVE ERYGMASCOPE.</p> + +<p>This permits of lowering and raising the apparatus at will, +without derangement, and without its being necessary to interrupt +the light and the observation.—<i>Revue Industrielle.</i></p> + +<hr /> +<h2><a id="iii_1" name="iii_1"></a>A NEW ELECTRIC BALLISTIC +TARGET.</h2> + +<p>The electrical target usually employed in determining velocities +of projectiles consists of a wooden frame on which is strung a +copper wire so as to make a continuous circuit arranged in parallel +vertical lines about one inch or one and one half inches apart.</p> + +<p>It frequently happens that a projectile will pass through this +target without breaking the circuit, either by squeezing between +the wires or because, when last repaired, the target was +short-circuited unnoticed, so that the cutting of the wires did not +break the circuit. The repair of this target takes considerable +time.</p> + +<p class="ctr"><a href="./images/8-target.png"><img src= +"./images/8-target_th.jpg" alt="BALLISTIC TARGET." title= +"TARGET" /></a></p> + +<p>Besides these objections to this target, another and more +serious one is the irregularity in the manner of breaking the +circuit. It has been proved that times required for a flat headed +and an ogival headed projectile to rupture the current are very +different.</p> + +<p>To remedy these defects a new and very ingenious target has been +devised and used with great success at the United States Military +Academy at West Point. The top of the target is a wooden strip, F, +on the upper side of which are screwed strips of copper, A A, about +1/2 in. wide, and 1/8 in. thick. The connection between two +adjoining strips is made by a copper cartridge, C, which is dropped +in a hole in the frame bored to receive it. This cartridge is the +one used in the Springfield rifle. Inside the cartridge is a spiral +spring, S, which, acting on the bottom of the hole and the head of +the cartridge, tends to make the latter spring up, and so break the +circuit.</p> + +<p>To the hook, H, which is attached to the cartridge, is +suspended, by means of a string, the lead weight, W, thus drawing +down the cartridge and making the circuit between A and A'. All the +weights being suspended the current comes in through the post, P, +passes along the copper strips and out of the corresponding post on +the other end.</p> + +<p>On firing the projectile cuts a string, and the spring at once +causes the cartridge to spring up, thus breaking the circuit.</p> + +<p>It is not possible for the projectile to squeeze between the +strings and not break the current, for in so doing the cartridge is +tipped slightly, which is sufficient, as it breaks the current on +one side.</p> + +<p>This target is used in connection with the Boulenge chronograph. +Two targets are established at a known distance apart, say 50 ft., +and the time required for the projectile to pass over this distance +is determined by finding the difference in the time of cutting of +the two targets, by finding the difference in the time of falling +of the two rods, caused by the demagnetization of two +electromagnets in the same circuit with the targets.</p> + +<p>By means of a disjunctor both rods are dropped at the same time, +the shorter one releasing a knife blade which makes a cut on the +longer one. Now both rods are hung from the magnets again and the +gun is fired.</p> + +<p>The projectile passes through the first target, breaks the +circuit, demagnetizes the magnet of the longer rod, and it begins +to fall. On passing through the second target, the projectile +causes the shorter rod to fall. This releases the knife blade, and +a second cut is made. The time corresponding to the distance +between these cuts is the time the longer rod was falling before +the second rod began to fall or the time between the cutting of the +two targets by the projectile.</p> + +<p>The distance between the cuts is measured, and the time +corresponding to it can easily be found. Then the velocity of the +projectile is equal to 50/t.</p> + +<p>To repair this target, strings are prepared in advance of +suitable length and looped at both ends, so that by placing the +hook of the cartridge in one loop and that of the weight in the +other the repair is quickly made.</p> + +<p>This target has been used on the West Point proving ground to +determine velocities over distances of 100 ft. interval to +distances of only 9 ft. interval, and has given most satisfactory +results.</p> + +<hr /> +<p class="ctr">[Continued from SUPPLEMENT, No. 786, page +12566.]</p> + +<h2><a id="iv_2" name="iv_2"></a>THE OUTLOOK FOR APPLIED +ENTOMOLOGY.<a id="FNanchor_1c" name="FNanchor_1c"></a><a href= +"#Footnote_1c"><sup>1</sup></a></h2> + +<h3>LEGISLATION.</h3> + +<p>The amount of legislation in different countries that has of +late years been deemed necessary or sufficiently important, in view +of injurious insects, is a striking evidence of the increased +attention paid to applied entomology; and while modern legislation +of this kind has been, on the whole, far more intelligent than +similar efforts in years gone by, many of the laws passed have +nevertheless been unwise, futile, and impracticable, and even +unnecessarily oppressive to other interests. The chief danger here +is the intervention of politics or political methods. Expert +counsel should guide our legislators and the steps taken should be +thorough in order to be effective. We have had of late years in +Germany very good evidence of the excellent results flowing from +thorough methods, and the recent legislation in Massachusetts +against the gypsy moth (<i>Ocneria dispar</i>), which at one time +threatened to become farcical, has, fortunately, proved more than +usually successful; the commission appointed to deal with the +subject having worked with energy and followed competent +advice.</p> + +<h3>PUBLICATION.</h3> + +<p>On the question of publication of the results of our labors it +is perhaps premature to dwell at length. Each of the experiment +stations is publishing its own bulletins and reports quite +independently of the others, but after a uniform plan recommended +by the association with which we meet here; and with but one +exception that has come to my notice, another important +recommendation of the same association—that these +publications shall be void of all personal matter—has been +kept in mind. The National Bureau of Experiment Stations at +Washington is doing what it can with the means at command to +further the general work by issuing the Experiment Station Record, +devoted chiefly to digests of the State station bulletins. There is +a serious question in my mind as to the utility of State digests by +the national department of results already published extensively by +the different States and distributed under government frank to all +similar institutions and to whomsoever is interested enough to ask +for them.</p> + +<p>Such digests may or may not be intelligently made, and, even +under the most favorable circumstances, will hardly serve any other +purpose than helping to the reference to the original articles, and +this could undoubtedly be done more satisfactorily to the stations +and to the people at large by general and classified indices to all +the State documents, made as full as possible and issued at stated +intervals. Only a small proportion of the bulletins have been so +far noticed by digest in this record, with no particular rule, so +far as I can see, in the selection. In point of fact, those will be +most apt to be noticed whose authors can find time to themselves +send or make for the purpose their own abstracts. This is, perhaps, +inevitable under present arrangements. Complete and satisfactory +digests of all, if intelligent and critical, imply a far greater +force than is at present at Prof. Atwater's command.</p> + +<p>Under these circumstances, it would seem wiser to devote all the +energies of the bureau to digests of the similar literature of +other countries, which would be of immense advantage to our people +and to the different station workers. Judging from the +recommendations and resolutions of the general association, this is +the view very generally held, but except in chemistry and special +industries like that of beet sugar, very little of that kind of +work has yet been attempted.</p> + +<p>What is true of the station publications in general is equally +true of special publications. As entomologist of the department, I +have been urged to bring together, at stated intervals, digests of +the entomological publications of the different stations. Such +digests to be of any value, however, should also be critical, and +it were a thankless task for any one to be critic or censor even of +that which needs correction or criticism. Moreover, to do this work +intelligently would require increase of the divisional force, which +at present is more advantageously employed, for, as already +intimated, I should have great doubts of the utility of these +digests.</p> + +<p>I believe, however, that the division should strive for such +increase of means as would justify the periodic publication, either +independently or as a part of the department record, of general and +classified indices to the entomological matter of the station +bulletins, and should work more and more toward giving results from +other parts of the world. This could, perhaps, best be done by +titles of subject and of author so spaced and printed on stout +paper that they could be cut and used in the ordinary card +catalogue. The recipient could cut and systematically place the +titles as fast as received.</p> + +<p>As to the character of the matter of the entomological +bulletins, it will inevitably be influenced by the needs and +demands of the people of the respective States, and while +originality should be kept in mind, there must needs be in the +earlier years of the work much restatement of what is already well +known. That some results have been published of work which reflects +no particular credit upon our calling is a mere incident of the new +positions created. Yet we may expect marked improvement from year +to year in this direction, and without being invidious, I would +cite those of Prof. Gillette's on his spraying experiments and on +the plum curculio and plum gouger, as models of what such bulletins +should be.</p> + +<p>Although the resolution offered at our last meeting by Prof. +Cook, to the effect that purely descriptive matter should be +excluded from the station bulletins, met with no favor, but was +laid on the table, by the general association, I am in full +sympathy with this position and am strongly of the opinion that in +the ordinary bulletins such purely technical and descriptive matter +should be reduced to the necessary minimum consistent with +clearness of statement and accuracy, and that if it is desired, on +the part of the station entomologists, to issue technical and +descriptive papers, a separate series of bulletins were better +instituted for this class of matter.</p> + +<p>Finally, for results which it is desired to promptly get before +the people, the agricultural press is at our disposal, and so far +as the entomological work of the department of agriculture is +concerned, the periodical bulletin, <i>Insect Life</i>, was +established for this purpose. Its columns are open to all station +workers, and I would here appeal to the members of the association +to help make it, as far as possible, national, by sending brief +notes and digests of their work as it progresses. Hitherto we have +been unable to make as much effort in this direction as we desired, +but in future it is our hope to make the bulletin, as far as +possible, a national medium through which the results of work done +in all parts of the country may quickly be put on record and +distributed, not only to all parts of our own country, but to all +parts of the world.</p> + +<p>The rapid growth and development of the national department and +the multiplication of its divisions have necessitated special modes +of publication and rendered the annual report almost an anachronism +so far as it pretends to be what it at one time was—a pretty +complete report of the scientific and other work of the department. +The attempts which I have made through the proper authorities to +get Congress to order more pretentious monographic works in quarto +volume similar to those issued by other departments of the +government have not met with encouragement, and in this direction +many of the stations will, let us hope, be able to do better.</p> + +<h3>CO-OPERATION.</h3> + +<p>Every other subject that might be considered on this occasion +must be subordinate to the one great question of co-operation. With +the large increase of actual workers in our favorite field, +distributed all over the country, the necessity for some +co-operation and co-ordination must be apparent to every one. Just +how this should be brought about or in what direction we may work +toward it, will be for this association in its deliberations to +decide. Nor will I venture to anticipate the deliberations and +conclusions of the special committee appointed to take the matter +into consideration, beyond the statement that there are many +directions in which we can adopt plans for mutual benefit. Take, +for instance, the introduction and dissemination of parasites. How +much greater will be the chance of success in any particular case +if we have all the different station entomologists interested in +some specific plan to be carried out in co-operation with the +national department, which ought to have better facilities of +introducing specimens to foreign countries or to different sections +of our own country than any of the State stations.</p> + +<p>Let us suppose that the fruit growers of one section of the +country, comprising several States in area, need the benefit in +their warfare against any particularly injurious insect of such +natural enemy or enemies as are known to help the fruit growers of +some other section. There will certainly be much greater chances of +success in the carrying out of any scheme of introduction if all +the workers in the one section may be called upon through some +central or national body to help in the introduction and +disposition of the desired material into the other section. Or, +take the case of the boll worm investigation already alluded to. +The chances of success would be much greater if the entomologists +in all the States interested were to give some attention to such +lepidopterous larvæ as are found to be affected with +contagious diseases and to follow out some specific plan of +cultivating and transmitting them to the party or parties with whom +the actual trials are intrusted. The argument applies with still +greater force to any international efforts. I need hardly multiply +instances. There is, it is true, nothing to prevent any individual +station entomologist from requesting co-operation of the other +stations, nor is there anything to prevent the national department +from doing likewise; but in all organization results are more apt +to flow from the power to direct rather than from mere liberty to +request or to plead. The station entomologist may be engrossed in +some line of research which he deems of more importance to the +people of his State, and may resent being called upon to divert his +energies; and with no central or national power to decide upon +plans of co-operation for the common weal, we are left to voluntary +methods, mutually devised, and it is here that this association +can, it seems to me, most fully justify its organization. And this +brings me to the question of</p> + +<h3>THE DEPARTMENT AND THE STATIONS.</h3> + +<p>Immediately connected with the question of co-operation is the +relation of the National Department of Agriculture and the State +experiment stations. The relation, instead of being vital and +authoritative, is, in reality, a subordinate one. Many persons +interested in the advancement of agriculture foresaw the advantage +of having experiment stations attached to the State agricultural +colleges founded under the Morrill act of 1862; but I think that in +the minds of most persons the establishment of these stations +implied some such connection with the national department as that +outlined in an address on Agricultural Advancement in the United +States, which I had the honor to deliver in 1879 before the +National Agricultural Congress, at Rochester, and in which the +following language was used:</p> + +<blockquote> +<p>"In the light of the past history of the German experimental +stations and their work, or of that in our own State of +Connecticut, the expediency of purchasing an experimental farm of +large dimensions in the vicinity of Washington is very +questionable. There can be no doubt, however, of the value of a +good experimental station there that shall have its branches in +every State of the Union. The results to flow from such stations +will not depend upon the number of acres at command, and it will be +far wiser and more economical for the commissioner to make each +agricultural college that accepted the government endowment +auxiliary to the national bureau, so that the experimental farm +that is now, or should be, connected with each of these +institutions might be at its service and under the general +management of the superintendent of the main station. There is +reason to believe that the directors of these colleges would +cheerfully have them constituted as experimental stations under the +direction of the department, and thus help to make it really +national—the head of a vast system that should ramify through +all parts of the land....</p> + +<p>"With the different State agricultural colleges, and the State +agricultural societies, or boards, we have every advantage for +building up a national bureau of agriculture worthy of the country +and its vast productive interests, and on a thoroughly economical +basis, such as that of Prussia, for instance."</p> +</blockquote> + +<p>In short, the view in mind was something in the nature of that +which has since been adopted by our neighbors of the North, where +there is a central or national station or farm at Ottawa and +sub-stations or branch farms at Nappan, Nova Scotia, Brandon, +Manitoba, Indian Head, N.W.T., and Agassiz, British Columbia, all +under the able direction of Mr. William Saunders, one of our +esteemed fellow workers. It was my privilege to be a good deal with +Mr. Saunders when he was in Europe studying the experience of other +countries in this matter, and the policy finally adopted in Canada +as a result of his labors is an eminently wise one, preventing some +of the difficulties and dangers which beset our plan, whether as +between State and nation or college and station.</p> + +<p>Under the present laws and with the vast influence which the +Association of Agricultural Colleges and Experiment Stations will +wield, both in Congress and in the different States, there is great +danger of transposition, in this agricultural body politic, of +those parts which in the animal body are denominated head and tail, +and the old saw to the effect that "the dog wags the tail because +the tail cannot wag the dog," will find another application. So far +as the law goes, the national department, which should hold a truly +national position toward State agricultural institutions depending +on federal support, can do little except by suggestion, whether in +the line of directing plans or in any way co-ordinating or +controlling the work of the different stations throughout the +country. The men who influenced and shaped the legislation which +resulted in the Hatch bill were careful that the department's +function should be to indicate, not to dictate; to advise and +assist, not to govern or regulate. We have, therefore, to depend on +such relationships and such plans of co-operation as will appear +advantageous to all concerned, and these can best be brought about +through such associations as are now in convention here.</p> + +<p>Without such plans there is great danger of such waste of energy +and means and duplication of results as will bring the work into +popular disfavor and invite disintegration, for already there is a +growing feeling that agricultural experiment is and will be +subordinated to the ordinary college work in the disposition of the +federal appropriations.</p> + +<p>What is true of the national department as a whole in its +connection with the State stations is true in a greater or less +degree of the different divisions of the department in connection +with the different specialists of the stations. With the +multiplicity of workers in any given direction in the different +States, the necessity for national work lessens. A favorite scheme +of mine in the past, for instance (and one I am glad to say fully +indorsed by Prof. Willits), was to endeavor to have a permanent +agent located in every section of the country that was sufficiently +distinctive in its agricultural resources and climate, or, as a yet +further elaboration of the same plan, one in each of the more +important agricultural States. The necessity for such State agents +has been lessened, if not obviated, by the Hatch bill, and the +subsequent modifications looking to permanent appropriations to the +State stations or colleges, which give no central power at +Washington. The question then arises, What function shall the +national department perform? Its influence and field for usefulness +have been lessened rather than augmented in the lines of actual +investigation in very many directions. Many a State is already far +better equipped both as to valuable surrounding land, laboratory +and library facilities, more liberal salaries, and greater freedom +from red tape, administrative routine, and restrictions as to +expenditures, than we are at Washington; and, except as a directing +agent and a useful servant, I cannot see where the future growth of +the department's influence is to be outside of those federal +functions which are executive. Just what that directing influence +is to be is the question of the hour, not only in the broader but +in the special sense. The same question, in a narrower sense, had +arisen in the case of the few States which employed State +entomologists. In the event, for instance, of an outbreak of some +injurious insect, or in the event of any particular economic +entomological question within the limits of the State having such +an officer, the United States entomologist would naturally feel +that any effort on his part would be unnecessary, or might even be +looked upon as an interference. He would feel that there was always +danger of mere duplication of observation or experiment, except +where appealed to for aid or co-operation. This is, perhaps, true +only of insects which are local or sectional, and is rather a +narrow view of the matter, but it is one brought home from +experience, and is certainly to be considered in our future plans. +The favor with which the museum work of the national division was +viewed by you at the meeting last November and the amount of +material sent on for determination would indicate that the building +up of a grand national reference collection will be most useful to +the station workers. But to do this satisfactorily we need your +co-operation, and I appeal to all entomologists to aid in this +effort by sending duplicates of their types to Washington, and thus +more fully insuring against ultimate loss thereof.</p> + +<h3>STATUS OF OUR SOCIETY.</h3> + +<p>This train of thought brings up the question of the status of +our society with the station entomologists as represented by the +committee of the general association. Those of us who had desired a +national association for the various purposes for which such +associations are formed, felt, I believe, if I may speak for them, +that the creation of the different experimental stations rendered +such an organization feasible. Your organization at Toronto and the +constitution adopted and amended at the meeting at Washington all +indicate that the chief object was the advancement of our chosen +work and that the strength of the association would come from the +experiment station entomologists. There was then no other +organization of the kind, nor any intimation that such a one would +be founded. Some of us therefore were surprised to learn from the +circular sent out by Prof. Forbes, its chairman, that the committee +appointed by the association of agricultural colleges and +experiment stations, and through which we had hoped to communicate +and co-operate with that association, was not in the proper sense a +committee, but a section which has prepared (and in fact was +required by the executive committee and the rules of the superior +body to prepare) a programme of papers and discussions for the +meeting to be held at the same time and place with our own. I +cannot but feel that this is in some respects a misfortune, and it +will devolve upon you to decide upon several questions of +importance that will materially affect our future existence. That +there is not room for two national organizations having the same +objects in view and meeting at the same time and place goes, I +think, without saying; and if the committee of the general +association is to be anything more than a committee in the proper +sense of the word, or if it is to assume with or without formal +constitution the functions of our own association, then our own +must necessarily be crippled, and to do any good at all must meet +at a different time and a different place. A committee or section, +or whatever it may be called, of the general association with which +we meet, would preclude active membership of any but those who come +within the constitution of that body. Our Canadian friends and many +others who have identified themselves with applied entomology, and +do not belong to any of our State or government institutions, would +be debarred from active representation, however liberal the +association may have been in inviting such to participate, without +power to vote in its deliberations. Our own association has, or +should have, no such limitations. Some of us who are entitled to +membership in both bodies may feel indifferent as to the course +finally decided upon, and that it will not make any difference +whether we have an outside and independent organization, as that of +the association of official chemists, or whether we do, as did the +botanists and horticulturists, waive independence in favor of more +direct connection with the general association, provided there is +some way whereby the committees of the general association are +given sufficient latitude and time to properly present their papers +and deliberate; but there are others who feel more sensitive as to +their action and are more immediately influenced by the feelings of +the main body. I hope that whatever action be taken at this +meeting, the general good and the promotion of economic entomology +will be kept in mind and that no sectional or personal feeling will +be allowed to influence our deliberations.</p> + +<h3>SUGGESTION AND COMMENT.</h3> + +<p>You will, I know, pardon me if, before concluding these remarks, +I venture to make a few comments which, though not altogether +agreeable, are made in all sincerity and in the hope of doing good. +The question as to how far purely technical and especially +descriptive and monographic work should be done by the different +stations or by the national department is one which I have already +alluded to and upon which we shall probably hold differing +opinions, and which will be settled according to the views of the +authorities at the different stations. Individually, I have ever +felt that one ostensibly engaged in applied entomology and paid by +the State or national government to the end that he may benefit the +agricultural community can be true to his trust only by largely +overcoming the pleasure of entomological work having no practical +bearing. I would, therefore, draw the line at descriptive work +except where it is incidental to the economic work and for the +purpose of giving accuracy to the popular and economic statements. +This would make our work essentially biological, for all biologic +investigation would be justified, not only because the life habits +of any insect, once ascertained, throw light on those of species +which are closely related to it, but because we can never know when +a species at present harmless may subsequently prove harmful, and +have to be classed among the species injurious to agriculture.</p> + +<p>On the question of credit to their original sources of results +already on record, it is hardly necessary for me to advise, because +good sense and the consensus of opinion will in the end justify or +condemn a writer according as he prove just and conscientious in +this regard.</p> + +<p>There is one principle that should guide every careful writer, +viz., that in any publications whatever, where facts or opinions +are put forth, it should always be made clear as to which are based +upon the author's personal experience and which are compiled or +stated upon the authority of others. We should have no patience +with a very common tendency to set forth facts, even those relating +to the most common and best known species, without the indications +to which I have referred. The tendency belittles our calling and is +generally misleading and confusing, especially for bibliographic +work, and cannot be too strongly deprecated.</p> + +<p>On this point there will hardly be any difference of opinion, +but I will allude to another question of credit upon which there +prevails a good deal of loose opinion and custom. It is the habit +of using illustrations of other authors without any indication of +their original source.</p> + +<p>This is an equally vicious custom and one to be condemned, +though I know that some have fallen into the habit, without +appreciation of its evil effect. It is, in my judgment, almost as +blameworthy as to use the language or the facts of another without +citing the authority.</p> + +<p>Every member of this association who has due appreciation of the +time and labor and special knowledge required to produce a good and +true illustration of the transformations and chief characteristics +of an insect will appreciate this criticism. However pardonable in +fugitive newspaper articles in respect of cuts which, from repeated +use, have become common or which have no individuality, the habit +inevitably gives a certain spurious character to more serious and +official publications, for assumption of originality, whether +intended or not, goes with uncredited matter whether of text or +figure. Nor is mere acknowledgment of loan or purchase to the +publisher, institution or individual who may own the block or stone +what I refer to. But that acknowledgment to the author of the +figure or the work in which it first appears which is part of +conscientious writing, and often a valuable index as to the +reliability of the figure.</p> + +<p>It were supererogation to point out to a body of this kind the +value of the most careful and thorough work in connection with life +histories and habits, often involving as it does much microscopic +study of structure. The officers of our institutions who control +the funds, and more or less fully our conduct, are apt to be +somewhat impatient and inappreciative of the time given to anatomic +work, and where it is given for the purpose of describing species +and of synopsizing or monographing higher groups, without reference +to agriculture, I am firmly of the belief that it diverts one from +economic work, but where pursued for a definite economic purpose it +cannot be too careful or too thorough and I know of no instances +better calculated to appeal to and modify the views of those +inclined to belittle such structural study than Phylloxera and +Icerya. On the careful comparison of the European and American +specimens of <i>Phylloxera vastatrix</i>, involving the most minute +structures and details, depended originally those important +economic questions which have resulted in legislation by many +different nations and the regeneration of the affected vineyards of +Europe, of our own Pacific coast, and of other parts of the world +by the use of American resistant stocks. In the case of <i>Icerya +purchasi</i> the possibilities of success in checking it by its +natural enemies hung at one time upon a question of specific +difference between it and the <i>Icerya sacchari</i> of +Signoret—a question of minute structure which the +descriptions left unsettled and which could only be settled by the +most careful structural study and the comparison of the types, +involving a trip to Europe.</p> + +<h3>CONCLUSION.</h3> + +<p>I have thus touched, gentlemen, upon a few of the many subjects +that crowd upon the mind for consideration on an occasion like +this—a few gleanings from a field which is passing rich in +promise and possibility. It is a field that some of us have +cultivated for many years and yet have only scratched the surface, +and if I have ventured to suggest or admonish, it is with the +feeling that my own labors in this field are ere long about to end +and that I may not have another occasion.</p> + +<p>At no time in the history of the world has there, I trow, been +gathered together such a body of devoted and capable workers in +applied entomology. It marks an era in our calling and, looking +back at the progress of the past fifteen years, we may well ponder +the possibilities of the next fifteen. They will be fruitful of +grand results in proportion as we persistently and combinedly +pursue the yet unsolved problems and are not tempted to the +immediate presentation of separate facts, which are so innumerable +and so easily observed that their very wealth becomes an element of +weakness. Epoch-making discoveries result only from this power of +following up unswervingly any given problem, or any fixed ideal. +The kerosene emulsion, the Cyclone nozzle, the history of +<i>Phylloxera vastatrix</i>, of <i>Phorodon humuli</i>, of +<i>Vedalia cardinalis</i>, are illustrations in point, and while we +may not expect frequent results as striking or of as wide +application as these, there is no end of important problems yet to +be solved and from the solution of which we may look for similar +beneficial results. Applied entomology is often considered a sordid +pursuit, but it only becomes so when the object is sordid. When +pursued with unselfish enthusiasm born of the love of investigation +and the delight in benefiting our fellow men, it is inspiring, and +there are few pursuits more deservedly so, considering the vast +losses to our farmers from insect injury and the pressing need that +the distressed husbandman has for every aid that can be given him. +Our work is elevating in its sympathies for the struggles and +suffering of others. Our standard should be high—the pursuit +of knowledge for the advancement of agriculture. No official +entomologist should lower it by sordid aims.</p> + +<p>During the recent political campaign the farmer must have been +sorely puzzled to know whether his interests needed protection or +not. On the abstract question of tariff protection to his products +we, as entomologists, may no more agree than do the politicians or +than does the farmer himself. But ours is a case of protection from +injurious insects, and upon that there can nowhere be division of +opinion. It is our duty to see that he gets it with as little tax +for the means as possible.</p> + +<a id="Footnote_1c" name="Footnote_1c"></a><a href= +"#FNanchor_1c">[1]</a> + +<div class="note">Address of Dr. C.V. Riley at the annual meeting +of the Association of Economic Entomologists, Champaign, Ills., +November 11 to 14, 1890.</div> + +<hr /> +<h2><a id="iv_1" name="iv_1"></a>POTASH SALTS.<a id="FNanchor_1d" +name="FNanchor_1d"></a><a href="#Footnote_1d"><sup>1</sup></a></h2> + +<p>My attention was attracted to potash salts as an insecticide, by +the casual remark of an intelligent farmer, that washing his young +pear trees with a muriate of potash solution cleared them of +scales. The value of this substance for insecticide purposes, +should its powers be sufficient, struck me at once, and I began +investigation. It was unluckily too late in the season for field +experiments of the nature desired; but it is the uniform testimony +of farmers who have used either the muriate or the kainit in the +cornfields, that they have there no trouble with grubs or cut +worms. Mr. E.B. Voorhees, the senior chemist of the station, +assures me that on his father's farm the fields were badly +infested, and replanting cornhills killed by grubs or wire worms +was a recognized part of the programme. Since using the potash +salts, however, they have had absolutely no trouble, and even their +previously worst-infested fields show no further trace of injury. +The same testimony comes from others, and I feel safe in +recommending these salts, preferably kainit, to those who are +troubled with cut worms or wire worms in corn.</p> + +<h3>EXPERIMENTS.</h3> + +<p>A lot of wire worms (<i>Iulus</i> sp.) brought in from potato +hills were put into a tin can with about three inches of soil and +some potato cuttings, and the soil was thoroughly moistened with +kainit, one ounce to one pint of water. Next morning all the +specimens were dead. A check lot in another can, moistened with +water only, were healthy and lived for some days afterward.</p> + +<p>A number of cabbage maggots placed on the soil impregnated with +the solution died within twelve hours.</p> + +<p>To test its actual killing power, used the solution, one ounce +kainit to one pint water, to spray a rose bush badly infested with +plant lice. Effect, all the lice dead ten hours later; the younger +forms were dropping within an hour.</p> + +<p>Sprayed several heads of wheat with the solution, and within +three hours all the aphides infesting them were dead.</p> + +<p>Some experiments on hairy caterpillars resulted +unsatisfactorily, the hair serving as a perfect protection against +the spray, even from the atomizer.</p> + +<p>To test its effect on the foliage, sprayed some tender shoots of +rose and grape leaves, blossoms, and clusters of young fruit. No +bad effect observable 24 hours later. There was on some of the +leaves a fine glaze of salt crystals, and a decided salt taste was +manifest on all.</p> + +<p>Muriate of potash of the same strength was tested as follows: +Sprayed on some greenhouse camellias badly infested by mealy bugs, +it killed nearly all within three hours, and six hours later not a +living insect was found. The plants were entirely uninjured by the +application.</p> + +<p>Thoroughly sprayed some rose bushes badly infested with aphides, +and carried off some of the worst branches. On these the lice were +dead next morning; but on the bushes the effect was not so +satisfactory, most of the winged forms and many mature wingless +specimens were unaffected, while the terminal shoots and very young +leaves were drooping as though frosted. All, however, recovered +later.</p> + +<p>The same experiment repeated on other, hardier roses, resulted +similarly so far as the effect on the aphides was concerned, but +there was no injury to the plant.</p> + +<p>Used this same mixture on the caterpillars of <i>Orgyia +leucostigma</i> with unsatisfactory effect, and with the same +results used it on a number of other larvæ. Used on the rose +leaf roller, <i>Cacæcia rosaceana</i>, it was promptly +effective.</p> + +<p>Tested for injury to plants, it injured the foliage and flowers +of wisteria, the younger leaves of maple and grape, and the finer +kinds of roses.</p> + +<p>From these few experiments kainit seems preferable to the +muriate, as acting more effectively on insects and not injuriously +on plants. For general use on plants it is not to be recommended. +It is otherwise on underground species, where the soil will be +penetrated by the salts and where the moisture evaporates but +slowly, and the salt has a longer and better chance to act. The +best method of application would be a broadcasting in fertilizing +quantity before or during a rain, so as to carry the material into +the soil at once. In cornfields infested with grubs or wire worms, +the application should be made before planting. Where it is to be +used to reach root lice, it should be used when the injury is +beginning. When strawberry beds are infested by the white grub, the +application should be made when cultivating or before setting +out.</p> + +<p>The potash salts have a high value as fertilizers, and any +application made will act as a stimulant as well as insecticide, +thus enabling the plants to overcome the insect injury as well as +destroying the insect.</p> + +<p>In speaking on this subject in Salem county, I learned from +farmers present that those using potash were not troubled with the +corn root louse to any extent, and also that young peach trees have +been successfully grown in old lice-infested orchards, where +previously all died, by first treating the soil with kainit of +potash.</p> + +<a id="Footnote_1d" name="Footnote_1d"></a><a href= +"#FNanchor_1d">[1]</a> + +<div class="note">By John B. Smith, entomologist. Potash as an +insecticide is not entirely new, but has never been brought out +with the prominence I think it deserves.—<i>N.J. Ag. Col. +Exp. St., Bulletin 75.</i></div> + +<hr /> +<p><a id="vii_1" name="vii_1"></a>A meteorological station has been +built on Mont Blanc, at an elevation of 13,300 feet, under the +direction of M. Vallot. It required six weeks to deliver the +materials. The instruments are self-registering and are to be +visited in summer every fifteen days if possible, the instruments +being left to register between the visits. In the winter the +observatory will be entirely inaccessible. This is the highest +scientific station in Europe, but is 847 feet lower than the Pike's +Peak station in Colorado.</p> + +<hr /> +<h2><a id="v_1" name="v_1"></a>THE EXPENSE MARGIN IN LIFE +INSURANCE.</h2> + +<p>The principle of mutuality requires that the burden of expense +in life insurance should be borne by all the members equally; but, +even with the most careful adjustment, the allowance usually made +is considerably in excess of what is needed in the regular +companies doing business on the "level premium" plan.</p> + +<p>It is customary in these companies to add to the net premium a +percentage thereof to cover the expense account. This practice, +though in harmony with the "commission system," is so clearly +defective and so far removed from the spirit of life insurance +mathematics, that it scarcely deserves even this passing +notice.</p> + +<p>It is generally understood that these corporations combine the +functions of the savings bank and life insurance company, and it is +only by separating the two in our minds as far as possible that we +can obtain a clear conception of the laws that should govern the +apportionment of the expenses among the great variety of +policies.</p> + +<p>While it is a comparatively simple matter to state the amount of +either the insurance or savings bank element in a single policy, it +is by no means easy, as things go, to classify the company's actual +expenses on this basis.</p> + +<p>Fortunately, we can pretty accurately determine what these +amounts should be in any particular case.</p> + +<p>In the first place, there are institutions in our midst devoted +solely to receiving and conserving small sums of money; doing, in +fact, exactly what our insurance companies are undertaking to do +with the reserve and contributions thereto. These savings banks are +required by law to make returns to the State commissioner, from +whose official report we can get a very good idea of the expense +attendant on doing this business.</p> + +<p>Confining ourselves to the city banks, where the conditions more +nearly resemble those of the insurance companies, we find in +thirty-eight combined institutions for saving in the State of +Massachusetts a deposit in 1888 of $192,174,566, taken care of at +an aggregate cost of $455,387, or about 24-100 of one per cent.</p> + +<p>The same ratio carried out for all the savings banks in +Massachusetts gives a trifle over 25-100 of one per cent.; we may, +therefore, consider ¼ of one per cent. as expressing pretty +nearly the cost of receiving, paying out, and investing the savings +of the people.</p> + +<p>We must remember in this connection that in the popular +estimation, the savings bank is an important factor in the public +welfare, and in the towns and smaller cities there are often found +public spirited men willing to give their services to encourage +this mode of saving; but public sentiment has not yet given to life +insurance the place which it is destined, sooner or later, to +occupy by the side of the savings bank. Hence the services of able +managers can only be obtained by a liberal outlay of the corporate +funds. A satisfactory adjustment of the matter of expenses will, +perhaps, do more than anything else to bring about this recognition +on the part of the public.</p> + +<p>In the case of the savings bank it is safe to say that for +double the present outlay a liberal salary could be paid to all the +officers. Following the analogy, we are led to infer that if this +be the case in savings banks, then ½ of one per cent. of the +reserve should be an ample allowance for the special labor required +in the purely banking portion of the business.</p> + +<p>In this we have the concurrence of the late Elizur Wright. In an +essay on this subject he says:</p> + +<blockquote> +<p>"The expenses of the five largest savings banks in Boston, in +1869, did not exceed 4-10 of one per cent. on $28,000,000 deposited +in them. They certainly had twice as many transactions, in +proportion to the deposits, as any life insurance company could +have with the same amount of reserve, so that ½ of one per +cent. on the reserve seems to be ample for all working expenses +save those of maintaining the agencies and collecting the +premiums."</p> +</blockquote> + +<p>This need hardly be looked upon as an admission that it costs +twice as much to care for the funds of a life insurance company as +for those of a savings bank. A liberal expense allowance must be +made at the outset, seeing that an error in this particular cannot +easily be rectified after the policy is issued. The dividend, or, +to speak more correctly, the annual return of surplus, will correct +any overpayment on this account.</p> + +<p>There is another expense which seems inevitable. This is the +government tax on insurance companies, amounting in the aggregate +to nearly 1/3 of one per cent. on the reserve.</p> + +<p>When we consider that these institutions are intended to +encourage thrift and to relieve the community from the care of +numberless widows and orphans, it seems a clear violation of the +principles of political economy to levy a tax on this business; +still, whatever our opinion may be as to the justice or injustice +of the imposition, the tax is maintained and must be provided for. +Consequently a further allowance of ½ of one per cent. must +be added to the net premium to cover the same, making a total of 1 +per cent. of the reserve for banking expenses and taxes. +Considering this point as settled for the time being, let us +proceed to investigate the insurance expenses.</p> + +<p>Here, again, we are fortunate in being able to refer to the +official reports of a class of corporations doing nearly, if not +quite pure insurance.</p> + +<p>The assessment societies, outside of the fraternal and +benevolent, reporting in 1889 to the insurance commissioner of +Massachusetts, show outstanding risks amounting to $733,515,366. +Losses to the amount of $7,270,238 were paid during the year at a +cost for transacting the business of $2,403,053, which includes +among other items "agency expenses and commissions," which amount +to about $1,203,000, or 17 per cent. of the cost value of the +insurance actually done. It would seem as if an allowance of 20 per +cent. would be a liberal one in the case of the regular companies, +which surely have as good facilities for doing business as the +assessment societies.</p> + +<p>As far as insurance is concerned, there is less difference +between regular and co-operative companies than is generally +supposed. Regular companies assess each policy in advance for a +year's insurance at a time, while co-operative societies furnish +insurance only from one assessment to another. The difficulty in +the way of collecting the assessment in the latter case would seem +to be greater than in the former, owing to the more permanent +nature of the regular insurance contract.</p> + +<p>In compensating agents the assessment companies naturally pay in +proportion to the insurance obtained, inasmuch as there is no other +basis to go upon, but regular companies usually pay the agent a +percentage of the premium <i>which includes a considerable trust +fund</i> over and above the assessment for actual insurance. It is +easily seen that by the last method the agent's compensation +increases in proportion to the amount of savings bank business +forced upon the company.</p> + +<p>To realize how far we are from anything like a scientific, not +to say common sense basis for insurance expenses, we have but to +examine the following list, which gives the ratios between the +expenditures for general expenses in 1889, and those for the +extension of the business. For every $100 used in a general way, +the different companies spend for commissions and agency expenses: +$37, $66, $67, $78, $91, $106, $110, $113, $120, $140, $157, $161, +$173, $175, $186, $189, $200, $202, $222, $264, $311, $346.</p> + +<p>It will doubtless be said that I am taking a very advanced +position when I say that in the ideal life insurance scheme there +is no place for the commission system. Solicitors will be a +necessity only so long as they are in the field, but fifty years of +life insurance has taught our community its true value and, thanks +to the modern press, the institution it is no more likely to fall +into desuetude than is Christianity or the moral law.</p> + +<p>For the convenience of bringing the company to the individual, +the latter should be willing to pay a fee. The man who renders +another a service or puts his superior knowledge at another's +disposal should look to the party benefited for his remuneration. +Any compensation given for such service to a go-between by a mutual +company is paid by all, and the question arises, Is the advantage +to the company of sufficient importance to warrant the imposition +of this tax upon all its members promiscuously? The following, from +the Massachusetts Insurance Commissioner's Report for 1885, leaves +no doubt as to the convictions of the writer on this important +matter:</p> + +<blockquote> +<p>"The expensiveness of the life insurance policy is not because +the level net premium is too high, for the premium is absolutely +just, and the policy holder gets full value; but the complaint +justly applies to the excessive expense charge. A person who wants +insurance, life or fire or other, should be able to buy it at first +cost without paying tribute of profits to middlemen. To that +complexion the matter will finally be brought by the force of +intelligent opinion, whatever resistance may be opposed by persons +whose thrift lies in the perpetuation of the expensive system now +in fashion."</p> +</blockquote> + +<p>It requires but a slight degree of prophetic vision to predict +that in a very few years the companies in self defense will be +obliged to change their method of compensating agents.</p> + +<p>Several companies have already begun the reform by grading +commissions; granting a percentage proportional to the amount of +insurance likely to be done on the policy. Other companies have +simply reduced the amount of the commission rate, thus virtually +withdrawing from active competition.</p> + +<p>This will, in a certain degree, explain the wide variation in +the figures given above, where it is noticed that, in five +companies out of twenty-two, the total agency expenditures amount +to less than the general expenses, while in six cases the companies +spend more than double as much on the former as on the latter. In +either class we find representatives of the five largest companies +in the country.</p> + +<p>On applying the foregoing ratios to the business of the existing +companies we find that, calling the theoretical expenses $100, the +actual expenditures for 1889 were as follows: $112.67, $118.34, +$150.40, $194.48, $208.16, $208.53, $228.66, $235.89, $248.44, +$250.79, $258.33, $258.57, $265.14, $267.19, $267.92, $274.47, +$294.17, $314.96, $335.70, $377.94, $616.70.</p> + +<p>In this discouraging exhibit there is one ray of comfort. The +combined assets of the two companies heading the list amount to +over $100,000,000. There is no question as to their financial +standing, and both show a large increase in membership over the +previous year. I may also say here that it is a difficult matter to +get at the actual "cost of insurance" in the various companies. +Many of them, on their own acknowledgment, do not compute the +advance cost of carrying their "amount at risk," and others, for +reasons of their own, do not care to state the figures. In cases +where the correct figures were not obtainable, I have assumed the +cost to have been 1-1/3 per cent. of the mean amount at risk.</p> + +<p>If we should, in our comparison, omit the actual agency expenses +and commissions, the ratios would stand as follows:</p> + +<p>Where I would allow $100 the companies actually used: $43.17, +$55.90, $65.21, $77.21, $82.39, $88.34, $91.99. $91.98. $92.19, +$94.65, $97.15. $99.55. $99.11. $102.86, $109.35, $125.05, $133.03, +$141.92, $195.90, $207.06, $287.72.</p> + +<p>As might be supposed, the first two ratios are those companies +before alluded to. These companies might have doubled their +advertising account and expended $300,000 between them on agents' +salaries, and still have kept within my allowance.</p> + +<p>Admitting, for the present at least, the reasonableness of the +proposed allowance for the expenses of the banking and insurance +departments of the business, we have before us the problem how to +equitably adjust the burden among the great variety of +policies.</p> + +<p>In the first place, <i>there should be no policy in the company +that does not contribute its proportionate share of the expense +allowance during every year of its life</i>. I make a special point +of this, for at present the policies which have become paid up, +either by the payment of a single premium at the outset or by the +completion of a stipulated number of payments, contribute +practically nothing to the expense account after the premium +payments cease.</p> + +<p>The following plan, I think, complies with all the requirements +of the problem. By the proposed method every policy, at all stages +of its existence, contributes its exact share to the expense fund, +whatever its plan of payment may be.</p> + +<p>Let us, as an illustration, examine the case of a ten year +endowment policy, taken out at age 30, and consider it under three +aspects, first, as paid for in advance by a single payment, second, +as paid by five annual payments, and third, as paid for annually +throughout the term. I have used this short term endowment policy +simply for convenience, the rule applying equally to policies of +longer term or to the ordinary life policy, which is, in fact, an +endowment policy payable at death or age 100.<a id="FNanchor_1e" +name="FNanchor_1e"></a><a href="#Footnote_1e"><sup>1</sup></a></p> + +<p>Taking the case of the single premium endowment policy for +$1,000, we find that the following sums are required, each year to +provide for the care of the reserve and to pay the government fees +(1 per cent. of reserve):</p> + +<div class="ctr"> +<table border="0" width="50%" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="left" /> +<col align="center" /> +<col span="2" align="right" /> +<col align="center" /> +<col align="right" /></colgroup> + +<tr> +<td>1st</td> +<td>year</td> +<td>$6.9982</td> +<td>6th</td> +<td>year</td> +<td>$8.4136</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>7.2560</td> +<td>7th</td> +<td>"</td> +<td>8.7381</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>7.5258</td> +<td>8th</td> +<td>"</td> +<td>9.0781</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>7.8082</td> +<td>9th</td> +<td>"</td> +<td>9.4346</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>8.1039</td> +<td>10th</td> +<td>"</td> +<td>9.8086</td> +</tr> +</table> +</div> + +<p>The insurance expenses should be covered by the 20 per cent. +allowance given below:</p> + +<div class="ctr"> +<table border="0" width="50%" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="left" /> +<col align="center" /> +<col span="2" align="right" /> +<col align="center" /> +<col align="right" /></colgroup> + +<tr> +<td>1st</td> +<td>year</td> +<td>$ .4422</td> +<td>6th</td> +<td>year</td> +<td>$ .2566</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>.4100</td> +<td>7th</td> +<td>"</td> +<td>.2076</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>.3762</td> +<td>8th</td> +<td>"</td> +<td>.1556</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>.3402</td> +<td>9th</td> +<td>"</td> +<td>.0988</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>.2996</td> +<td>10th</td> +<td>"</td> +<td>.0344</td> +</tr> +</table> +</div> + +<p>Consequently the total contribution required from this policy +each year is:</p> + +<div class="ctr"> +<table width="50%" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="left" /> +<col align="center" /> +<col span="2" align="right" /> +<col align="center" /> +<col align="right" /></colgroup> + +<tr> +<td>1st</td> +<td>year</td> +<td>$7.4404</td> +<td>6th</td> +<td>year</td> +<td>$8.6702</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>7.6660</td> +<td>7th</td> +<td>"</td> +<td>8.9457</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>7.9020</td> +<td>8th</td> +<td>"</td> +<td>9.2337</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>8.1484</td> +<td>9th</td> +<td>"</td> +<td>9.5334</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>8.4034</td> +<td>10th</td> +<td>"</td> +<td>9.8430</td> +</tr> +</table> +</div> + +<p>The present value of all these contributions is found to be, at +4 per cent. interest, $71.6394; in other words, this sum paid at +the outset, provides a fund from which we may deduct the current +expenses of each year in advance, and by accumulating the balance +at the assumed rate of interest from year to year, we shall have +enough to pay the anticipated expenses, leaving nothing over.</p> + +<p>In the above case the sums in hand at the beginning of the year +are as follows:</p> + +<div class="ctr"> +<table width="50%" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="left" /> +<col align="center" /> +<col span="2" align="right" /> +<col align="center" /> +<col align="right" /></colgroup> + +<tr> +<td>1st</td> +<td>year</td> +<td>$71.3694</td> +<td>6th</td> +<td>year</td> +<td>$42.6981</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>66.7669</td> +<td>7th</td> +<td>"</td> +<td>35.3890</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>61.4650</td> +<td>8th</td> +<td>"</td> +<td>27.5009</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>55.7055</td> +<td>9th</td> +<td>"</td> +<td>18.9979</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>49.4594</td> +<td>10th</td> +<td>"</td> +<td>9.8430</td> +</tr> +</table> +</div> + +<p>We find a somewhat different condition existing during the first +years of a 5-year endowment policy. As there is more insurance and +less banking, the requirements are as follows:</p> + +<div class="ctr"> +<table align="center" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="right" /> +<col align="center" /> +<col align="right" span="4" /></colgroup> + +<tr> +<th></th> +<th></th> +<th>1 P. Ct.<br /> + on Reserve.</th> +<th>20 P. Ct.<br /> + on Cost.</th> +<th>Total.</th> +<th>Initial Fund.</th> +</tr> + +<tr> +<td>1st</td> +<td>year</td> +<td>$1.5038</td> +<td>$1.2572</td> +<td>$2.7610</td> +<td>$12.9769</td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>3.0406</td> +<td>1.0216</td> +<td>4.0622</td> +<td>23.6015</td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>4.6503</td> +<td>.7852</td> +<td>5.4355</td> +<td>33.2979</td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>6.3367</td> +<td>.5378</td> +<td>6.8745</td> +<td>41.9538</td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>8.1039</td> +<td>.2996</td> +<td>8.4035</td> +<td>49.4594</td> +</tr> + +<tr> +<td>6th</td> +<td>"</td> +<td>8.4136</td> +<td>.2566</td> +<td>8.6702</td> +<td>42.6981</td> +</tr> + +<tr> +<td>7th</td> +<td>"</td> +<td>8.7381</td> +<td>.2076</td> +<td>8.9257</td> +<td>35.3890</td> +</tr> + +<tr> +<td>8th</td> +<td>"</td> +<td>9.0781</td> +<td>.1556</td> +<td>9.2337</td> +<td>27.5009</td> +</tr> + +<tr> +<td>9th</td> +<td>"</td> +<td>9.4346</td> +<td>.0988</td> +<td>9.5334</td> +<td>18.9979</td> +</tr> + +<tr> +<td>10th</td> +<td>"</td> +<td>9.8086</td> +<td>.0344</td> +<td>9.8430</td> +<td>9.8430</td> +</tr> +</table> +</div> + +<p>As the premium payments extend over only five years, the expense +contributions must all be paid during that time and are most +conveniently made by a uniform addition to the net premium.</p> + +<p>The present value of the amounts in column 3 is $60.0819, and +the equivalent annuity for five years is $12.9769. This amount, +received for five consecutive years, will put the company in funds +to pay current expenses and leave a reserve of $42.6981 at the +beginning of the sixth year, which, as we have seen in the analysis +of the single-premium policy, is the sum required for future +expenses on the paid up basis.</p> + +<p>In like manner we find that the 10-year annuity equivalent to +the present value of the annual contributions in the case of an +annual-payment policy is $5.534, thus:</p> + +<div class="ctr"> +<table align="center" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="6"> +<col align="right" /> +<col align="center" /> +<col align="right" span="4" /></colgroup> + +<tr> +<th></th> +<th></th> +<th>1 P. Ct.<br /> + on Reserve.</th> +<th>20 P. Ct.<br /> + on Cost.</th> +<th>Total.</th> +<th>Initial Fund.</th> +</tr> + +<tr> +<td>1st</td> +<td>year</td> +<td>$.8234</td> +<td>$1.3514</td> +<td>$2.1748</td> +<td>$ 5.5340</td> +<td></td> +</tr> + +<tr> +<td>2d</td> +<td>"</td> +<td>1.6473</td> +<td>1.2478</td> +<td>2.8951</td> +<td>9.0275</td> +<td></td> +</tr> + +<tr> +<td>3d</td> +<td>"</td> +<td>2.5096</td> +<td>1.1388</td> +<td>3.6484</td> +<td>11.9116</td> +<td></td> +</tr> + +<tr> +<td>4th</td> +<td>"</td> +<td>3.4124</td> +<td>1.0210</td> +<td>4.4334</td> +<td>14.1277</td> +<td></td> +</tr> + +<tr> +<td>5th</td> +<td>"</td> +<td>4.3572</td> +<td>.8916</td> +<td>5.2488</td> +<td>15.6161</td> +<td></td> +</tr> + +<tr> +<td>6th</td> +<td>"</td> +<td>5.3479</td> +<td>.7534</td> +<td>6.1013</td> +<td>16.3160</td> +<td></td> +</tr> + +<tr> +<td>7th</td> +<td>"</td> +<td>6.3853</td> +<td>.5966</td> +<td>6.9819</td> +<td>16.1572</td> +<td></td> +</tr> + +<tr> +<td>8th</td> +<td>"</td> +<td>7.4726</td> +<td>.4270</td> +<td>7.8996</td> +<td>15.0763</td> +<td></td> +</tr> + +<tr> +<td>9th</td> +<td>"</td> +<td>8.6127</td> +<td>.2418</td> +<td>8.8545</td> +<td>12.9977</td> +<td></td> +</tr> + +<tr> +<td>10th</td> +<td>"</td> +<td>9.8086</td> +<td>.0344</td> +<td>9.8430</td> +<td>9.8430</td> +<td></td> +</tr> +</table> +</div> + +<p>The present value of the ten yearly expense items given in the +"total" column above is $46.6812, which is equal to a ten-year +annuity of $5.534. The several premiums stand now as follows:</p> + +<p class="ctr">ENDOWMENT: $1,000, AGE 30, PAYABLE AT DEATH OR +40</p> + +<div class="ctr"> +<table align="center" border="0" cellpadding="4" cellspacing="0" +summary=""> +<colgroup span="3"> +<col align="left" /> +<col align="right" span="3" /></colgroup> + +<tr> +<td></td> +<td>Net Prem.<a id="FNanchor_2e" name="FNanchor_2e"></a><a href= +"#Footnote_2e"><sup>2</sup></a></td> +<td>Margin.</td> +<td>Total.</td> +</tr> + +<tr> +<td>At single premium.</td> +<td>$687.228</td> +<td>$71.6394</td> +<td>$758.8674</td> +</tr> + +<tr> +<td>At five premiums.</td> +<td>150.615</td> +<td>12.9769</td> +<td>163.5939</td> +</tr> + +<tr> +<td>At annual premiums.</td> +<td>84.172</td> +<td>5.5340</td> +<td>89.7060</td> +</tr> +</table> +</div> + +<p>By the actuaries' rate we have, with the customary loading for +expense:</p> + +<blockquote> +<p>Single premium: $721.66 (loaded, $34.36). Five premiums, $188.70 +(loaded $37.78). Annual premium, $105.65 (loaded $21.11).</p> +</blockquote> + +<p>Admitting the correctness of the new method, we must conclude +that the present single premium is not sufficiently loaded to cover +its own expenses, while the annual payment policy pays more than +its just share. A prominent and thoroughly informed life insurance +president says in this connection: "Many of the policies, +particularly the short term endowments, are charged with too high a +percentage of expenses to prove a good investment at maturity or +profitable to the insured in case of surrender." This is not to be +wondered at when the applicant for a 10-year endowment policy sees +at a glance that he must pay, in the gross, more than is returned +unless he should die in the interim, in which case a plain "life" +or "term" policy would have answered the purpose. Under the new +system of assessing expenses one form is as desirable as another, +from the standpoint of the insured or the company.</p> + +<p>The new premium for the 10-year endowment policy, $89.71, +commends itself at once to the applicant, who can easily see that +his total outlay must fall short of the amount ultimately to be +realized, of course, disregarding interest and probable dividends +in both cases.</p> + +<p>In discounting the future expense contributions I have not taken +the chances of dying into account. Hence the expense reserve in any +instance applies only to that individual case, and, in the event of +death or surrender before the maturity of the policy, the amount of +the expense fund not used would naturally revert to the +insured.</p> + +<p>The scheme of expense assessment outlined above will doubtless +be pronounced impracticable by the majority of insurance men.</p> + +<p>Such a far reaching reform is too much to hope for, at least in +the immediate future.</p> + +<p>No well informed life insurance expert will deny that there are +opportunities for improvement in the business, but to graft new +methods on old companies is a hopeless undertaking.</p> + +<p>It is well, however, to have new methods well matured in advance +of the public demand, and I feel convinced that the ideas here set +forth are in the line of the reform which, before long, must be +instituted by the companies if they would retain the confidence and +patronage of the community.</p> + +<p>Doubtless many insurance presidents could tell of suggestions +which have impressed them favorably and which they would gladly +have adopted were it not for the injustice done thereby to older +members and the changes necessary to bring existing contracts into +conformity with the new system. Similar objections may be urged +against the ideas here advanced, and I must confess I hardly see a +way by which the present suggestions can be utilized by existing +companies. We can only hope that sooner or later some of the new +theories may be practically tested. Meanwhile the companies at +present in the field are doing a great work for the good of +humanity, even though their methods may be, in some particulars, +more practical than scientific.</p> + +<div class="ctr"> +<table summary="" width="100%"> +<tr> +<td align="left">Winchester, Mass.</td> +<td align="right">FRANK J. WILLS.</td> +</tr> +</table> +</div> + +<a id="Footnote_1e" name="Footnote_1e"></a><a href= +"#FNanchor_1e">[1]</a> + +<div class="note">The expense allowance on a plain life policy for +$1,000, taken at age 33, would be about $5.29; net premium (com. +ex. 4 per cent.), $18.04; total office premium, $23.33; present +rate $24.10.</div> + +<a id="Footnote_2e" name="Footnote_2e"></a><a href= +"#FNanchor_2e">[2]</a> + +<div class="note">Thirty American offices. Discount from middle of +year, Vx-½ or (M x 1.01961) / Dx.</div> + +<hr /> +<h2><a id="vii_2" name="vii_2"></a>THE FLOOD AT KARLSBAD.</h2> + +<p>During the flood which occurred in Germany and Bohemia, the last +week of November, Karlsbad was especially unfortunate; it suffered +such an inundation as had never before been known in the +"Sprudelstadt." On the evening of November 23, the Tepl was very +much swollen by the rain, which had continued for several days, but +it was supposed that there was no danger of a flood, as the bed of +the river had been put in proper condition. During the forenoon of +November 24, the water suddenly began to rise with such astonishing +rapidity that within half an hour all the lower streets were like +turbulent rivers and the Alte and Neue Wiese were transformed into +a lake. The stores on the Alte Wiese were under water to the roofs, +and the proprietors, who were trying to save their goods, were +surprised by the water and had to take refuge in the trees. They +were rescued by having ropes thrown to them, and during this work a +catastrophe occurred which was a great misfortune to all classes of +citizens. The beloved burgermeister of Karlsbad, Dr. Rudolf Knoll, +who had just recovered from a severe illness, was, with others, +directing the work from the balcony of one of the houses, when a +rope by which a man was being drawn through the water broke, and +the man was carried off by the waves. The fright and excitement of +the scene gave the burgermeister a shock which caused his instant +death, but the man who was in danger was brought safely out of the +water.</p> + +<p>The water was 9 ft. in Marienbaderstrasse, the Marktplatz, +Muhlbadgasse, the Sprudelgasse, Kreuzgasse, Kaiserstrasse, and +Egerstrasse, and flooded the quay, causing great destruction. All +places of business were flooded, the doors and iron shutters were +pushed in by the force of the water and the goods were carried away +or ruined.</p> + +<p>The house called "Zum Kaffeebaum" was undermined and part of it +fell to the ground; the same fate was feared for other buildings. +The Sophien and Curhaus bridges were carried away. Other bridges +were greatly damaged, and the masonry along the banks of the river +was partially destroyed. The Sprudelgasse was completely washed +out, and the condition of the Muhlbadgasse was almost as bad. The +fire department with its apparatus had great difficulty in saving +the inhabitants and guests, as there were very few boats or +pontoons at their command, and the soldiers (Pionniere) from Prague +and the firemen from the neighboring towns did not arrive until +evening. Fortunately the water began to fall in the night, and the +next day it had gone down so that it left its terrible work +visible. The Sprudel and the mineral springs were not injured, but, +on the other hand, the water pipes of the bathing establishments +and the gas pipes were completely destroyed.—<i>Illustrirte +Zeitung.</i></p> + +<hr /> +<h2><a id="ix_2" name="ix_2"></a>THEATRICAL WATER PLAYS.</h2> + +<p>In one of the plays at Hengler's Circus in London a water scene +is introduced, for which purpose the main ring is flooded with +water in a manner which is both striking and interesting.</p> + +<p class="ctr"><img src="./images/12-circus.png" alt= +"FLOODING A CIRCUS RING." title="CIRCUS RING" /><br /> + FLOODING A CIRCUS RING.</p> + +<p>The ring is entirely lined with stout macintosh sheeting, and +into this, from two large conduits. 23,000 gallons of water are +poured, the tank being filled to a depth of some 2 ft. in the +remarkably short time of 35 seconds. A steamboat and other small +craft are then launched and the adventures of the heroine then +proceed. She falls overboard, we believe, but is saved after +desperate and amusing struggles. Our engravings, which are from the +<i>Graphic</i>, illustrate the mode of filling the ring with water, +and the steamboat launch.</p> + +<p class="ctr"><img src="./images/12-boat.png" alt= +"A THEATRICAL STEAMBOAT." title="STEAMBOAT" /><br /> + A THEATRICAL STEAMBOAT.</p> + +<hr /> +<h2><a id="ix_1" name="ix_1"></a>SCIENCE IN THE THEATER.</h2> + +<p>In the pretty little hall of the Boulevard des Italiens, at +Paris, a striking exhibition of simulated hypnotism is given every +evening.</p> + +<p>This entertainment, which has met with much success, was devised +by Mr. Melies, director of the establishment, which was founded +many years ago by the celebrated prestidigitator whose popular name +(Robert Houdin) it still bears. This performance carries +instruction with it, for it shows how easily the most surprising +phenomena of the pathologic state can be imitated. To this effect, +several exhibitions are given every evening.</p> + +<p>Mr. Harmington, a convinced disciple of Mesmer, asks for a +subject, and finds one in the hall. A young artist named Marius +presents himself. Mr. Harmington makes him perform all sorts of +extravagant acts, accompanied with a continuous round of pantomimes +that are rendered the more striking by the supposed state of +somnipathy of the subject. At the moment at which Marius is +finishing his most extraordinary exercises, a policeman suddenly +breaks in upon the stage in order to execute the recent orders +relative to hypnotism. But he himself is subjugated by Mr. +Harmington and thrown down by the vibrations of which the +encephalus of this terrible magnetizer is the center. When the +curtain falls, the representative of authority is struggling +against the catalepsy that is overcoming him.</p> + +<p>All the phenomena of induced sleep are successively simulated +with much naturalness by Mr. Jules David, who plays the part of +Marius in this pleasing little performance.</p> + +<p>At a certain moment, after skillfully simulated passes made by +the magnetizer, Mr. David suddenly becomes as rigid as a stick of +wood, and falls in pivoting on his heels (Fig. 1). Did not Mr. +Harmington run to his assistance, he would inevitably crack his +skull upon the floor, but the magnetizer stands just behind him in +order to receive him in his arms. Then he lifts him, and places him +upon two chairs just as he would do with a simple board. He places +the head of the subject upon the seat of one of the chairs and the +heels upon that of the other. Mr. David then remains in a state of +perfect immobility. Not a muscle is seen to relax, and not a motion +betrays the persistence of life in him. The simulation is +perfect.</p> + +<p class="ctr"><a href="./images/13-fig1.png"><img src= +"./images/13-fig1_th.jpg" alt="FIG. 1.—CATALEPTIC RIGIDITY." +title="RIGIDITY" /></a><br clear="all" /> + FIG. 1.—CATALEPTIC RIGIDITY.</p> + +<p>In order to complete the astonishment of the spectators, Mr. +Harmington seats himself triumphantly upon the abdomen of the +subject and slowly raises his feet and holds them suspended in the +air to show that it is the subject only that supports him, without +the need of any other point of support than the two chairs (Fig. +2).</p> + +<p class="ctr"><a href="./images/13-fig2.png"><img src= +"./images/13-fig2_th.jpg" alt= +"FIG. 2.—EXPERIMENT ON THE SAME SUBJECT." title= +"EXPERIMENT" /></a><br clear="all" /> + FIG. 2.—EXPERIMENT ON THE SAME SUBJECT.</p> + +<p>Usually, there are plenty of persons ingenuous enough to think +that Mr. David is actually in a cataleptic sleep, one of the +characters of which is cadaveric rigidity.</p> + +<p>As Mr. David's neck is entirely bare, it is not possible to +suppose that the simulator of catalepsy wears an iron corset +concealed beneath his clothing. He has performed a feat of strength +and skill rendered easy by the exercise that he has given to the +muscles occupying the <i>colliciæ</i> of his vertebral +column. This part of the muscular system is greatly developed in +the weakest and least hardy persons. In fact, in order that man may +keep a vertical position and execute an infinite multitude of +motions in which stability is involved, nature has had to give him +a large number of different organs. The muscles of the back are +arranged upon several superposed layers, the vertebral column is +doubly recurved in order that it may have more strength, and, +finally, rachidion nerves issue from each vertebra in order to +regulate the contraction of each muscular fasciculus according to +the requirements of equilibrium. The trick is so easy that we have +seen youths belonging to the Ligue d'Education Physique immediately +imitate Mr. David after seeing him operate but once.</p> + +<p>For the sake of those who would like to perform it, we shall add +that Mr. David takes care to bend his body in the form of an arch +in such a way that the convexity shall be beneath. As Mr. +Harmington never fails to place himself in the center of the line +that joins Mr. David's head and heels, his weight is divided into +two parts, that is to say, 88 pounds on each side of the point of +support. The result is that the stress necessary is less than that +of a strong man of the Halle lifting a bag of wheat to his shoulder +or of an athlete supporting a human pyramid. The force of +contraction of the muscular fibers brought into play in this +experiment is much greater than is commonly believed. In his +lectures on physiology, Milne-Edwards cites some facts that prove +that it may exceed 600 pounds per square inch of section.</p> + +<p class="ctr"><a href="./images/13-fig3.png"><img src= +"./images/13-fig3_th.jpg" alt="FIG. 3.—THE PERFORATE ARM." +title="PERFORATE ARM" /></a><br clear="all" /> + FIG. 3.—THE PERFORATE ARM.</p> + +<p>The experiment on cadaveric rigidity is followed by others in +insensibility. Mr. David, without wincing, allows a poignard to be +thrust into his arm, which Mr. Harmington has previously +"cataleptized" (Fig. 3). This trick is performed by means of a +blade divided into two parts that are connected by a semicircle. +This process is well known to prestidigitators, but it might be +executed in a genuine manner. In fact, on replacing the poignard by +one of the gold needles used by physicians for acupuncture, it +would be possible to dispense with prestidigitation. Under such +conditions it is possible to transpierce a person's arm. The pain +is supportable, and consists in the sensation of a prick produced +in the passage of the needle through the skin. As for the muscular +flesh, that is of itself perfectly insensible. The needle, upon the +necessary antiseptic precautions being taken, may traverse the +veins and arteries with impunity, provided that it is not allowed +to remain long enough to bring about the formation of a clot of +coagulated blood (Fig. 4).</p> + +<p class="ctr"><img src="./images/13-fig4.png" alt= +"FIG. 4.—AN ARM TRANSPIERCED BY A NEEDLE." title= +"ARM PIERCED BY NEEDLE" /><br /> + FIG. 4.—AN ARM TRANSPIERCED BY A NEEDLE.</p> + +<p>We think it of interest to add that it is necessary that the +experiment be performed by a practitioner if one desires to +demonstrate upon himself a very curious physiological fact that has +been known from the remotest antiquity. It has been employed for +several thousand years in Chinese medicine, for opening a passage +for the bad spirits that produce diseases. For some years past a +much more serious use has been made of it in European medicine for +introducing electric currents into the interior of the organism. In +this case the perimeter of the needle is insulated, and the +electricity flows into the organism through the point. We have +several times had these operations performed upon ourselves, and +this permits us to assert that the above mentioned facts are +absolutely true.—<i>La Nature.</i></p> + +<hr /> +<h2><a id="xi_1" name="xi_1"></a>NEWER PHYSIOLOGY AND +PATHOLOGY.</h2> + +<h3>By Prof. SAMUEL BELL, M.D.</h3> + +<p>Physiology has for many decades been a science founded on +experiment, and pathology has been rapidly pressing forward in the +same direction. To read the accounts of how certain conclusions +have been arrived at in the laboratory, by ingenious devices and by +skillful manipulations, is as fascinating as any tale of +adventure.</p> + +<p>When the microscope began its work, how discouraging was the +vastness and complexity of the discoveries which it brought to +light; how many years has it been diligently used, and how +uncertain are we still about many of its revelations! But what a +happy conjecture of man, and as proper environment takes place we +may reach better results! Let me give an illustration:</p> + +<p>Some thirty years ago, Virchow began his studies and lectures +upon cellular pathology. The enthusiasm which he awakened spread +over the whole medical world. The wonderful attention to detail, +the broad philosophy which signalized his observations, were alike +remarkable. His class room was packed with students from every +country, who thought it no hardship to struggle for a seat at eight +o'clock in the morning. With his blackboard behind him and +specimens of pathology before him, and microscopes coursing upon +railway tracks around the tables which filled the room, he was the +embodiment of the teacher; his highest honor was as discoverer. The +life and importance of the cell, both in health and disease, it has +been his work to discover and to teach. The point of view from +which he has classified tumors is founded on this basis, and +remains the accepted method. The light which he cast upon the +nature of inflammation has not yet been obscured, and while other +phenomena appear, the multiplication of cells and nuclei and the +formation of connective tissue in the process of inflammation will +always call to mind his labors.</p> + +<p>To one of Virchow's pupils, Prof. Recklinghausen, we chiefly owe +our knowledge of the phenomena of diapedesis as a part of the +inflammatory activity. How incredible it seems that masses of +living matter can make their way through the walls of blood vessels +which do not rupture and which have no visible apertures!</p> + +<p>Virchow fixed his attention upon the forms and activities of the +cells, their multiplication and degradation, and how they build up +tissues, both healthy and morbid.</p> + +<p>To another matter with which, both literally and metaphorically, +the air is filled, we must also make allusion. The existence of +micro-organisms in countless numbers is no new fact, but the +influence they may exert over living tissues has only lately become +the subject of earnest attention. So long as they were not known to +have any practical bearing upon human welfare, they interested +almost nobody, but when, however, it was shown that putrefaction of +meat is due to the agency of the <i>bacterium termo</i>, and the +decomposition of albumen to the <i>bacillus subtilis</i>; when +anthrax in cattle and sheep was found to depend on the <i>bacillus +anthracis</i>, and that in human beings it caused malignant +pustules; when suppuration of wounds was found to be associated +with micrococci; and when it was announced that by a process of +inoculation cattle could be protected against anthrax, and that by +carbolic spray and other well known precautions the suppuration of +wounds could be prevented—all the world lent its ears and +investigation at once began.</p> + +<p>Because labors in bacteriology promised to be fruitful in +practical results, the workers speedily became innumerable, and we +are accumulating a wondrous store of facts. How long now is the +list of diseases in which germs make their appearance—in +pneumonia, in endocarditis, in erysipelas, in pyæmia, in +tuberculosis, and so on and so on. One of the most striking +illustrations is the gonococcus of gonorrhœa, whose presence +in and around gives to the pus cells their virulent properties, and +when transferred to the eye works such lamentable mischief. Without +their existence the inoculation of pus in the healthy eye is +harmless; pus bearing the gonococci excites the most intense +inflammation. Similar suppurative action in the cornea is often +caused by infection of cocci. The proof of causation may be found +in the fact that the most effective cure now practiced for such +suppuration is to sterilize them by the actual cautery. Rosenbach +says that he knows six distinct microbes which are capable of +exciting suppuration in man. Their activity may be productive of a +poison, or putrefactive alkaloid, which is absorbed.</p> + +<p>There are at present two prominent theories in regard to the +infections which produce disease. The first is based upon chemical +processes, the second upon the multiplication of living organisms. +The chemical theory maintains that after the infectious element has +been received into the body it acts as a ferment, and gives rise to +certain morbid processes, upon the principle of catalysis. The +theory of organisms, or the germ theory, maintains that the +infectious elements are living organisms, which, being received +into the system, are reproduced indefinitely, and excite morbid +processes which are characteristic of certain types of disease. +This latter theory so readily explains many of the facts connected +with the development and reproduction of infectious diseases, that +it has been unqualifiedly adopted by a large number of +investigators. The proofs of this theory had not, however, advanced +beyond the demonstrations of the presence of certain forms of +bacteria in the pathological changes of a very limited number of +infectious diseases, until February, 1882, when Koch announced his +discovery of the tubercle bacillus, since which time nearly every +disease has its supposed microbe, and the race is, indeed, swift in +which the would-be discoverers press forward with new germs for +public favor.</p> + +<p>The term bacteria or microbe refers to particles of matter, +microscopic in size, which belong to the vegetable kingdom, where +they are known as fungi. If we examine a drop of stagnant water +under the microscope, amplifying say four hundred diameters, we see +it loaded with minute bodies, some mere points, others slightly +elongated into rods, all actively in motion and in various +positions, a countless confusion. If evaporation now takes place, +all is still. If we now apply moisture, the dried-up granules will +show activity, as though they had not been disturbed.</p> + +<p>All these different organisms have become familiar to us under +the generic term bacteria, which is a very unfortunate application, +as it really applies to only a single class of fungi. Cohn calls +them schizomycetes, and makes the following classifications:</p> + +<div class="note"> +<p>1. <i>Sphero-bacteria</i>, or microbes.</p> + +<p>2. <i>Micro-bacteria</i>, or bacteria.</p> + +<p>3. <i>Desmo-bacteria</i>, or bacilli.</p> + +<p>4. <i>Spiroteria</i>, or spirillæ.</p> +</div> + +<p>The <i>spiro-bacteria</i>, or micrococci, are the simplest of +the fungi, and appear as minute organisms of spherical form. They +multiply by fission, a single coccus forming two, these two +producing four, and so on. They present a variety of appearances +under the microscope. From single isolated specimens (which under +the highest magnifying power present nothing beyond minute points) +you will observe them in pairs, again in fours, or in clusters of +hundreds (forming zoöglea) and still adhering together, +forming chains. When a given specimen is about to divide, it is +seen to elongate slightly, then a constriction is formed, which +deepens until complete fission ensues.</p> + +<p>Micrococci possess no visible structure. They consist of a +minute droplet of protoplasm (mycroprotein) surrounded by a +delicate cell membrane. Certain forms are embedded in a capsule +(diameter 0.0008 to 0.0001 millimeter).</p> + +<p>These little organisms, when observed in a fluid like blood, +sputum, etc., are found to present very active movements, although +provided with no organs of locomotion.</p> + +<p>This Brownian motion is possessed by almost every minute +particle of matter, organic and inorganic, and is not due to any +inherent power of the individual. They are almost omnipresent, +abounding in the air, the earth, the water, are always found in +millions where moist organic matter is undergoing decomposition, +and are associated with the processes of fermentation—in +fact, they are essential to it. The souring of milk succeeds the +multiplication of these germs. Certain varieties are pigmented, and +we observe colonies of chromogenic cocci multiplying upon slices of +boiled potato, eggs, etc., presenting all the colors of the +rainbow. All of these germs are not the cause of disease. Certain +species, however (termed pathogenic), are always associated with +certain diseased conditions.</p> + +<p>The <i>bacteria-termo</i>—micro-bacteria—are +slightly elongated, and inasmuch as they multiply by division, +frequently appear coupled together, linked in pairs, and in chains. +They are generally found in putrefying liquids, especially +infusions of vegetable matter. They possess mobility to a +remarkable degree. Observing a field of bacteria-termo under the +microscope, they may be seen actively engaged in twining and +twisting. A flagellum has been demonstrated as attached to one or +both extremities. This is too minute to be generally resolved, even +if it is a common appendage.</p> + +<p><i>Desmo-bacteria</i> (or bacilli) are rod-like organisms, +occurring of various lengths and different thicknesses. In a slide +of the bacillus of tuberculosis and anthrax, we notice at intervals +dots which represent the spores from which, as the rods break up, +future bacilli are developed.</p> + +<p>Then we have <i>spiro-bacteria,</i> the spirilla and the +spirochetæ; the former having short open spirals, the latter +long and closely wound spirals. The <i>spirillum, volutans</i> is +often found in drinking water, and in common with some other +specimens of this class is provided with flagellæ, sometimes +at both extremities, which furnish the means of rapid locomotion. +The spiro-bacteria multiply by spores, although little is at +present known of their life history. They frequently are attached +together at their extremities, forming zigzag chains.</p> + +<p>We have seen that bacteria differ greatly in appearance from the +elongated dot of the bacterium proper, to the elongated rod or +cylinder of the bacillus, and the long spirals of spiro-bacteria. +It is unfortunate that they are not sufficiently constant in habit +to always attach themselves to one or the other of these genera. +The micrococcus has a habit of elongating at times until it is +impossible to recognize him except as a bacterium; while bacilli, +again, break up until their particles exactly resemble +micrococci.</p> + +<p>Bacteria cannot exist without water; certain forms require +oxygen, while others thrive equally well without it; some thrive in +solution of simple salts, while others require albuminoid +material.</p> + +<p>Bacteriology, with its relation to the science of medicine, is +of importance to every investigating physician; it covers our +knowledge of the relation of these minute organisms to the +ætiology of disease. What has been gained as to practical +application in the treatment of disease? This question is not +infrequently asked in a sneering manner. We can, in reply, say that +the results are not all in the future. It is encouraging that +results have been attained which have had a very important +practical bearing, and that these complaints come generally from +individuals least acquainted with scientific investigations in +bacteriology.</p> + +<p>In the study of the relation of a given bacterium to a certain +disease, it becomes necessary to attend carefully to three +different operations: First, the organism supposed to cause the +disease must be found and isolated. Second, it must be cultivated +through several generations in order that absolute purity may be +secured. Lastly, the germ must be again introduced into a healthy +living being. If the preceding steps be carried out, and the +original disease be communicated by inoculation, and the germs be +again found in the diseased body, we have no alternative; we must +conclude that we have ascertained the cause of the disease. The +importance of being familiar with the ætiology of the disease +before we can expect to combat it with any well-grounded hope of +success is evident.</p> + +<p>If the sputum of a phthisical patient be submitted to the +skilled microscopist, he is nearly always able to demonstrate +bacilli, but this goes for very little. Because bacilli are found +in phthisis, it is no more certain that they are the cause of +phthisis than it is certain that cheese mites are the cause of +cheese. Well, suppose we were to inject sputum from a phthisical +person into the lower animal and tuberculosis follows, and then +announce to the profession that we have demonstrated the relation +of the cause and effect between bacilli and phthisis? Why we would +start such an uproar of objections as would speedily convince us +that there was much work yet in the domain of bacteriology.</p> + +<p>The scientific investigators would say you have injected with +the sputum into the blood of your unfortunate patient, pus, +morphological elements, and perhaps half a dozen other forms of +bacteria, any one of which is just as likely to produce the disease +as the bacillus you have selected.</p> + +<p>The first important step is, first isolate your bacillus. If I +were to take a glass plate, one side of which is coated with a +thick solution of peptonized gelatin, and allow the water to +collect, the gelatinous matter will become solid. If now, with a +wire dipped in some tuberculous matter, I draw a line along the +gelatin, I have deposited at intervals along this line, specimens +of tubercle bacilli. If this plate be now kept at a proper +temperature, after a few days, wherever the bacilli have been +caught, a grayish spot will appear, which, easily seen with the +naked eye, gradually spreads and becomes larger. These spots are +colonies containing thousands of bacilli. Let us return to our +gelatin plate.</p> + +<p>We find a spot which answers to the description of a colony of +tubercle bacilli. We now take a minute particle from this colony on +a wire and convey it to the surface of some hardened blood serum in +a test tube. We plug the tube so that no air germs may drop in, and +place it in an incubator at the proper temperature. After several +days, if no contamination be present, a colony of bacilli will +appear around the spot where we sowed the spores. Let us repeat the +process.</p> + +<p>Take a particle from this colony, and transfer it to another +tube. This is our second culture. This must be repeated until we +are satisfied that we have secured a <i>pure</i> culture. If this +be carried to the twenty-fifth generation, we may be assured that +there remains no pus, no ptomaines, nothing but the desired +bacilli.</p> + +<p>It is a proper material now for inoculation, and if we inoculate +some of the lower animals, for instance the monkey, we produce a +disease identical with phthisis pulmpnalis. Bacteria also afford +peculiar chemical reactions. For example, nitric acid will +discharge all the color from all bacilli artificially dyed with +anilin, except those of tubercle and anthrax. One species is +stained readily with a dye that leaves another unaltered. Thus we +are enabled in the laboratory to determine whether the bacilli +found in sputum, for example, are from tubercle or are the bacteria +of decomposition.</p> + +<p>From what I have said of the tubercle bacillus, it would seem +thoroughly demonstrated that it is the cause of tubercle in these +animals. But we must walk cautiously here. These are not human +beings, who know that like results would follow their inoculation. +The animals used by Koch are animals very subject to tubercle.</p> + +<p>We must, from the very nature of our environment, be constantly +inhaling these germs as we pass through the wards of our hospitals; +yes, they are floating in the air of our streets and dwellings. It +becomes necessary then for us to inquire: If bacteria cause +disease, in what manner do they produce it? The healthy organism is +always beset with a multitude of non-pathogenic bacteria. They +occupy the natural cavities, especially the alimentary canal. They +feed on the substances lying in their neighborhood, whether brought +into the body or secreted by the tissues. In so doing they set up +chemical changes in their substances. Where the organs are acting +normally these fungi work no mischief. The products of +decomposition thus set up are harmless, or are conveyed out of the +body before they begin to be active.</p> + +<p>If bacteria develop to an inordinate degree, if the contents of +organs are not frequently discharged, fermentative processes may be +set up, which result in disease. Bacteria must always multiply and +exist at the expense of the body which they infest, and the more +weakened the vital forces become, the more favorable is the soil +for their development.</p> + +<p>Septicæmia is caused by the absorption of the products of +putrefaction, induced before bacteria can multiply inside or +outside the body. Bacteria must find a congenial soil. The +so-called cholera bacillus must gain access to the intestinal tract +before it finds conditions suitable to colonization. It does not +seem to multiply in the stomach or in the blood, but once injected +into the duodenum develops with astonishing rapidity, and the +delicate epithelial cells of the villi become swollen, soften and +break down, exposing the mucosa.</p> + +<p>It has been shown that <i>bouillon</i> in which Loeffler's +diphtheria bacillus has grown, and which has been passed through +unglazed porcelain filters, shows the presence of a poison which is +capable of producing the same results upon inoculation as the pure +culture of the bacillus itself. Zarniko, working upon the same +organism, obtained a number of positive results that led him to +declare this bacillus is the cause of epidemic diphtheria, in spite +of many assertions to the contrary. Chantmesse and Widal record the +results of their work as to what will most easily and effectively +destroy the bacillus of diphtheria.</p> + +<p>The only three substances that actually checked and destroyed +its vitality were phenic acid (5 per cent.), camphor (20 per +cent.), olive oil (25 per cent.), in combination. For the last I +substitute glycerine, because this allows the mixture to penetrate +farther into the mucous membrane than oil, the latter favoring a +tendency to pass over the surface. This mixture when heated +separates into two layers, the upper one viscid and forming a sort +of "glycerol," the lower clear. The latter will completely +sterilize a thread dipped in a pure culture of the diphtheria +bacillus. Corrosive sublimate was not examined because in strong +enough doses it would be dangerous and in weaker ones it would be +useless.</p> + +<p>The facts obtained in regards to the streptococcus of erysipelas +are reported as follows: That both chemical and experimental +evidence teach the extreme ease of a renewed attack of the disease; +that it is possible to kill guinea pigs by an intoxication when +they are immune to an inoculation of the culture in ordinary +quantities. And this latter fact should warn experimenters trying +to obtain immunity in man by the inoculation of non-pathogenic +bacteria, because the same results may be reached.</p> + +<p>A new theory in regard to fevers and the relation of +micro-organisms is suggested by Roussy, viz.: That it is a +fermentation produced by a diastase or soluble ferment found in all +micro-organisms and cells, and which they use in attacking and +transforming matter, either inside their substance or without +it.</p> + +<p>The resemblance of the malaria parasite to that of recurrent +fever is noted in the work of Sacharoff. He states that there +exists in the blood of those suffering from recurrent fever a +hæmatozoon, which is most prominent after the fever has begun +to fall, when it is of enormous proportions, twenty or more +diameters of a red blood corpuscle, although smaller ones may still +be found. The parasite consists of a delicate amœboid body +containing a multitude of dark, round, uniform, sharply outlined, +movable granules. Besides these, the protoplasm contains a +generally grayish homogeneous nucleus as large as one or two red +blood corpuscles. The protoplasm sends out pseudopodia (with +granules), which sometimes separate and appear as small delicate +pieces of protoplasm. They vary in size, and are often swallowed by +the red blood corpuscles in which they grow, and finally develop +into the above mentioned amœboid bodies.</p> + +<p>Prof. J. Lewis Smith has made a great many autopsies of children +dead from cholera infantum, and almost invariably found the stomach +and liver in a comparatively healthy condition. Ganghen, who has +given this subject considerable study, denies the existence of any +specific germ in the summer diarrhea of infants, but claims to have +found three different germs in the intestines of children suffering +from cholera infantum, each producing a chemical poison which is +capable of producing vomiting, purging, and even death. A great +variety of germs are found in drinking water, and no doubt +countless numbers are taken into the digestive tract, and the +principal reason why pathological conditions do not occur more +frequently is on account of the germicidal qualities of the gastric +juice.</p> + +<p>The comma bacillus of Koch, and the typhoid fever germ of +Eberth, are especially destroyed in normal gastric juice. When the +germs are very numerous, they run the gauntlet of the stomach (as +the gastric juice is secreted only during digestion); and once in +the alkaline intestinal canal they are capable of setting up +disease, other conditions contributing—ill health, deranged +digestion, etc.</p> + +<p>Mittnam has made a study of bacteria beneath the nails, and +reports, after examining persons following different occupations, +having found numerous varieties of micro-organisms; which are +interesting from a scientific standpoint relative to the importance +of thoroughly cleansing the hands before undertaking any surgical +procedure. He found, out of twenty-five experiments, 78 varieties +of bacteria, of which 36 were classed as micrococci, 21 diplococci, +18 rods, 3 sarcinæ, and 1 yeast. Cooks, barbers, waiters, +etc., were examined.</p> + +<p>The blood, defibrinated and freshly drawn, has marked germicidal +action; for bacteria its action is decidedly deadly, even hours +after it has been drawn from the body. Especially were anti-germic +qualities noticed upon pathogenic bacteria. Buchner put the bacilli +of anthrax in a quantity of blood, and in two hours the number was +reduced from 4,800 to 56, and in three hours only 3 living bacteria +remained. Other bacteria were experimented upon in blood with +similar results, but the destruction of the organism from +putrefaction was much less marked, and on some varieties the blood +had little or no action.</p> + +<p>It is not the object of these remarks to even give a +<i>résumé</i> of the <i>status præsens</i> of +bacteriology, but simply to stimulate thought in that direction. +The claims of some of the ultra-bacteriologists may never be +realized, but enough has been accomplished to revolutionize the +treatment of certain diseases, and the observing student will do +well to keep his eye on the microbe, as it seems from the latest +investigations that its star is in the ascendant. And who can +prognosticate but that in the next decade an entire revolution in +the ætiology and treatment of many diseases may take +place?</p> + +<p>Detroit, Mich.</p> + +<hr /> +<h2><a id="xi_3" name="xi_3"></a>THE COMPOSITION OF KOCH'S +LYMPH.</h2> + +<h3>WHAT PROFESSOR KOCH SAYS IT IS, AND WHAT IT CAN DO.</h3> + +<h3>(By Cable to the <i>Medical Record</i>.)</h3> + +<h3>BERLIN, January 15, 1891.</h3> + +<p>The curiosity to know the composition of the famous lymph has +been gratified by the publication to-day of an article by Professor +Koch on the subject. In the following, as will be seen, he +reaffirms his original convictions and acknowledges the valuable +assistance he has received from those who have used his fluid, and +thus helped him in the accumulation of experience.</p> + +<p>Professor Koch says: Two months ago I published the results of +my experiments with the new remedy for tuberculosis, since which +time many physicians who received the preparation have been enabled +to become acquainted with its properties through their own +experiments. So far as I have been able to review the statements +published and the communications received by letter, my predictions +have been fully and completely confirmed. The general consensus of +opinion is that the remedy has a specific action upon tubercular +tissues, and is, therefore, applicable as a very delicate and sure +reagent for discovering latent and diagnosing doubtful tuberculous +processes. Regarding the curative effects of the remedy, most +reports agree that, despite the comparatively short duration of its +application, many patients have shown more or less pronounced +improvement. It has been affirmed that in not a few cases even a +cure has been established. Standing quite by itself is the +assertion that the remedy may not only be dangerous in cases which +have advanced too far—a fact which may forthwith be +conceded—but also that it actually promotes the tuberculous +process, being therefore injurious.</p> + +<p>During the past six weeks I myself have had opportunity to bring +together further experiences touching the curative effects and +diagnostic application of the remedy in the cases of about one +hundred and fifty sufferers from tuberculosis of the most varied +types in this city and in the Moabit Hospital.</p> + +<p>I can only say that everything I have latterly seen accords with +my previous observations. There has been nothing to modify in what +I before reported. As long as it was only a question of proving the +accuracy of my indications, it was needless for any one to know +what the remedy contained or whence it was derived. On the +contrary, subsequent testing would necessarily be more unbiased, +the less people knew of the remedy itself. Now, after sufficient +confirmatory testing, the importance of the remedy is proved, my +next task is to extend my study of the remedy beyond the field +where it has hitherto been applied, and if possible to apply the +principle underlying the discovery to other diseases.</p> + +<p>This task naturally demands a full knowledge of the remedy. I +therefore consider that the time has arrived when the requisite +indications in this direction shall be made. This is done in what +follows.</p> + +<p>Before going into the remedy itself, I deem it necessary for the +better understanding of its mode of operation to state briefly the +way by which I arrived at the discovery. If a healthy guinea pig be +inoculated with the pure cultivation of German Kultur of tubercle +bacilli, the wound caused by the inoculation mostly closes over +with a sticky matter, and appears in its early days to heal. Only +after ten to fourteen days a hard nodule presents itself, which, +soon breaking, forms an ulcerating sore, which continues until the +animal dies. Quite a different condition of things occurs when a +guinea pig already suffering from tuberculosis is inoculated. An +animal successfully inoculated from four to six weeks before is +best adapted for this purpose. In such an animal the small +indentation assumes the same sticky covering at the beginning, but +no nodules form. On the contrary, on the day following, or the +second day after the inoculation, the place where the lymph is +injected shows a strange change. It becomes hard and assumes a +darker coloring, which is not confined to the inoculation spot, but +spreads to the neighboring parts until it attains a diameter of +from 0.05 to 1 cm.</p> + +<p>In a few days it becomes more and more manifest that the skin +thus changed is necrotic, finally falling off, leaving a flat +ulceration which usually heals rapidly and permanently without any +involvement of the adjacent lymphatic glands. Thus the injected +tubercular bacilli quite differently affect the skin of a healthy +guinea pig from one affected with tuberculosis. This effect is not +exclusively produced with living tubercular bacilli, but is also +observed with the dead bacilli, the result being the same whether, +as I discovered by experiments at the outset, the bacilli are +killed by a somewhat prolonged application of a low temperature or +boiling heat or by means of certain chemicals. This peculiar fact I +followed up in all directions, and this further result was +obtained—that killed pure cultivations of tubercular bacilli, +after rinsing in water, might be injected in great quantities under +healthy guinea pig's skin without anything occurring beyond local +suppuration. Such injections belong to the simplest and surest +means of producing suppurations free from living bacteria.</p> + +<p>Tuberculous guinea pigs, on the other hand, are killed by the +injection of very small quantities of such diluted cultivations. In +fact, within six to forty-eight hours, according to the strength of +the dose, an injection which is not sufficient to produce the death +of the animal may cause extended necrosis to the skin in the +vicinity of the place of injection. If the dilution is still +further diluted until it is scarcely visibly clouded, the animals +inoculated remain alive and a noticeable improvement in their +condition soon supervenes. If the injections are continued at +intervals of from one to two days, the ulcerating inoculation wound +becomes smaller and finally scars over, which otherwise it never +does; the size of the swollen lymphatic glands is reduced, the body +becomes better nourished, and the morbid process ceases, unless it +has gone too far, in which case the animal perishes from +exhaustion. By this means the basis of a curative process against +tuberculosis was established.</p> + +<p>Against the practical application of such dilutions of dead +tubercle bacilli there presented itself the fact that the tubercle +bacilli are not absorbed at the inoculation points, nor do they +disappear in another way, but for a long time remain unchanged, and +engender greater or smaller suppurative foci. Anything, therefore, +intended to exercise a healing effect on the tuberculous process +must be a soluble substance which would be liberated to a certain +extent by the fluids of the body floating around the tubercle +bacilli, and be transferred in a fairly rapid manner to the juices +of the body; while the substance producing suppuration apparently +remains behind in the tubercular bacilli, or dissolves but very +slowly. The only important point was, therefore, to induce outside +the body the process going on inside, if possible, and to extract +from the tubercular bacilli alone the curative substance. This +demanded time and toil, until I finally succeeded, with the aid of +a forty to fifty per cent. solution of glycerine, in obtaining an +effective substance from the tubercular bacilli. With the fluid so +obtained I made further experiments on animals, and finally on +human beings. These fluids were given to other physicians to enable +them to repeat the experiments.</p> + +<p>The remedy which is used in the new treatment consists of a +glycerine extract, derived from the pure cultivation of tubercle +bacilli. Into the simple extract there naturally passes from the +tubercular bacilli, besides the effective substance, all the other +matter soluble in fifty per cent. glycerine.</p> + +<p>Consequently, it contains a certain quantity of mineral salts, +coloring substances, and other unknown extractive matters. Some of +these substances can be removed from it tolerably easily. The +effective substance is insoluble in absolute alcohol. It can be +precipitated by it, though not, indeed, in a pure condition, but +still combined with the other extractive matter. It is likewise +insoluble in alcohol. The coloring matter may also be removed, +rendering it possible to obtain from the extract a colorless, dry +substance containing the effective principle in a much more +concentrated form than the original glycerine solution. For +application in practice this purification of the glycerine extract +offers no advantage, because the substances so eliminated are +unessential for the human organism. The process of purification +would make the cost of the remedy unnecessarily high.</p> + +<p>Regarding the constitution of the more effective substances, +only surmises may for the present be expressed. It appears to me to +be derivative from albuminous bodies, having a close affinity to +them. It does not belong to the group of so-called toxalbumins, +because it bears high temperatures, and in the dialyzer goes easily +and quickly through the membrane. The proportion of the substance +in the extract to all appearance is very small. It is estimated at +fractions of one per cent., which, if correct, we should have to do +with a matter whose effects upon organisms attacked with +tuberculosis go far beyond what is known to us of the strongest +drugs.</p> + +<p>Regarding the manner in which the specific action of the remedy +on tuberculous tissue is to be represented, various hypotheses may +naturally be put forward. Without wishing to affirm that my view +affords the best explanation, I represent the process myself in the +following manner:</p> + +<p>The tubercle bacilli produced when growing in living tissues, +the same as in artificial cultivations, contain substances which +variously and notably unfavorably influence living elements in +their vicinity. Among these is a substance which in a certain +degree of concentration kills or so alters living protoplasm that +it passes into a condition that Weigert describes as coagulation +necrosis. In tissue thus become necrotic the bacillus finds such +unfavorable conditions of nourishment that it can grow no more and +sometimes dies.</p> + +<p>This explains the remarkable phenomenon that in organs newly +attacked with tuberculosis, for instance in guinea pigs' spleen and +liver, which then are covered with gray nodules, numbers of bacilli +are found, whereas they are rare or wholly absent when the +enormously enlarged spleen consists almost entirely of whitish +substance in a condition of coagulation necrosis, such as is often +found in cases of natural death in tuberculous guinea pigs. The +single bacillus cannot, therefore, induce necrosis at a great +distance, for as soon as necrosis attains a certain extension the +growth of the bacillus subsides, and therewith the production of +the necrotizing substance. A kind of reciprocal compensation thus +occurs, causing the vegetation of isolated bacilli to remain so +extraordinarily restricted, as, for instance, in lupus and +scrofulous glands.</p> + +<p>In such cases the necrosis generally extends only to a part of +the cells, which then, with further growth, assume the peculiar +form of riesen zelle, or giant cells. Thus, in this interpretation, +follow first the explanation Weigert gives of the production of +giant cells.</p> + +<p>If now one increased artificially in the vicinity of the +bacillus the amount of necrotizing substance in the tissue, the +necrosis would spread a greater distance. The conditions of +nourishment for the bacillus would thereby become more unfavorable +than usual.</p> + +<p>In the first place the tissue which had become necrotic over a +large extent would decay and detach itself, and where such were +possible would carry off the inclosed bacilli and eject them +outwardly, so far disturbing their vegetation that they would much +more speedily be killed than under ordinary circumstances.</p> + +<p>It is just in looking at such changes that the effect of the +remedy appears to consist. It contains a certain quantity of +necrotizing substance, a correspondingly large dose of which +injures certain tissue elements even in a healthy person, and +perhaps the white blood corpuscles or adjacent cells, thereby +producing fever and a complication of symptoms, whereas with +tuberculous patients a much smaller quantity suffices to induce at +certain places, namely, where tubercle bacilli are vegetating and +have already impregnated the adjacent region with the same +necrotizing matter, more or less extensive necrosis of the cells, +with the phenomena in the whole organism which result from and are +connected with it.</p> + +<p>For the present, at least, it is impossible to explain the +specific influence which the remedy, in accurately defined doses, +exercises upon tuberculous tissue, and the possibility of +increasing the doses with such remarkable rapidity, and the +remedial effects which have unquestionably been produced under not +too favorable circumstances.</p> + +<p>Of the consumptive patients whom he described as temporarily +cured, two have been returned to the Moabit Hospital for further +observation.</p> + +<p>No bacilli have appeared in their sputum for the past three +months, and their phthisical symptoms have gradually and completely +disappeared.</p> + +<hr /> +<h2><a id="ii_1" name="ii_1"></a>CAN WE SEPARATE ANIMALS FROM +PLANTS?</h2> + +<h3>By ANDREW WILSON.</h3> + +<p>One of the plainest points connected with the study of living +things is the power we apparently possess of separating animals +from plants. So self-evident appears this power that the popular +notion scoffs at the idea of science modestly disclaiming its +ability to separate the one group of living beings from the other. +Is there any danger of confusing a bird with the tree amid the +foliage of which it builds its nest, or of mistaking a cow for the +grass it eats? These queries are, of course, answerable in one way +only. Unfortunately (for the querists), however, they do not +include or comprehend the whole difficulty. They merely assert, +what is perfectly true, that we are able, without trouble, to mark +off the higher animals from the higher plants. What science +inquires is, whether we are able to separate <i>all</i> animals +from <i>all</i> plants, and to fix a definite boundary line, so as +to say that all the organisms on the one side of the line are +assuredly animals, while all the others on the opposite side of the +line may be declared to be truly plants. It is exactly this task +which science declares to be among the impossibilities of +knowledge. Away down in the depths of existence and among the +groundlings of life the identity of living things becomes of a +nature which is worse than confusing, and which renders it a futile +task to attempt to separate the two worlds of life. The +hopelessness of the task, indeed, has struck some observers so +forcibly that they have proposed to constitute a third +kingdom—the <i>Regnum Protisticum</i>—between the +animal and the plant worlds, for the reception of the host of +doubtful organisms. This third kingdom would resemble the casual +ward of a workhouse, in that it would receive the waifs and strays +of life which could not find a refuge anywhere else.</p> + +<p>A very slight incursion into biological fields may serve to show +forth the difficulties of naturalists when the task of separating +animals from plants is mooted for discussion. To begin with, if we +suppose our popular disbeliever to assert that animals and plants +are always to be distinguished by shape and form, it is easy enough +to show him that here, as elsewhere, appearances are deceptive. +What are we to say of a sponge, or a sea anemone, of corals, of +zoophytes growing rooted from oyster shells, of sea squirts, and of +sea mats? These, each and all of them, are true animals, but they +are so plant-like that, as a matter of fact, they are often +mistaken by seaside visitors for plants. This last remark holds +especially true of the zoophytes and the sea mats. Then, on the +other hand, we can point to hundreds of lower plants, from the +yeast plant onward, which show none of the ordinary features of +plant life at all. They possess neither roots, stems, branches, +leaves, nor flowers, so that on this first count of the indictment +the naturalist gains the day.</p> + +<p>Power of movement, to which the popular doubter is certain to +appeal, is an equally baseless ground of separation. For all the +animals I have above named are rooted and fixed, while many true +plants of lower grade are never rooted at all. The yeast plant, the +<i>Algæ</i> that swarm in our ponds, and the diatoms that +crowd the waters, exemplify plants that are as free as animals; and +many of them, besides, in their young state especially (e.g., the +seaweeds), swim about freely in the water as if they were roving +animalcules. On the second count, also, science gains the day; +power of motion is no legitimate ground at all for distinguishing +one living being as an animal, while absence of movement is +similarly no reason for assuming that the fixed organism must of +necessity be a plant. Then comes the microscopic evidence. What can +this wonder glass do in the way of drawing boundary lines betwixt +the living worlds? The reply again is disappointing to the doubter; +for the microscope teaches us that the tissues of animals and +plants are built upon kindred lines. We meet with cells and fibers +in both. The cell is in each case the primitive expression of the +whole organism. Beyond cells and fibers we see the wonderful living +substance, <i>protoplasm</i>, which is alike to our senses in the +two kingdoms, although, indeed, differing much here and there in +the results of its work. On purely microscopic grounds, we cannot +separate animals from plants. There is no justification for rigidly +assuming that this is a plant or that an animal on account of +anything the microscope can disclose. A still more important point +in connection with this protoplasm question consists in the fact +that as we go backward to the beginnings of life, both in animals +and plants, we seem to approach nearer and nearer to an identity of +substance which baffles the microscope with all its powers of +discernment. Every animal and every plant begins existence as a +mere speck of this living jelly. The germ of each is a protoplasm +particle, which, whatever traces of structure it may exhibit, is +practically unrecognizable as being definitely animal or plant in +respect of its nature. Later on, as we know, the egg or germ shows +traces of structure in the case of the higher animals and plants; +while even lowly forms of life exhibit more or less characteristic +phases when they reach their adult stage. But, of life's +beginnings, the microscope is as futile as a kind scientific +touchstone for distinguishing animals from plants as is power of +movement, or shape, or form.</p> + +<p>A fourth point of appeal in the matter is found within the +domain of the chemist. Chemistry, with its subtile powers of +analysis, with its many-sided possibilities of discovering the +composition of things, and with its ability to analyze for us even +the light of the far distant stars, only complicates the +difficulties of the biologist. For, while of old it was assumed +that a particular element, nitrogen, was peculiar to animals, and +that carbon was an element peculiar to plants, we now know that +both elements are found in animals, just as both occur in plants. +The chemistry of living things, moreover, when it did grow to +become a staple part of science, revealed other and greater +anomalies than these. It showed that certain substances which were +supposed to be peculiar to plants, and to be made and manufactured +by them alone, were also found in animals. Chlorophyl is the green +coloring matter of plants, and is, of course, a typical product of +the vegetable world; yet it is made by such animals as the hydra of +the brooks and ponds, and by many animalcules and some worms. +Starch is surely a typical plant product, yet it is undoubtedly +manufactured, or at least stored up, by animals—a work +illustrated by the liver of man himself, which occasionally +produces sugar out of its starch.</p> + +<p>Again, there is a substance called <i>cellulose</i>, found well +nigh universally in plants. Of this substance, which is akin to +starch, the walls or envelopes of the cells of plant tissues are +composed. Yet we find those curious animals, the sea squirts, found +on rocks and stones at low-water mark, manufacturing cellulose to +form part and parcel of the outer covering of their sac-like +bodies. Here it is as if the animal, like a dishonest manufacturer, +had infringed the patent rights of the plant. On the fourth count, +then—that of chemical composition—the verdict is that +nothing that chemistry can teach us may serve definitely, clearly, +and exactly to set a boundary line or to erect a partition wall +between the two worlds of life. There yet remains for us to +consider a fifth head—that of the food.</p> + +<p>In the matter of the feeding of the two great living worlds we +might perchance light upon some adequate grounds for making up the +one kingdom from the other. What the consideration of form, +movement, chemical composition, and microscopic structure could not +effect for us in this way, it might be supposed the investigation +of the diet of animals and plants would render clear. Our hopes of +distinguishing the one group from the other by reference to the +food on which animals and plants subsist are, however, dashed to +the ground; and the diet question leaves us, therefore, when it has +been discussed, in the same quandary as before.</p> + +<p>Nevertheless, it is an interesting story, this of the nutrition +of animals and plants. A large amount of scientific information is +to be gleaned from such a study, which may very well be commenced +by our having regard to the matters on which a <i>green</i> plant +feeds. I emphasize the word "green," because it so happens that +when a plant has no chlorophyl (as green color is named in the +plant world) its feeding is of diverse kind to that which a green +plant exhibits. The mushroom or other fungus may be taken as an +illustration of a plant which represents the non-green race, while +every common plant, from a bit of grass to an oak tree, exemplifies +the green-bearing order of the vegetable tribes.</p> + +<p>Suppose we were to invite a green plant to dinner, the +<i>menu</i> would have to be very differently arranged from that +which would satisfy a human or other animal guest. The soup would +be represented for the plant's delectation by water, the fish by +minerals, the joint by carbonic acid gas, and the dessert by +ammonia. On these four items a green plant feeds, out of them it +builds up its living frame. Note that its diet is of inorganic or +non-living matter. It derives its sustenance from soil and air, yet +out of these lifeless matters the green plant elaborates and +manufactures its living matter, or protoplasm. It is a more +wonderful organism than the animal, for while the latter can only +make new protoplasm when living matter is included in its food +supply, the green plant, by the exercise of its vital chemistry, +can transform that which is not living into that which is +life-possessing.</p> + +<p>The green plant in other words, raises non-living into living +matter, while the animal can only transform living matters into its +like. This is why the plant is called a constructive organism, +while the animal is, contrariwise, named a destructive one. The +result of the plant's existence is to build up, that of the +animal's life is to break down its substance, as the result of its +work, into non-living matter. The animal's body is, in fact, +breaking down into the very things on which the green plant feeds. +We ourselves are perpetually dissipating our substance in our acts +of life and work into the carbonic acid, water, ammonia, and +minerals on which plants feed. We "die daily" in as true a sense as +that in which the apostle used the term. And out of the debris of +the animal frame the green plant builds up leaf and flower, stein +and branch, and all the other tokens of its beauty and its +life.</p> + +<p>If, then, an animal can only live upon living matter—that +is to say on the bodies of other animals or of plants—with +water, minerals and oxygen gas from the air thrown in to boot, we +might be tempted to hold that in such distinctive ways and works we +had at last found a means of separating animals from plants. +Unfortunately, this view may be legitimately disputed and rendered +null and void, on two grounds. First of all, the mushrooms and +their friends and neighbors, all true plants, do not feed as do the +green tribes. And secondly, many of the green plants themselves can +be shown to have taken very kindly to an animal mode of diet.</p> + +<p>A mushroom, thus, because it has no green color, lives upon +water, oxygen, minerals, and organic matter. You can only grow +mushrooms where there is plenty of animal matter in a state of +decay, and as for the oxygen, they habitually inhale that gas as if +they were animals. Non-green plants thus want a most characteristic +action of their green neighbors. For the latter in daylight take in +the carbonic acid gas, which is composed of carbon and oxygen. +Under the combined influence of the green color and the light, they +split up the gas into its two elements, retaining the carbon for +food and allowing the oxygen to escape to the atmosphere. Alas! +however, in the dark our green plant becomes essentially like an +animal as regards its gas food, for then it is an absorber of +oxygen, while it gives off carbonic acid. If to take in carbonic +acid and to give out oxygen be held to be a feature characteristic +of a plant, it is one, as has been well said, which disappears with +the daylight in green plants, and which is not witnessed at all in +plants that have no green color.</p> + +<p>So far, we have seen that not even the food of plants and +animals can separate the one kingdom of life from the other. The +mushroom bars the way and the green plant's curious behavior by +night and by day respectively, in the matter of its gas food, once +more assimilates animal life and plant life in a remarkable manner. +Still more interesting is the fact, already noticed, that even +among the green tribes there are to be found many and various +lapses from the stated rules of their feeding. Thus what are we to +say of the parasitic mistletoe, which, while it has grown leaves of +its own, and can, therefore, obtain so much carbon food from the +air on its own account, nevertheless drinks up the sap of the oak +or apple which forms its host, and thus illustrates the spectacle +of a green plant feeding like an animal, on living matter? Or, what +may we think of such plants as the sundew, the Venus' fly trap, the +pitcher plants, the side saddle plants, the butterworts and +bladderworts, and others of their kind, which not only capture +insects, often by ingenious and complex lures, but also digest the +animal food thus captured? A sundew thus spreads out its lure in +the shape of its leaf studded with sensitive tentacles, each capped +by a glistening drop of gummy secretion. Entangled in this +secretion, the fly is further fixed to the leaf by the tentacles +which bend over it and inclose it in their fold. Then is poured out +upon the insect's body a digestive acid fluid, and the substance of +the dissolved and digested animal is duly absorbed by the plant. So +also the Venus' fly trap captures insects by means of its leaf, +which closes upon the prey when certain sensitive hairs have given +the signal that the animal has been trapped. Within the leaf the +insect is duly digested as before, and its substance applied to the +nutrition of the plant. Such plants, moreover, cannot flourish +perfectly unless duly supplied with their animal food. Such +illustrations of exceptions to the rule of green plant feeding +simply have the effect of abolishing the distinctions which the +diet question might be supposed to raise between animals and +plants. We may return to the sundews and other insect catchers; +meanwhile, I have said enough to show that to the question, "Can we +separate animals from plants?" a very decided negative reply must +be given. Life everywhere exhibits too many points of contact to +admit of any boundary line being drawn between the two great groups +which make up the sum total of organic +existence.—<i>Illustrated London News.</i></p> + +<hr /> +<h2><a id="xii_2" name="xii_2"></a>THE RECOVERY OF SILVER AND GOLD +FROM PLATING AND GILDING SOLUTIONS.</h2> + +<p>In view of the rapid development and extension of the methods of +electro-plating with silver and gold, and of the large amount of +spent liquors containing silver or gold thus produced, it has long +been desirable to find methods by which these metals can be +recovered from the spent liquors. The processes hitherto adopted +generally necessitate the tedious and unpleasant evaporation of the +cyanide liquors, or else involve a series of chemical operations +which are somewhat difficult to carry out, so that actually the +used-up baths are sold to some firm which undertakes this recovery +as a particular branch of its business.</p> + +<p>A process invented by Stockmuir and Fleischmann, and worked out +by them in the chemical laboratory of the Bavarian Industrial +Museum, is, however, exceedingly simple, and is employed in many +establishments.</p> + +<p>In order to remove silver from a potassium cyanide silver +solution, it is only necessary to allow a clean piece of plate zinc +to remain in the liquid for two days; even better results are +obtained by the use of iron conjointly with the zinc. In the first +case, the silver often adheres firmly to the zinc, while in the +second it always separates out as a powder. It is then only +necessary to wash the precipitated powder, which usually contains +copper (since spent silver solutions always contain copper), dry +it, and then dissolve it in hot concentrated sulphuric acid, water +being added, and the dissolved silver precipitated by strips of +copper. The silver thus obtained is perfectly pure. If the amount +of copper present is only small, it can usually be removed by +fusing the precipitated powder with a little niter and borax.</p> + +<p>In this way a spent silver bath was found to contain per +liter</p> + +<div class="ctr"> +<table border="0" cellpadding="4" cellspacing="0" summary=""> +<colgroup span="2"> +<col align="left" /> +<col align="right" /> +<col align="center" /></colgroup> + +<tr> +<td>1st experiment</td> +<td>1.5706</td> +<td>grms.</td> +</tr> + +<tr> +<td>2d experiment</td> +<td>1.5694</td> +<td>"</td> +</tr> + +<tr> +<td></td> +<td>———</td> +</tr> + +<tr> +<td>Mean</td> +<td>1.5700</td> +<td>"</td> +</tr> +</table> +</div> + +<p>The presence of silver could not be qualitatively ascertained in +the residual liquor.</p> + +<p>Although sheet zinc, or zinc and iron sheets, serve so well for +the precipitation of silver, they cannot be employed for the +recovery of gold. The latter separates out in such a case very +incompletely and as a firmly adhering lustrous film in the zinc. On +the other hand, finely divided zinc, the so-called zinc dust, is an +excellent substance to employ for precipitating gold quantitatively +and in the form of powder from spent cyanide liquors. When zinc +dust is added to a spent gold bath and the liquid periodically +stirred or shaken, all the gold is precipitated in two or three +days. The amount of zinc to be added naturally depends on the +quantity of gold present. Freshly prepared gold baths for gilding +in the cold contain on the average 3.5 grms. gold per liter, while +those used for the hot process contain 10.75 grms. To precipitate +all the gold in the original bath, 1.74 grms. or 0.37-0.5 grms. +zinc dust would be necessary, and, of course, a much smaller +quantity would be sufficient for the spent liquors. Since the +precipitation takes place more rapidly when an excess of zinc dust +is present, it is generally advisable to add ¼ or at the +most ½ kilo, of zinc dust to every 100 liters of +solution.</p> + +<p>The precipitated gold, which contains zinc dust and usually +silver and copper, is washed, freed from zinc by hydrochloric acid, +and then from silver and copper by nitric acid and thus obtained +pure.</p> + +<p>A spent bath treated in this way gave the following amounts of +gold per liter:</p> + +<div class="ctr"> +<table border="0" cellpadding="4" cellspacing="0" summary=""> +<colgroup span="2" align="left"></colgroup> + +<tr> +<td>1st experiment</td> +<td>0.2626</td> +</tr> + +<tr> +<td>2d experiment</td> +<td>0.2634</td> +</tr> + +<tr> +<td>Mean</td> +<td>0.2630 grms.</td> +</tr> +</table> +</div> + +<p>The presence of gold in the residual cyanide solution could not +be qualitatively detected. The potassium cyanide of the solutions +obtained by this process should be converted into ferrocyanide by +heating with ferrous sulphate and milk of lime, since this +substance is not poisonous and can therefore be got rid of without +danger. It would, however, be more economical and, considering the +large amount of cyanide present, more profitable to work it up into +Prussian blue.</p> + +<hr /> +<h3>A new Catalogue of Valuable Papers</h3> + +<p>Contained in SCIENTIFIC AMERICAN SUPPLEMENT during the past ten +years, sent <i>free of charge</i> to any address. MUNN & CO., +361 Broadway, New York.</p> + +<hr /> +<h3>THE SCIENTIFIC AMERICAN</h3> + +<h2>Architects and Builders Edition</h2> + +<p class="ctr"><b>$2.50 a Year. Single Copies, 25 cts.</b></p> + +<p>This is a Special Edition of the SCIENTIFIC AMERICAN, issued +monthly—on the first day of the month. Each number contains +about forty large quarto pages, equal to about two hundred ordinary +book pages, forming, practically, a large and splendid <b>Magazine +of Architecture</b>, richly adorned with <i>elegant platen in +colors</i> and with fine engravings, illustrating the most +interesting examples of modern Architectural Construction and +allied subjects.</p> + +<p>A special feature is the presentation in each number of a +variety of the latest and best plans for private residences, city +and country, including those of very moderate cost as well as the +more expensive. Drawings in perspective and in color are given, +together with full Plans, Specifications, Costs, Bills of Estimate, +and Sheets of Details.</p> + +<p>No other building paper contains so many plans, details, and +specifications regularly presented as the SCIENTIFIC AMERICAN. +Hundreds of dwellings have already been erected on the various +plans we have issued during the past year, and many others are in +process of construction.</p> + +<p>Architects, Builders, and Owners will find this work valuable in +furnishing fresh and useful suggestions. All who contemplate +building or improving homes, or erecting structures of any kind, +have before them in this work an almost <i>endless series of the +latest and best examples</i> from which to make selections, thus +saving time and money.</p> + +<p>Many other subjects, including Sewerage, Piping, Lighting, +Warming, Ventilating, Decorating, Laying out of Grounds, etc., are +illustrated. An extensive Compendium of Manufacturers' +Announcements is also given, in which the most reliable and +approved Building Materials, Goods, Machines, Tools, and Appliances +are described and illustrated, with addresses of the makers, +etc.</p> + +<p>The fullness, richness, cheapness, and convenience of this work +have won for it the <b>Largest Circulation</b> of any Architectural +publication in the world.</p> + +<p>A Catalogue of valuable books on Architecture, Building, +Carpentry, Masonry, Heating, Warming, Lighting, Ventilation, and +all branches of industry pertaining to the art of Building, is +supplied free of charge, sent to any address.</p> + +<p class="ctr"><b>MUNN & CO., Publishers,</b></p> + +<p class="ctr"><b>361 Broadway, New York.</b></p> + +<hr /> +<h3>Building Plans and Specifications.</h3> + +<p>In connection with the publication of the BUILDING EDITION of +the SCIENTIFIC AMERICAN, Messrs. Munn & Co. furnish plans and +specifications for buildings of every kind, including Churches, +Schools, Stores, Dwellings, Carriage Houses, Barns, etc.</p> + +<p>In this work they are assisted by able and experienced +architects. Full plans, details, and specifications for the various +buildings illustrated in this paper can be supplied.</p> + +<p>Those who contemplate building, or who wish to alter, improve, +extend, or add to existing buildings, whether wings, porches, bay +windows, or attic rooms, are invited to communicate with the +undersigned. Our work extends to all parts of the country. +Estimates, plans, and drawings promptly prepared. Terms moderate. +Address</p> + +<p class="ctr"><b>MUNN & CO., 361 BROADWAY, NEW YORK.</b></p> + +<hr /> +<h3>Scientific American Supplement.</h3> + +<p class="ctr"><b>PUBLISHED WEEKLY.</b></p> + +<p class="ctr"><b>Terms of Subscription, $5 a year.</b></p> + +<p>Sent by mail, postage prepaid, to subscribers in any part of the +United States or Canada. Six dollars a year, sent, prepaid, to any +foreign country.</p> + +<p>All the back numbers of THE SUPPLEMENT, from the commencement, +January 1, 1876, can be had. Price, 10 cents each.</p> + +<p>All the back volumes of THE SUPPLEMENT can likewise be supplied. +Two volumes are issued yearly. Price of each volume, $2.50 stitched +in paper, or $3.50 bound in stiff covers.</p> + +<p>COMBINED RATES.—One copy of SCIENTIFIC AMERICAN and one +copy of SCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, +$7.00.</p> + +<p>A liberal discount to booksellers, news agents, and +canvassers.</p> + +<p class="ctr"><b>MUNN & CO., Publishers</b>,</p> + +<p class="ctr"><b>361 Broadway, New York, N.Y.</b></p> + +<hr /> +<h2>Useful Engineering Books</h2> + +<p>Manufacturers, Agriculturists, Chemists, Engineers, Mechanics, +Builders, men of leisure, and professional men, of all classes, +need good books in the line of their respective callings. Our post +office department permits the transmission of books through the +mails at very small cost. A comprehensive catalogue of useful books +by different authors, on more than fifty different subjects, has +recently been published, for free circulation, at the office of +this paper. Subjects classified with names of author. Persons +desiring a copy have only to ask for it, and it will be mailed to +them. Address, MUNN & CO., 361 Broadway, New York.</p> + +<hr /> +<h2>PATENTS.</h2> + +<p>In connection with the <b>Scientific American</b>, Messrs. MUNN +& Co. are solicitors of American and Foreign Patents, have had +42 years' experience, and now have the largest establishment in the +world. Patents are obtained on the best terms.</p> + +<p>A special notice is made in the <b>Scientific American</b> of +all inventions patented through this Agency, with the name and +residence of the Patentee. By the immense circulation thus given, +public attention is directed to the merits of the new patent, and +sales or introduction often easily effected.</p> + +<p>Any person who has made a new discovery or invention can +ascertain, free of charge, whether a patent can probably be +obtained, by writing to MUNN & Co. We also send free our Hand +Book about the Patent Laws, Patents, Caveats, Trade Marks, their +costs and how procured. Address</p> + +<p class="ctr"><b>MUNN & Co.</b>,</p> + +<p class="ctr"><b>361 Broadway, New York.</b></p> + +<p class="ctr"><b>Branch Office, 622 and 624 F St., Washington, +D.C.</b></p> + + + + + + + +<pre> + + + + + +End of the Project Gutenberg EBook of Scientific American Supplement, No. +787, January 31, 1891, by Various + +*** END OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + +***** This file should be named 14009-h.htm or 14009-h.zip ***** +This and all associated files of various formats will be found in: + https://www.gutenberg.org/1/4/0/0/14009/ + +Produced by Victoria Woosley, Don Kretz, Juliet Sutherland, Charles +Franks and the PG Distributed Proofreading Team + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. Special rules, +set forth in the General Terms of Use part of this license, apply to +copying and distributing Project Gutenberg-tm electronic works to +protect the PROJECT GUTENBERG-tm concept and trademark. Project +Gutenberg is a registered trademark, and may not be used if you +charge for the eBooks, unless you receive specific permission. If you +do not charge anything for copies of this eBook, complying with the +rules is very easy. You may use this eBook for nearly any purpose +such as creation of derivative works, reports, performances and +research. They may be modified and printed and given away--you may do +practically ANYTHING with public domain eBooks. Redistribution is +subject to the trademark license, especially commercial +redistribution. + + + +*** START: FULL LICENSE *** + +THE FULL PROJECT GUTENBERG LICENSE +PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK + +To protect the Project Gutenberg-tm mission of promoting the free +distribution of electronic works, by using or distributing this work +(or any other work associated in any way with the phrase "Project +Gutenberg"), you agree to comply with all the terms of the Full Project +Gutenberg-tm License (available with this file or online at +https://gutenberg.org/license). + + +Section 1. General Terms of Use and Redistributing Project Gutenberg-tm +electronic works + +1.A. By reading or using any part of this Project Gutenberg-tm +electronic work, you indicate that you have read, understand, agree to +and accept all the terms of this license and intellectual property +(trademark/copyright) agreement. If you do not agree to abide by all +the terms of this agreement, you must cease using and return or destroy +all copies of Project Gutenberg-tm electronic works in your possession. +If you paid a fee for obtaining a copy of or access to a Project +Gutenberg-tm electronic work and you do not agree to be bound by the +terms of this agreement, you may obtain a refund from the person or +entity to whom you paid the fee as set forth in paragraph 1.E.8. + +1.B. "Project Gutenberg" is a registered trademark. It may only be +used on or associated in any way with an electronic work by people who +agree to be bound by the terms of this agreement. There are a few +things that you can do with most Project Gutenberg-tm electronic works +even without complying with the full terms of this agreement. See +paragraph 1.C below. There are a lot of things you can do with Project +Gutenberg-tm electronic works if you follow the terms of this agreement +and help preserve free future access to Project Gutenberg-tm electronic +works. See paragraph 1.E below. + +1.C. The Project Gutenberg Literary Archive Foundation ("the Foundation" +or PGLAF), owns a compilation copyright in the collection of Project +Gutenberg-tm electronic works. Nearly all the individual works in the +collection are in the public domain in the United States. If an +individual work is in the public domain in the United States and you are +located in the United States, we do not claim a right to prevent you from +copying, distributing, performing, displaying or creating derivative +works based on the work as long as all references to Project Gutenberg +are removed. Of course, we hope that you will support the Project +Gutenberg-tm mission of promoting free access to electronic works by +freely sharing Project Gutenberg-tm works in compliance with the terms of +this agreement for keeping the Project Gutenberg-tm name associated with +the work. You can easily comply with the terms of this agreement by +keeping this work in the same format with its attached full Project +Gutenberg-tm License when you share it without charge with others. + +1.D. The copyright laws of the place where you are located also govern +what you can do with this work. Copyright laws in most countries are in +a constant state of change. If you are outside the United States, check +the laws of your country in addition to the terms of this agreement +before downloading, copying, displaying, performing, distributing or +creating derivative works based on this work or any other Project +Gutenberg-tm work. The Foundation makes no representations concerning +the copyright status of any work in any country outside the United +States. + +1.E. Unless you have removed all references to Project Gutenberg: + +1.E.1. The following sentence, with active links to, or other immediate +access to, the full Project Gutenberg-tm License must appear prominently +whenever any copy of a Project Gutenberg-tm work (any work on which the +phrase "Project Gutenberg" appears, or with which the phrase "Project +Gutenberg" is associated) is accessed, displayed, performed, viewed, +copied or distributed: + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + +1.E.2. If an individual Project Gutenberg-tm electronic work is derived +from the public domain (does not contain a notice indicating that it is +posted with permission of the copyright holder), the work can be copied +and distributed to anyone in the United States without paying any fees +or charges. If you are redistributing or providing access to a work +with the phrase "Project Gutenberg" associated with or appearing on the +work, you must comply either with the requirements of paragraphs 1.E.1 +through 1.E.7 or obtain permission for the use of the work and the +Project Gutenberg-tm trademark as set forth in paragraphs 1.E.8 or +1.E.9. + +1.E.3. If an individual Project Gutenberg-tm electronic work is posted +with the permission of the copyright holder, your use and distribution +must comply with both paragraphs 1.E.1 through 1.E.7 and any additional +terms imposed by the copyright holder. Additional terms will be linked +to the Project Gutenberg-tm License for all works posted with the +permission of the copyright holder found at the beginning of this work. + +1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm +License terms from this work, or any files containing a part of this +work or any other work associated with Project Gutenberg-tm. + +1.E.5. Do not copy, display, perform, distribute or redistribute this +electronic work, or any part of this electronic work, without +prominently displaying the sentence set forth in paragraph 1.E.1 with +active links or immediate access to the full terms of the Project +Gutenberg-tm License. + +1.E.6. You may convert to and distribute this work in any binary, +compressed, marked up, nonproprietary or proprietary form, including any +word processing or hypertext form. However, if you provide access to or +distribute copies of a Project Gutenberg-tm work in a format other than +"Plain Vanilla ASCII" or other format used in the official version +posted on the official Project Gutenberg-tm web site (www.gutenberg.org), +you must, at no additional cost, fee or expense to the user, provide a +copy, a means of exporting a copy, or a means of obtaining a copy upon +request, of the work in its original "Plain Vanilla ASCII" or other +form. Any alternate format must include the full Project Gutenberg-tm +License as specified in paragraph 1.E.1. + +1.E.7. Do not charge a fee for access to, viewing, displaying, +performing, copying or distributing any Project Gutenberg-tm works +unless you comply with paragraph 1.E.8 or 1.E.9. + +1.E.8. You may charge a reasonable fee for copies of or providing +access to or distributing Project Gutenberg-tm electronic works provided +that + +- You pay a royalty fee of 20% of the gross profits you derive from + the use of Project Gutenberg-tm works calculated using the method + you already use to calculate your applicable taxes. The fee is + owed to the owner of the Project Gutenberg-tm trademark, but he + has agreed to donate royalties under this paragraph to the + Project Gutenberg Literary Archive Foundation. Royalty payments + must be paid within 60 days following each date on which you + prepare (or are legally required to prepare) your periodic tax + returns. Royalty payments should be clearly marked as such and + sent to the Project Gutenberg Literary Archive Foundation at the + address specified in Section 4, "Information about donations to + the Project Gutenberg Literary Archive Foundation." + +- You provide a full refund of any money paid by a user who notifies + you in writing (or by e-mail) within 30 days of receipt that s/he + does not agree to the terms of the full Project Gutenberg-tm + License. You must require such a user to return or + destroy all copies of the works possessed in a physical medium + and discontinue all use of and all access to other copies of + Project Gutenberg-tm works. + +- You provide, in accordance with paragraph 1.F.3, a full refund of any + money paid for a work or a replacement copy, if a defect in the + electronic work is discovered and reported to you within 90 days + of receipt of the work. + +- You comply with all other terms of this agreement for free + distribution of Project Gutenberg-tm works. + +1.E.9. If you wish to charge a fee or distribute a Project Gutenberg-tm +electronic work or group of works on different terms than are set +forth in this agreement, you must obtain permission in writing from +both the Project Gutenberg Literary Archive Foundation and Michael +Hart, the owner of the Project Gutenberg-tm trademark. Contact the +Foundation as set forth in Section 3 below. + +1.F. + +1.F.1. Project Gutenberg volunteers and employees expend considerable +effort to identify, do copyright research on, transcribe and proofread +public domain works in creating the Project Gutenberg-tm +collection. Despite these efforts, Project Gutenberg-tm electronic +works, and the medium on which they may be stored, may contain +"Defects," such as, but not limited to, incomplete, inaccurate or +corrupt data, transcription errors, a copyright or other intellectual +property infringement, a defective or damaged disk or other medium, a +computer virus, or computer codes that damage or cannot be read by +your equipment. + +1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right +of Replacement or Refund" described in paragraph 1.F.3, the Project +Gutenberg Literary Archive Foundation, the owner of the Project +Gutenberg-tm trademark, and any other party distributing a Project +Gutenberg-tm electronic work under this agreement, disclaim all +liability to you for damages, costs and expenses, including legal +fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT +LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE +PROVIDED IN PARAGRAPH F3. YOU AGREE THAT THE FOUNDATION, THE +TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE +LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR +INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH +DAMAGE. + +1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a +defect in this electronic work within 90 days of receiving it, you can +receive a refund of the money (if any) you paid for it by sending a +written explanation to the person you received the work from. If you +received the work on a physical medium, you must return the medium with +your written explanation. The person or entity that provided you with +the defective work may elect to provide a replacement copy in lieu of a +refund. If you received the work electronically, the person or entity +providing it to you may choose to give you a second opportunity to +receive the work electronically in lieu of a refund. If the second copy +is also defective, you may demand a refund in writing without further +opportunities to fix the problem. + +1.F.4. Except for the limited right of replacement or refund set forth +in paragraph 1.F.3, this work is provided to you 'AS-IS' WITH NO OTHER +WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO +WARRANTIES OF MERCHANTIBILITY OR FITNESS FOR ANY PURPOSE. + +1.F.5. Some states do not allow disclaimers of certain implied +warranties or the exclusion or limitation of certain types of damages. +If any disclaimer or limitation set forth in this agreement violates the +law of the state applicable to this agreement, the agreement shall be +interpreted to make the maximum disclaimer or limitation permitted by +the applicable state law. The invalidity or unenforceability of any +provision of this agreement shall not void the remaining provisions. + +1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the +trademark owner, any agent or employee of the Foundation, anyone +providing copies of Project Gutenberg-tm electronic works in accordance +with this agreement, and any volunteers associated with the production, +promotion and distribution of Project Gutenberg-tm electronic works, +harmless from all liability, costs and expenses, including legal fees, +that arise directly or indirectly from any of the following which you do +or cause to occur: (a) distribution of this or any Project Gutenberg-tm +work, (b) alteration, modification, or additions or deletions to any +Project Gutenberg-tm work, and (c) any Defect you cause. + + +Section 2. Information about the Mission of Project Gutenberg-tm + +Project Gutenberg-tm is synonymous with the free distribution of +electronic works in formats readable by the widest variety of computers +including obsolete, old, middle-aged and new computers. It exists +because of the efforts of hundreds of volunteers and donations from +people in all walks of life. + +Volunteers and financial support to provide volunteers with the +assistance they need, is critical to reaching Project Gutenberg-tm's +goals and ensuring that the Project Gutenberg-tm collection will +remain freely available for generations to come. In 2001, the Project +Gutenberg Literary Archive Foundation was created to provide a secure +and permanent future for Project Gutenberg-tm and future generations. +To learn more about the Project Gutenberg Literary Archive Foundation +and how your efforts and donations can help, see Sections 3 and 4 +and the Foundation web page at https://www.pglaf.org. + + +Section 3. Information about the Project Gutenberg Literary Archive +Foundation + +The Project Gutenberg Literary Archive Foundation is a non profit +501(c)(3) educational corporation organized under the laws of the +state of Mississippi and granted tax exempt status by the Internal +Revenue Service. The Foundation's EIN or federal tax identification +number is 64-6221541. Its 501(c)(3) letter is posted at +https://pglaf.org/fundraising. Contributions to the Project Gutenberg +Literary Archive Foundation are tax deductible to the full extent +permitted by U.S. federal laws and your state's laws. + +The Foundation's principal office is located at 4557 Melan Dr. S. +Fairbanks, AK, 99712., but its volunteers and employees are scattered +throughout numerous locations. Its business office is located at +809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887, email +business@pglaf.org. Email contact links and up to date contact +information can be found at the Foundation's web site and official +page at https://pglaf.org + +For additional contact information: + Dr. Gregory B. Newby + Chief Executive and Director + gbnewby@pglaf.org + + +Section 4. Information about Donations to the Project Gutenberg +Literary Archive Foundation + +Project Gutenberg-tm depends upon and cannot survive without wide +spread public support and donations to carry out its mission of +increasing the number of public domain and licensed works that can be +freely distributed in machine readable form accessible by the widest +array of equipment including outdated equipment. Many small donations +($1 to $5,000) are particularly important to maintaining tax exempt +status with the IRS. + +The Foundation is committed to complying with the laws regulating +charities and charitable donations in all 50 states of the United +States. Compliance requirements are not uniform and it takes a +considerable effort, much paperwork and many fees to meet and keep up +with these requirements. We do not solicit donations in locations +where we have not received written confirmation of compliance. To +SEND DONATIONS or determine the status of compliance for any +particular state visit https://pglaf.org + +While we cannot and do not solicit contributions from states where we +have not met the solicitation requirements, we know of no prohibition +against accepting unsolicited donations from donors in such states who +approach us with offers to donate. + +International donations are gratefully accepted, but we cannot make +any statements concerning tax treatment of donations received from +outside the United States. U.S. laws alone swamp our small staff. + +Please check the Project Gutenberg Web pages for current donation +methods and addresses. Donations are accepted in a number of other +ways including including checks, online payments and credit card +donations. To donate, please visit: https://pglaf.org/donate + + +Section 5. General Information About Project Gutenberg-tm electronic +works. + +Professor Michael S. Hart was the originator of the Project Gutenberg-tm +concept of a library of electronic works that could be freely shared +with anyone. For thirty years, he produced and distributed Project +Gutenberg-tm eBooks with only a loose network of volunteer support. + + +Project Gutenberg-tm eBooks are often created from several printed +editions, all of which are confirmed as Public Domain in the U.S. +unless a copyright notice is included. Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + https://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. + + +</pre> + +</body> +</html> + diff --git a/old/14009-h/images/1-boat.png b/old/14009-h/images/1-boat.png Binary files differnew file mode 100644 index 0000000..deded01 --- /dev/null +++ b/old/14009-h/images/1-boat.png diff --git a/old/14009-h/images/1-boat_th.jpg b/old/14009-h/images/1-boat_th.jpg Binary files differnew file mode 100644 index 0000000..10893af --- /dev/null +++ b/old/14009-h/images/1-boat_th.jpg diff --git a/old/14009-h/images/12-boat.png b/old/14009-h/images/12-boat.png Binary files differnew file mode 100644 index 0000000..e68fa7d --- /dev/null +++ b/old/14009-h/images/12-boat.png diff --git a/old/14009-h/images/12-circus.png b/old/14009-h/images/12-circus.png Binary files differnew file mode 100644 index 0000000..125adab --- /dev/null +++ b/old/14009-h/images/12-circus.png diff --git a/old/14009-h/images/13-fig1.png b/old/14009-h/images/13-fig1.png Binary files differnew file mode 100644 index 0000000..8cc66b2 --- /dev/null +++ b/old/14009-h/images/13-fig1.png diff --git a/old/14009-h/images/13-fig1_th.jpg b/old/14009-h/images/13-fig1_th.jpg Binary files differnew file mode 100644 index 0000000..61c8693 --- /dev/null +++ b/old/14009-h/images/13-fig1_th.jpg diff --git a/old/14009-h/images/13-fig2.png b/old/14009-h/images/13-fig2.png Binary files differnew file mode 100644 index 0000000..a16fb0b --- /dev/null +++ b/old/14009-h/images/13-fig2.png diff --git a/old/14009-h/images/13-fig2_th.jpg b/old/14009-h/images/13-fig2_th.jpg Binary files differnew file mode 100644 index 0000000..4b9a6fb --- /dev/null +++ b/old/14009-h/images/13-fig2_th.jpg diff --git a/old/14009-h/images/13-fig3.png b/old/14009-h/images/13-fig3.png Binary files differnew file mode 100644 index 0000000..43a81f5 --- /dev/null +++ b/old/14009-h/images/13-fig3.png diff --git a/old/14009-h/images/13-fig3_th.jpg b/old/14009-h/images/13-fig3_th.jpg Binary files differnew file mode 100644 index 0000000..873b4d3 --- /dev/null +++ b/old/14009-h/images/13-fig3_th.jpg diff --git a/old/14009-h/images/13-fig4.png b/old/14009-h/images/13-fig4.png Binary files differnew file mode 100644 index 0000000..88dfc8d --- /dev/null +++ b/old/14009-h/images/13-fig4.png diff --git a/old/14009-h/images/2-fig1.png b/old/14009-h/images/2-fig1.png Binary files differnew file mode 100644 index 0000000..a7ca8a3 --- /dev/null +++ b/old/14009-h/images/2-fig1.png diff --git a/old/14009-h/images/2-fig2.png b/old/14009-h/images/2-fig2.png Binary files differnew file mode 100644 index 0000000..7d92ebd --- /dev/null +++ b/old/14009-h/images/2-fig2.png diff --git a/old/14009-h/images/2-fig3.png b/old/14009-h/images/2-fig3.png Binary files differnew file mode 100644 index 0000000..45df230 --- /dev/null +++ b/old/14009-h/images/2-fig3.png diff --git a/old/14009-h/images/2-fig4.png b/old/14009-h/images/2-fig4.png Binary files differnew file mode 100644 index 0000000..ff5a00a --- /dev/null +++ b/old/14009-h/images/2-fig4.png diff --git a/old/14009-h/images/2-fig5.png b/old/14009-h/images/2-fig5.png Binary files differnew file mode 100644 index 0000000..3d607ce --- /dev/null +++ b/old/14009-h/images/2-fig5.png diff --git a/old/14009-h/images/2-fig6.png b/old/14009-h/images/2-fig6.png Binary files differnew file mode 100644 index 0000000..64f7f12 --- /dev/null +++ b/old/14009-h/images/2-fig6.png diff --git a/old/14009-h/images/3-station.png b/old/14009-h/images/3-station.png Binary files differnew file mode 100644 index 0000000..74d6f2a --- /dev/null +++ b/old/14009-h/images/3-station.png diff --git a/old/14009-h/images/3-station_th.jpg b/old/14009-h/images/3-station_th.jpg Binary files differnew file mode 100644 index 0000000..8a5c04f --- /dev/null +++ b/old/14009-h/images/3-station_th.jpg diff --git a/old/14009-h/images/4-fig1.png b/old/14009-h/images/4-fig1.png Binary files differnew file mode 100644 index 0000000..4f73033 --- /dev/null +++ b/old/14009-h/images/4-fig1.png diff --git a/old/14009-h/images/4-fig2.png b/old/14009-h/images/4-fig2.png Binary files differnew file mode 100644 index 0000000..58cf06f --- /dev/null +++ b/old/14009-h/images/4-fig2.png diff --git a/old/14009-h/images/4-water.png b/old/14009-h/images/4-water.png Binary files differnew file mode 100644 index 0000000..fc69d95 --- /dev/null +++ b/old/14009-h/images/4-water.png diff --git a/old/14009-h/images/4-water_th.jpg b/old/14009-h/images/4-water_th.jpg Binary files differnew file mode 100644 index 0000000..9b69dc4 --- /dev/null +++ b/old/14009-h/images/4-water_th.jpg diff --git a/old/14009-h/images/5-goodyear.png b/old/14009-h/images/5-goodyear.png Binary files differnew file mode 100644 index 0000000..8777de8 --- /dev/null +++ b/old/14009-h/images/5-goodyear.png diff --git a/old/14009-h/images/5-goodyear_th.jpg b/old/14009-h/images/5-goodyear_th.jpg Binary files differnew file mode 100644 index 0000000..56e64fc --- /dev/null +++ b/old/14009-h/images/5-goodyear_th.jpg diff --git a/old/14009-h/images/6-fig51.png b/old/14009-h/images/6-fig51.png Binary files differnew file mode 100644 index 0000000..6de4505 --- /dev/null +++ b/old/14009-h/images/6-fig51.png diff --git a/old/14009-h/images/6-fig52.png b/old/14009-h/images/6-fig52.png Binary files differnew file mode 100644 index 0000000..6d68e0d --- /dev/null +++ b/old/14009-h/images/6-fig52.png diff --git a/old/14009-h/images/7-fig53.png b/old/14009-h/images/7-fig53.png Binary files differnew file mode 100644 index 0000000..57661cd --- /dev/null +++ b/old/14009-h/images/7-fig53.png diff --git a/old/14009-h/images/7-fig54.png b/old/14009-h/images/7-fig54.png Binary files differnew file mode 100644 index 0000000..5942700 --- /dev/null +++ b/old/14009-h/images/7-fig54.png diff --git a/old/14009-h/images/8-fig55.png b/old/14009-h/images/8-fig55.png Binary files differnew file mode 100644 index 0000000..7c049d8 --- /dev/null +++ b/old/14009-h/images/8-fig55.png diff --git a/old/14009-h/images/8-fig56.png b/old/14009-h/images/8-fig56.png Binary files differnew file mode 100644 index 0000000..21d718a --- /dev/null +++ b/old/14009-h/images/8-fig56.png diff --git a/old/14009-h/images/8-scope.png b/old/14009-h/images/8-scope.png Binary files differnew file mode 100644 index 0000000..40546bb --- /dev/null +++ b/old/14009-h/images/8-scope.png diff --git a/old/14009-h/images/8-scope_th.jpg b/old/14009-h/images/8-scope_th.jpg Binary files differnew file mode 100644 index 0000000..c981d04 --- /dev/null +++ b/old/14009-h/images/8-scope_th.jpg diff --git a/old/14009-h/images/8-target.png b/old/14009-h/images/8-target.png Binary files differnew file mode 100644 index 0000000..b6629cb --- /dev/null +++ b/old/14009-h/images/8-target.png diff --git a/old/14009-h/images/8-target_th.jpg b/old/14009-h/images/8-target_th.jpg Binary files differnew file mode 100644 index 0000000..a303149 --- /dev/null +++ b/old/14009-h/images/8-target_th.jpg diff --git a/old/14009-h/images/title.png b/old/14009-h/images/title.png Binary files differnew file mode 100644 index 0000000..0a7a0c2 --- /dev/null +++ b/old/14009-h/images/title.png diff --git a/old/14009-h/images/title_th.jpg b/old/14009-h/images/title_th.jpg Binary files differnew file mode 100644 index 0000000..2c5acda --- /dev/null +++ b/old/14009-h/images/title_th.jpg diff --git a/old/14009.txt b/old/14009.txt new file mode 100644 index 0000000..c02884a --- /dev/null +++ b/old/14009.txt @@ -0,0 +1,5136 @@ +The Project Gutenberg EBook of Scientific American Supplement, No. 787, +January 31, 1891, by Various + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Scientific American Supplement, No. 787, January 31, 1891 + +Author: Various + +Release Date: November 10, 2004 [EBook #14009] + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + + + + +Produced by Victoria Woosley, Don Kretz, Juliet Sutherland, Charles +Franks and the PG Distributed Proofreading Team + + + + + +[Illustration] + + + + +SCIENTIFIC AMERICAN SUPPLEMENT NO. 787 + + + + +NEW YORK, January 31, 1891 + +Scientific American Supplement. Vol. XXXI., No. 787. + +Scientific American established 1845 + +Scientific American Supplement, $5 a year. + +Scientific American and Supplement, $7 a year. + + * * * * * + + + + +TABLE OF CONTENTS. + + +I. BIOGRAPHY.--CHARLES GOODYEAR.--The life and discoveries of + the inventor of vulcanized India rubber, with portrait.--1 + illustration + +II. BIOLOGY.--Can we Separate Animals from Plants?--By ANDREW + WILSON.--A debated point well discussed.--The bases on which + distinctions must be drawn + +III. ELECTRICITY.--A New Electric Ballistic Target.--A target + for investigations of the velocity of projectiles, now in use at + the United States Military Academy, West Point, N.Y.--1 + illustration. + + Electric Erygmascope.--An electric lighting apparatus for + examining earth strata in bore holes for geologists' and + prospectors' use.--1 illustration + + The Electro-Magnet.--By Prof. SILVANUS THOMPSON.--Continuation + of this exhaustive treatise, giving further details on special + points of construction.--1 illustrations + +IV. ENTOMOLOGY.--Potash Salts.--The use of potash salts as + insecticides, with accounts of experiments + + The Outlook for Applied Entomology.--By Dr. C.V. RILEY, U.S. + entomologist.--The conclusion of Prof. Riley's lecture, treating + of the branch of entomology with which his name is so honorably + associated + +V. INSURANCE.--The Expense Margin in Life Insurance.--Elaborate + review of the necessary expenses of conducting the insurance of + lives, with tables and calculations + +VI. MATHEMATICS.--The Trisection of Any Angle.--By FREDERIC R. + HONEY, Ph.B.--A very ingenious demonstration of this problem, + based on the properties of conjugate hyperbolas + +VII. METEOROLOGY.--Note on the Mt. Blanc Meteorological Station + + The Flood at Karlsbad.--Account of the recent flood and of its + destructive effects.--1 illustration + +VIII. MECHANICAL ENGINEERING.--Station for Testing Agricultural + Machines.--A proposed establishment for applying dynamometer + tests to agricultural machines.--1 illustration + + Steam Engine Valves.--By THOMAS HAWLEY.--A review of modern + slide valve practice, the lap, cut-off, and other points.--6 + illustrations + +IX. MISCELLANEOUS.--Science in the Theater.--Curious examples of + stage effect in fictitious mesmerizing and hypnotizing.--4 + illustrations + + Theatrical Water Plays.--Recent episodes in real water plays at + Hengler's Circus, London.--2 illustrations + +X. NAVAL ENGINEERING.--The French Ironclad War Ship Colbert.--An + armored wood and iron ship, with central battery.--1 + illustration + +XI. PHYSIOLOGY AND HYGIENE.--Newer Physiology and Pathology.--By + Prof. SAMUEL BELL. M.D.--An excellent presentation of modern + practice in the light of bacteriology + + Test Card Hints.--How to test the eyes for selecting eyeglasses + and spectacles + + The Composition of Koch's Lymph.--What Prof. Koch says it is and + what it can do.--The cabled account of the disclosure so long + waited for + +XII. TECHNOLOGY.--Firing Points of Various Explosives.--The + leading explosives, with the temperature of their exploding + points tabulated + + The Recovery of Gold and Silver from Plating and Gilding + Solutions--A paper of interest to silver and gold platers, as + well as photographers + + Water Softening and Purifying Apparatus.--An apparatus for + treatment of sewage, etc., chemically and by deposition.--1 + illustration + + * * * * * + + + + +THE FRENCH IRONCLAD WAR SHIP COLBERT. + + +The central battery ironclad Colbert is one of the ten ships of the +French navy that constitute the group ranking next in importance to +the squadron of great turret ships, of which the Formidable is the +largest. The group consists of six types, as follows: + + 1. The Ocean type; three vessels; the Marengo, Ocean, and Suffren. + 2. The Friedland type, of which no others are built. + 3. The Richelieu type, of which no others are built. + 4. The Colbert type, of which there are two; the Colbert and the + Trident. + 5. The Redoubtable type, of which no others are built. + 6. The Devastation type, of which no others are built. + +[Illustration: THE FRENCH IRONCLAD WAR SHIP COLBERT.] + +The Colbert was launched at Brest in 1875, and her sister ship, the +Trident, in 1876. Both are of iron and wood, and the following are the +principal dimensions of the Colbert, which apply very closely to the +Trident: She is 321 ft. 6 in. long, 59 ft. 6 in. beam, and 29 ft. 6 +in. draught aft. Her displacement is 8,457 tons, her indicated horse +power is 4,652, and her speed 14.4 knots. She has coal carrying +capacity for 700 tons, and her crew numbers 706. The thickness of her +armor belt is 8.66 in., that protecting the central battery is 6.29 +in. thick, which is also the thickness of the transverse armored +bulkheads, while the deck is 0.43 in. in thickness. The armament of +the Colbert consists of eight 10.63 in. guns, two 9.45 in., six 5.51 +in., two quick firing guns, and fourteen revolving and machine +guns.--_Engineering._ + + * * * * * + +A compound locomotive, built by the Rhode Island Locomotive Works, has +been tried on the Union Elevated Railroad, Brooklyn, N.Y. The engine +can be run either single or compound. The economy in fuel was 37.7 per +cent, and in water 23.8 per cent, over a simple engine which was +tested at the same time. The smoothness of running and the stillness +and comparative absence of cinders was fully demonstrated. + + * * * * * + + + + +STEAM ENGINE VALVES. + +[Footnote: Lecture delivered at Wells Memorial Institute, Boston, in +the Lowell Free Course for Engineers. From report in the _Boston +Journal of Commerce_.] + +By THOMAS HAWLEY. + +RIDING CUT-OFF VALVES--PECULIARITIES AND MERITS OF THE DIFFERENT +STYLES. + + +In considering the slide valve in its simple form with or without lap, +we find there are certain limitations to its use as a valve that would +give the best results. The limitation of most importance is that its +construction will not allow of the proper cut off to obtain all the +benefits of expansion without hindering the perfect action of the +valve in other particulars. At this economical cut off the opening of +the steam port is very little and very narrow, and although this is +attempted to be overcome by exceedingly wide ports, sixteen inches in +width in many cases in locomotive work, this great width adds largely +to the unbalanced area of the valve. The exhausting functions of the +valve are materially changed at the short cut off, and when much lap +is added to overcome this defect, there usually takes place a choking +of the exhaust port. You might inquire, why not make the port wider, +but this would increase the minimum amount of load on the valve, and +this must not be overlooked. Then the cut off is a fixed one, and we +can govern only by throttling the pressure we have raised in the +boiler or by using a cut off governor and the consequent wastes of an +enormous clearance space. You will observe, therefore, that the plain +slide valve engine gives the most general satisfaction at about +two-thirds cut off and a very low economic result. The best of such +engines will require forty-five to fifty pounds of steam per horse +power per hour, and to generate this, assuming an evaporation of nine +pounds of water to a pound of coal, would require between five and six +pounds of coal per horse power per hour. And the only feature that the +valve has specially to commend it is its extreme simplicity and the +very little mechanism required to operate it. + +Yet this is of considerable importance, and in consideration of some +special features at its latest cut off, the attempt has been many +times made to take advantage of these features. For instance, at 90 deg. +advance, the valve opens very rapidly indeed and fully satisfies our +requirements of a perfect valve. This is one good point, and in this +position also the exhaust and compression can be regulated very +closely and as desired without much lap, and as the opening of the +exhaust port comes with the eccentric at its most rapid movement the +release is very quick and as we would have it. This is only possible +at the most uneconomic position of the valve as regards cut off. + +The aim of many engineers has been to take advantage of these matters +by using the valve with 90 deg. angular advance of eccentric ahead of +crank, for the admission, release, and compression of the steam, and +provide another means of cutting off, besides the one already referred +to, viz., cutting off the supply of steam to the chest, and overcome +the objection in this one of large clearance spaces. This is done by +means of riding cut off valves, often called expansion valves, of +which, perhaps, the most widely known types in this vicinity are the +Kendall & Roberts engine and the Buckeye. The former is used in the +simplest form of riding cut off, while the Buckeye has many peculiar +features that engineers, I find, are too prone to overlook in a casual +examination of the engine. In these uses of the slide valve, too, +means are suggested and carried out of practically balancing the +valve. + +The origin of the riding cut off is most generally attributed to +Gonzenbach. His arrangement had two steam chests, the lower one +provided with the ordinary slide valve of late cut off, and steam was +cut off from this steam chest by the expansion valve covering the +ports connecting with the upper steam chest. This had the old +disadvantage that all the steam in the lower chest expanded with that +in the cylinder, at a consequent considerable loss. This was further +improved by causing the riding cut off to be upon the top of the main +valve, instead of its chest, and resulted in a considerable reduction +of the clearance space. + +This is the simplest form, and is shown in Fig. 1. The steam is +supplied by a passage through the main valve which operates exactly as +an ordinary slide valve would. That is, the inside edges of the steam +passage are the same as the ordinary valve, the additional piece on +each end, if I may so term it, being merely to provide a passage for +the steam which can be closed, instead of allowing the steam to pass +the edge. The eccentric of the main valve is fastened to the shaft to +give the proper amount of lead, and the desired release and +compression, and the expansion valve is operated by a separate +eccentric fastened in line with or 180 deg. ahead of the crank. When the +piston, therefore, commences to move from the crank end to open the +port, D, the expansion valve is forced by its eccentric in the +opposite direction, and is closing the steam port and would have +closed it before the piston reached quarter stroke, thus allowing the +steam then in the cylinder to do work by expansion. The eccentric +operating this expansion valve may be set to close this steam port at +any point in the stroke that is desired, the closing occurring when +the expansion valve has covered the steam port. Continuing the +movements of the valves, the two would move together until one or the +other reached its dead center, when the movements would be in opposite +directions. + +[Illustration: FIG. 1.] + +There are three ways of effecting the cut off in such engines, the +main valve meanwhile being undisturbed, its eccentric fastened +securely so as not to disturb the points of lead, release, and +compression. All that is required is to cause the edge of the +expansion valve to cover the steam port earlier in the stroke, and +this can be done, first, by increasing the angular advance of the cut +off eccentric; second, by adding lap to the cut off valve; and third +by changing the throw of the eccentric. In all these instances the +riding valve is caused to reach the edge of the steam port earlier in +the stroke. We will take first, as the simplest, those methods by +which the lap of the cut off valve is increased. + +It will be noted that there is but one edge of this valve that is +required to do any work, and that is to close the valve. The +eccentrics are so placed that the passage in the main valve is opened +long before the main valve itself is ready to admit steam to the +cylinder, so that only the outer edges are the ones to be considered, +and it will be readily seen that the two valves traveling in opposite +directions, any lap added to the working edge of the cut off valve +will cause it to reach the edge and therefore close the port earlier +than it would if there was less lap. And we might carry it to the +extreme that we could add lap enough that the steam passage would not +be opened at all. + +In Fig. 2 is shown the method by which this is accomplished, in what +is called Meyer's valve, and such as is used in the Kendall & Roberts +engine. We have only one point to look after, the cut off, so we can +add all the lap we wish without disturbing anything else. In this +engine the lap is changed by hand by means of a little hand wheel on a +stem that extends out of the rear of the steam chest. The valve is in +two sections, and when it is desired to cut off earlier, the hand +wheel is turned in such a direction that the right and left hand +screws controlling the cut off valve move one valve portion back and +the other forward, which would, if they were one valve and they should +be so considered, have the effect of lengthening them, or adding lap +to them. The result would be that the riding valve would reach the +edge of the steam port earlier in the stroke, bringing about an +earlier cut off. If the cut off is desired to be later, the hand wheel +is so turned that the right and left hand screws will bring the valve +sections nearer together, thus practically taking off lap. Now this +may be done by hand or it may be done by the action of a governor. + +[Illustration: FIG. 2.] + +In the latter case the governor at each change of load turns the right +and left hand screws to add or take away lap, as the load demands an +earlier or later cut off; in other cases the governor moves a rack in +mesh with a gear by which the valve sections are brought closer +together or are separated. The difficulty with the case where the hand +wheel is turned by hand is that the cut off is fixed where you leave +it, and governing can only be at the throttle. For this reason +anywhere near full boiler pressure would not be obtained in the +cylinder of the engine. If the load was a constant one, and the cut +off could be fixed at about one-third, causing the throttle to open +its widest, very good results would be obtained, but there is no +margin left for governing. + +If the load should increase at such a time the governor could not +control it under these conditions, and it would lead to a decrease in +speed unless the lap was again changed to give a later cut off. On +this account the general practice soon becomes to leave the cut off at +the later point and give range to the throttle, and we come back once +more to the plain slide valve cutting off at half stroke, and the only +gain there is, is in a quick port opening and quick cut off. But these +matters are more than offset by the wire drawing between the steam +pipe and chest, through the throttle, and the fact that there is added +to the friction of the engine the friction of this additional slide +valve and a considerable liability to have a leaky valve. + +In the case where the governor changes the position of the cut off +valve a greater decree of economy would result. In this engine, of +which the Lambertville engine is a type, the main valve is a long D +slide, with multiple ports at the ends through which the steam enters +the cylinders. It is operated from an eccentric on the crank shaft in +the usual manner. The cut off valve is also operated from the motion +on an eccentric fixed upon the crank shaft. The rod or stem of the cut +off valve passes through the main valve rod and slide. Upon the outer +end of the cut off valve rod are tappets fastened to engage with +tappets on the eccentric valve rod. Connection between the cut off +eccentric, therefore, and the cut off valve is only by means of the +engagement of these tappets. The eccentric rod is fastened to a rocker +arm having motion swinging about a pin or bearing in the governor +slide, which may be raised or lowered by a cam operated by the +governor. The cut off slide is of cylindrical shape and incloses a +spring and dash pot with disks attached by means of which the valve is +closed. The motion for operating the valves is relatively in the same +direction, the cut off eccentric having the greatest throw and greater +angular advance to cause it to open earlier and quickly before the +main valve is ready to admit steam. The cut off eccentric rod swinging +the rocker arm, the tappets thereon engage with those upon the cut off +valve rod and open the passages to the main valve, and in their +movement compress the spring in the main valve. According as the speed +of the engine, the rock arm will be raised or lowered so that the +tappets upon the eccentric rod may keep in engagement a shorter or +longer time before they disengage, thus allowing the spring that has +been compressed by the movement of the cut off valve to close that +valve quickly and the supply of steam to the engine, the cut off valve +traveling with the main valve for the balance of the stroke. This +device will give a remarkably quick opening and a quick cut off, but +in view of the fact that the governor has so much to do, its delicacy +is impaired and a quick response to the demands of the load changing +not so likely to occur. The cut off cannot be as quick as in some +other engines, because the valves are moving in opposite directions, +and while this fact would help, so far as shortening the distance to +be traveled before cut off, the resistance of the valves to travel in +opposite directions, or rather the tendency of the valve to travel +with the main valve, hinders its rapid action. + +[Illustration: FIG. 3.] + +This is one great objection to the rack and gear operated by the +governor, that two flat valves riding upon each other and sliding in +opposite directions at times require a considerable amount of force to +move them, and as only a slight change in load is required by the +load, the governor cannot handle the work as delicately as it should. +It is too much for the governor to do well. To overcome this +difficulty the Ryder cut-off, shown in Fig. 3, was made by the +Delamater people, of New York. The main slide valve is hollowed in the +back and the ports cut diagonally across the valve to form almost a +letter V. The expansion valve is V-shaped, and circular to fit its +circular-seat. The valve rod of the expansion valve has a sector upon +it and operated by a gear upon the governor stem, which rotates the +valve rod, and the edge of the valve rod is brought farther over the +steam port, thus practically adding lap to the valve. Little movement +is found necessary to make the ordinary change in cut-off, and it is +found to be much easier to move the riding valve across the valve than +in a direction directly opposite. It would require considerable force +to move the upper valve by the governor faster than the lower, or in a +direction opposite to that in which it is moving, but very little +force applied sideways at the same time it is moving forward will give +it a sideways motion. In this device the governor has only to exert +this side pressure and therefore has less to do than if it were called +upon to move the upper valve directly against the movement of the +lower. + +Something similar is the valve of the Woodbury engine, of Rochester, +N.Y. The cut-off valve is cylindrical, covering diagonal ports +directly opposite, and is caused to be rotated by the action of the +governor that operates a rack in mesh with a segment. Very little +movement will effect a considerable change in the lappage of the +valve, the valve turning about one-quarter a revolution for the +extremes of cut off. The cut off valve rod works through a bracket and +its end terminates in a ball in a socket on the end of the eccentric +rod. In this case the governor has not as much to do as in other +instances. + +[Illustration: FIG. 4.] + +Still another method of effecting this change in cut off, but hardly +by increasing the lap of the valve, is shown in the next drawing, Fig. +4. The cut off valve is held upon the main valve by the pressure of +steam upon its back and rides with it until it comes in contact with +the cut off wedge-shaped blocks, when its motion is arrested, and the +main valve continuing its movement the steam port is closed by the +main valve passing beneath the cut off valve. Thus the main valve +travels and carries the cut off valve upon its back again until the +cut off valve strikes the wedge on the other end and the cut off is +effected. The relative positions of the blocks are determined by the +governor, that will raise or lower them so that the cut off valve will +engage with them earlier or later as desired. This device was designed +specially as an inexpensive method of changing the common slide valve +into an automatic cut off. The cut off would not be as quick as in +other cases we have cited, depending here upon the movement of the +lower valve alone, and that, too, is in its slowest movement; whereas +in the other cases, the edges approaching each other, by the differing +movement of the valves the cut off is very rapid, provided the +distance to travel is not long. In this device considerable noise must +result by the cut off valve striking the cut off blocks, and a +considerable amount of leakage is likely to occur past this valve. + +But there is one great objection in the valve gears thus far cited, +that the travel of the expansion valve upon the main valve is +variable. I have in mind the case of a Kendall & Roberts engine, which +had been run for a long time at no better economy than would be +obtained from a plain slide valve engine, and when it was attempted to +get an earlier cut off by separating the two cut off valves, they had +worn so much in their old place on the valve that shoulders were found +sufficient to cause a disagreeable noise and a leaky valve. This is +very apt to occur, not only where the valve is run for a long time on +one seat, but in cases of variation of the travel of the expansion +valve. The result is that a change will bring about a leaky valve, +something that every engineer abhors. + +The construction of the Buckeye engine, which is also of this type, is +such that the travel of the valve on the back of the main valve is +always the same, no matter what the cut off may be. Then this engine +makes use of our second proposition as a means of effecting the cut +off, viz., by advancing the eccentric. You will readily observe that +anything that will cause the cut off valve to reach a certain point +earlier in the stroke will bring about an earlier cut off as it +hastens everything all around. This is the plan pursued in the +Buckeye, in which the governor, of the shaft type, turns the eccentric +forward or back according as the load demands. Then, in addition, the +valve is balanced partially, the attempt not being made to produce an +absolutely balanced valve, on the ground that there should be friction +enough to keep the surfaces bright and to prevent leakage. The most +perfect valve will, of course, be entirely balanced under all +conditions of pressure so as to move with perfect ease. With the +riding cut off valve in connection with the plain slide valve, this is +not accomplished, and it does not matter whether it is partially +unbalanced to prevent leakage or not, the fact that it is not entirely +balanced prevents it reaching the ideal valve. + +[Illustration: Fig. 5] + +This valve, Fig. 5, differs from the others also in this particular, +that the exhaust takes place at the end of the valve instead of under +the arch. Two eccentrics are used, the one for the main valve being +fastened to the shaft and the other riding loosely upon it and +connected to the fly wheel governor, by which it may be turned forward +or back as the load requires. The three points of lead, or admission +and exhaust and compression, are fixed and independent of the changes +and cut off. The motion of the main eccentric is given to a rocker +arm, the pivot of which is at the bottom, and from the upper end the +valve rod transfers the motion to the valve without reversing the +motion, as is done sometimes in the slide valve to overcome the +effects of the angularity of the connecting rod. The action of the +rocker arm, therefore, so far as the main valve in the Buckeye is +concerned, is no different than that which would occur if no rocker +arm intervened. The motion of the cut off eccentric, through its +eccentric rod, is given to a rocker rocking in a bearing in the center +of the main rocker arm (see Fig. 6). The motion of this eccentric is +reversed, so far as the cut off valve is concerned, and when the cut +off eccentric is moving forward, the cut off valve is being pushed +back. The main valve rod is hollow, and the cut off valve rod passes +through it. + +[Illustration: Fig. 6] + +The cut off eccentric can be placed in any position to cause it to cut +off as desired, and by drawing the valve forward, by increasing the +angular advance of the eccentric, the cut off valve is caused to reach +and cover the steam passage in the main valve earlier in the stroke. +Instead of being ahead of the crank, the main eccentric in this +arrangement follows the crank, on account of the exhaust and steam +edges being exactly opposite from those in the ordinary slide. What is +the steam edge of the common slide is in this the exhaust edge, and +what is the exhaust edge in the common valve is the steam edge in this +one. The valve, therefore, must be moved in the opposite direction +from what is ordinarily the case, the main eccentric being not 90 deg. +behind the crank. It has a rapid and full opening just the same, for +it is at this point behind the crank, or ahead of it, that the +eccentric gives to the valve its quickest movement, or between the +eccentric dead centers. The cut off eccentric is considerably ahead of +the main eccentric, and about even with the crank. If it was not for +the reversal of motion of the cut off valve through the rocker arm +this eccentric would be about in line with the crank, but on the other +end. The movement of the cut off valve, therefore, at the time of port +opening is very little, being about on its dead center, passing which, +it immediately commences to close. + +The object of the peculiar construction of the rocker arm, and the +pivot for the cut off rocker being placed thereon, is to provide equal +travel on the back of the main valve, no matter what the cut off. I +have already explained, in connection with the slide valve, that +advancing the eccentric does not change the movement of the valve on +its seat, but simply its relation to the movement of the piston. You +will see that this is unchanged as using the main valve as a seat or +any other seat. If the main valve was to remain stationary, and only +the cut off valve to be operated by its eccentric, the movement of +this cut off valve on a certain plane would be the same for all +positions of the eccentric. + +Moving the main slide does not affect the matter in any way, for it +moves at the same time the pivot of the cut off, and while the cut off +seat has assumed a different position with reference to the engine, it +is still as though stationary so far as the cut off valve is +concerned. This is the object of this peculiar construction, and not, +as some engineers suppose, simply to make an odd way of doing things. +And the object of it all is to give at all cut offs the same amount of +travel, so that there might be no unequal wear to bring about a leak, +to prevent which a perfect balancing has been sacrificed. + +Referring to the valve and this engine as to how it will satisfy our +requirements of a perfect valve gear, we find that the first +requirement of a rapid and full opening is met, in that the opening +occurs when the main eccentric is moving very rapidly, yet not its +fastest, and while this opening will be very satisfactory, it is not +so rapid an opening as is obtained in some other forms of valves and +valve gears, but this could be overcome very readily by increasing the +lead a trifle, and in my experience with these engines I find that the +practice is very general by engineers and by builders themselves to +give them a considerable amount of lead. As to the second requirement, +the maintenance of initial pressure until cut off, giving a straight +steam line, cards from this engine will not be found to show that the +engine satisfies this requirement, and for this reason, that the +cut-off valve commences to close the port immediately after the piston +commences to move. The cut off eccentric you will remember is set to +move with the crank or very nearly so, and the lighter the load, the +greater will this fact appear. For the lightest loads the governor +places the eccentric in advance of the crank, so that the cut off +valve will commence to close the port before steam is admitted by the +main valve to the engine. Now, the later the cut off, the less will +this wire drawing appear at first, and the shorter the cut off, the +amount of wire drawing increases sensibly. The operation of the valve, +therefore, in this particular, cannot be considered as meeting our +requirement that the port shall be held open full width until ready to +be closed. Many men claim for this engine that the closing occurs when +the cut off eccentric is moving its fastest. This is a fact, and if we +consider the point of cut off only to be the point of absolute cut +off, the cut off must be instantaneous, for there is an instantaneous +point where the cut off is final only to be considered. The reasoning +applied here would hold good also to a less extent on the slide valve, +but is not the point of absolute cut off. We want to note how long it +is from the time the valve commences to close at all until finally +closed, and, as I have shown you, this is considerable in this engine. + +Referring to the point of cut off finally, it is determined upon by a +governor of the fly wheel type. The eccentric is loose about the +shaft, and arms projecting therefrom are connected by other arms to +the extremity of an arm upon which is mounted a weight, and which is +attached to the spokes of the fly wheel, or special governor wheel in +this case, and which is fastened to the crank shaft. As the speed +increases through throwing off a portion of the load the governor +weights fly out, and this movement is transferred through the lever +connections to the eccentric, causing it to be turned ahead, and the +manner hastening the movement of the cut off valve on its seat and +causing it to reach and cover the edge of the steam port earlier in +the stroke. This engine was the pioneer in governors of this +character, the advantage being, in addition to its necessity for the +work of turning the eccentric ahead or back, that the liability of the +engine to run away, as very often happens from the breaking of the +governor belt or a similar cause, was not possible. + +The cut off valve has a travel considerably beyond the edge of the +steam passage after the valve is closed, and this has one advantage, +that the valve is less liable to leak, and to this must be added the +loss from the friction of this moving valve, and moving too in +opposition to the main valve. In our perfect valve, as we outlined it, +the valve does not move after the port is closed. The exhausting +functions of the valve are very good, giving a quick opening and a +full opening, because this opening occurs when the eccentric is moving +its fastest. The engine also possesses a distinct advantage in having +remarkably small clearance spaces. The length of the steam passage is +very small in comparison with any form of engine, and having but two +ports instead of four, as in the Corliss and four valve type. + +In these there must be included in the clearance, that to the exhaust +port as well as the steam port, adding a considerable amount where the +piston comes close to the head. As the engines leave the maker's hand +the engines are provided with a considerable amount of lap to give +plenty of compression, but are, of course, capable of having more +added to increase compression, or some planed off to decrease it. + +One of the peculiar things about this engine is the failure to realize +anywhere near boiler pressure, noticeable in every case that has come +under my notice. The considerable lead gives it for an instant, but it +soon falls away, indicating the steam chest pressure only by a peak at +the junction of the admission and steam lines. This is probably due to +the fact that the cut off valve commences closing the steam passage so +soon after steam is admitted, and in this particular does not satisfy +the requirements of a perfect valve. There is this about the engine, +that above all others of this type there has come under my notice +fewer engines of this type with a maladjustment of valves from +tampering by incompetent engineers. + + * * * * * + + + + +FIRING POINTS OF VARIOUS EXPLOSIVES. + + +An apparatus, devised by Horsley, was used, which consisted of an iron +stand with a ring support holding a hemispherical iron vessel, in +which paraffin or tin was put. Above this was another movable support, +from which a thermometer was suspended and so adjusted that its bulb +was immersed in molten material in the iron vessel. A thin copper +cartridge case, 5/8 in. in diameter and 1-5/16 in. long, was suspended +over the bath by means of a triangle, so that the end of the case was +1 in. below the surface of the liquid. On beginning the experiment the +material in the bath was heated to just above the melting point, the +thermometer was inserted in it, and a minute quantity of the explosive +was placed in the bottom of the cartridge case. The temperature marked +by the thermometer was noted as the _initial temperature_, the +cartridge case containing the explosive was inserted in the bath, and +the temperature quickly raised until the explosive flashed off or +exploded, when the temperature marked by the thermometer was again +noted as the _firing point_. The tables given show the results of +about six experiments with each explosive. The initial temperatures +range from 65 deg. to 280 deg. C. in some cases, but as the firing points +remained fairly constant, only the extremes of the latter are quoted +in the following table: + + + --------------------------------+----------------------- + Description of Explosive. | Firing Point in deg. C. + --------------------------------+----------------------- + Compressed military gun-cotton. | 186 - 201 + Air-dried military gun-cotton. | 179 - 186 + " " " | 186 - 189 + " " " | 137 - 139 + " " " | 154 - 161 + Gun-cotton dried at 65 deg. C. | 136 - 141 + Air-dried collodion gun-cotton. | 186 - 191 + " " " | 197 - 199 + " " " | 193 - 195 + Air-dried gun-cotton. | 192 - 197 + " " | 194 - 199 + Hydro-nitrocellulose. | 201 - 213 + Nitroglycerin. | 203 - 205 + Kieselghur dynamite. No. 1. | 197 - 200 + Explosive gelatin. | 203 - 209 + Explosive gelatin, camphorated. | 174 - 182 + Mercury fulminate. | 175 - 181 + Gunpowder. | 278 - 287 + Hill's picric powder. | 273 - 283 + " " " | 273 - 290 + Forcite, No. 1. | 184 - 200 + Atlas powder, 75 per cent. | 175 - 185 + Emmensite, No. 1. | 167 - 184 + Emmensite, No. 2. | 165 - 177 + Emmensite, No. 5. | 205 - 217 + --------------------------------+----------------------- + _--C.E. Munroe, J. Amer. Chem. Soc._ + + + * * * * * + + + + +STATION FOR TESTING AGRICULTURAL MACHINES. + + +The minister of agriculture has recently established a special +laboratory for testing agricultural _materiel_. This establishment, +which is as yet but little known, is destined to render the greatest +services to manufacturers and cultivators. + +In fact, agriculture now has recourse to physics and mechanics as well +as to chemistry. Now, although there were agricultural laboratories +whose mission it was to fix the choice of the cultivator upon such or +such a seed or fertilizer, there was no official establishment +designed to inform him as to the value of machines, the models of +which are often very numerous. _Chemical_ advice was to be had, but +_mechanical_ advice was wanting. It is such a want that has just been +supplied. Upon the report presented by Mr. Tisserand, director of +agriculture, a ministerial decree of the 24th of January, 1888, +ordered the establishment of an experimental station. Mr. Ringelmann, +professor of rural engineering at the school of Grignon, was put in +charge of the installation of it, and was appointed its director. He +immediately began to look around for a site, and on the 17th of +December, 1888, the Municipal Council of Paris, taking into +consideration the value of such an establishment to the city's +industries, decided that a plot of ground of an area of 3,309 square +meters, situated on Jenner Street, should be put at the disposal of +the minister of agriculture for fifteen years for the establishment +thereon of a trial station. This land, bordering on a very wide street +and easy of access, opposite the municipal buildings, offers, through +its area, its situation, and its neigborhood, indisputable advantages. +A fence 70 meters in extent surrounds the station. An iron gate opens +upon a paved path that ends at the station. + +The year 1889 was devoted to the installation, and the station is now +in full operation. The tests that can be made here are many, and +concern all kinds of apparatus, even those connected with the electric +lighting that the agriculturist may employ to facilitate his +exploitation. However, the tests that are oftenest made are (1) of +rotary apparatus, such as mills, thrashing machines, etc.; (2) of +traction machines, such as wagons, carts, plows, etc.; and (3) of +lifting apparatus. It is possible, also, to make experiments on the +resistance of materials. + +The experimental hall contains a 7 horse power gas motor, dynamometers +with automatic registering apparatus, counters, balances, etc. A small +machine shop contains a lathe, a forge, a drilling machine, etc. The +main shaft is 12 meters in length and is 7 centimeters in diameter. It +is supported at a distance of one meter from the floor by four pillow +blocks, and is formed of three sections united by movable coupling +boxes. Out of these 12 meters, 9 are in the hall and 3 extend beyond +the hall to an annex, 14 meters in length and 4 in width, in which +tests are made of machines whose operation creates dust. When the +machines to be tested require more than the power of seven horses that +the motor gives, the persons interested furnish a movable engine, +which, placed under the annex, actuates the driving shaft. Alongside +of the main building there is a ring for experimenting upon machines +actuated by a horse whim. There will soon be erected in the center of +the grounds an 18 meter tower for experiments on pumps. Platforms +spaced 5 meters apart, a crane at the top, and some gauging apparatus +will complete this hydraulic installation. + +The equipment of the hall is very complete, and is fitted for all +kinds of experiments. + +[Illustration: STATION FOR TESTING AGRICULTURAL MACHINES--DYNAMOMETER + FOR TESTING ROTARY MACHINES.] + +The tests of rotary machines are made by means of a dynamometer (see +figure). Two fast pulleys and one loose pulley are interposed between +the machine to be tested and the motor. The pulley connected with the +motor carries along the one connected with the machine, through the +intermedium of spring plates, whose strength varies with the nature of +the apparatus to be tested. The greater or less elongation of these +plates gives the tangential stress exerted by the driving pulley to +carry along the pulley that actuates the machine to be tested. This +elongation is registered by means of a pencil connected with the +spring plates, and which draws a diagram upon a sheet of paper. At the +same time, a special totalizer gives the stress in kilogrammeters. +Besides, the pulley shaft actuates a revolution counter, and a clock +measures the time employed in the experiment. In order to obtain a +simultaneous starting and stopping point for all these apparatus, they +are connected electrically, and, through the maneuver of a commutator, +are all controlled at once. The electric current is furnished by two +series of bichromate batteries. + +The tests of traction machines are effected by means of a +three-wheeled vehicle carrying a dynamometer. The front wheel is +capable of turning freely in the horizontal plane, and the dynamometer +is mounted upon a frame provided with a screw that permits of +regulating its position according to the slope of the ground. The +method of suspension of the dynamometer allows it to take +automatically the inclination of the line of traction without any +torsion of the plates. There are two models of this vehicle, one +designed to be drawn by a man, and the other by a horse. + +The station is provided, in addition, with registering pressure +gauges, a large double dynamometric indicator, a counter of +electricity, balances of precision, etc. + +An apparatus designed for measuring the rendering of presses is now in +course of construction. + +Although the station has been in operation only from the 1st of +January, twenty-five machines have already been presented to be +tested.--_Extract from Le Genie Civil_. + + * * * * * + + + + +WATER SOFTENING AND PURIFYING APPARATUS. + + +We have recently had brought under our notice a system of water and +sewage purification which appears to possess several substantial +advantages. Chief among these are simplicity in construction and +operation, economy in first cost and working and efficiency in action. +This system is the invention of Messrs. Slack & Brownlow, of Canning +Works, Upper Medlock Street, Manchester, and the apparatus adopted in +carrying it out is here illustrated. It consists of an iron +cylindrical tank having inside a series of plates arranged in a spiral +direction around a fixed center, and sloping downward at a +considerable angle outward. The water to be purified and softened +flows through the large inlet tube to the bottom, mixing on its way +with the necessary chemicals, and entering the apparatus at the +bottom, rises to the top, passing spirally round the whole +circumference, and depositing on the plates all solids and impurities. + +All that is needed in the way of attention, even when dealing with +sewage, or the most polluted waters, is stated to be the mixing in the +small tanks the necessary chemical reagents, at the commencement of +the working day; and at the close of the day the opening of the mud +cocks shown in our engraving, to remove the collected deposit upon the +plates. For the past six months this system has been in operation at a +dye works in Manchester, successfully purifying and softening the +foul waters of the river Medlock. It is stated that 84,000 gallons per +day can be easily purified by an apparatus 7 feet in diameter. The +chemicals used are chiefly lime, soda, and alumina, and the cost of +treatment is stated to vary from a farthing to twopence per 1,000 +gallons, according to the degree of impurity of the water or sewage +treated. + +The results of working at Manchester show that all the visible filth +is removed from the Medlock's inky waters, besides which the hardness +of the water is reduced to about 6 deg. from a normal condition of about +30 deg.. The effluent is fit for all the varied uses of a dye works, and +is stated to be perfectly capable of sustaining fish life. With +results such as these the system should have a promising future before +it in respect of sewage treatment, as well as the purification and +softening of water generally for industrial and manufacturing +purposes.--_Iron._ + +[Illustration: WATER SOFTENING AND PURIFYING APPARATUS.] + + * * * * * + + + + +THE TRISECTION OF ANY ANGLE. + +By FREDERIC R. HONEY, Ph.B., Yale University. + + +The following analysis shows that with the aid of an hyperbola any +arc, and therefore any angle, may be trisected. + +If the reader should not care to follow the analytical work, the +construction is described in the last paragraph--referring to Fig. II. + +Let a b c d (Fig. I.) be the arc subtending a given angle. Draw the +chord a d and bisect it at o. Through o draw e f perpendicular +to a d. + +We wish to find the locus of a point c whose distance from a given +straight line e f is one-half the distance from a given point d. + +In order to write the equation of this curve, refer it to the +co-ordinate axes a d (axis of X) and e f (axis of Y), intersecting +at the origin o. + + Let g c = x + +Therefore, from the definition c d = 2x + + Let o d = D + [Hence] h d = D-x + + Let c h = y + [Hence] (2x) squared = y squared + (D-x) squared + or 4x squared = y squared + D squared-2Dx + x squared + [Hence] y squared-3x squared + D squared-2Dx = o [I.] + +This is the equation of an hyperbola whose center is on the axis of +abscisses. In order to determine the position of the center, eliminate +the x term, and find the distance from the origin o to a new origin +o'. + + Let E = distance from o to o' + [Hence] x = x' + E + +Substituting this value of x in equation I. + + y squared-3(x' + E) squared + D squared-2D(x' + E) = o + or y squared-3x squared-6Ex'-3E squared + D squared-2Dx'-2DE = o [II.] + +In this equation the x' terms should disappear. + + [Hence] -6Ex' - 2Dx' = o + [Hence] -E = - D/3 + +That is, the distance from the origin o to the new origin or the +center of the hyperbola o' is equal to one-third of the distance +from o to d; and the minus sign indicates that the measurement +should be laid off to the left of the origin o. Substituting this +value of E in equation II., and omitting accents-- + + We have + + y squared - 3x squared + 2Dx - D squared/3 + D squared - 2Dx + 2D squared/3 = o + [Hence] y squared - 3x squared = - 4D squared/3 + +[Illustration: Fig I] + +[Illustration: Fig II] + +This is the equation of an hyperbola referred to its center o' as +the origin of co-ordinates. To write it in the ordinary form, that is +in terms of the transverse and conjugate axes, multiply each term by +C, i.e., + __ + Let \/C = semi-transverse axis. + +[TEX: \sqrt{C} = \text{semi-transverse axis.}] + + Thus Cy squared - 3Cx squared = - 4CD squared/3. [III.] + +When in this form the product of the coefficients of the x squared and y squared +terms should be equal to the remaining term. + +That is + + 3C squared = - 4CD squared/3. + [Hence] C = 4D squared/9. + +And equation III. becomes: + + + 4D squared 4D squared 16D^{4} + ----- y squared - ----- x squared = - --------- + 9 3 27 + +[TEX: \frac{4D^2}{9} y^2 - \frac{4D^2}{3} x^2 = -\frac{16D^4}{27}] + ____ + / 4D squared 2D + The semi-transverse axis = \/ ----- = ---- + 9 3 + +[TEX: \text{The semi-transverse axis} = \sqrt{\frac{4D^2}{9}} += \frac{2D}{3}] + ____ + / 4D squared 2D + The semi-conjugate axis = \/ ----- = ----- + 3 ___ + \/ 3 + +[TEX: \text{The semi-conjugate axis} = \sqrt{\frac{4D^2}{3}} += \frac{2D}{\sqrt{3}}] + +Since the distance from the center of the curve to either focus is +equal to the square root of the sum of the squares of the semi-axes, +the distance from o' to either focus + + ____________ + /4D squared 4D squared 4D + = /\ /----- + ----- = ---- + \/ 9 3 3 + +[TEX: \sqrt{\frac{4D^2}{9} + \frac{4D^2}{3}} = \frac{4D}{3}] + +We can therefore make the following construction (Fig. II.) Draw a d +the chord of the arc a c d. Trisect a d at o' and k. Produce +d a to l, making a l = a o' = o' k = k d. With a k as a +transverse axis, and l and d as foci, construct the branch of the +hyperbola k c c' c", which will intersect all arcs having the common +chord a d at c, c', c", etc., making the arcs c d, c' d, c" +d, etc., respectively, equal to one-third of the arcs a c d, a c' d, +a c" d, etc. + + * * * * * + + + + +TEST CARD HINTS. + +By Dr. F. OGDEN STOUT. + + +I know it is the custom with a great many if not the majority of +opticians to fit a customer without knowing whether he has presbyopia, +hypermetropia, or any of the other errors of refraction. Their method +is first to try a convex, and if this does not improve, a concave, +etc., until the proper one is found. This, of course, amounts to the +same thing if the right glass is found. But in practice it will be +found both time saving and more satisfactory to first decide with what +error you have to deal. It is very simple, and, where you have no +other means of diagnosing (such as the ophthalmoscope), it does away +with the necessity of trying so many lenses before the proper one is +found. You should have a distance test card placed at a distance of +twenty feet from the person you are examining, and in a good light. + +A distance test card consists of letters of various sizes which it has +been found can be seen at certain distances by people with good +vision. Thus the largest letter is marked with a cc, meaning that this +should be seen at two hundred feet, and another line, XX, at twenty +feet, which is the proper distance for testing vision for distance, +for the reason that a normal eye is at rest when looking at any object +twenty feet from it or beyond, and the rays coming from it are +parallel and come to a focus on the retina. You must also have a near +vision test card with lines that should be seen by a normal eye from +ten to seventy-two inches, and a card of radiating lines for +astigmatism. With this preparation you are ready to proceed. To +illustrate, the first customer comes and tells you that up to six +months ago he had very good vision, but he finds now that, especially +at night, he has trouble in reading or writing, and that he finds he +can see better a little farther away. His head aches and eyes smart. +You will of course say that this is a very simple case. It must be old +sight (presbyopia). Probably it is if he is old enough (45), but you +must prove this for yourself, without asking his age, which is +embarrassing in the case of a lady. If you direct him to the distance +card twenty feet away, and find that he can see every one down to and +including the one marked XX, his vision is up to the standard for +distance, and you know that he can have no astigmatism worth +correcting, nor any near sight, as both of these affect vision for +distance, but he may have far sight or old sight or both combined. You +must find which it is. + +If, while he is still looking at the twenty-foot line, you place in +front of the eyes a weak convex and he tells you he sees just as well +with as without, it proves the existence of far-sight or +hypermetropia, and the strongest convex that still leaves vision as +good for distance as without any, corrects the manifest. But if the +weak convex blurs it, it shows that there is some defect in focusing, +if the near vision is below normal. You therefore know that you have a +case of old sight or presbyopia, requiring the weakest convex to +correct it, that will enable your customer to see the finest line on +the near card at the required distance. + +The next customer that comes to be fitted with glasses can only see +the line marked XL on the distance card at 20 feet or about one-half +of what he should see, which leads you to think that there is no far +sight, for vision for distance is good except in very high degrees of +this error. Nor can there be old-sight, for vision for distance is +good in old-sight until after the fifty-fifth year, but it can be near +sight (myopia) or astigmatism, or both. We next try the near card and +find that even the finest line can be seen clearly if held +sufficiently close to the eyes. We now know that this is a case of +near sight, and we must fit them with glasses for distance. The +weakest concave that will enable him to see the line that should be +seen on the distance card at 20 feet is the proper one to give him for +use.--_The Optician._ + + * * * * * + + + + +CHARLES GOODYEAR. + + +CHARLES GOODYEAR was born in New Haven, December 29, 1800. He was the +son of Amasa Goodyear, and the eldest among six children. His father +was quite proud of being a descendant of Stephen Goodyear, one of the +founders of the colony of New Haven in 1638. + +Amasa Goodyear owned a little farm on the neck of land in New Haven +which is now known as Oyster Point, and it was here that Charles spent +the earliest years of his life. When, however, he was quite young, his +father secured an interest in a patent for the manufacture of ivory +buttons, and looking for a convenient location for a small mill, +settled at Naugatuck, Conn., where he made use of the valuable water +power that is there. Aside from his manufacturing, the elder Goodyear +ran a farm, and between the two lines of industry kept young Charles +pretty busy. + +In 1816, Charles left his home and went to Philadelphia to learn the +hardware business. He worked at this very industriously until he was +twenty-one years old, and then, returning to Connecticut, entered into +partnership with his father at the old stand in Naugatuck, where they +manufactured not only ivory and metal buttons, but a variety of +agricultural implements, which were just beginning to be appreciated +by the farmers. In August of 1824 he was united in marriage with +Clarissa Beecher, a woman of remarkable strength of character and +kindness of disposition, and one who in after years was of the +greatest assistance to the impulsive inventor. Two years later he +removed again to Philadelphia, and there opened a hardware store. His +specialties were the valuable agricultural implements that his firm +had been manufacturing, and after the first distrust of home made +goods had worn away--for all agricultural implements were imported +from England at that time--he found himself established at the head of +a successful business. + +This continued to increase until it seemed but a question of a few +years until he would be a very wealthy man. Between 1829 and 1830 he +suddenly broke down in health, being troubled with dyspepsia. At the +same time came the failure of a number of business houses that +seriously embarrassed his firm. They struggled on, however, for some +time, but were finally obliged to fail. The ten years that followed +this were full of the bitterest struggles and trials to Goodyear. +Under the law that then existed he was imprisoned time after time for +debts, even while he was trying to perfect inventions that should pay +off his indebtedness. + +Between the years 1831 and 1832 he began to hear about gum elastic and +very carefully examined every article that appeared in the newspapers +relative to this new material. The Roxbury Rubber Company, of Boston, +had been for some time experimenting with the gum, and believing that +they had found means for manufacturing goods from it, had a large +plant and were sending their goods all over the country. It was some +of their goods that first attracted his attention. Soon after this +Goodyear visited New York, and went at once to the store of the +Roxbury Rubber Company. While there, he examined with considerable +care some of their life preservers, and it struck him that the tube +used for inflation was not very perfect. He, therefore, on his return +to Philadelphia, made some tubes and brought them down to New York and +showed them to the manager of the Roxbury Rubber Company. + +This gentlemen was so pleased with the ingenuity that Goodyear had +shown in manufacturing these tubes, that he talked very freely with +him and confessed to him that the business was on the verge of ruin, +that the goods had to be tested for a year before they could tell +whether they were perfect or not, and to their surprise, thousands of +dollars worth of goods that they had supposed were all right were +coming back to them, the gum having rotted and made them so offensive +that it was necessary to bury them in the ground to get them out of +the way. + +Goodyear at once made up his mind to experiment on this gum and see if +he could not overcome its stickiness. + +He, therefore, returned to Philadelphia, and, as usual, met a +creditor, who had him arrested and thrown into prison. While there, he +tried his first experiments with India rubber. The gum was very cheap +then, and by heating it and working it in his hands, he managed to +incorporate in it a certain amount of magnesia which produced a +beautiful white compound and appeared to take away the stickiness. + +He therefore thought he had discovered the secret, and through the +kindness of friends was put in the way of further perfecting his +invention at a little place in New Haven. The first thing that he made +here was shoes, and he used his own house for grinding room, calender +room, and vulcanizing department, and his wife and children helped to +make up the goods. His compound at this time was India rubber, +lampblack, and magnesia, the whole dissolved in turpentine and spread +upon the flannel cloth which served as the lining for the shoes. It +was not long, however, before he discovered that the gum, even treated +this way, became sticky, and then those who had supplied the money for +the furtherance of these experiments, completely discouraged, made up +their minds that they could go no further, and so told the inventor. + +[Illustration: CHARLES GOODYEAR.] + +He, however, had no mind to stop here in his experiments, but, selling +his furniture and placing his family in a quiet boarding place, he +went to New York, and there, in an attic, helped by a friendly +druggist, continued his experiments. His next step in this line was to +compound the rubber with magnesia and then boil it in quicklime and +water. This appeared to really solve the problem, and he made some +beautiful goods. At once it was noised abroad that India rubber had +been so treated that it lost its stickiness, and he received medals +and testimonials and seemed on the high road to success, till one day +he noticed that a drop of weak acid, falling on the cloth, neutralized +the alkali, and immediately the rubber was soft again. To see this, +with his knowledge of what rubber should do, proved to him at once +that his process was not a successful one. He therefore continued +experimenting, and after preparing his mixtures in his attic in New +York, would walk three miles to the mill of a Mr. Pike, at Greenwich +village, and there try various experiments. + +In the line of these, he discovered that rubber, dipped in nitric +acid, formed a surface cure, and he made a great many goods with this +acid cure which were spoken of, and which even received a letter of +commendation from Andrew Jackson. + +The constant and varied experiments that Goodyear went through with +affected his health more or less, and at one time he came very near +being suffocated by gas generated in his laboratory. That he did not +die then everybody knows, but he was thrown then into a fever by the +accident and came very near losing his life. + +It was there that he formed an acquaintance with Dr. Bradshaw, who was +very much pleased with the samples of rubber goods that he saw in +Goodyear's room, and when the doctor went to Europe he took them with +him, where they attracted a great deal of attention, but beyond that +nothing was done about them. Now that he appeared to have success, he +found no difficulty in obtaining a partner, and together the two +gentlemen fitted up a factory and began to make clothing, life +preservers, rubber shoes, and a great variety of rubber goods. They +also had a large factory, with special machinery, built at Staten +Island, where he removed his family and again had a home of his own. +Just about this time, when everything looked bright, the great panic +of 1836-1837 came, and swept away the entire fortune of his associate +and left Goodyear without a cent, and no means of earning one. + +His next move was to go to Boston, where he became acquainted with J. +Haskins, of the Roxbury Rubber Company, and found in him a firm +friend, who loaned him money and stood by him when no one would have +anything to do with the visionary inventor. Mr. Chaffee was also +exceedingly kind and ever ready to lend a listening ear to his plans, +and to also assist him in a pecuniary way. It was about this time that +it occurred to Mr. Chaffee that much of the trouble that they had +experienced in working India rubber might come from the solvent that +was used. He therefore invented a huge machine for doing the mixing +by mechanical means. The goods that were made in this way were +beautiful to look at, and it appeared, as it had before, that all +difficulties were overcome. + +Goodyear discovered a new method for making rubber shoes and got a +patent on it, which he sold to the Providence Company, in Rhode +Island. + +The secret of making the rubber so that it would stand heat and cold +and acids, however, had not been discovered, and the goods were +constantly growing sticky and decomposing and being returned. + +In 1838 he, for the first time, met Nathaniel Hayward, who was then +running a factory in Woburn. Some time after this Goodyear himself +moved to Woburn, all the time continuing his experiments. He was very +much interested in Hayward's sulphur experiments for drying rubber, +but it appears that neither of them at that time appreciated the fact +that it needed heat to make the sulphur combine with the rubber and to +vulcanize it. + +The circumstances attending the discovery of his celebrated process is +thus described by Mr. Goodyear himself in his book, "Gum Elastic." It +will be observed that he makes use of the third person in all +references to himself: + + "In the summer of 1838 he became acquainted with Mr. Nathaniel + Hayward, of Woburn, Mass., who had been employed as the foreman of + the Eagle Company at Woburn, where he had made use of sulphur by + impregnating the solvent with it. It was through him that the + writer (Charles Goodyear, who makes use all through his book of + the third person) received the first knowledge of the use of + sulphur as a drier of gum elastic. + + "Mr. Hayward was left in possession of the factory which was + abandoned by the Eagle Company. Soon after this it was occupied by + the writer, who employed him for the purpose of manufacturing life + preservers and other articles by the acid gas process. At this + period he made many novel and useful applications of this + substance. Among other fancy articles he had newspapers printed on + the gum elastic drapery, and the improvement began to be highly + appreciated. He therefore now entered, as he thought, upon a + successful career for the future. A far different result awaited + him. + + "It was supposed by others as well as himself that a change was + wrought through the mass of the goods acted upon by the acid gas, + and that the whole body of the article was made better than the + native gum. The surface of the goods really was so, but owing to + the eventual decomposition of the goods beneath the surface, the + process was pronounced by the public a complete failure. Thus + instead of realizing the large fortune which by all acquainted + with his prospects was considered certain, his whole invention + would not bring him a week's living. + + "He was obliged for the want of means to discontinue + manufacturing, and Mr. Hayward left his employment. The inventor + now applied himself alone, with unabated ardor and diligence, to + detect the cause of his misfortune and if possible to retrieve the + lost reputation of his invention. On one occasion he made some + experiments to ascertain the effect of heat upon the same compound + that had decomposed in the articles previously manufactured, and + was surprised to find that the specimen, being carelessly brought + in contact with a hot stove, charred like leather. He endeavored + to call the attention of his brother as well as some other + individuals who were present, and who were acquainted with the + manufacture of gum elastic, to this effect as remarkable and + unlike any before known, since gum elastic always melted when + exposed to a high degree of heat. The occurrence did not at the + time appear to them to be worthy of notice. It was considered as + one of the frequent appeals that he was in the habit of making in + behalf of some new experiment. He, however, directly inferred that + if the process of charring could be stopped at the right point, it + might divest the gum of its native adhesiveness throughout, which + would make it better than the native gum. + + "He made another trial of heating a similar fabric, before an open + fire. The same effect, that of charring the gum, followed, but + there were further and very satisfactory indications of ultimate + success in producing the desired result, as upon the edge of the + charred portions of the fabric there appeared a line, or border, + that was not charred, but perfectly cured. + + "These facts have been stated precisely as they occurred in + reference to the acid gas, as well as the vulcanizing process. + + "The incidents attending the discovery of both have a strong + resemblance, so much so they may be considered parallel cases. It + being now known that the results of the vulcanizing process are + produced by means and in a manner which would not have been + anticipated from any reasoning on the subject, and that they have + not yet been satisfactorily accounted for, it has been sometimes + asked, how the inventor came to make the discovery? The answer has + already been given. It may be added that he was many years seeking + to accomplish this object, and that he allowed nothing to escape + his notice that related to the subject. Like the falling of an + apple, it was suggestive of an important fact to one whose mind + was previously prepared to draw an inference from any occurrence + which might favor the object of his research. While the inventor + admits that these discoveries were not the results of scientific + chemical investigations, _he is not willing to admit that they + were the result of what is commonly termed accident_; he claims + them to be the result of the closest application and observation. + + "The discoloring and charring of the specimens proved nothing and + discovered nothing of value, but quite the contrary, for in the + first instance, as stated in the acid gas improvement, the + specimen acted upon was thrown away as worthless and left for some + time; in the latter instance, the specimen that was charred was in + like manner disregarded by others. + + "It may, therefore, be considered as one of those cases where the + leading of the Creator providentially aids his creatures, by what + are termed 'accidents,' to attain those things which are not + attainable by the powers of reasoning he has conferred on them." + +Now that Goodyear was sure that he had the key to the intricate puzzle +that he had worked over for so many years, he began at once to tell +his friends about it and to try to secure capital, but they had +listened to their sorrow so many times that his efforts were futile. +For a number of years be struggled and experimented and worked along +in a small way, his family suffering with himself the pangs of the +extremest poverty. At last he went to New York and showed some of his +samples to William Ryder, who, with his brother Emory, at once +appreciated the value of the discovery and started in to +manufacturing. Even here Goodyear's bad luck seemed to follow him, for +the Ryder Bros. failed and it was impossible to continue the business. + +He had, however, started a small factory at Springfield, Mass., and +his brother-in-law, Mr. De Forest, who was a wealthy woolen +manufacturer, took Ryder's place, and the work of making the invention +practical was continued. In 1844 it was so far perfected that Goodyear +felt it safe to take out a patent. The factory at Springfield was run +by his brothers, Nelson and Henry. + +In 1843 Henry started one in Naugatuck, and in 1844 introduced +mechanical mixing in place of the mixture by the use of solvents. + +In the year 1852 Goodyear went to Europe, a trip that he had long +planned, and saw Hancock, then in the employ of Charles Macintosh & +Co. Hancock admitted in evidence that the first piece of vulcanized +rubber he ever saw came from America, but claimed to have reinvented +vulcanization and secured patents in Great Britain, but it is _a +remarkable fact_ that Charles Goodyear's French patent was the first +publication in Europe of this discovery. + +In 1852 a French company were licensed by Mr. Goodyear to make shoes, +and a great deal of interest was felt in the new business. In 1855 the +French emperor gave to Charles Goodyear the grand medal of honor and +decorated him with the cross of the legion of honor in recognition of +his services as a public benefactor, but the French courts +subsequently set aside his French patents on the ground of the +importation of vulcanized goods from America by licenses under the +United States patents. He died July 1, 1860, at the Fifth Avenue +Hotel, New York City.--_India Rubber World_. + + * * * * * + +[Continued from SUPPLEMENT, No. 786, page 12558.] + + + + +THE ELECTROMAGNET. + +[Footnote: Lectures delivered before the Society of Arts, London, +1890. From the Journal of the Society.] + +BY PROFESSOR SILVANUS P. THOMPSON, D. SC., B.A., M.I.E.E. + +III. + +RESEARCHES OF PROFESSOR HUGHES. + + +[Illustration: FIG. 51.--HUGHES' ELECTROMAGNET.] + +His object was to find out the best form of electromagnet, the best +distance between the poles, and the best form of armature for the +rapid work required in Hughes' printing telegraphs. One word about +Hughes' magnets. This diagram (Fig. 51) shows the form of the well +known Hughes' electromagnet. I feel almost ashamed to say those words +"well known," because on the Continent everybody knows what you mean +by a Hughes' electromagnet. In England scarcely anyone knows what you +mean. Englishmen do not even know that Professor Hughes has invented a +special form of electromagnet. Hughes' special form is this: A +permanent steel magnet, generally a compound one, having soft iron +pole pieces, and a couple of coils on the pole pieces only. As I have +to speak of Hughes' special contrivance among the mechanisms that will +occupy our attention later on, I only now refer to this magnet in one +particular. If you wish a magnet to work rapidly, you will secure the +most rapid action, not when the coils are distributed all along, but +when they are heaped up near, not necessarily entirely on, the poles. +Hughes made a number of researches to find out what the right length +and thickness of these pole pieces should be. It was found an +advantage not to use too thin pole pieces, otherwise the magnetism +from the permanent magnet did not pass through the iron without +considerable reluctance, being choked by insufficiency of section: +also not to use too thick pieces, otherwise they presented too much +surface for leakage across from one to the other. Eventually a +particular length was settled upon, in proportion about six times the +diameter, or rather longer. In the further researches that Hughes made +he used a magnet of shorter form, not shown here, more like those +employed in relays, and with an armature from 2 to 3 millimeters +thick, 1 centimeter wide and 5 centimeters long. The poles were turned +over at the top toward one another. Hughes tried whether there was any +advantage in making those poles approach one another, and whether +there was any advantage in having as long an armature as 5 +centimeters. He tried all the different kinds, and plotted out the +results of observations in curves, which could be compared and +studied. His object was to ascertain the conditions which would give +the strongest pull, not with a steady current, but with such currents +as were required for operating his printing telegraph instruments; +currents which lasted but one to twenty hundredths of a second. He +found it was decidedly an advantage to shorten the length of the +armature, so that it did not protrude far over the poles. In fact, he +got a sufficient magnetic circuit to secure all the attractive power +that he needed, without allowing as much chance of leakage as there +would have been had the armature extended a longer distance over the +poles. He also tried various forms of armature having very various +cross sections. + + +POSITION AND FORM OF ARMATURE. + +In one of Du Moncel's papers on electromagnets[1] you will also find a +discussion on armatures, and the best forms for working in different +positions. Among other things in Du Moncel you will find this paradox: +that whereas using a horseshoe magnet with fat poles, and a flat piece +of soft iron for armature, it sticks on far tighter when put on +edgeways; on the other hand, if you are going to work at a distance, +across air, the attraction is far greater when it is set flatways. I +explained the advantage of narrowing the surfaces of contact by the +law of traction, B squared, coming in. Why should we have for action at a +distance the greater advantage from placing the armature flatway to +the poles? It is simply that you thereby reduce the reluctance offered +by the air gap to the flow of the magnetic lines. Du Moncel also tried +the difference between round armatures and flat ones, and found that a +cylindrical armature was only attracted about half as strongly as a +prismatic armature having the same surface when at the same distance. +Let us examine this fact in the light of the magnetic circuit. The +poles are flat. You have at a certain distance away a round armature; +there is a certain distance between its nearest side and the polar +surfaces. If you have at the same distance away a flat armature having +the same surface, and, therefore, about the same tendency to leak, why +do you get a greater pull in this case than in that? I think it is +clear that if they are at the same distance away, giving the same +range of motion, there is a greater magnetic reluctance in the case of +the round armature, although there is the same periphery, because, +though the nearest part of the surface is at the prescribed distance, +the rest of the under surface is farther away; so that the gain found +in substituting an armature with a flat surface is a gain resulting +from the diminution in the resistance offered by the air gap. + +[Footnote 1: "La Lumiere Electrique," vol. ii.] + + +POLE PIECES ON HORSESHOE MAGNETS. + +Another of Du Moncel's researches[2] relates to the effect of polar +projections or shoes--movable pole pieces, if you like--upon a +horseshoe electromagnet. The core of this magnet was of round iron 4 +centimeters in diameter, and the parallel limbs were 10 centimeters +long and 6 centimeters apart. The shoes consisted of two flat pieces +of iron slotted out at one end, so that they could be slid along over +the poles and brought nearer together. The attraction exerted on a +flat armature across air gaps 2 millimeters thick was measured by +counterpoising. Exciting this electromagnet with a certain battery, it +was found that the attraction was greatest when the shoes were pushed +to about 15 millimeters, or about one-quarter of the interpolar +distance, apart. The numbers were as follows: + + Distance between + shoes. Attraction, + Millimeters. in grammes. + + 2 900 + 10 1,012 + 15 1,025 + 25 965 + 40 890 + 60 550 + +[Footnote 2: "La Lumiere Electrique," vol. iv., p. 129.] + +With a stronger battery the magnet without shoes had an attraction of +885 grammes, but with the shoes 15 millimeters apart, 1,195 grammes. +When one pole only was employed, the attraction, which was 88 grammes +without a shoe, was _diminished_ by adding a shoe to 39 grammes! + + +CONTRAST BETWEEN ELECTROMAGNETS AND PERMANENT MAGNETS. + +Now I want particularly to ask you to guard against the idea that all +these results obtained from electromagnets are equally applicable to +permanent magnets of steel; they are not, for this simple reason. With +an electromagnet, when you put the armature near, and make the +magnetic circuit better, you not only get more magnetic lines going +through that armature, but you get more magnetic lines going through +the whole of the iron. You get more magnetic lines round the bend when +you put an armature on to the poles, because you have a magnetic +circuit of less reluctance with the same external magnetizing power in +the coils acting around it. Therefore, in that case, you will have a +greater magnetic flux all the way round. The data obtained with the +electromagnet (Fig. 42), with the exploring coil, C, on the bend of +the core, where the armature was in contact, and when it was removed +are most significant. When the armature was present it multiplied the +total magnetic flow tenfold for weak currents and nearly threefold for +strong currents. But with a steel horseshoe, magnetized once for all, +the magnetic lines that flow around the bend of the steel are a fixed +quantity, and, however much you diminish the reluctance of the +magnetic circuit, you do not create or evoke any more. When the +armature is away the magnetic lines arch across, not at the ends of +the horseshoe only, but from its flanks; the whole of the magnetic +lines leaking somehow across the space. Where you have put the +armature on, these lines, instead of arching out into space as freely +as they did, pass for the most part along the steel limbs and through +the iron armature. You may still have a considerable amount of +leakage, but you have not made one line more go through the bent part. +You have absolutely the same number going through the bend with the +armature off as with the armature on. You do not add to the total +number by reducing the magnetic reluctance, because you are not +working under the influence of a constantly impressed magnetizing +force. By putting the armature on to a steel horseshoe magnet you +only _collect_ the magnetic lines, you do not _multiply_ them. This is +not a matter of conjecture. A group of my students have been making +experiments in the following way: They took this large steel horseshoe +magnet (Fig. 52), the length of which, from end to end, through the +steel, is 421/2 inches. A light, narrow frame was constructed so that it +could be slipped on over the magnet, and on it were wound 30 turns of +fine wire, to serve as an exploring coil. The ends of this coil were +carried to a distant part of the laboratory, and connected to a +sensitive ballistic galvanometer. The mode of experimenting is as +follows: + +The coil is slipped on over the magnet (or over its armature) to any +desired position. The armature of the magnet is placed gently upon the +poles, and time enough is allowed to elapse for the galvanometer +needle to settle to zero. The armature is then suddenly detached. The +first swing measures the change, due to removing the armature, in the +number of magnetic lines that pass through the coil in the particular +position. + +[Illustration: FIG. 52.--EXPERIMENT WITH PERMANENT MAGNET.] + +I will roughly repeat the experiment before you: The spot of light on +the screen is reflected from my galvanometer at the far end of the +table. I place the exploring coil just over the pole, and slide on the +armature; then close the galvanometer circuit. Now I detach the +armature, and you observe the large swing. I shift the exploring coil, +right up to the bend; replace the armature; wait until the spot of +light is brought to rest at the zero of the scale. Now, on detaching +the armature, the movement of the spot of light is quite +imperceptible. In our careful laboratory experiments, the effect was +noticed inch by inch all along the magnet. The effect when the +exploring coil was over the bend was not as great as 1-3000th part of +the effect when the coil was hard up to the pole. We are, therefore, +justified in saying that the number of magnetic lines in a permanently +magnetized steel horseshoe magnet is not altered by the presence or +absence of the armature. + +You will have noticed that I always put on the armature gently. It +does not do to slam on the armature; every time you do so, you knock +some of the so-called permanent magnetism out of it. But you may pull +off the armature as suddenly as you like. It does the magnet good +rather than harm. There is a popular superstition that you ought never +to pull off the keeper of a magnet suddenly. On investigation, it is +found that the facts are just the other way. You may pull off the +keeper as suddenly as you like, but you should never slam it on. + +From these experimental results I pass to the special design of +electromagnets for special purposes. + + +ELECTROMAGNETS FOR MAXIMUM TRACTION. + +These have already been dealt with in the preceding lecture; the +characteristic feature of all the forms suitable for traction being +the compact magnetic circuit. + +Several times it has been proposed to increase the power of +electromagnets by constructing them with intermediate masses of iron +between the central core and the outside, between the layers of +windings. All these constructions are founded on fallacies. Such iron +is far better placed either right inside the coils or right outside +them, so that it may properly constitute a part of the magnetic +circuit. The constructions known as Camacho's and Cance's, and one +patented by Mr. S.A. Varley, in 1877, belonging to this delusive order +of ideas, are now entirely obsolete. + +Another construction which is periodically brought forward as a +novelty is the use of iron windings of wire or strip in place of +copper winding. The lower electric conductivity of iron, as compared +with copper, makes such a construction wasteful of exciting power. To +apply equal magnetizing power by means of an iron coil implies the +expenditure of about six times as many watts as need be expended if +the coil is of copper. + + +ELECTROMAGNETS FOR MAXIMUM RANGE OF ATTRACTION. + +We have already laid down the principle which will enable us to design +electromagnets to act at a distance. We want our magnet to project, as +it were, its force across the greatest length of air gap. Clearly, +then, such a magnet must have a very large magnetizing power, with +many ampere turns upon it, to be able to make the required number of +magnetic lines pass across the air resistance. Also it is clear that +the poles must not be too close together for its work, otherwise the +magnetic lines at one pole will be likely to curl round and take short +cuts to the other pole. There must be a wider width between the poles +than is desirable in electromagnets for traction. + + +ELECTROMAGNETS OF MINIMUM WEIGHT. + +In designing an apparatus to put on board a boat or a balloon, where +weight is a consideration of primary importance, there is again a +difference. There are three things that come into play--iron, copper, +and electric current. The current weighs nothing, therefore, if you +are going to sacrifice everything else to weight, you may have +comparatively little iron, but you must have enough copper to be able +to carry the electric current; and under such circumstances you must +not mind heating your wires nearly red hot to pass the biggest +possible current. Provide as little copper as you conveniently can, +sacrificing economy in that case to the attainment of your object; +but, of course, you must use fireproof material, such as asbestos, for +insulating, instead of cotton or silk. + + +A USEFUL GUIDING PRINCIPLE. + +In all cases of design there is one leading principle which will be +found of great assistance, namely, that a magnet always tends so to +act as though it tried to diminish the length of its magnetic circuit. +It tries to grow more compact. This is the reverse of that which holds +good with an electric current. The electric circuit always tries to +enlarge itself, so as to inclose as much space as possible, but the +magnetic circuit always tries to make itself as compact as possible. +Armatures are drawn in as near as can be, to close up the magnetic +circuit. Many two-pole electromagnets show a tendency to bend together +when the current is turned on. One form in particular, which was +devised by Ruhmkorff for the purpose of repeating Faraday's celebrated +experiment on the magnetic rotation of polarized light, is liable to +this defect. Indeed, this form of electromagnet is often designed very +badly, the yoke being too thin, both mechanically and magnetically, +for the purpose which it has to fulfill. + +Here is a small electric bell, constructed by Wagener, of Wiesbaden, +the construction of which illustrates this principle. The +electromagnet, a horseshoe, lies horizontally; its poles are provided +with protruding curved pins of brass. Through the armature are drilled +two holes, so that it can be hung upon the two brass pins; and when so +hung up it touches the ends of the iron cores just at one edge, being +held from more perfect contact by a spring. There is no complete gap, +therefore, in the magnetic circuit. When the current comes and applies +a magnetizing power, it finds the magnetic circuit already complete in +the sense that there are no absolute gaps. But the circuit can be +bettered by tilting the armature to bring it flat against the polar +ends, that being indeed the mode of motion. This is a most reliable +and sensitive pattern of bell. + +[Illustration: FIG. 53.--ELECTROMAGNETIC POP-GUN.] + +_Electromagnetic Pop-gun._--Here is another curious illustration of +the tendency to complete the magnetic circuit. Here is a tubular +electromagnet (Fig. 53), consisting of a small bobbin, the core of +which is an iron tube about two inches long. There is nothing very +unusual about it; it will stick on, as you see, to pieces of iron when +the current is turned on. It clearly is an ordinary electromagnet in +that respect. Now suppose I take a little round rod of iron, about an +inch long, and put it into the end of the tube, what will happen when +I turn on my current? In this apparatus as it stands, the magnetic +circuit consists of a short length of iron, and then all the rest is +air. The magnetic circuit will try to complete itself, not by +shortening the iron, but by _lengthening_ it; by pushing the piece of +iron out so as to afford more surface for leakage. That is exactly +what happens; for, as you see, when I turn on the current, the little +piece of iron shoots out and drops down. You see that little piece of +iron shoot out with considerable force. It becomes a sort of magnetic +popgun. This is an experiment which has been twice discovered. I found +it first described by Count Du Moncel, in the pages of _La Lumiere +Electrique_, under the name of the "pistolet electromagnetique;" and +Mr. Shelford Bidwell invented it independently. I am indebted to him +for the use of this apparatus. He gave an account of it to the +Physical Society, in 1885, but the reporter missed it, I suppose, as +there is no record in the society's proceedings. + + +ELECTROMAGNETS FOR USE WITH ALTERNATING CURRENTS. + +When you are designing electromagnets for use with alternating +currents, it is necessary to make a change in one respect, namely, you +must so laminate the iron that internal eddy currents shall not occur; +indeed, for all rapid-acting electromagnetic apparatus it is a good +rule that the iron must not be solid. It is not usual with telegraphic +instruments to laminate them by making up the core of bundles of iron +plates or wires, but they are often made with tubular cores, that is +to say, the cylindrical iron core is drilled with a hole down the +middle, and the tube so formed is slit with a saw cut to prevent the +circulation of currents in the substance of the tube. Now when +electromagnets are to be employed with rapidly alternating currents, +such as are used for electric lighting, the frequency of the +alternations being usually about 100 periods per second, slitting the +cores is insufficient to guard against eddy currents; nothing short of +completely laminating the cores is a satisfactory remedy. I have here, +thanks to the Brush Electric Engineering Company, an electromagnet of +the special form that is used in the Brush arc lamp when required for +the purpose of working in an alternating current circuit. It has two +bobbins that are screwed up against the top of an iron box at the head +of the lamp. The iron slab serves as a kind of yoke to carry the +magnetism across the top. There are no fixed cores In the bobbins, +which are entered by the ends of a pair of yoked plungers. Now in the +ordinary Brush lamp for use with a steady current, the plungers are +simply two round pieces of iron tapped into a common yoke; but for +alternate current working this construction must not be used, and +instead a U-shaped double plunger is used, made up of laminated iron, +riveted together. Of course it is no novelty to use a laminated core; +that device, first used by Joule, and then by Cowper, has been +repatented rather too often during the past fifty years to be +considered as a recent invention. + +The alternate rapid reversals of the magnetism in the magnetic field +of an electromagnet, when excited by alternating electric currents, +sets up eddy currents in every piece of undivided metal within range. +All frames, bobbin tubes, bobbin ends, and the like, must be most +carefully slit, otherwise they will overheat. If a domestic flat iron +is placed on the top of the poles of a properly laminated +electromagnet, supplied with alternating currents, the flat iron is +speedily heated up by the eddy currents that are generated internally +within it. The eddy currents set up by induction in neighboring masses +of metal, especially in good conducting metals such as copper, give +rise to many curious phenomena. For example, a copper disk or copper +ring placed over the pole of a straight electromagnet so excited is +violently repelled. These remarkable phenomena have been recently +investigated by Professor Elihu Thomson, with whose beautiful and +elaborate researches we have lately been made conversant in the pages +of the technical journals. He rightly attributes many of the repulsion +phenomena to the lag in phase of the alternating currents thus induced +in the conducting metal. The electromagnetic inertia, or +self-inductive property of the electric circuit, causes the currents +to rise and fall later in time than the electromotive forces by which +they are occasioned. In all such cases the impedance which the circuit +offers is made up of two things--resistance and inductance. Both these +causes tend to diminish the amount of current that flows, and the +inductance also tends to delay the flow. + + +ELECTROMAGNETS FOR QUICKEST ACTION. + +I have already mentioned Hughes' researches on the form of +electromagnet best adapted for rapid signaling. I have also +incidentally mentioned the fact that where rapidly varying currents +are employed, the strength of the electric current that a given +battery can yield is determined not so much by the resistance of the +electric circuit as by its electric inertia. It is not a very easy +task to explain precisely what happens to an electric circuit when the +current is turned on suddenly. The current does not suddenly rise to +its full value, being retarded by inertia. The ordinary law of Ohm in +its simple form no longer applies; one needs to apply that other law +which bears the name of the law of Helmholtz, the use of which is to +give us an expression, not for the final value of the current, but for +its value at any short time, t, after the current has been turned on. +The strength of the current after a lapse of a short time, t, cannot +be calculated by the simple process of taking the electromotive force +and dividing it by the resistance, as you would calculate steady +currents. + +In symbols, Helmholtz's law is: + + i_{t} = E/R ( 1 - e^{-(R/L)t} ) + +In this formula i_{t} means the strength of the current after the +lapse of a short time t; E is the electromotive force; R, the +resistance of the whole circuit; L, its coefficient of self-induction; +and _e_ the number 2.7183, which is the base of the Napierian +logarithms. Let us look at this formula; in its general form it +resembles Ohm's law, but with a new factor, namely, the expression +contained within the brackets. The factor is necessarily a fractional +quantity, for it consists of unity less a certain negative +exponential, which we will presently further consider. If the factor +within brackets is a quantity less than unity, that signifies that +i_{t} will be less than E / R. Now the exponential of negative sign, +and with negative fractional index, is rather a troublesome thing to +deal with in a popular lecture. Our best way is to calculate some +values, and then plot it out as a curve. When once you have got it +into the form of a curve, you can begin to think about it, for the +curve gives you a mental picture of the facts that the long formula +expresses in the abstract. Accordingly we will take the following +case. Let E = 2 volts; R = 1 ohm; and let us take a relatively large +self-induction, so as to exaggerate the effect; say let L = 10 quads. +This gives us the following: + + ________________________________________ + | | | | + | t_{(sec.)} | e^{+(R/L)t} | i_{t} | + --------------+--------------+---------| + | 0 | 1 | 0 | + | 1 | 1.105 | 0.950 | + | 2 | 1.221 | 1.810 | + | 5 | 1.649 | 3.936 | + | 10 | 2.718 | 6.343 | + | 20 | 7.389 | 8.646 | + | 30 | 20.08 | 9.501 | + | 60 | 403.4 | 9.975 | + | 120 | 16200.0 | 9.999 | + ---------------------------------------- + +In this case the value of the steady current as calculated by Ohm's +law is 10 amperes, but Helmholtz's law shows us that with the great +self-induction which we have assumed to be present, the current, even +at the end of 30 seconds, has only risen up to within 5 percent. of +its final value; and only at the end of two minutes has practically +attained full strength. These values are set out in the highest curve +in Fig. 54, in which, however, the further supposition is made that +the number of spirals, S, in the coils of the electromagnet is 100, so +that when the current attains its full value of 10 amperes, the full +magnetizing power will be Si = 1000. It will be noticed that the +curve rises from zero at first steeply and nearly in a straight line, +then bends over, and then becomes nearly straight again, as it +gradually rises to its limiting value. The first part of the +curve--that relating to the strength of the current after _very small_ +interval of time--is the period within which the strength of the +current is governed by inertia (i.e., the self-induction) rather than +by resistance. In reality the current is not governed either by the +self-induction or by the resistance alone, but by the ratio of the +two. This ratio is sometimes called the "time constant" of the +circuit, for it represents _the time_ which the current takes in that +circuit to rise to a definite fraction of its final value. + + E = 10 + r = 1 + R = 100 + L = 10 + + Si + 1000 + _..------------------------------- + | . _ _--------- + | . .---- + | . .- 2 IN SERIES + | . .- + | - + | .: - : + | .: . : + 500 | . : __- -:--------------------------- + | . : _.- - : 2 IN PARALLEL + | . :. - : + | . / : - : + | . / - : + |. / - : : + |./. : : + |/_____:_____________:____________________________ t + 10 20 40 60 80 100 120 + + FIG. 54.--CURVES OF RISE OF CURRENTS. + +This definite fraction is the fraction (e - 1)/e; or in decimals, +0.634. All curves of rise of current are alike in general shape, they +differ only in scale, that is to say, they differ only in the height +to which they will ultimately rise, and in the time they will take to +attain this fraction of their final value. + +_Example (1)._--Suppose E = 10; R = 200 ohms; L = 8. The final value +of the current will be 0.025 amp. or 25 milliamperes. Then the time +constant will be 8 / 400 = 1-50th sec. + +_Example (2)._--The P.O. Standard "A" relay has R = 400 ohms; L = +3.25. It works with 0.5 milliampere current, and therefore will work +with 5 Daniell cells through a line of 9,600 ohms. Under these +circumstances the time constant of the instrument on short circuit is +0.0081 sec. + +It will be noted that the time constant of a circuit can be reduced +either by diminishing the self-induction or by increasing the +resistance. In Fig. 54 the position of the time constant for the top +curve is shown by the vertical dotted line at 10 seconds. The current +will take 10 seconds to rise to 0.634 of its final value. This +retardation of the rise of current is simply due to the presence of +coils and electromagnets in the circuit; the current as it grows being +retarded because it has to create magnetic fields in these coils, and +so sets up opposing electromotive forces that prevent it from growing +all at once to its full strength. Many electricians, unacquainted with +Helmholtz's law, have been in the habit of accounting for this by +saying that there is a lag in the iron of the electromagnet cores. +They tell you that an iron core cannot be magnetized suddenly, that it +takes time to acquire its magnetism. They think it is one of the +properties of iron. But we know that the only true time lag in the +magnetization of iron, that which is properly termed "viscous +hysteresis," does not amount to any great percentage of the whole +amount of magnetization, takes comparatively a long time to show +itself, and cannot therefore be the cause of the retardation which we +are considering. There are also electricians who will tell you that +when magnetization is suddenly evoked in an iron bar, there are +induction currents set up in the iron which oppose and delay its +magnetization. That they oppose the magnetization is perfectly true, +but if you carefully laminate the iron so as to eliminate eddy +currents, you will find, strangely enough, that the magnetism rises +still more slowly to its final value. For by laminating the iron you +have virtually increased the self-inductive action, and increased the +time constant of the circuit, so that the currents rise more slowly +than before. The lag is not in the iron, but in the magnetizing +current, and the current being retarded, the magnetization is of +course retarded also. + + +CONNECTING COILS FOR QUICKEST ACTION. + +Now let us apply these most important though rather intricate +considerations to the practical problems of the quick working of the +electromagnet. Take the case of an electromagnet forming some part of +the receiving apparatus of a telegraph system in which it is desired +to secure very rapid working. Suppose the two coils that are wound +upon the horseshoe core are connected together in series. The +coefficient of self-induction for these two is four times as great as +that of either separately; coefficients of self-induction being +proportional to the square of the number of turns of wire that +surround a given core. Now if the two coils instead of being put in +series are put in parallel, the coefficient of self-induction will be +reduced to the same value as if there were only one coil, because half +the line current (which is practically unaltered) will go through each +coil. Hence the time constant of the circuit when the coils are in +parallel will be a quarter of that which it is when the coils are in +series; on the other hand, for a given line current, the final +magnetizing power of the two coils in parallel is only half what it +would be with the coil in series. The two lower curves in Fig. 54 +illustrate this, from which it is at once plain that the magnetizing +power for very brief currents is greater when the two coils are put in +parallel with one another than when they are joined in series. + +Now this circumstance has been known for some time to telegraph +engineers. It has been patented several times over. It has formed the +theme of scientific papers, which have been read both in France and in +England. The explanation generally given of the advantage of uniting +the coils in parallel is, I think, fallacious; namely that the "extra +currents" (i.e., currents due to self-induction) set up in the two +coils are induced in such directions as tend to help one another when +the coils are in series, and to neutralize one another when they are +in parallel. It is a fallacy, because in neither case do they +neutralize one another. Whichever way the current flows to make the +magnetism, it is opposed in the coils while the current is rising, +and helped in the coils while the current is falling, by the so-called +extra currents. If the current is rising in both coils at the same +moment, then, whether the coils are in series or in parallel, the +effect of self-induction is to retard the rise of the current. The +advantage of parallel grouping is simply that it reduces the time +constant. + + +BATTERY GROUPING FOR QUICKEST ACTION. + +One may consider the question of grouping the battery cells from the +same point of view. How does the need for rapid working, and the +question of time constant, affect the best mode of grouping the +battery cells? The amateur's rule, which tells you to so arrange your +battery that its internal resistance should be equal to the external +resistance, gives you a result wholly wrong for rapid working. The +supposed best arrangement will not give you (at the expense even of +economy) the best result that might be got out of the given number of +cells. Let us take an example and calculate it out, and place the +results graphically before our eyes in the form of curves. Suppose the +line and electromagnet have together a resistance of 6 ohms, and that +we have 24 small Daniell cells, each of electromotive force say 1 volt, +and of internal resistance 4 ohms. Also let the coefficient of +self-induction of the electromagnet and circuit be 6 quadrants. When +all the cells are in series, the resistance of the battery will be 96 +ohms, the total resistance of the circuit 102 ohms, and the full value +of the current 0.235 ampere. When all the cells are in parallel, the +resistance of the battery will be 0.133 ohm, the total resistance +6.133 ohms, and the full value of the current 0.162 ampere. According +to the amateur rule of grouping cells so that internal resistance +equals external, we must arrange the cells in 4 parallels, each having +6 cells in series, so that the internal resistance of the battery will +be 6 ohms, total resistance of circuit 12 ohms, full value of current +0.5 ampere. Now the corresponding time constants of the circuit in the +three cases (calculated by dividing the coefficient of self-induction +by the total resistance) will be respectively--in series, 0.06 sec.; +in parallel, 0.5 sec.; grouped for maximum steady current, 0.96 sec. +From these data we may now draw the three curves, as in Fig. 55, +wherein the abscissae are the values of time in seconds and the +ordinates the current. The faint vertical dotted lines mark the time +constants in the three cases. It will be seen that when rapid working +is required the magnetizing current will rise, during short intervals +of time, more rapidly if all the cells are put in series than it will +do if the cells are grouped according to the amateur rule. + + | + 5| . + | . + | . + 4| MAXIMUM . + | OUTPUT \ . + | . + 3| . + | . : ALL IN SERIES + | _-------------------:------------------------------ + 2| .- - : + | - - : + | -: - : + 1| / : - : ALL IN PARALLEL + |. : . : _________-------- + |- :__ : ---------- + +-----------------------------:------------------------------- + 0 1 2 3 4 5 6 7 8 9 10 + +FIG. 55.--CURVES OF RISE OF CURRENT WITH DIFFERENT GROUPINGS OF BATTERY. + +When they are all put in series, so that the battery has a much +greater resistance than the rest of the circuit, the current rises +much more rapidly, because of the smallness of the time constant, +although it never attains the same ultimate maximum as when grouped in +the other way. That is to say, if there is self-induction as well as +resistance in the circuit, the amateur rule does not tell you the best +way of arranging the battery. There is another mode of regarding the +matter which is helpful. Self-induction, while the current is growing, +acts as if there were a sort of spurious addition to the resistance of +the circuit; and while the current is dying away it acts of course in +the other way, as if there were a subtraction from the resistance. +Therefore you ought to arrange the battery so that the internal +resistance is equal to the real resistance of the circuit, plus the +spurious resistance during that time. But how much is the spurious +resistance during that time? It is a resistance proportional to the +time that has elapsed since the current was turned on. So then it +comes to a question of the length of time for which you want to work +it. What fraction of a second do you require your signal to be given +in? What is the rate of the vibrator of your electric bell? Suppose +you have settled that point, and that the short time during which the +current is required to rise is called t; then the apparent resistance +at time t after the current is turned on is given by the formula: + + R_{t} = R x e^{(R/L)t} + ( e^{(R/L)t} - 1 ) + + +TIME CONSTANTS OF ELECTROMAGNETS. + +I may here refer to some determinations made by M. Vaschy,[1] +respecting the coefficients of self-induction of the electromagnets of +a number of pieces of telegraphic apparatus. Of these I must only +quote one result, which is very significant. It relates to the +electromagnet of a Morse receiver of the pattern habitually used on +the French telegraph lines. + + L, in quadrants. + Bobbins, separately, without iron cores. 0.233 and 0.265 + Bobbins, separately, with iron cores. 1.65 and 1.71 + Bobbins, with cores joined by yoke, + coils in series 6.37 + Bobbins, with armature resting on poles. 10.68 + +[Footnote 1: "Bulletin de la Societe Internationale des Electriciens," +1886.] + +It is interesting to note how the perfecting of the magnetic circuit +increases the self-induction. + +Thanks to the kindness of Mr. Preece, I have been furnished with some +most valuable information about the coefficients of self-induction, +and the resistance of the standard pattern of relays, and other +instruments which are used in the British postal telegraph service, +from which data one is able to say exactly what the time constants of +those instruments will be on a given circuit, and how long in their +case the current will take to rise to any given fraction of its final +value. Here let me refer to a very capital paper by Mr. Preece in an +old number of the "Journal of the Society of Telegraph Engineers," a +paper "On Shunts," in which he treats this question, not as perfectly +as it could now be treated with the fuller knowledge we have in 1890 +about the coefficients of self-induction, but in a very useful and +practical way. He showed most completely that the more perfect the +magnetic circuit is--though of course you are getting more magnetism +from your current--the more is that current retarded. Mr. Preece'e +mode of experiment was extremely simple. He observed the throw of the +galvanometer when the circuit which contained the battery and the +electromagnet was opened by a key which at the same moment connected +the electromagnet wires to the galvanometer. The throw of the +galvanometer was assumed to represent the extra current which flowed +out. Fig. 56 represents a few of the results of Mr. Preece's paper. + + +==========+ + |=| |=| |=| |=| |=| + \======= \======= =======/ ======= ======= + | | | | | | | | | | + | | | | | | | | | | + | | | |--| | | | | | + ======= ======= ======= /======= =======\ + |=| |=| |=| |=| |=| + + +===========+ +==========+ +===== ======+ + |=| |=| |=| |=| |=| |=| + ======= =======/ B\======= =======/A A\======= =======/B + | | | | | | | | | | | | + | | | | | | | | | | | | + | |--| | | | | | | | | | + ======= ======= A======= =======B =======B =======A + |=| |=| |=| |=| |=| |=| + +==========+ +==========+ +====== =====+ + + FIG. 56.--ELECTROMAGNETS OF RELAY, AND THEIR EFFECTS. + +Take from an ordinary relay a coil, with its iron core, half the +electromagnet, so to speak, without any yoke or armature. Connect it +up as described, and observe the throw given to the galvanometer. The +amount of throw obtained from the single coil was taken as unity, and +all others were compared with it. If you join up two such coils as +they are usually joined, in series, but without any iron yoke across +the cores, the throw was 17. Putting the iron yoke across the cores, +to constitute a horseshoe form, 496 was the throw; that is to say, the +tendency of this electromagnet to retard the current was 496 times as +great as that of the simple coil. But when an armature was put over +the top, the effect ran up to 2,238. By the mere device of putting the +coils in parallel, instead of in series, the 2,238 came down to 502, a +little less than the quarter value which would have been expected. +Lastly, when the armature and yoke were both of them split in the +middle, as is done in fact in all the standard patterns of the British +postal telegraph relays, the throw of the galvanometer was brought +down from 502 to 26. Relays so constructed will work excessively +rapidly. Mr. Preece states that with the old pattern of relay having +so much self-induction as to give a galvanometer throw of 1,688, the +speed of signaling was only from 50 to 60 words per minute, whereas, +with the standard relays constructed on the new plan, the speed of +signaling is from 400 to 450 words per minute. It is a very +interesting and beautiful result to arrive at from the experimental +study of these magnetic circuits. + + +SHORT CORES _versus_ LONG CORES. + +In considering the forms that are best for rapid action, it ought to +be mentioned that the effects of hysteresis in retarding changes in +the magnetization of iron cores are much more noticeable in the case +of nearly closed magnetic circuits than in short pieces. +Electromagnets with iron armatures in contact across their poles will +retain, after the current has been cut off, a very large part of their +magnetism, even if the cores be of the softest of iron. But so soon as +the armature is wrenched off, the magnetism disappears. An air gap in +a magnetic circuit always tends to hasten demagnetizing. A magnetic +circuit composed of a long air path and a short iron path demagnetizes +itself much more rapidly than one composed of a short air path and a +long iron path. In long pieces of iron the mutual action of the +various parts tends to keep in them any magnetization that they may +possess; hence they are less readily demagnetized. In short pieces, +where these mutual actions are feeble or almost absent, the +magnetization is less stable, and disappears almost instantly on the +cessation of the magnetizing force. Short bits and small spheres of +iron have no magnetic memory. Hence the cause of the commonly received +opinion among telegraph engineers that for rapid work electromagnets +must have short cores. As we have seen, the only reason for employing +long cores is to afford the requisite length for winding the wire +which is necessary for carrying the needful circulation of current to +force the magnetism across the air gaps. If, for the sake of rapidity +of action, length has to be sacrificed, then the coils must be heaped +up more thickly on the short cores. The electromagnets in American +patterns of telegraphic apparatus usually have shorter cores, and a +relatively greater thickness of winding upon them, than those of +European patterns. + + * * * * * + + + + +ELECTRIC ERYGMASCOPE. + + +The erygmascope is the name of an electric lighting apparatus designed +for the examination of the strata of earth traversed by boring +apparatus. + +It consists of a very powerful incandescent lamp inclosed in a +metallic cylinder. One of the two semi-cylindrical sides constitutes +the reflector, and the other, which is of thick glass, allows of the +passage of the luminous rays, which thus illuminate with great +brilliancy the strata of earth traversed by the instrument. The base, +which is inclined at an angle of 45 deg., is an elliptical mirror, and the +top, of straight section, is open in order to permit the observer +standing at the mouth of the well, and provided with a powerful +spyglass, to see in the mirror the image of the earth. The lamp is so +mounted that its upwardly emitted rays are intercepted. + +The whole apparatus is suspended from a long cable, formed of two +conducting wires, which winds around a windlass with metallic +journals which are electrically insulated. These journals communicate, +through the intermedium of two friction springs, with the conductors +on the one hand and, on the other, with the poles of an automatic and +portable battery. + +[Illustration: THE TROUVE ERYGMASCOPE.] + +This permits of lowering and raising the apparatus at will, without +derangement, and without its being necessary to interrupt the light +and the observation.--_Revue Industrielle._ + + * * * * * + + + + +A NEW ELECTRIC BALLISTIC TARGET. + + +The electrical target usually employed in determining velocities of +projectiles consists of a wooden frame on which is strung a copper +wire so as to make a continuous circuit arranged in parallel vertical +lines about one inch or one and one half inches apart. + +It frequently happens that a projectile will pass through this target +without breaking the circuit, either by squeezing between the wires or +because, when last repaired, the target was short-circuited unnoticed, +so that the cutting of the wires did not break the circuit. The repair +of this target takes considerable time. + + _______________________________________________________ + | { + | +-------------__ --------------__---------------- } + | | _ // \\ // \\ } { + | | |_| || C_{0} || A || || || A { } + | | P \\ // \\ // } { + | +------------- --------------- ---------------- } + | F { + |_______________________________________________________} + + Plan. + P C + =|= _________ + |===| ========= A A + ========| | S |========\_______/================= + |spring | | | + | | | | | + |S_ | __| |__ __| + ||| | | + ___________|||______________| |_____________________ + | + | Section. + H / + \+/ + | + | + | + | + | + | + _____+_____ + | | + | W | + | | + |___________| + + +Besides these objections to this target, another and more serious one +is the irregularity in the manner of breaking the circuit. It has been +proved that times required for a flat headed and an ogival headed +projectile to rupture the current are very different. + +To remedy these defects a new and very ingenious target has been +devised and used with great success at the United States Military +Academy at West Point. The top of the target is a wooden strip, F, on +the upper side of which are screwed strips of copper, A A, about 1/2 +in. wide, and 1/8 in. thick. The connection between two adjoining +strips is made by a copper cartridge, C, which is dropped in a hole in +the frame bored to receive it. This cartridge is the one used in the +Springfield rifle. Inside the cartridge is a spiral spring, S, which, +acting on the bottom of the hole and the head of the cartridge, tends +to make the latter spring up, and so break the circuit. + +To the hook, H, which is attached to the cartridge, is suspended, by +means of a string, the lead weight, W, thus drawing down the cartridge +and making the circuit between A and A'. All the weights being +suspended the current comes in through the post, P, passes along the +copper strips and out of the corresponding post on the other end. + +On firing the projectile cuts a string, and the spring at once causes +the cartridge to spring up, thus breaking the circuit. + +It is not possible for the projectile to squeeze between the strings +and not break the current, for in so doing the cartridge is tipped +slightly, which is sufficient, as it breaks the current on one side. + +This target is used in connection with the Boulenge chronograph. Two +targets are established at a known distance apart, say 50 ft., and the +time required for the projectile to pass over this distance is +determined by finding the difference in the time of cutting of the two +targets, by finding the difference in the time of falling of the two +rods, caused by the demagnetization of two electromagnets in the same +circuit with the targets. + +By means of a disjunctor both rods are dropped at the same time, the +shorter one releasing a knife blade which makes a cut on the longer +one. Now both rods are hung from the magnets again and the gun is +fired. + +The projectile passes through the first target, breaks the circuit, +demagnetizes the magnet of the longer rod, and it begins to fall. On +passing through the second target, the projectile causes the shorter +rod to fall. This releases the knife blade, and a second cut is made. +The time corresponding to the distance between these cuts is the time +the longer rod was falling before the second rod began to fall or the +time between the cutting of the two targets by the projectile. + +The distance between the cuts is measured, and the time corresponding +to it can easily be found. Then the velocity of the projectile is +equal to 50/t. + +To repair this target, strings are prepared in advance of suitable +length and looped at both ends, so that by placing the hook of the +cartridge in one loop and that of the weight in the other the repair +is quickly made. + +This target has been used on the West Point proving ground to +determine velocities over distances of 100 ft. interval to distances +of only 9 ft. interval, and has given most satisfactory results. + + * * * * * + +[Continued from SUPPLEMENT, No. 786, page 12566.] + + + + +THE OUTLOOK FOR APPLIED ENTOMOLOGY. + +[Footnote: Address of Dr. C.V. Riley at the annual meeting of the +Association of Economic Entomologists, Champaign, Ills., November 11 +to 14, 1890.] + +LEGISLATION. + + +The amount of legislation in different countries that has of late +years been deemed necessary or sufficiently important, in view of +injurious insects, is a striking evidence of the increased attention +paid to applied entomology; and while modern legislation of this kind +has been, on the whole, far more intelligent than similar efforts in +years gone by, many of the laws passed have nevertheless been unwise, +futile, and impracticable, and even unnecessarily oppressive to other +interests. The chief danger here is the intervention of politics or +political methods. Expert counsel should guide our legislators and the +steps taken should be thorough in order to be effective. We have had +of late years in Germany very good evidence of the excellent results +flowing from thorough methods, and the recent legislation in +Massachusetts against the gypsy moth (_Ocneria dispar_), which at one +time threatened to become farcical, has, fortunately, proved more than +usually successful; the commission appointed to deal with the subject +having worked with energy and followed competent advice. + + +PUBLICATION. + +On the question of publication of the results of our labors it is +perhaps premature to dwell at length. Each of the experiment stations +is publishing its own bulletins and reports quite independently of the +others, but after a uniform plan recommended by the association with +which we meet here; and with but one exception that has come to my +notice, another important recommendation of the same association--that +these publications shall be void of all personal matter--has been kept +in mind. The National Bureau of Experiment Stations at Washington is +doing what it can with the means at command to further the general +work by issuing the Experiment Station Record, devoted chiefly to +digests of the State station bulletins. There is a serious question in +my mind as to the utility of State digests by the national department +of results already published extensively by the different States and +distributed under government frank to all similar institutions and to +whomsoever is interested enough to ask for them. + +Such digests may or may not be intelligently made, and, even under the +most favorable circumstances, will hardly serve any other purpose than +helping to the reference to the original articles, and this could +undoubtedly be done more satisfactorily to the stations and to the +people at large by general and classified indices to all the State +documents, made as full as possible and issued at stated intervals. +Only a small proportion of the bulletins have been so far noticed by +digest in this record, with no particular rule, so far as I can see, +in the selection. In point of fact, those will be most apt to be +noticed whose authors can find time to themselves send or make for the +purpose their own abstracts. This is, perhaps, inevitable under +present arrangements. Complete and satisfactory digests of all, if +intelligent and critical, imply a far greater force than is at present +at Prof. Atwater's command. + +Under these circumstances, it would seem wiser to devote all the +energies of the bureau to digests of the similar literature of other +countries, which would be of immense advantage to our people and to +the different station workers. Judging from the recommendations and +resolutions of the general association, this is the view very +generally held, but except in chemistry and special industries like +that of beet sugar, very little of that kind of work has yet been +attempted. + +What is true of the station publications in general is equally true of +special publications. As entomologist of the department, I have been +urged to bring together, at stated intervals, digests of the +entomological publications of the different stations. Such digests to +be of any value, however, should also be critical, and it were a +thankless task for any one to be critic or censor even of that which +needs correction or criticism. Moreover, to do this work intelligently +would require increase of the divisional force, which at present is +more advantageously employed, for, as already intimated, I should have +great doubts of the utility of these digests. + +I believe, however, that the division should strive for such increase +of means as would justify the periodic publication, either +independently or as a part of the department record, of general and +classified indices to the entomological matter of the station +bulletins, and should work more and more toward giving results from +other parts of the world. This could, perhaps, best be done by titles +of subject and of author so spaced and printed on stout paper that +they could be cut and used in the ordinary card catalogue. The +recipient could cut and systematically place the titles as fast as +received. + +As to the character of the matter of the entomological bulletins, it +will inevitably be influenced by the needs and demands of the people +of the respective States, and while originality should be kept in +mind, there must needs be in the earlier years of the work much +restatement of what is already well known. That some results have been +published of work which reflects no particular credit upon our calling +is a mere incident of the new positions created. Yet we may expect +marked improvement from year to year in this direction, and without +being invidious, I would cite those of Prof. Gillette's on his +spraying experiments and on the plum curculio and plum gouger, as +models of what such bulletins should be. + +Although the resolution offered at our last meeting by Prof. Cook, to +the effect that purely descriptive matter should be excluded from the +station bulletins, met with no favor, but was laid on the table, by +the general association, I am in full sympathy with this position and +am strongly of the opinion that in the ordinary bulletins such purely +technical and descriptive matter should be reduced to the necessary +minimum consistent with clearness of statement and accuracy, and that +if it is desired, on the part of the station entomologists, to issue +technical and descriptive papers, a separate series of bulletins were +better instituted for this class of matter. + +Finally, for results which it is desired to promptly get before the +people, the agricultural press is at our disposal, and so far as the +entomological work of the department of agriculture is concerned, the +periodical bulletin, _Insect Life_, was established for this purpose. +Its columns are open to all station workers, and I would here appeal +to the members of the association to help make it, as far as possible, +national, by sending brief notes and digests of their work as it +progresses. Hitherto we have been unable to make as much effort in +this direction as we desired, but in future it is our hope to make the +bulletin, as far as possible, a national medium through which the +results of work done in all parts of the country may quickly be put on +record and distributed, not only to all parts of our own country, but +to all parts of the world. + +The rapid growth and development of the national department and the +multiplication of its divisions have necessitated special modes of +publication and rendered the annual report almost an anachronism so +far as it pretends to be what it at one time was--a pretty complete +report of the scientific and other work of the department. The +attempts which I have made through the proper authorities to get +Congress to order more pretentious monographic works in quarto volume +similar to those issued by other departments of the government have +not met with encouragement, and in this direction many of the stations +will, let us hope, be able to do better. + + +CO-OPERATION. + +Every other subject that might be considered on this occasion must be +subordinate to the one great question of co-operation. With the large +increase of actual workers in our favorite field, distributed all over +the country, the necessity for some co-operation and co-ordination +must be apparent to every one. Just how this should be brought about +or in what direction we may work toward it, will be for this +association in its deliberations to decide. Nor will I venture to +anticipate the deliberations and conclusions of the special committee +appointed to take the matter into consideration, beyond the statement +that there are many directions in which we can adopt plans for mutual +benefit. Take, for instance, the introduction and dissemination of +parasites. How much greater will be the chance of success in any +particular case if we have all the different station entomologists +interested in some specific plan to be carried out in co-operation +with the national department, which ought to have better facilities of +introducing specimens to foreign countries or to different sections of +our own country than any of the State stations. + +Let us suppose that the fruit growers of one section of the country, +comprising several States in area, need the benefit in their warfare +against any particularly injurious insect of such natural enemy or +enemies as are known to help the fruit growers of some other section. +There will certainly be much greater chances of success in the +carrying out of any scheme of introduction if all the workers in the +one section may be called upon through some central or national body +to help in the introduction and disposition of the desired material +into the other section. Or, take the case of the boll worm +investigation already alluded to. The chances of success would be much +greater if the entomologists in all the States interested were to give +some attention to such lepidopterous larvae as are found to be affected +with contagious diseases and to follow out some specific plan of +cultivating and transmitting them to the party or parties with whom +the actual trials are intrusted. The argument applies with still +greater force to any international efforts. I need hardly multiply +instances. There is, it is true, nothing to prevent any individual +station entomologist from requesting co-operation of the other +stations, nor is there anything to prevent the national department +from doing likewise; but in all organization results are more apt to +flow from the power to direct rather than from mere liberty to request +or to plead. The station entomologist may be engrossed in some line of +research which he deems of more importance to the people of his State, +and may resent being called upon to divert his energies; and with no +central or national power to decide upon plans of co-operation for the +common weal, we are left to voluntary methods, mutually devised, and +it is here that this association can, it seems to me, most fully +justify its organization. And this brings me to the question of + + +THE DEPARTMENT AND THE STATIONS. + +Immediately connected with the question of co-operation is the +relation of the National Department of Agriculture and the State +experiment stations. The relation, instead of being vital and +authoritative, is, in reality, a subordinate one. Many persons +interested in the advancement of agriculture foresaw the advantage of +having experiment stations attached to the State agricultural colleges +founded under the Morrill act of 1862; but I think that in the minds +of most persons the establishment of these stations implied some such +connection with the national department as that outlined in an address +on Agricultural Advancement in the United States, which I had the +honor to deliver in 1879 before the National Agricultural Congress, at +Rochester, and in which the following language was used: + + "In the light of the past history of the German experimental + stations and their work, or of that in our own State of + Connecticut, the expediency of purchasing an experimental farm of + large dimensions in the vicinity of Washington is very + questionable. There can be no doubt, however, of the value of a + good experimental station there that shall have its branches in + every State of the Union. The results to flow from such stations + will not depend upon the number of acres at command, and it will + be far wiser and more economical for the commissioner to make each + agricultural college that accepted the government endowment + auxiliary to the national bureau, so that the experimental farm + that is now, or should be, connected with each of these + institutions might be at its service and under the general + management of the superintendent of the main station. There is + reason to believe that the directors of these colleges would + cheerfully have them constituted as experimental stations under + the direction of the department, and thus help to make it really + national--the head of a vast system that should ramify through all + parts of the land.... + + "With the different State agricultural colleges, and the State + agricultural societies, or boards, we have every advantage for + building up a national bureau of agriculture worthy of the country + and its vast productive interests, and on a thoroughly economical + basis, such as that of Prussia, for instance." + +In short, the view in mind was something in the nature of that which +has since been adopted by our neighbors of the North, where there is a +central or national station or farm at Ottawa and sub-stations or +branch farms at Nappan, Nova Scotia, Brandon, Manitoba, Indian Head, +N.W.T., and Agassiz, British Columbia, all under the able direction of +Mr. William Saunders, one of our esteemed fellow workers. It was my +privilege to be a good deal with Mr. Saunders when he was in Europe +studying the experience of other countries in this matter, and the +policy finally adopted in Canada as a result of his labors is an +eminently wise one, preventing some of the difficulties and dangers +which beset our plan, whether as between State and nation or college +and station. + +Under the present laws and with the vast influence which the +Association of Agricultural Colleges and Experiment Stations will +wield, both in Congress and in the different States, there is great +danger of transposition, in this agricultural body politic, of those +parts which in the animal body are denominated head and tail, and the +old saw to the effect that "the dog wags the tail because the tail +cannot wag the dog," will find another application. So far as the law +goes, the national department, which should hold a truly national +position toward State agricultural institutions depending on federal +support, can do little except by suggestion, whether in the line of +directing plans or in any way co-ordinating or controlling the work of +the different stations throughout the country. The men who influenced +and shaped the legislation which resulted in the Hatch bill were +careful that the department's function should be to indicate, not to +dictate; to advise and assist, not to govern or regulate. We have, +therefore, to depend on such relationships and such plans of +co-operation as will appear advantageous to all concerned, and these +can best be brought about through such associations as are now in +convention here. + +Without such plans there is great danger of such waste of energy and +means and duplication of results as will bring the work into popular +disfavor and invite disintegration, for already there is a growing +feeling that agricultural experiment is and will be subordinated to +the ordinary college work in the disposition of the federal +appropriations. + +What is true of the national department as a whole in its connection +with the State stations is true in a greater or less degree of the +different divisions of the department in connection with the different +specialists of the stations. With the multiplicity of workers in any +given direction in the different States, the necessity for national +work lessens. A favorite scheme of mine in the past, for instance (and +one I am glad to say fully indorsed by Prof. Willits), was to endeavor +to have a permanent agent located in every section of the country that +was sufficiently distinctive in its agricultural resources and +climate, or, as a yet further elaboration of the same plan, one in +each of the more important agricultural States. The necessity for such +State agents has been lessened, if not obviated, by the Hatch bill, +and the subsequent modifications looking to permanent appropriations +to the State stations or colleges, which give no central power at +Washington. The question then arises, What function shall the national +department perform? Its influence and field for usefulness have been +lessened rather than augmented in the lines of actual investigation in +very many directions. Many a State is already far better equipped both +as to valuable surrounding land, laboratory and library facilities, +more liberal salaries, and greater freedom from red tape, +administrative routine, and restrictions as to expenditures, than we +are at Washington; and, except as a directing agent and a useful +servant, I cannot see where the future growth of the department's +influence is to be outside of those federal functions which are +executive. Just what that directing influence is to be is the question +of the hour, not only in the broader but in the special sense. The +same question, in a narrower sense, had arisen in the case of the few +States which employed State entomologists. In the event, for instance, +of an outbreak of some injurious insect, or in the event of any +particular economic entomological question within the limits of the +State having such an officer, the United States entomologist would +naturally feel that any effort on his part would be unnecessary, or +might even be looked upon as an interference. He would feel that there +was always danger of mere duplication of observation or experiment, +except where appealed to for aid or co-operation. This is, perhaps, +true only of insects which are local or sectional, and is rather a +narrow view of the matter, but it is one brought home from experience, +and is certainly to be considered in our future plans. The favor with +which the museum work of the national division was viewed by you at +the meeting last November and the amount of material sent on for +determination would indicate that the building up of a grand national +reference collection will be most useful to the station workers. But +to do this satisfactorily we need your co-operation, and I appeal to +all entomologists to aid in this effort by sending duplicates of their +types to Washington, and thus more fully insuring against ultimate +loss thereof. + + +STATUS OF OUR SOCIETY. + +This train of thought brings up the question of the status of our +society with the station entomologists as represented by the committee +of the general association. Those of us who had desired a national +association for the various purposes for which such associations are +formed, felt, I believe, if I may speak for them, that the creation of +the different experimental stations rendered such an organization +feasible. Your organization at Toronto and the constitution adopted +and amended at the meeting at Washington all indicate that the chief +object was the advancement of our chosen work and that the strength of +the association would come from the experiment station entomologists. +There was then no other organization of the kind, nor any intimation +that such a one would be founded. Some of us therefore were surprised +to learn from the circular sent out by Prof. Forbes, its chairman, +that the committee appointed by the association of agricultural +colleges and experiment stations, and through which we had hoped to +communicate and co-operate with that association, was not in the +proper sense a committee, but a section which has prepared (and in +fact was required by the executive committee and the rules of the +superior body to prepare) a programme of papers and discussions for +the meeting to be held at the same time and place with our own. I +cannot but feel that this is in some respects a misfortune, and it +will devolve upon you to decide upon several questions of importance +that will materially affect our future existence. That there is not +room for two national organizations having the same objects in view +and meeting at the same time and place goes, I think, without saying; +and if the committee of the general association is to be anything more +than a committee in the proper sense of the word, or if it is to +assume with or without formal constitution the functions of our own +association, then our own must necessarily be crippled, and to do any +good at all must meet at a different time and a different place. A +committee or section, or whatever it may be called, of the general +association with which we meet, would preclude active membership of +any but those who come within the constitution of that body. Our +Canadian friends and many others who have identified themselves with +applied entomology, and do not belong to any of our State or +government institutions, would be debarred from active representation, +however liberal the association may have been in inviting such to +participate, without power to vote in its deliberations. Our own +association has, or should have, no such limitations. Some of us who +are entitled to membership in both bodies may feel indifferent as to +the course finally decided upon, and that it will not make any +difference whether we have an outside and independent organization, as +that of the association of official chemists, or whether we do, as did +the botanists and horticulturists, waive independence in favor of more +direct connection with the general association, provided there is some +way whereby the committees of the general association are given +sufficient latitude and time to properly present their papers and +deliberate; but there are others who feel more sensitive as to their +action and are more immediately influenced by the feelings of the main +body. I hope that whatever action be taken at this meeting, the +general good and the promotion of economic entomology will be kept in +mind and that no sectional or personal feeling will be allowed to +influence our deliberations. + + +SUGGESTION AND COMMENT. + +You will, I know, pardon me if, before concluding these remarks, I +venture to make a few comments which, though not altogether agreeable, +are made in all sincerity and in the hope of doing good. The question +as to how far purely technical and especially descriptive and +monographic work should be done by the different stations or by the +national department is one which I have already alluded to and upon +which we shall probably hold differing opinions, and which will be +settled according to the views of the authorities at the different +stations. Individually, I have ever felt that one ostensibly engaged +in applied entomology and paid by the State or national government to +the end that he may benefit the agricultural community can be true to +his trust only by largely overcoming the pleasure of entomological +work having no practical bearing. I would, therefore, draw the line at +descriptive work except where it is incidental to the economic work +and for the purpose of giving accuracy to the popular and economic +statements. This would make our work essentially biological, for all +biologic investigation would be justified, not only because the life +habits of any insect, once ascertained, throw light on those of +species which are closely related to it, but because we can never know +when a species at present harmless may subsequently prove harmful, and +have to be classed among the species injurious to agriculture. + +On the question of credit to their original sources of results already +on record, it is hardly necessary for me to advise, because good sense +and the consensus of opinion will in the end justify or condemn a +writer according as he prove just and conscientious in this regard. + +There is one principle that should guide every careful writer, viz., +that in any publications whatever, where facts or opinions are put +forth, it should always be made clear as to which are based upon the +author's personal experience and which are compiled or stated upon the +authority of others. We should have no patience with a very common +tendency to set forth facts, even those relating to the most common +and best known species, without the indications to which I have +referred. The tendency belittles our calling and is generally +misleading and confusing, especially for bibliographic work, and +cannot be too strongly deprecated. + +On this point there will hardly be any difference of opinion, but I +will allude to another question of credit upon which there prevails a +good deal of loose opinion and custom. It is the habit of using +illustrations of other authors without any indication of their +original source. + +This is an equally vicious custom and one to be condemned, though I +know that some have fallen into the habit, without appreciation of its +evil effect. It is, in my judgment, almost as blameworthy as to use +the language or the facts of another without citing the authority. + +Every member of this association who has due appreciation of the time +and labor and special knowledge required to produce a good and true +illustration of the transformations and chief characteristics of an +insect will appreciate this criticism. However pardonable in fugitive +newspaper articles in respect of cuts which, from repeated use, have +become common or which have no individuality, the habit inevitably +gives a certain spurious character to more serious and official +publications, for assumption of originality, whether intended or not, +goes with uncredited matter whether of text or figure. Nor is mere +acknowledgment of loan or purchase to the publisher, institution or +individual who may own the block or stone what I refer to. But that +acknowledgment to the author of the figure or the work in which it +first appears which is part of conscientious writing, and often a +valuable index as to the reliability of the figure. + +It were supererogation to point out to a body of this kind the value +of the most careful and thorough work in connection with life +histories and habits, often involving as it does much microscopic +study of structure. The officers of our institutions who control the +funds, and more or less fully our conduct, are apt to be somewhat +impatient and inappreciative of the time given to anatomic work, and +where it is given for the purpose of describing species and of +synopsizing or monographing higher groups, without reference to +agriculture, I am firmly of the belief that it diverts one from +economic work, but where pursued for a definite economic purpose it +cannot be too careful or too thorough and I know of no instances +better calculated to appeal to and modify the views of those inclined +to belittle such structural study than Phylloxera and Icerya. On the +careful comparison of the European and American specimens of +_Phylloxera vastatrix_, involving the most minute structures and +details, depended originally those important economic questions which +have resulted in legislation by many different nations and the +regeneration of the affected vineyards of Europe, of our own Pacific +coast, and of other parts of the world by the use of American +resistant stocks. In the case of _Icerya purchasi_ the possibilities +of success in checking it by its natural enemies hung at one time upon +a question of specific difference between it and the _Icerya sacchari_ +of Signoret--a question of minute structure which the descriptions +left unsettled and which could only be settled by the most careful +structural study and the comparison of the types, involving a trip to +Europe. + + +CONCLUSION. + +I have thus touched, gentlemen, upon a few of the many subjects that +crowd upon the mind for consideration on an occasion like this--a few +gleanings from a field which is passing rich in promise and +possibility. It is a field that some of us have cultivated for many +years and yet have only scratched the surface, and if I have ventured +to suggest or admonish, it is with the feeling that my own labors in +this field are ere long about to end and that I may not have another +occasion. + +At no time in the history of the world has there, I trow, been +gathered together such a body of devoted and capable workers in +applied entomology. It marks an era in our calling and, looking back +at the progress of the past fifteen years, we may well ponder the +possibilities of the next fifteen. They will be fruitful of grand +results in proportion as we persistently and combinedly pursue the yet +unsolved problems and are not tempted to the immediate presentation of +separate facts, which are so innumerable and so easily observed that +their very wealth becomes an element of weakness. Epoch-making +discoveries result only from this power of following up unswervingly +any given problem, or any fixed ideal. The kerosene emulsion, the +Cyclone nozzle, the history of _Phylloxera vastatrix_, of _Phorodon +humuli_, of _Vedalia cardinalis_, are illustrations in point, and +while we may not expect frequent results as striking or of as wide +application as these, there is no end of important problems yet to be +solved and from the solution of which we may look for similar +beneficial results. Applied entomology is often considered a sordid +pursuit, but it only becomes so when the object is sordid. When +pursued with unselfish enthusiasm born of the love of investigation +and the delight in benefiting our fellow men, it is inspiring, and +there are few pursuits more deservedly so, considering the vast losses +to our farmers from insect injury and the pressing need that the +distressed husbandman has for every aid that can be given him. Our +work is elevating in its sympathies for the struggles and suffering of +others. Our standard should be high--the pursuit of knowledge for the +advancement of agriculture. No official entomologist should lower it +by sordid aims. + +During the recent political campaign the farmer must have been sorely +puzzled to know whether his interests needed protection or not. On the +abstract question of tariff protection to his products we, as +entomologists, may no more agree than do the politicians or than does +the farmer himself. But ours is a case of protection from injurious +insects, and upon that there can nowhere be division of opinion. It is +our duty to see that he gets it with as little tax for the means as +possible. + + * * * * * + + + + +POTASH SALTS. + +[Footnote: By John B. Smith, entomologist. Potash as an insecticide is +not entirely new, but has never been brought out with the prominence I +think it deserves.--_N.J. Ag. Col. Exp. St., Bulletin 75._] + + +My attention was attracted to potash salts as an insecticide, by the +casual remark of an intelligent farmer, that washing his young pear +trees with a muriate of potash solution cleared them of scales. The +value of this substance for insecticide purposes, should its powers be +sufficient, struck me at once, and I began investigation. It was +unluckily too late in the season for field experiments of the nature +desired; but it is the uniform testimony of farmers who have used +either the muriate or the kainit in the cornfields, that they have +there no trouble with grubs or cut worms. Mr. E.B. Voorhees, the +senior chemist of the station, assures me that on his father's farm +the fields were badly infested, and replanting cornhills killed by +grubs or wire worms was a recognized part of the programme. Since +using the potash salts, however, they have had absolutely no trouble, +and even their previously worst-infested fields show no further trace +of injury. The same testimony comes from others, and I feel safe in +recommending these salts, preferably kainit, to those who are troubled +with cut worms or wire worms in corn. + + +EXPERIMENTS. + +A lot of wire worms (_Iulus_ sp.) brought in from potato hills were +put into a tin can with about three inches of soil and some potato +cuttings, and the soil was thoroughly moistened with kainit, one ounce +to one pint of water. Next morning all the specimens were dead. A +check lot in another can, moistened with water only, were healthy and +lived for some days afterward. + +A number of cabbage maggots placed on the soil impregnated with the +solution died within twelve hours. + +To test its actual killing power, used the solution, one ounce kainit +to one pint water, to spray a rose bush badly infested with plant +lice. Effect, all the lice dead ten hours later; the younger forms +were dropping within an hour. + +Sprayed several heads of wheat with the solution, and within three +hours all the aphides infesting them were dead. + +Some experiments on hairy caterpillars resulted unsatisfactorily, the +hair serving as a perfect protection against the spray, even from the +atomizer. + +To test its effect on the foliage, sprayed some tender shoots of rose +and grape leaves, blossoms, and clusters of young fruit. No bad effect +observable 24 hours later. There was on some of the leaves a fine +glaze of salt crystals, and a decided salt taste was manifest on all. + +Muriate of potash of the same strength was tested as follows: Sprayed +on some greenhouse camellias badly infested by mealy bugs, it killed +nearly all within three hours, and six hours later not a living insect +was found. The plants were entirely uninjured by the application. + +Thoroughly sprayed some rose bushes badly infested with aphides, and +carried off some of the worst branches. On these the lice were dead +next morning; but on the bushes the effect was not so satisfactory, +most of the winged forms and many mature wingless specimens were +unaffected, while the terminal shoots and very young leaves were +drooping as though frosted. All, however, recovered later. + +The same experiment repeated on other, hardier roses, resulted +similarly so far as the effect on the aphides was concerned, but there +was no injury to the plant. + +Used this same mixture on the caterpillars of _Orgyia leucostigma_ +with unsatisfactory effect, and with the same results used it on a +number of other larvae. Used on the rose leaf roller, _Cacaecia +rosaceana_, it was promptly effective. + +Tested for injury to plants, it injured the foliage and flowers of +wisteria, the younger leaves of maple and grape, and the finer kinds +of roses. + +From these few experiments kainit seems preferable to the muriate, as +acting more effectively on insects and not injuriously on plants. For +general use on plants it is not to be recommended. It is otherwise on +underground species, where the soil will be penetrated by the salts +and where the moisture evaporates but slowly, and the salt has a +longer and better chance to act. The best method of application would +be a broadcasting in fertilizing quantity before or during a rain, so +as to carry the material into the soil at once. In cornfields infested +with grubs or wire worms, the application should be made before +planting. Where it is to be used to reach root lice, it should be used +when the injury is beginning. When strawberry beds are infested by the +white grub, the application should be made when cultivating or before +setting out. + +The potash salts have a high value as fertilizers, and any application +made will act as a stimulant as well as insecticide, thus enabling the +plants to overcome the insect injury as well as destroying the insect. + +In speaking on this subject in Salem county, I learned from farmers +present that those using potash were not troubled with the corn root +louse to any extent, and also that young peach trees have been +successfully grown in old lice-infested orchards, where previously all +died, by first treating the soil with kainit of potash. + + * * * * * + + +A meteorological station has been built on Mont Blanc, at an elevation +of 13,300 feet, under the direction of M. Vallot. It required six +weeks to deliver the materials. The instruments are self-registering +and are to be visited in summer every fifteen days if possible, the +instruments being left to register between the visits. In the winter +the observatory will be entirely inaccessible. This is the highest +scientific station in Europe, but is 847 feet lower than the Pike's +Peak station in Colorado. + + * * * * * + + + + +THE EXPENSE MARGIN IN LIFE INSURANCE. + + +The principle of mutuality requires that the burden of expense in life +insurance should be borne by all the members equally; but, even with +the most careful adjustment, the allowance usually made is +considerably in excess of what is needed in the regular companies +doing business on the "level premium" plan. + +It is customary in these companies to add to the net premium a +percentage thereof to cover the expense account. This practice, though +in harmony with the "commission system," is so clearly defective and +so far removed from the spirit of life insurance mathematics, that it +scarcely deserves even this passing notice. + +It is generally understood that these corporations combine the +functions of the savings bank and life insurance company, and it is +only by separating the two in our minds as far as possible that we can +obtain a clear conception of the laws that should govern the +apportionment of the expenses among the great variety of policies. + +While it is a comparatively simple matter to state the amount of +either the insurance or savings bank element in a single policy, it is +by no means easy, as things go, to classify the company's actual +expenses on this basis. + +Fortunately, we can pretty accurately determine what these amounts +should be in any particular case. + +In the first place, there are institutions in our midst devoted solely +to receiving and conserving small sums of money; doing, in fact, +exactly what our insurance companies are undertaking to do with the +reserve and contributions thereto. These savings banks are required by +law to make returns to the State commissioner, from whose official +report we can get a very good idea of the expense attendant on doing +this business. + +Confining ourselves to the city banks, where the conditions more +nearly resemble those of the insurance companies, we find in +thirty-eight combined institutions for saving in the State of +Massachusetts a deposit in 1888 of $192,174,566, taken care of at an +aggregate cost of $455,387, or about 24-100 of one per cent. + +The same ratio carried out for all the savings banks in Massachusetts +gives a trifle over 25-100 of one per cent.; we may, therefore, +consider 1/4 of one per cent. as expressing pretty nearly the cost of +receiving, paying out, and investing the savings of the people. + +We must remember in this connection that in the popular estimation, +the savings bank is an important factor in the public welfare, and in +the towns and smaller cities there are often found public spirited men +willing to give their services to encourage this mode of saving; but +public sentiment has not yet given to life insurance the place which +it is destined, sooner or later, to occupy by the side of the savings +bank. Hence the services of able managers can only be obtained by a +liberal outlay of the corporate funds. A satisfactory adjustment of +the matter of expenses will, perhaps, do more than anything else to +bring about this recognition on the part of the public. + +In the case of the savings bank it is safe to say that for double the +present outlay a liberal salary could be paid to all the officers. +Following the analogy, we are led to infer that if this be the case in +savings banks, then 1/2 of one per cent. of the reserve should be an +ample allowance for the special labor required in the purely banking +portion of the business. + +In this we have the concurrence of the late Elizur Wright. In an essay +on this subject he says: + + "The expenses of the five largest savings banks in Boston, in + 1869, did not exceed 4-10 of one per cent. on $28,000,000 + deposited in them. They certainly had twice as many transactions, + in proportion to the deposits, as any life insurance company could + have with the same amount of reserve, so that 1/2 of one per cent. + on the reserve seems to be ample for all working expenses save + those of maintaining the agencies and collecting the premiums." + +This need hardly be looked upon as an admission that it costs twice as +much to care for the funds of a life insurance company as for those of +a savings bank. A liberal expense allowance must be made at the +outset, seeing that an error in this particular cannot easily be +rectified after the policy is issued. The dividend, or, to speak more +correctly, the annual return of surplus, will correct any overpayment +on this account. + +There is another expense which seems inevitable. This is the +government tax on insurance companies, amounting in the aggregate to +nearly 1/3 of one per cent. on the reserve. + +When we consider that these institutions are intended to encourage +thrift and to relieve the community from the care of numberless widows +and orphans, it seems a clear violation of the principles of political +economy to levy a tax on this business; still, whatever our opinion +may be as to the justice or injustice of the imposition, the tax is +maintained and must be provided for. Consequently a further allowance +of 1/2 of one per cent. must be added to the net premium to cover the +same, making a total of 1 per cent. of the reserve for banking +expenses and taxes. Considering this point as settled for the time +being, let us proceed to investigate the insurance expenses. + +Here, again, we are fortunate in being able to refer to the official +reports of a class of corporations doing nearly, if not quite pure +insurance. + +The assessment societies, outside of the fraternal and benevolent, +reporting in 1889 to the insurance commissioner of Massachusetts, show +outstanding risks amounting to $733,515,366. Losses to the amount of +$7,270,238 were paid during the year at a cost for transacting the +business of $2,403,053, which includes among other items "agency +expenses and commissions," which amount to about $1,203,000, or 17 per +cent. of the cost value of the insurance actually done. It would seem +as if an allowance of 20 per cent. would be a liberal one in the case +of the regular companies, which surely have as good facilities for +doing business as the assessment societies. + +As far as insurance is concerned, there is less difference between +regular and co-operative companies than is generally supposed. Regular +companies assess each policy in advance for a year's insurance at a +time, while co-operative societies furnish insurance only from one +assessment to another. The difficulty in the way of collecting the +assessment in the latter case would seem to be greater than in the +former, owing to the more permanent nature of the regular insurance +contract. + +In compensating agents the assessment companies naturally pay in +proportion to the insurance obtained, inasmuch as there is no other +basis to go upon, but regular companies usually pay the agent a +percentage of the premium _which includes a considerable trust fund_ +over and above the assessment for actual insurance. It is easily seen +that by the last method the agent's compensation increases in +proportion to the amount of savings bank business forced upon the +company. + +To realize how far we are from anything like a scientific, not to say +common sense basis for insurance expenses, we have but to examine the +following list, which gives the ratios between the expenditures for +general expenses in 1889, and those for the extension of the business. +For every $100 used in a general way, the different companies spend +for commissions and agency expenses: $37, $66, $67, $78, $91, $106, +$110, $113, $120, $140, $157, $161, $173, $175, $186, $189, $200, +$202, $222, $264, $311, $346. + +It will doubtless be said that I am taking a very advanced position +when I say that in the ideal life insurance scheme there is no place +for the commission system. Solicitors will be a necessity only so long +as they are in the field, but fifty years of life insurance has taught +our community its true value and, thanks to the modern press, the +institution it is no more likely to fall into desuetude than is +Christianity or the moral law. + +For the convenience of bringing the company to the individual, the +latter should be willing to pay a fee. The man who renders another a +service or puts his superior knowledge at another's disposal should +look to the party benefited for his remuneration. Any compensation +given for such service to a go-between by a mutual company is paid by +all, and the question arises, Is the advantage to the company of +sufficient importance to warrant the imposition of this tax upon all +its members promiscuously? The following, from the Massachusetts +Insurance Commissioner's Report for 1885, leaves no doubt as to the +convictions of the writer on this important matter: + + "The expensiveness of the life insurance policy is not because the + level net premium is too high, for the premium is absolutely just, + and the policy holder gets full value; but the complaint justly + applies to the excessive expense charge. A person who wants + insurance, life or fire or other, should be able to buy it at + first cost without paying tribute of profits to middlemen. To that + complexion the matter will finally be brought by the force of + intelligent opinion, whatever resistance may be opposed by persons + whose thrift lies in the perpetuation of the expensive system now + in fashion." + +It requires but a slight degree of prophetic vision to predict that in +a very few years the companies in self defense will be obliged to +change their method of compensating agents. + +Several companies have already begun the reform by grading +commissions; granting a percentage proportional to the amount of +insurance likely to be done on the policy. Other companies have simply +reduced the amount of the commission rate, thus virtually withdrawing +from active competition. + +This will, in a certain degree, explain the wide variation in the +figures given above, where it is noticed that, in five companies out +of twenty-two, the total agency expenditures amount to less than the +general expenses, while in six cases the companies spend more than +double as much on the former as on the latter. In either class we find +representatives of the five largest companies in the country. + +On applying the foregoing ratios to the business of the existing +companies we find that, calling the theoretical expenses $100, the +actual expenditures for 1889 were as follows: $112.67, $118.34, +$150.40, $194.48, $208.16, $208.53, $228.66, $235.89, $248.44, +$250.79, $258.33, $258.57, $265.14, $267.19, $267.92, $274.47, +$294.17, $314.96, $335.70, $377.94, $616.70. + +In this discouraging exhibit there is one ray of comfort. The combined +assets of the two companies heading the list amount to over +$100,000,000. There is no question as to their financial standing, and +both show a large increase in membership over the previous year. I may +also say here that it is a difficult matter to get at the actual "cost +of insurance" in the various companies. Many of them, on their own +acknowledgment, do not compute the advance cost of carrying their +"amount at risk," and others, for reasons of their own, do not care to +state the figures. In cases where the correct figures were not +obtainable, I have assumed the cost to have been 1-1/3 per cent. of +the mean amount at risk. + +If we should, in our comparison, omit the actual agency expenses and +commissions, the ratios would stand as follows: + +Where I would allow $100 the companies actually used: $43.17, $55.90, +$65.21, $77.21, $82.39, $88.34, $91.99. $91.98. $92.19, $94.65, +$97.15. $99.55. $99.11. $102.86, $109.35, $125.05, $133.03, $141.92, +$195.90, $207.06, $287.72. + +As might be supposed, the first two ratios are those companies before +alluded to. These companies might have doubled their advertising +account and expended $300,000 between them on agents' salaries, and +still have kept within my allowance. + +Admitting, for the present at least, the reasonableness of the +proposed allowance for the expenses of the banking and insurance +departments of the business, we have before us the problem how to +equitably adjust the burden among the great variety of policies. + +In the first place, _there should be no policy in the company that +does not contribute its proportionate share of the expense allowance +during every year of its life_. I make a special point of this, for at +present the policies which have become paid up, either by the payment +of a single premium at the outset or by the completion of a stipulated +number of payments, contribute practically nothing to the expense +account after the premium payments cease. + +The following plan, I think, complies with all the requirements of the +problem. By the proposed method every policy, at all stages of its +existence, contributes its exact share to the expense fund, whatever +its plan of payment may be. + +Let us, as an illustration, examine the case of a ten year endowment +policy, taken out at age 30, and consider it under three aspects, +first, as paid for in advance by a single payment, second, as paid by +five annual payments, and third, as paid for annually throughout the +term. I have used this short term endowment policy simply for +convenience, the rule applying equally to policies of longer term or +to the ordinary life policy, which is, in fact, an endowment policy +payable at death or age 100.[1] + +[Footnote 1: The expense allowance on a plain life policy for $1,000, +taken at age 33, would be about $5.29; net premium (com. ex. 4 per +cent.), $18.04; total office premium, $23.33; present rate $24.10.] + +Taking the case of the single premium endowment policy for $1,000, we +find that the following sums are required, each year to provide for +the care of the reserve and to pay the government fees (1 per cent. of +reserve): + + 1st year $6.9982 | 6th year $8.4136 + 2d " 7.2560 | 7th " 8.7381 + 3d " 7.5258 | 8th " 9.0781 + 4th " 7.8082 | 9th " 9.4346 + 5th " 8.1039 | 10th " 9.8086 + +The insurance expenses should be covered by the 20 per cent. allowance +given below: + + 1st year $ .4422 | 6th year $ .2566 + 2d " .4100 | 7th " .2076 + 3d " .3762 | 8th " .1556 + 4th " .3402 | 9th " .0988 + 5th " .2996 | 10th " .0344 + +Consequently the total contribution required from this policy each +year is: + + 1st year $7.4404 | 6th year $8.6702 + 2d " 7.6660 | 7th " 8.9457 + 3d " 7.9020 | 8th " 9.2337 + 4th " 8.1484 | 9th " 9.5334 + 5th " 8.4034 | 10th " 9.8430 + +The present value of all these contributions is found to be, at 4 per +cent. interest, $71.6394; in other words, this sum paid at the outset, +provides a fund from which we may deduct the current expenses of each +year in advance, and by accumulating the balance at the assumed rate +of interest from year to year, we shall have enough to pay the +anticipated expenses, leaving nothing over. + +In the above case the sums in hand at the beginning of the year are as +follows: + + 1st year $71.3694 | 6th year $42.6981 + 2d " 66.7669 | 7th " 35.3890 + 3d " 61.4650 | 8th " 27.5009 + 4th " 55.7055 | 9th " 18.9979 + 5th " 49.4594 | 10th " 9.8430 + +We find a somewhat different condition existing during the first years +of a 5-year endowment policy. As there is more insurance and less +banking, the requirements are as follows: + + ------------+----------+-----------+--------+---------+ + | 1 P. Ct. | 20 P. Ct. | | | + | on | on | Total. | Initial | + | Reserve. | Cost. | | Fund. | + ------------+----------+-----------+--------+---------+ + 1st year | $1.5038 | $1.2572 |$2.7610 |$12.9769 | + 2d " | 3.0406 | 1.0216 | 4.0622 | 23.6015 | + 3d " | 4.6503 | .7852 | 5.4355 | 33.2979 | + 4th " | 6.3367 | .5378 | 6.8745 | 41.9538 | + 5th " | 8.1039 | .2996 | 8.4035 | 49.4594 | + 6th " | 8.4136 | .2566 | 8.6702 | 42.6981 | + 7th " | 8.7381 | .2076 | 8.9257 | 35.3890 | + 8th " | 9.0781 | .1556 | 9.2337 | 27.5009 | + 9th " | 9.4346 | .0988 | 9.5334 | 18.9979 | + 10th " | 9.8086 | .0344 | 9.8430 | 9.8430 | + ------------+----------+-----------+--------+---------+ + +As the premium payments extend over only five years, the expense +contributions must all be paid during that time and are most +conveniently made by a uniform addition to the net premium. + +The present value of the amounts in column 3 is $60.0819, and the +equivalent annuity for five years is $12.9769. This amount, received +for five consecutive years, will put the company in funds to pay +current expenses and leave a reserve of $42.6981 at the beginning of +the sixth year, which, as we have seen in the analysis of the +single-premium policy, is the sum required for future expenses on the +paid up basis. + +In like manner we find that the 10-year annuity equivalent to the +present value of the annual contributions in the case of an +annual-payment policy is $5.534, thus: + + ------------+----------+-----------+--------+---------+ + | 1 P. Ct. | 20 P. Ct. | | | + | on | on | Total. | Initial | + | Reserve. | Cost. | | Fund. | + ------------+----------+-----------+--------+---------+ + 1st year | $.8234 | $1.3514 |$2.1748 |$ 5.5340 | + 2d " | 1.6473 | 1.2478 | 2.8951 | 9.0275 | + 3d " | 2.5096 | 1.1388 | 3.6484 | 11.9116 | + 4th " | 3.4124 | 1.0210 | 4.4334 | 14.1277 | + 5th " | 4.3572 | .8916 | 5.2488 | 15.6161 | + 6th " | 5.3479 | .7534 | 6.1013 | 16.3160 | + 7th " | 6.3853 | .5966 | 6.9819 | 16.1572 | + 8th " | 7.4726 | .4270 | 7.8996 | 15.0763 | + 9th " | 8.6127 | .2418 | 8.8545 | 12.9977 | + 10th " | 9.8086 | .0344 | 9.8430 | 9.8430 | + ------------+----------+-----------+--------+---------+ + +The present value of the ten yearly expense items given in the "total" +column above is $46.6812, which is equal to a ten-year annuity of +$5.534. The several premiums stand now as follows: + + ENDOWMENT: $1,000, AGE 30, PAYABLE AT DEATH OR 40 + + Net Prem.[2] Margin. Total. + +At single premium. $687.228 $71.6394 $758.8674 +At five premiums. 150.615 12.9769 163.5939 +At annual premiums. 84.172 5.5340 89.7060 + +[Footnote 2: Thirty American offices. Discount from middle of year, +Vx-1/2 or (M x 1.01961) / Dx.] + +By the actuaries' rate we have, with the customary loading for +expense: + + Single premium: $721.66 (loaded, $34.36). Five premiums, $188.70 + (loaded $37.78). Annual premium, $105.65 (loaded $21.11). + +Admitting the correctness of the new method, we must conclude that the +present single premium is not sufficiently loaded to cover its own +expenses, while the annual payment policy pays more than its just +share. A prominent and thoroughly informed life insurance president +says in this connection: "Many of the policies, particularly the short +term endowments, are charged with too high a percentage of expenses to +prove a good investment at maturity or profitable to the insured in +case of surrender." This is not to be wondered at when the applicant +for a 10-year endowment policy sees at a glance that he must pay, in +the gross, more than is returned unless he should die in the interim, +in which case a plain "life" or "term" policy would have answered the +purpose. Under the new system of assessing expenses one form is as +desirable as another, from the standpoint of the insured or the +company. + +The new premium for the 10-year endowment policy, $89.71, commends +itself at once to the applicant, who can easily see that his total +outlay must fall short of the amount ultimately to be realized, of +course, disregarding interest and probable dividends in both cases. + +In discounting the future expense contributions I have not taken the +chances of dying into account. Hence the expense reserve in any +instance applies only to that individual case, and, in the event of +death or surrender before the maturity of the policy, the amount of +the expense fund not used would naturally revert to the insured. + +The scheme of expense assessment outlined above will doubtless be +pronounced impracticable by the majority of insurance men. + +Such a far reaching reform is too much to hope for, at least in the +immediate future. + +No well informed life insurance expert will deny that there are +opportunities for improvement in the business, but to graft new +methods on old companies is a hopeless undertaking. + +It is well, however, to have new methods well matured in advance of +the public demand, and I feel convinced that the ideas here set forth +are in the line of the reform which, before long, must be instituted +by the companies if they would retain the confidence and patronage of +the community. + +Doubtless many insurance presidents could tell of suggestions which +have impressed them favorably and which they would gladly have adopted +were it not for the injustice done thereby to older members and the +changes necessary to bring existing contracts into conformity with the +new system. Similar objections may be urged against the ideas here +advanced, and I must confess I hardly see a way by which the present +suggestions can be utilized by existing companies. We can only hope +that sooner or later some of the new theories may be practically +tested. Meanwhile the companies at present in the field are doing a +great work for the good of humanity, even though their methods may be, +in some particulars, more practical than scientific. + +Winchester, Mass. FRANK J. WILLS. + + * * * * * + + + + +THE FLOOD AT KARLSBAD. + + +During the flood which occurred in Germany and Bohemia, the last week +of November, Karlsbad was especially unfortunate; it suffered such an +inundation as had never before been known in the "Sprudelstadt." On +the evening of November 23, the Tepl was very much swollen by the +rain, which had continued for several days, but it was supposed that +there was no danger of a flood, as the bed of the river had been put +in proper condition. During the forenoon of November 24, the water +suddenly began to rise with such astonishing rapidity that within half +an hour all the lower streets were like turbulent rivers and the Alte +and Neue Wiese were transformed into a lake. The stores on the Alte +Wiese were under water to the roofs, and the proprietors, who were +trying to save their goods, were surprised by the water and had to +take refuge in the trees. They were rescued by having ropes thrown to +them, and during this work a catastrophe occurred which was a great +misfortune to all classes of citizens. The beloved burgermeister of +Karlsbad, Dr. Rudolf Knoll, who had just recovered from a severe +illness, was, with others, directing the work from the balcony of one +of the houses, when a rope by which a man was being drawn through the +water broke, and the man was carried off by the waves. The fright and +excitement of the scene gave the burgermeister a shock which caused +his instant death, but the man who was in danger was brought safely +out of the water. + +The water was 9 ft. in Marienbaderstrasse, the Marktplatz, +Muhlbadgasse, the Sprudelgasse, Kreuzgasse, Kaiserstrasse, and +Egerstrasse, and flooded the quay, causing great destruction. All +places of business were flooded, the doors and iron shutters were +pushed in by the force of the water and the goods were carried away or +ruined. + +The house called "Zum Kaffeebaum" was undermined and part of it fell +to the ground; the same fate was feared for other buildings. The +Sophien and Curhaus bridges were carried away. Other bridges were +greatly damaged, and the masonry along the banks of the river was +partially destroyed. The Sprudelgasse was completely washed out, and +the condition of the Muhlbadgasse was almost as bad. The fire +department with its apparatus had great difficulty in saving the +inhabitants and guests, as there were very few boats or pontoons at +their command, and the soldiers (Pionniere) from Prague and the +firemen from the neighboring towns did not arrive until evening. +Fortunately the water began to fall in the night, and the next day it +had gone down so that it left its terrible work visible. The Sprudel +and the mineral springs were not injured, but, on the other hand, the +water pipes of the bathing establishments and the gas pipes were +completely destroyed.--_Illustrirte Zeitung._ + + * * * * * + + + + +THEATRICAL WATER PLAYS. + + +In one of the plays at Hengler's Circus in London a water scene is +introduced, for which purpose the main ring is flooded with water in a +manner which is both striking and interesting. + +[Illustration: FLOODING A CIRCUS RING.] + +The ring is entirely lined with stout macintosh sheeting, and into +this, from two large conduits. 23,000 gallons of water are poured, the +tank being filled to a depth of some 2 ft. in the remarkably short +time of 35 seconds. A steamboat and other small craft are then +launched and the adventures of the heroine then proceed. She falls +overboard, we believe, but is saved after desperate and amusing +struggles. Our engravings, which are from the _Graphic_, illustrate +the mode of filling the ring with water, and the steamboat launch. + +[Illustration: A THEATRICAL STEAMBOAT.] + + * * * * * + + + + +SCIENCE IN THE THEATER. + + +In the pretty little hall of the Boulevard des Italiens, at Paris, a +striking exhibition of simulated hypnotism is given every evening. + +This entertainment, which has met with much success, was devised by +Mr. Melies, director of the establishment, which was founded many +years ago by the celebrated prestidigitator whose popular name (Robert +Houdin) it still bears. This performance carries instruction with it, +for it shows how easily the most surprising phenomena of the +pathologic state can be imitated. To this effect, several exhibitions +are given every evening. + +Mr. Harmington, a convinced disciple of Mesmer, asks for a subject, +and finds one in the hall. A young artist named Marius presents +himself. Mr. Harmington makes him perform all sorts of extravagant +acts, accompanied with a continuous round of pantomimes that are +rendered the more striking by the supposed state of somnipathy of the +subject. At the moment at which Marius is finishing his most +extraordinary exercises, a policeman suddenly breaks in upon the stage +in order to execute the recent orders relative to hypnotism. But he +himself is subjugated by Mr. Harmington and thrown down by the +vibrations of which the encephalus of this terrible magnetizer is the +center. When the curtain falls, the representative of authority is +struggling against the catalepsy that is overcoming him. + +All the phenomena of induced sleep are successively simulated with +much naturalness by Mr. Jules David, who plays the part of Marius in +this pleasing little performance. + +At a certain moment, after skillfully simulated passes made by the +magnetizer, Mr. David suddenly becomes as rigid as a stick of wood, +and falls in pivoting on his heels (Fig. 1). Did not Mr. Harmington +run to his assistance, he would inevitably crack his skull upon the +floor, but the magnetizer stands just behind him in order to receive +him in his arms. Then he lifts him, and places him upon two chairs +just as he would do with a simple board. He places the head of the +subject upon the seat of one of the chairs and the heels upon that of +the other. Mr. David then remains in a state of perfect immobility. +Not a muscle is seen to relax, and not a motion betrays the +persistence of life in him. The simulation is perfect. + +[Illustration: FIG. 1.--CATALEPTIC RIGIDITY.] + +In order to complete the astonishment of the spectators, Mr. +Harmington seats himself triumphantly upon the abdomen of the subject +and slowly raises his feet and holds them suspended in the air to show +that it is the subject only that supports him, without the need of +any other point of support than the two chairs (Fig. 2). + +[Illustration: FIG. 2.--EXPERIMENT ON THE SAME SUBJECT.] + +Usually, there are plenty of persons ingenuous enough to think that +Mr. David is actually in a cataleptic sleep, one of the characters of +which is cadaveric rigidity. + +As Mr. David's neck is entirely bare, it is not possible to suppose +that the simulator of catalepsy wears an iron corset concealed beneath +his clothing. He has performed a feat of strength and skill rendered +easy by the exercise that he has given to the muscles occupying the +_colliciae_ of his vertebral column. This part of the muscular system +is greatly developed in the weakest and least hardy persons. In fact, +in order that man may keep a vertical position and execute an infinite +multitude of motions in which stability is involved, nature has had to +give him a large number of different organs. The muscles of the back +are arranged upon several superposed layers, the vertebral column is +doubly recurved in order that it may have more strength, and, finally, +rachidion nerves issue from each vertebra in order to regulate the +contraction of each muscular fasciculus according to the requirements +of equilibrium. The trick is so easy that we have seen youths +belonging to the Ligue d'Education Physique immediately imitate Mr. +David after seeing him operate but once. + +For the sake of those who would like to perform it, we shall add that +Mr. David takes care to bend his body in the form of an arch in such a +way that the convexity shall be beneath. As Mr. Harmington never fails +to place himself in the center of the line that joins Mr. David's head +and heels, his weight is divided into two parts, that is to say, 88 +pounds on each side of the point of support. The result is that the +stress necessary is less than that of a strong man of the Halle +lifting a bag of wheat to his shoulder or of an athlete supporting a +human pyramid. The force of contraction of the muscular fibers brought +into play in this experiment is much greater than is commonly +believed. In his lectures on physiology, Milne-Edwards cites some +facts that prove that it may exceed 600 pounds per square inch of +section. + +[Illustration: FIG. 3.--THE PERFORATE ARM.] + +The experiment on cadaveric rigidity is followed by others in +insensibility. Mr. David, without wincing, allows a poignard to be +thrust into his arm, which Mr. Harmington has previously +"cataleptized" (Fig. 3). This trick is performed by means of a blade +divided into two parts that are connected by a semicircle. This +process is well known to prestidigitators, but it might be executed in +a genuine manner. In fact, on replacing the poignard by one of the +gold needles used by physicians for acupuncture, it would be possible +to dispense with prestidigitation. Under such conditions it is +possible to transpierce a person's arm. The pain is supportable, and +consists in the sensation of a prick produced in the passage of the +needle through the skin. As for the muscular flesh, that is of itself +perfectly insensible. The needle, upon the necessary antiseptic +precautions being taken, may traverse the veins and arteries with +impunity, provided that it is not allowed to remain long enough to +bring about the formation of a clot of coagulated blood (Fig. 4). + +[Illustration: FIG. 4.--AN ARM TRANSPIERCED BY A NEEDLE.] + +We think it of interest to add that it is necessary that the +experiment be performed by a practitioner if one desires to +demonstrate upon himself a very curious physiological fact that has +been known from the remotest antiquity. It has been employed for +several thousand years in Chinese medicine, for opening a passage for +the bad spirits that produce diseases. For some years past a much more +serious use has been made of it in European medicine for introducing +electric currents into the interior of the organism. In this case the +perimeter of the needle is insulated, and the electricity flows into +the organism through the point. We have several times had these +operations performed upon ourselves, and this permits us to assert +that the above mentioned facts are absolutely true.--_La Nature._ + + * * * * * + + + + +NEWER PHYSIOLOGY AND PATHOLOGY. + +By Prof. SAMUEL BELL, M.D. + + +Physiology has for many decades been a science founded on experiment, +and pathology has been rapidly pressing forward in the same direction. +To read the accounts of how certain conclusions have been arrived at +in the laboratory, by ingenious devices and by skillful manipulations, +is as fascinating as any tale of adventure. + +When the microscope began its work, how discouraging was the vastness +and complexity of the discoveries which it brought to light; how many +years has it been diligently used, and how uncertain are we still +about many of its revelations! But what a happy conjecture of man, and +as proper environment takes place we may reach better results! Let me +give an illustration: + +Some thirty years ago, Virchow began his studies and lectures upon +cellular pathology. The enthusiasm which he awakened spread over the +whole medical world. The wonderful attention to detail, the broad +philosophy which signalized his observations, were alike remarkable. +His class room was packed with students from every country, who +thought it no hardship to struggle for a seat at eight o'clock in the +morning. With his blackboard behind him and specimens of pathology +before him, and microscopes coursing upon railway tracks around the +tables which filled the room, he was the embodiment of the teacher; +his highest honor was as discoverer. The life and importance of the +cell, both in health and disease, it has been his work to discover and +to teach. The point of view from which he has classified tumors is +founded on this basis, and remains the accepted method. The light +which he cast upon the nature of inflammation has not yet been +obscured, and while other phenomena appear, the multiplication of +cells and nuclei and the formation of connective tissue in the process +of inflammation will always call to mind his labors. + +To one of Virchow's pupils, Prof. Recklinghausen, we chiefly owe our +knowledge of the phenomena of diapedesis as a part of the inflammatory +activity. How incredible it seems that masses of living matter can +make their way through the walls of blood vessels which do not rupture +and which have no visible apertures! + +Virchow fixed his attention upon the forms and activities of the +cells, their multiplication and degradation, and how they build up +tissues, both healthy and morbid. + +To another matter with which, both literally and metaphorically, the +air is filled, we must also make allusion. The existence of +micro-organisms in countless numbers is no new fact, but the influence +they may exert over living tissues has only lately become the subject +of earnest attention. So long as they were not known to have any +practical bearing upon human welfare, they interested almost nobody, +but when, however, it was shown that putrefaction of meat is due to +the agency of the _bacterium termo_, and the decomposition of albumen +to the _bacillus subtilis_; when anthrax in cattle and sheep was found +to depend on the _bacillus anthracis_, and that in human beings it +caused malignant pustules; when suppuration of wounds was found to be +associated with micrococci; and when it was announced that by a +process of inoculation cattle could be protected against anthrax, and +that by carbolic spray and other well known precautions the +suppuration of wounds could be prevented--all the world lent its ears +and investigation at once began. + +Because labors in bacteriology promised to be fruitful in practical +results, the workers speedily became innumerable, and we are +accumulating a wondrous store of facts. How long now is the list of +diseases in which germs make their appearance--in pneumonia, in +endocarditis, in erysipelas, in pyaemia, in tuberculosis, and so on and +so on. One of the most striking illustrations is the gonococcus of +gonorrhoea, whose presence in and around gives to the pus cells +their virulent properties, and when transferred to the eye works such +lamentable mischief. Without their existence the inoculation of pus in +the healthy eye is harmless; pus bearing the gonococci excites the +most intense inflammation. Similar suppurative action in the cornea is +often caused by infection of cocci. The proof of causation may be +found in the fact that the most effective cure now practiced for such +suppuration is to sterilize them by the actual cautery. Rosenbach says +that he knows six distinct microbes which are capable of exciting +suppuration in man. Their activity may be productive of a poison, or +putrefactive alkaloid, which is absorbed. + +There are at present two prominent theories in regard to the +infections which produce disease. The first is based upon chemical +processes, the second upon the multiplication of living organisms. The +chemical theory maintains that after the infectious element has been +received into the body it acts as a ferment, and gives rise to certain +morbid processes, upon the principle of catalysis. The theory of +organisms, or the germ theory, maintains that the infectious elements +are living organisms, which, being received into the system, are +reproduced indefinitely, and excite morbid processes which are +characteristic of certain types of disease. This latter theory so +readily explains many of the facts connected with the development and +reproduction of infectious diseases, that it has been unqualifiedly +adopted by a large number of investigators. The proofs of this theory +had not, however, advanced beyond the demonstrations of the presence +of certain forms of bacteria in the pathological changes of a very +limited number of infectious diseases, until February, 1882, when Koch +announced his discovery of the tubercle bacillus, since which time +nearly every disease has its supposed microbe, and the race is, +indeed, swift in which the would-be discoverers press forward with new +germs for public favor. + +The term bacteria or microbe refers to particles of matter, +microscopic in size, which belong to the vegetable kingdom, where they +are known as fungi. If we examine a drop of stagnant water under the +microscope, amplifying say four hundred diameters, we see it loaded +with minute bodies, some mere points, others slightly elongated into +rods, all actively in motion and in various positions, a countless +confusion. If evaporation now takes place, all is still. If we now +apply moisture, the dried-up granules will show activity, as though +they had not been disturbed. + +All these different organisms have become familiar to us under the +generic term bacteria, which is a very unfortunate application, as it +really applies to only a single class of fungi. Cohn calls them +schizomycetes, and makes the following classifications: + + 1. _Sphero-bacteria_, or microbes. + 2. _Micro-bacteria_, or bacteria. + 3. _Desmo-bacteria_, or bacilli. + 4. _Spiroteria_, or spirillae. + +The _spiro-bacteria_, or micrococci, are the simplest of the fungi, +and appear as minute organisms of spherical form. They multiply by +fission, a single coccus forming two, these two producing four, and so +on. They present a variety of appearances under the microscope. From +single isolated specimens (which under the highest magnifying power +present nothing beyond minute points) you will observe them in pairs, +again in fours, or in clusters of hundreds (forming zooeglea) and still +adhering together, forming chains. When a given specimen is about to +divide, it is seen to elongate slightly, then a constriction is +formed, which deepens until complete fission ensues. + +Micrococci possess no visible structure. They consist of a minute +droplet of protoplasm (mycroprotein) surrounded by a delicate cell +membrane. Certain forms are embedded in a capsule (diameter 0.0008 to +0.0001 millimeter). + +These little organisms, when observed in a fluid like blood, sputum, +etc., are found to present very active movements, although provided +with no organs of locomotion. + +This Brownian motion is possessed by almost every minute particle of +matter, organic and inorganic, and is not due to any inherent power of +the individual. They are almost omnipresent, abounding in the air, the +earth, the water, are always found in millions where moist organic +matter is undergoing decomposition, and are associated with the +processes of fermentation--in fact, they are essential to it. The +souring of milk succeeds the multiplication of these germs. Certain +varieties are pigmented, and we observe colonies of chromogenic cocci +multiplying upon slices of boiled potato, eggs, etc., presenting all +the colors of the rainbow. All of these germs are not the cause of +disease. Certain species, however (termed pathogenic), are always +associated with certain diseased conditions. + +The _bacteria-termo_--micro-bacteria--are slightly elongated, and +inasmuch as they multiply by division, frequently appear coupled +together, linked in pairs, and in chains. They are generally found in +putrefying liquids, especially infusions of vegetable matter. They +possess mobility to a remarkable degree. Observing a field of +bacteria-termo under the microscope, they may be seen actively engaged +in twining and twisting. A flagellum has been demonstrated as attached +to one or both extremities. This is too minute to be generally +resolved, even if it is a common appendage. + +_Desmo-bacteria_ (or bacilli) are rod-like organisms, occurring of +various lengths and different thicknesses. In a slide of the bacillus +of tuberculosis and anthrax, we notice at intervals dots which +represent the spores from which, as the rods break up, future bacilli +are developed. + +Then we have _spiro-bacteria,_ the spirilla and the spirochetae; the +former having short open spirals, the latter long and closely wound +spirals. The _spirillum, volutans_ is often found in drinking water, +and in common with some other specimens of this class is provided with +flagellae, sometimes at both extremities, which furnish the means of +rapid locomotion. The spiro-bacteria multiply by spores, although +little is at present known of their life history. They frequently are +attached together at their extremities, forming zigzag chains. + +We have seen that bacteria differ greatly in appearance from the +elongated dot of the bacterium proper, to the elongated rod or +cylinder of the bacillus, and the long spirals of spiro-bacteria. It +is unfortunate that they are not sufficiently constant in habit to +always attach themselves to one or the other of these genera. The +micrococcus has a habit of elongating at times until it is impossible +to recognize him except as a bacterium; while bacilli, again, break up +until their particles exactly resemble micrococci. + +Bacteria cannot exist without water; certain forms require oxygen, +while others thrive equally well without it; some thrive in solution +of simple salts, while others require albuminoid material. + +Bacteriology, with its relation to the science of medicine, is of +importance to every investigating physician; it covers our knowledge +of the relation of these minute organisms to the aetiology of disease. +What has been gained as to practical application in the treatment of +disease? This question is not infrequently asked in a sneering manner. +We can, in reply, say that the results are not all in the future. It +is encouraging that results have been attained which have had a very +important practical bearing, and that these complaints come generally +from individuals least acquainted with scientific investigations in +bacteriology. + +In the study of the relation of a given bacterium to a certain +disease, it becomes necessary to attend carefully to three different +operations: First, the organism supposed to cause the disease must be +found and isolated. Second, it must be cultivated through several +generations in order that absolute purity may be secured. Lastly, the +germ must be again introduced into a healthy living being. If the +preceding steps be carried out, and the original disease be +communicated by inoculation, and the germs be again found in the +diseased body, we have no alternative; we must conclude that we have +ascertained the cause of the disease. The importance of being familiar +with the aetiology of the disease before we can expect to combat it +with any well-grounded hope of success is evident. + +If the sputum of a phthisical patient be submitted to the skilled +microscopist, he is nearly always able to demonstrate bacilli, but +this goes for very little. Because bacilli are found in phthisis, it +is no more certain that they are the cause of phthisis than it is +certain that cheese mites are the cause of cheese. Well, suppose we +were to inject sputum from a phthisical person into the lower animal +and tuberculosis follows, and then announce to the profession that we +have demonstrated the relation of the cause and effect between bacilli +and phthisis? Why we would start such an uproar of objections as would +speedily convince us that there was much work yet in the domain of +bacteriology. + +The scientific investigators would say you have injected with the +sputum into the blood of your unfortunate patient, pus, morphological +elements, and perhaps half a dozen other forms of bacteria, any one of +which is just as likely to produce the disease as the bacillus you +have selected. + +The first important step is, first isolate your bacillus. If I were to +take a glass plate, one side of which is coated with a thick solution +of peptonized gelatin, and allow the water to collect, the gelatinous +matter will become solid. If now, with a wire dipped in some +tuberculous matter, I draw a line along the gelatin, I have deposited +at intervals along this line, specimens of tubercle bacilli. If this +plate be now kept at a proper temperature, after a few days, wherever +the bacilli have been caught, a grayish spot will appear, which, +easily seen with the naked eye, gradually spreads and becomes larger. +These spots are colonies containing thousands of bacilli. Let us +return to our gelatin plate. + +We find a spot which answers to the description of a colony of +tubercle bacilli. We now take a minute particle from this colony on a +wire and convey it to the surface of some hardened blood serum in a +test tube. We plug the tube so that no air germs may drop in, and +place it in an incubator at the proper temperature. After several +days, if no contamination be present, a colony of bacilli will appear +around the spot where we sowed the spores. Let us repeat the process. + +Take a particle from this colony, and transfer it to another tube. +This is our second culture. This must be repeated until we are +satisfied that we have secured a _pure_ culture. If this be carried to +the twenty-fifth generation, we may be assured that there remains no +pus, no ptomaines, nothing but the desired bacilli. + +It is a proper material now for inoculation, and if we inoculate some +of the lower animals, for instance the monkey, we produce a disease +identical with phthisis pulmpnalis. Bacteria also afford peculiar +chemical reactions. For example, nitric acid will discharge all the +color from all bacilli artificially dyed with anilin, except those of +tubercle and anthrax. One species is stained readily with a dye that +leaves another unaltered. Thus we are enabled in the laboratory to +determine whether the bacilli found in sputum, for example, are from +tubercle or are the bacteria of decomposition. + +From what I have said of the tubercle bacillus, it would seem +thoroughly demonstrated that it is the cause of tubercle in these +animals. But we must walk cautiously here. These are not human beings, +who know that like results would follow their inoculation. The animals +used by Koch are animals very subject to tubercle. + +We must, from the very nature of our environment, be constantly +inhaling these germs as we pass through the wards of our hospitals; +yes, they are floating in the air of our streets and dwellings. It +becomes necessary then for us to inquire: If bacteria cause disease, +in what manner do they produce it? The healthy organism is always +beset with a multitude of non-pathogenic bacteria. They occupy the +natural cavities, especially the alimentary canal. They feed on the +substances lying in their neighborhood, whether brought into the body +or secreted by the tissues. In so doing they set up chemical changes +in their substances. Where the organs are acting normally these fungi +work no mischief. The products of decomposition thus set up are +harmless, or are conveyed out of the body before they begin to be +active. + +If bacteria develop to an inordinate degree, if the contents of organs +are not frequently discharged, fermentative processes may be set up, +which result in disease. Bacteria must always multiply and exist at +the expense of the body which they infest, and the more weakened the +vital forces become, the more favorable is the soil for their +development. + +Septicaemia is caused by the absorption of the products of +putrefaction, induced before bacteria can multiply inside or outside +the body. Bacteria must find a congenial soil. The so-called cholera +bacillus must gain access to the intestinal tract before it finds +conditions suitable to colonization. It does not seem to multiply in +the stomach or in the blood, but once injected into the duodenum +develops with astonishing rapidity, and the delicate epithelial cells +of the villi become swollen, soften and break down, exposing the +mucosa. + +It has been shown that _bouillon_ in which Loeffler's diphtheria +bacillus has grown, and which has been passed through unglazed +porcelain filters, shows the presence of a poison which is capable of +producing the same results upon inoculation as the pure culture of the +bacillus itself. Zarniko, working upon the same organism, obtained a +number of positive results that led him to declare this bacillus is +the cause of epidemic diphtheria, in spite of many assertions to the +contrary. Chantmesse and Widal record the results of their work as to +what will most easily and effectively destroy the bacillus of +diphtheria. + +The only three substances that actually checked and destroyed its +vitality were phenic acid (5 per cent.), camphor (20 per cent.), olive +oil (25 per cent.), in combination. For the last I substitute +glycerine, because this allows the mixture to penetrate farther into +the mucous membrane than oil, the latter favoring a tendency to pass +over the surface. This mixture when heated separates into two layers, +the upper one viscid and forming a sort of "glycerol," the lower +clear. The latter will completely sterilize a thread dipped in a pure +culture of the diphtheria bacillus. Corrosive sublimate was not +examined because in strong enough doses it would be dangerous and in +weaker ones it would be useless. + +The facts obtained in regards to the streptococcus of erysipelas are +reported as follows: That both chemical and experimental evidence +teach the extreme ease of a renewed attack of the disease; that it is +possible to kill guinea pigs by an intoxication when they are immune +to an inoculation of the culture in ordinary quantities. And this +latter fact should warn experimenters trying to obtain immunity in man +by the inoculation of non-pathogenic bacteria, because the same +results may be reached. + +A new theory in regard to fevers and the relation of micro-organisms +is suggested by Roussy, viz.: That it is a fermentation produced by a +diastase or soluble ferment found in all micro-organisms and cells, +and which they use in attacking and transforming matter, either inside +their substance or without it. + +The resemblance of the malaria parasite to that of recurrent fever is +noted in the work of Sacharoff. He states that there exists in the +blood of those suffering from recurrent fever a haematozoon, which is +most prominent after the fever has begun to fall, when it is of +enormous proportions, twenty or more diameters of a red blood +corpuscle, although smaller ones may still be found. The parasite +consists of a delicate amoeboid body containing a multitude of dark, +round, uniform, sharply outlined, movable granules. Besides these, the +protoplasm contains a generally grayish homogeneous nucleus as large +as one or two red blood corpuscles. The protoplasm sends out +pseudopodia (with granules), which sometimes separate and appear as +small delicate pieces of protoplasm. They vary in size, and are often +swallowed by the red blood corpuscles in which they grow, and finally +develop into the above mentioned amoeboid bodies. + +Prof. J. Lewis Smith has made a great many autopsies of children dead +from cholera infantum, and almost invariably found the stomach and +liver in a comparatively healthy condition. Ganghen, who has given +this subject considerable study, denies the existence of any specific +germ in the summer diarrhea of infants, but claims to have found three +different germs in the intestines of children suffering from cholera +infantum, each producing a chemical poison which is capable of +producing vomiting, purging, and even death. A great variety of germs +are found in drinking water, and no doubt countless numbers are taken +into the digestive tract, and the principal reason why pathological +conditions do not occur more frequently is on account of the +germicidal qualities of the gastric juice. + +The comma bacillus of Koch, and the typhoid fever germ of Eberth, are +especially destroyed in normal gastric juice. When the germs are very +numerous, they run the gauntlet of the stomach (as the gastric juice +is secreted only during digestion); and once in the alkaline +intestinal canal they are capable of setting up disease, other +conditions contributing--ill health, deranged digestion, etc. + +Mittnam has made a study of bacteria beneath the nails, and reports, +after examining persons following different occupations, having found +numerous varieties of micro-organisms; which are interesting from a +scientific standpoint relative to the importance of thoroughly +cleansing the hands before undertaking any surgical procedure. He +found, out of twenty-five experiments, 78 varieties of bacteria, of +which 36 were classed as micrococci, 21 diplococci, 18 rods, 3 +sarcinae, and 1 yeast. Cooks, barbers, waiters, etc., were examined. + +The blood, defibrinated and freshly drawn, has marked germicidal +action; for bacteria its action is decidedly deadly, even hours after +it has been drawn from the body. Especially were anti-germic qualities +noticed upon pathogenic bacteria. Buchner put the bacilli of anthrax +in a quantity of blood, and in two hours the number was reduced from +4,800 to 56, and in three hours only 3 living bacteria remained. Other +bacteria were experimented upon in blood with similar results, but the +destruction of the organism from putrefaction was much less marked, +and on some varieties the blood had little or no action. + +It is not the object of these remarks to even give a _resume_ of the +_status praesens_ of bacteriology, but simply to stimulate thought in +that direction. The claims of some of the ultra-bacteriologists may +never be realized, but enough has been accomplished to revolutionize +the treatment of certain diseases, and the observing student will do +well to keep his eye on the microbe, as it seems from the latest +investigations that its star is in the ascendant. And who can +prognosticate but that in the next decade an entire revolution in the +aetiology and treatment of many diseases may take place? + +Detroit, Mich. + + * * * * * + + + + +THE COMPOSITION OF KOCH'S LYMPH. + +WHAT PROFESSOR KOCH SAYS IT IS, AND WHAT IT CAN DO. + +(By Cable to the _Medical Record_.) + +BERLIN, January 15, 1891. + + +The curiosity to know the composition of the famous lymph has been +gratified by the publication to-day of an article by Professor Koch on +the subject. In the following, as will be seen, he reaffirms his +original convictions and acknowledges the valuable assistance he has +received from those who have used his fluid, and thus helped him in +the accumulation of experience. + +Professor Koch says: Two months ago I published the results of my +experiments with the new remedy for tuberculosis, since which time +many physicians who received the preparation have been enabled to +become acquainted with its properties through their own experiments. +So far as I have been able to review the statements published and the +communications received by letter, my predictions have been fully and +completely confirmed. The general consensus of opinion is that the +remedy has a specific action upon tubercular tissues, and is, +therefore, applicable as a very delicate and sure reagent for +discovering latent and diagnosing doubtful tuberculous processes. +Regarding the curative effects of the remedy, most reports agree that, +despite the comparatively short duration of its application, many +patients have shown more or less pronounced improvement. It has been +affirmed that in not a few cases even a cure has been established. +Standing quite by itself is the assertion that the remedy may not only +be dangerous in cases which have advanced too far--a fact which may +forthwith be conceded--but also that it actually promotes the +tuberculous process, being therefore injurious. + +During the past six weeks I myself have had opportunity to bring +together further experiences touching the curative effects and +diagnostic application of the remedy in the cases of about one hundred +and fifty sufferers from tuberculosis of the most varied types in this +city and in the Moabit Hospital. + +I can only say that everything I have latterly seen accords with my +previous observations. There has been nothing to modify in what I +before reported. As long as it was only a question of proving the +accuracy of my indications, it was needless for any one to know what +the remedy contained or whence it was derived. On the contrary, +subsequent testing would necessarily be more unbiased, the less people +knew of the remedy itself. Now, after sufficient confirmatory testing, +the importance of the remedy is proved, my next task is to extend my +study of the remedy beyond the field where it has hitherto been +applied, and if possible to apply the principle underlying the +discovery to other diseases. + +This task naturally demands a full knowledge of the remedy. I +therefore consider that the time has arrived when the requisite +indications in this direction shall be made. This is done in what +follows. + +Before going into the remedy itself, I deem it necessary for the +better understanding of its mode of operation to state briefly the way +by which I arrived at the discovery. If a healthy guinea pig be +inoculated with the pure cultivation of German Kultur of tubercle +bacilli, the wound caused by the inoculation mostly closes over with a +sticky matter, and appears in its early days to heal. Only after ten +to fourteen days a hard nodule presents itself, which, soon breaking, +forms an ulcerating sore, which continues until the animal dies. Quite +a different condition of things occurs when a guinea pig already +suffering from tuberculosis is inoculated. An animal successfully +inoculated from four to six weeks before is best adapted for this +purpose. In such an animal the small indentation assumes the same +sticky covering at the beginning, but no nodules form. On the +contrary, on the day following, or the second day after the +inoculation, the place where the lymph is injected shows a strange +change. It becomes hard and assumes a darker coloring, which is not +confined to the inoculation spot, but spreads to the neighboring parts +until it attains a diameter of from 0.05 to 1 cm. + +In a few days it becomes more and more manifest that the skin thus +changed is necrotic, finally falling off, leaving a flat ulceration +which usually heals rapidly and permanently without any involvement of +the adjacent lymphatic glands. Thus the injected tubercular bacilli +quite differently affect the skin of a healthy guinea pig from one +affected with tuberculosis. This effect is not exclusively produced +with living tubercular bacilli, but is also observed with the dead +bacilli, the result being the same whether, as I discovered by +experiments at the outset, the bacilli are killed by a somewhat +prolonged application of a low temperature or boiling heat or by means +of certain chemicals. This peculiar fact I followed up in all +directions, and this further result was obtained--that killed pure +cultivations of tubercular bacilli, after rinsing in water, might be +injected in great quantities under healthy guinea pig's skin without +anything occurring beyond local suppuration. Such injections belong to +the simplest and surest means of producing suppurations free from +living bacteria. + +Tuberculous guinea pigs, on the other hand, are killed by the +injection of very small quantities of such diluted cultivations. In +fact, within six to forty-eight hours, according to the strength of +the dose, an injection which is not sufficient to produce the death of +the animal may cause extended necrosis to the skin in the vicinity of +the place of injection. If the dilution is still further diluted until +it is scarcely visibly clouded, the animals inoculated remain alive +and a noticeable improvement in their condition soon supervenes. If +the injections are continued at intervals of from one to two days, the +ulcerating inoculation wound becomes smaller and finally scars over, +which otherwise it never does; the size of the swollen lymphatic +glands is reduced, the body becomes better nourished, and the morbid +process ceases, unless it has gone too far, in which case the animal +perishes from exhaustion. By this means the basis of a curative +process against tuberculosis was established. + +Against the practical application of such dilutions of dead tubercle +bacilli there presented itself the fact that the tubercle bacilli are +not absorbed at the inoculation points, nor do they disappear in +another way, but for a long time remain unchanged, and engender +greater or smaller suppurative foci. Anything, therefore, intended to +exercise a healing effect on the tuberculous process must be a soluble +substance which would be liberated to a certain extent by the fluids +of the body floating around the tubercle bacilli, and be transferred +in a fairly rapid manner to the juices of the body; while the +substance producing suppuration apparently remains behind in the +tubercular bacilli, or dissolves but very slowly. The only important +point was, therefore, to induce outside the body the process going on +inside, if possible, and to extract from the tubercular bacilli alone +the curative substance. This demanded time and toil, until I finally +succeeded, with the aid of a forty to fifty per cent. solution of +glycerine, in obtaining an effective substance from the tubercular +bacilli. With the fluid so obtained I made further experiments on +animals, and finally on human beings. These fluids were given to other +physicians to enable them to repeat the experiments. + +The remedy which is used in the new treatment consists of a glycerine +extract, derived from the pure cultivation of tubercle bacilli. Into +the simple extract there naturally passes from the tubercular bacilli, +besides the effective substance, all the other matter soluble in fifty +per cent. glycerine. + +Consequently, it contains a certain quantity of mineral salts, +coloring substances, and other unknown extractive matters. Some of +these substances can be removed from it tolerably easily. The +effective substance is insoluble in absolute alcohol. It can be +precipitated by it, though not, indeed, in a pure condition, but still +combined with the other extractive matter. It is likewise insoluble in +alcohol. The coloring matter may also be removed, rendering it +possible to obtain from the extract a colorless, dry substance +containing the effective principle in a much more concentrated form +than the original glycerine solution. For application in practice this +purification of the glycerine extract offers no advantage, because the +substances so eliminated are unessential for the human organism. The +process of purification would make the cost of the remedy +unnecessarily high. + +Regarding the constitution of the more effective substances, only +surmises may for the present be expressed. It appears to me to be +derivative from albuminous bodies, having a close affinity to them. It +does not belong to the group of so-called toxalbumins, because it +bears high temperatures, and in the dialyzer goes easily and quickly +through the membrane. The proportion of the substance in the extract +to all appearance is very small. It is estimated at fractions of one +per cent., which, if correct, we should have to do with a matter whose +effects upon organisms attacked with tuberculosis go far beyond what +is known to us of the strongest drugs. + +Regarding the manner in which the specific action of the remedy on +tuberculous tissue is to be represented, various hypotheses may +naturally be put forward. Without wishing to affirm that my view +affords the best explanation, I represent the process myself in the +following manner: + +The tubercle bacilli produced when growing in living tissues, the same +as in artificial cultivations, contain substances which variously and +notably unfavorably influence living elements in their vicinity. Among +these is a substance which in a certain degree of concentration kills +or so alters living protoplasm that it passes into a condition that +Weigert describes as coagulation necrosis. In tissue thus become +necrotic the bacillus finds such unfavorable conditions of nourishment +that it can grow no more and sometimes dies. + +This explains the remarkable phenomenon that in organs newly attacked +with tuberculosis, for instance in guinea pigs' spleen and liver, +which then are covered with gray nodules, numbers of bacilli are +found, whereas they are rare or wholly absent when the enormously +enlarged spleen consists almost entirely of whitish substance in a +condition of coagulation necrosis, such as is often found in cases of +natural death in tuberculous guinea pigs. The single bacillus cannot, +therefore, induce necrosis at a great distance, for as soon as +necrosis attains a certain extension the growth of the bacillus +subsides, and therewith the production of the necrotizing substance. A +kind of reciprocal compensation thus occurs, causing the vegetation of +isolated bacilli to remain so extraordinarily restricted, as, for +instance, in lupus and scrofulous glands. + +In such cases the necrosis generally extends only to a part of the +cells, which then, with further growth, assume the peculiar form of +riesen zelle, or giant cells. Thus, in this interpretation, follow +first the explanation Weigert gives of the production of giant cells. + +If now one increased artificially in the vicinity of the bacillus the +amount of necrotizing substance in the tissue, the necrosis would +spread a greater distance. The conditions of nourishment for the +bacillus would thereby become more unfavorable than usual. + +In the first place the tissue which had become necrotic over a large +extent would decay and detach itself, and where such were possible +would carry off the inclosed bacilli and eject them outwardly, so far +disturbing their vegetation that they would much more speedily be +killed than under ordinary circumstances. + +It is just in looking at such changes that the effect of the remedy +appears to consist. It contains a certain quantity of necrotizing +substance, a correspondingly large dose of which injures certain +tissue elements even in a healthy person, and perhaps the white blood +corpuscles or adjacent cells, thereby producing fever and a +complication of symptoms, whereas with tuberculous patients a much +smaller quantity suffices to induce at certain places, namely, where +tubercle bacilli are vegetating and have already impregnated the +adjacent region with the same necrotizing matter, more or less +extensive necrosis of the cells, with the phenomena in the whole +organism which result from and are connected with it. + +For the present, at least, it is impossible to explain the specific +influence which the remedy, in accurately defined doses, exercises +upon tuberculous tissue, and the possibility of increasing the doses +with such remarkable rapidity, and the remedial effects which have +unquestionably been produced under not too favorable circumstances. + +Of the consumptive patients whom he described as temporarily cured, +two have been returned to the Moabit Hospital for further observation. + +No bacilli have appeared in their sputum for the past three months, +and their phthisical symptoms have gradually and completely +disappeared. + + * * * * * + + + + +CAN WE SEPARATE ANIMALS FROM PLANTS? + +By ANDREW WILSON. + + +One of the plainest points connected with the study of living things +is the power we apparently possess of separating animals from plants. +So self-evident appears this power that the popular notion scoffs at +the idea of science modestly disclaiming its ability to separate the +one group of living beings from the other. Is there any danger of +confusing a bird with the tree amid the foliage of which it builds its +nest, or of mistaking a cow for the grass it eats? These queries are, +of course, answerable in one way only. Unfortunately (for the +querists), however, they do not include or comprehend the whole +difficulty. They merely assert, what is perfectly true, that we are +able, without trouble, to mark off the higher animals from the higher +plants. What science inquires is, whether we are able to separate +_all_ animals from _all_ plants, and to fix a definite boundary line, +so as to say that all the organisms on the one side of the line are +assuredly animals, while all the others on the opposite side of the +line may be declared to be truly plants. It is exactly this task which +science declares to be among the impossibilities of knowledge. Away +down in the depths of existence and among the groundlings of life the +identity of living things becomes of a nature which is worse than +confusing, and which renders it a futile task to attempt to separate +the two worlds of life. The hopelessness of the task, indeed, has +struck some observers so forcibly that they have proposed to +constitute a third kingdom--the _Regnum Protisticum_--between the +animal and the plant worlds, for the reception of the host of doubtful +organisms. This third kingdom would resemble the casual ward of a +workhouse, in that it would receive the waifs and strays of life which +could not find a refuge anywhere else. + +A very slight incursion into biological fields may serve to show forth +the difficulties of naturalists when the task of separating animals +from plants is mooted for discussion. To begin with, if we suppose our +popular disbeliever to assert that animals and plants are always to be +distinguished by shape and form, it is easy enough to show him that +here, as elsewhere, appearances are deceptive. What are we to say of a +sponge, or a sea anemone, of corals, of zoophytes growing rooted from +oyster shells, of sea squirts, and of sea mats? These, each and all of +them, are true animals, but they are so plant-like that, as a matter +of fact, they are often mistaken by seaside visitors for plants. This +last remark holds especially true of the zoophytes and the sea mats. +Then, on the other hand, we can point to hundreds of lower plants, +from the yeast plant onward, which show none of the ordinary features +of plant life at all. They possess neither roots, stems, branches, +leaves, nor flowers, so that on this first count of the indictment the +naturalist gains the day. + +Power of movement, to which the popular doubter is certain to appeal, +is an equally baseless ground of separation. For all the animals I +have above named are rooted and fixed, while many true plants of lower +grade are never rooted at all. The yeast plant, the _Algae_ that swarm +in our ponds, and the diatoms that crowd the waters, exemplify plants +that are as free as animals; and many of them, besides, in their young +state especially (e.g., the seaweeds), swim about freely in the water +as if they were roving animalcules. On the second count, also, science +gains the day; power of motion is no legitimate ground at all for +distinguishing one living being as an animal, while absence of +movement is similarly no reason for assuming that the fixed organism +must of necessity be a plant. Then comes the microscopic evidence. +What can this wonder glass do in the way of drawing boundary lines +betwixt the living worlds? The reply again is disappointing to the +doubter; for the microscope teaches us that the tissues of animals and +plants are built upon kindred lines. We meet with cells and fibers in +both. The cell is in each case the primitive expression of the whole +organism. Beyond cells and fibers we see the wonderful living +substance, _protoplasm_, which is alike to our senses in the two +kingdoms, although, indeed, differing much here and there in the +results of its work. On purely microscopic grounds, we cannot separate +animals from plants. There is no justification for rigidly assuming +that this is a plant or that an animal on account of anything the +microscope can disclose. A still more important point in connection +with this protoplasm question consists in the fact that as we go +backward to the beginnings of life, both in animals and plants, we +seem to approach nearer and nearer to an identity of substance which +baffles the microscope with all its powers of discernment. Every +animal and every plant begins existence as a mere speck of this living +jelly. The germ of each is a protoplasm particle, which, whatever +traces of structure it may exhibit, is practically unrecognizable as +being definitely animal or plant in respect of its nature. Later on, +as we know, the egg or germ shows traces of structure in the case of +the higher animals and plants; while even lowly forms of life exhibit +more or less characteristic phases when they reach their adult stage. +But, of life's beginnings, the microscope is as futile as a kind +scientific touchstone for distinguishing animals from plants as is +power of movement, or shape, or form. + +A fourth point of appeal in the matter is found within the domain of +the chemist. Chemistry, with its subtile powers of analysis, with its +many-sided possibilities of discovering the composition of things, and +with its ability to analyze for us even the light of the far distant +stars, only complicates the difficulties of the biologist. For, while +of old it was assumed that a particular element, nitrogen, was +peculiar to animals, and that carbon was an element peculiar to +plants, we now know that both elements are found in animals, just as +both occur in plants. The chemistry of living things, moreover, when +it did grow to become a staple part of science, revealed other and +greater anomalies than these. It showed that certain substances which +were supposed to be peculiar to plants, and to be made and +manufactured by them alone, were also found in animals. Chlorophyl is +the green coloring matter of plants, and is, of course, a typical +product of the vegetable world; yet it is made by such animals as the +hydra of the brooks and ponds, and by many animalcules and some worms. +Starch is surely a typical plant product, yet it is undoubtedly +manufactured, or at least stored up, by animals--a work illustrated by +the liver of man himself, which occasionally produces sugar out of its +starch. + +Again, there is a substance called _cellulose_, found well nigh +universally in plants. Of this substance, which is akin to starch, the +walls or envelopes of the cells of plant tissues are composed. Yet we +find those curious animals, the sea squirts, found on rocks and stones +at low-water mark, manufacturing cellulose to form part and parcel of +the outer covering of their sac-like bodies. Here it is as if the +animal, like a dishonest manufacturer, had infringed the patent rights +of the plant. On the fourth count, then--that of chemical +composition--the verdict is that nothing that chemistry can teach us +may serve definitely, clearly, and exactly to set a boundary line or +to erect a partition wall between the two worlds of life. There yet +remains for us to consider a fifth head--that of the food. + +In the matter of the feeding of the two great living worlds we might +perchance light upon some adequate grounds for making up the one +kingdom from the other. What the consideration of form, movement, +chemical composition, and microscopic structure could not effect for +us in this way, it might be supposed the investigation of the diet of +animals and plants would render clear. Our hopes of distinguishing the +one group from the other by reference to the food on which animals and +plants subsist are, however, dashed to the ground; and the diet +question leaves us, therefore, when it has been discussed, in the same +quandary as before. + +Nevertheless, it is an interesting story, this of the nutrition of +animals and plants. A large amount of scientific information is to be +gleaned from such a study, which may very well be commenced by our +having regard to the matters on which a _green_ plant feeds. I +emphasize the word "green," because it so happens that when a plant +has no chlorophyl (as green color is named in the plant world) its +feeding is of diverse kind to that which a green plant exhibits. The +mushroom or other fungus may be taken as an illustration of a plant +which represents the non-green race, while every common plant, from a +bit of grass to an oak tree, exemplifies the green-bearing order of +the vegetable tribes. + +Suppose we were to invite a green plant to dinner, the _menu_ would +have to be very differently arranged from that which would satisfy a +human or other animal guest. The soup would be represented for the +plant's delectation by water, the fish by minerals, the joint by +carbonic acid gas, and the dessert by ammonia. On these four items a +green plant feeds, out of them it builds up its living frame. Note +that its diet is of inorganic or non-living matter. It derives its +sustenance from soil and air, yet out of these lifeless matters the +green plant elaborates and manufactures its living matter, or +protoplasm. It is a more wonderful organism than the animal, for while +the latter can only make new protoplasm when living matter is included +in its food supply, the green plant, by the exercise of its vital +chemistry, can transform that which is not living into that which is +life-possessing. + +The green plant in other words, raises non-living into living matter, +while the animal can only transform living matters into its like. This +is why the plant is called a constructive organism, while the animal +is, contrariwise, named a destructive one. The result of the plant's +existence is to build up, that of the animal's life is to break down +its substance, as the result of its work, into non-living matter. The +animal's body is, in fact, breaking down into the very things on which +the green plant feeds. We ourselves are perpetually dissipating our +substance in our acts of life and work into the carbonic acid, water, +ammonia, and minerals on which plants feed. We "die daily" in as true +a sense as that in which the apostle used the term. And out of the +debris of the animal frame the green plant builds up leaf and flower, +stein and branch, and all the other tokens of its beauty and its life. + +If, then, an animal can only live upon living matter--that is to say +on the bodies of other animals or of plants--with water, minerals and +oxygen gas from the air thrown in to boot, we might be tempted to hold +that in such distinctive ways and works we had at last found a means +of separating animals from plants. Unfortunately, this view may be +legitimately disputed and rendered null and void, on two grounds. +First of all, the mushrooms and their friends and neighbors, all true +plants, do not feed as do the green tribes. And secondly, many of the +green plants themselves can be shown to have taken very kindly to an +animal mode of diet. + +A mushroom, thus, because it has no green color, lives upon water, +oxygen, minerals, and organic matter. You can only grow mushrooms +where there is plenty of animal matter in a state of decay, and as for +the oxygen, they habitually inhale that gas as if they were animals. +Non-green plants thus want a most characteristic action of their green +neighbors. For the latter in daylight take in the carbonic acid gas, +which is composed of carbon and oxygen. Under the combined influence +of the green color and the light, they split up the gas into its two +elements, retaining the carbon for food and allowing the oxygen to +escape to the atmosphere. Alas! however, in the dark our green plant +becomes essentially like an animal as regards its gas food, for then +it is an absorber of oxygen, while it gives off carbonic acid. If to +take in carbonic acid and to give out oxygen be held to be a feature +characteristic of a plant, it is one, as has been well said, which +disappears with the daylight in green plants, and which is not +witnessed at all in plants that have no green color. + +So far, we have seen that not even the food of plants and animals can +separate the one kingdom of life from the other. The mushroom bars the +way and the green plant's curious behavior by night and by day +respectively, in the matter of its gas food, once more assimilates +animal life and plant life in a remarkable manner. Still more +interesting is the fact, already noticed, that even among the green +tribes there are to be found many and various lapses from the stated +rules of their feeding. Thus what are we to say of the parasitic +mistletoe, which, while it has grown leaves of its own, and can, +therefore, obtain so much carbon food from the air on its own account, +nevertheless drinks up the sap of the oak or apple which forms its +host, and thus illustrates the spectacle of a green plant feeding like +an animal, on living matter? Or, what may we think of such plants as +the sundew, the Venus' fly trap, the pitcher plants, the side saddle +plants, the butterworts and bladderworts, and others of their kind, +which not only capture insects, often by ingenious and complex lures, +but also digest the animal food thus captured? A sundew thus spreads +out its lure in the shape of its leaf studded with sensitive +tentacles, each capped by a glistening drop of gummy secretion. +Entangled in this secretion, the fly is further fixed to the leaf by +the tentacles which bend over it and inclose it in their fold. Then is +poured out upon the insect's body a digestive acid fluid, and the +substance of the dissolved and digested animal is duly absorbed by the +plant. So also the Venus' fly trap captures insects by means of its +leaf, which closes upon the prey when certain sensitive hairs have +given the signal that the animal has been trapped. Within the leaf the +insect is duly digested as before, and its substance applied to the +nutrition of the plant. Such plants, moreover, cannot flourish +perfectly unless duly supplied with their animal food. Such +illustrations of exceptions to the rule of green plant feeding simply +have the effect of abolishing the distinctions which the diet question +might be supposed to raise between animals and plants. We may return +to the sundews and other insect catchers; meanwhile, I have said +enough to show that to the question, "Can we separate animals from +plants?" a very decided negative reply must be given. Life everywhere +exhibits too many points of contact to admit of any boundary line +being drawn between the two great groups which make up the sum total +of organic existence.--_Illustrated London News._ + + * * * * * + + + + +THE RECOVERY OF SILVER AND GOLD FROM PLATING AND GILDING SOLUTIONS. + + +In view of the rapid development and extension of the methods of +electro-plating with silver and gold, and of the large amount of spent +liquors containing silver or gold thus produced, it has long been +desirable to find methods by which these metals can be recovered from +the spent liquors. The processes hitherto adopted generally +necessitate the tedious and unpleasant evaporation of the cyanide +liquors, or else involve a series of chemical operations which are +somewhat difficult to carry out, so that actually the used-up baths +are sold to some firm which undertakes this recovery as a particular +branch of its business. + +A process invented by Stockmuir and Fleischmann, and worked out by +them in the chemical laboratory of the Bavarian Industrial Museum, is, +however, exceedingly simple, and is employed in many establishments. + +In order to remove silver from a potassium cyanide silver solution, it +is only necessary to allow a clean piece of plate zinc to remain in +the liquid for two days; even better results are obtained by the use +of iron conjointly with the zinc. In the first case, the silver often +adheres firmly to the zinc, while in the second it always separates +out as a powder. It is then only necessary to wash the precipitated +powder, which usually contains copper (since spent silver solutions +always contain copper), dry it, and then dissolve it in hot +concentrated sulphuric acid, water being added, and the dissolved +silver precipitated by strips of copper. The silver thus obtained is +perfectly pure. If the amount of copper present is only small, it can +usually be removed by fusing the precipitated powder with a little +niter and borax. + +In this way a spent silver bath was found to contain per liter + + 1st experiment 1.5706 grms. + 2d " 1.5694 " + ------ + Mean 1.5700 " + +The presence of silver could not be qualitatively ascertained in the +residual liquor. + +Although sheet zinc, or zinc and iron sheets, serve so well for the +precipitation of silver, they cannot be employed for the recovery of +gold. The latter separates out in such a case very incompletely and as +a firmly adhering lustrous film in the zinc. On the other hand, finely +divided zinc, the so-called zinc dust, is an excellent substance to +employ for precipitating gold quantitatively and in the form of powder +from spent cyanide liquors. When zinc dust is added to a spent gold +bath and the liquid periodically stirred or shaken, all the gold is +precipitated in two or three days. The amount of zinc to be added +naturally depends on the quantity of gold present. Freshly prepared +gold baths for gilding in the cold contain on the average 3.5 grms. +gold per liter, while those used for the hot process contain 10.75 +grms. To precipitate all the gold in the original bath, 1.74 grms. or +0.37-0.5 grms. zinc dust would be necessary, and, of course, a much +smaller quantity would be sufficient for the spent liquors. Since the +precipitation takes place more rapidly when an excess of zinc dust is +present, it is generally advisable to add 1/4 or at the most 1/2 kilo, of +zinc dust to every 100 liters of solution. + +The precipitated gold, which contains zinc dust and usually silver and +copper, is washed, freed from zinc by hydrochloric acid, and then from +silver and copper by nitric acid and thus obtained pure. + +A spent bath treated in this way gave the following amounts of gold +per liter: + + 1st experiment 0.2626 + 2d " 0.2634 + Mean 0.2630 grms. + +The presence of gold in the residual cyanide solution could not be +qualitatively detected. The potassium cyanide of the solutions +obtained by this process should be converted into ferrocyanide by +heating with ferrous sulphate and milk of lime, since this substance +is not poisonous and can therefore be got rid of without danger. It +would, however, be more economical and, considering the large amount +of cyanide present, more profitable to work it up into Prussian blue. + + * * * * * + + +A NEW CATALOGUE OF VALUABLE PAPERS + +Contained in SCIENTIFIC AMERICAN SUPPLEMENT during the past ten years, +sent _free of charge_ to any address. MUNN & CO., 361 Broadway, New +York. + + * * * * * + + +THE SCIENTIFIC AMERICAN + +ARCHITECTS AND BUILDERS EDITION + +$2.50 A YEAR. SINGLE COPIES, 25 CTS. + +This is a Special Edition of the SCIENTIFIC AMERICAN, issued +monthly--on the first day of the month. Each number contains about +forty large quarto pages, equal to about two hundred ordinary book +pages, forming, practically, a large and splendid Magazine of +Architecture, richly adorned with _elegant platen in colors_ and with +fine engravings, illustrating the most interesting examples of modern +Architectural Construction and allied subjects. + +A special feature is the presentation in each number of a variety of +the latest and best plans for private residences, city and country, +including those of very moderate cost as well as the more expensive. +Drawings in perspective and in color are given, together with full +Plans, Specifications, Costs, Bills of Estimate, and Sheets of +Details. + +No other building paper contains so many plans, details, and +specifications regularly presented as the SCIENTIFIC AMERICAN. +Hundreds of dwellings have already been erected on the various plans +we have issued during the past year, and many others are in process of +construction. + +Architects, Builders, and Owners will find this work valuable in +furnishing fresh and useful suggestions. All who contemplate building +or improving homes, or erecting structures of any kind, have before +them in this work an almost _endless series of the latest and best +examples_ from which to make selections, thus saving time and money. + +Many other subjects, including Sewerage, Piping, Lighting, Warming, +Ventilating, Decorating, Laying out of Grounds, etc., are illustrated. +An extensive Compendium of Manufacturers' Announcements is also given, +in which the most reliable and approved Building Materials, Goods, +Machines, Tools, and Appliances are described and illustrated, with +addresses of the makers, etc. + +The fullness, richness, cheapness, and convenience of this work have +won for it the Largest Circulation of any Architectural publication in +the world. + +A Catalogue of valuable books on Architecture, Building, Carpentry, +Masonry, Heating, Warming, Lighting, Ventilation, and all branches of +industry pertaining to the art of Building, is supplied free of +charge, sent to any address. + +MUNN & CO., Publishers, + +361 Broadway, New York. + + * * * * * + + +BUILDING PLANS AND SPECIFICATIONS. + +In connection with the publication of the BUILDING EDITION of the +SCIENTIFIC AMERICAN, Messrs. Munn & Co. furnish plans and +specifications for buildings of every kind, including Churches, +Schools, Stores, Dwellings, Carriage Houses, Barns, etc. + +In this work they are assisted by able and experienced architects. +Full plans, details, and specifications for the various buildings +illustrated in this paper can be supplied. + +Those who contemplate building, or who wish to alter, improve, extend, +or add to existing buildings, whether wings, porches, bay windows, or +attic rooms, are invited to communicate with the undersigned. Our work +extends to all parts of the country. Estimates, plans, and drawings +promptly prepared. Terms moderate. Address + +MUNN & CO., 361 BROADWAY, NEW YORK. + + * * * * * + + +SCIENTIFIC AMERICAN SUPPLEMENT. + +PUBLISHED WEEKLY. + +Terms of Subscription, $5 a year. + +Sent by mail, postage prepaid, to subscribers in any part of the +United States or Canada. Six dollars a year, sent, prepaid, to any +foreign country. + +All the back numbers of THE SUPPLEMENT, from the commencement, January +1, 1876, can be had. Price, 10 cents each. + +All the back volumes of THE SUPPLEMENT can likewise be supplied. Two +volumes are issued yearly. Price of each volume, $2.50 stitched in +paper, or $3.50 bound in stiff covers. + +COMBINED RATES.--One copy of SCIENTIFIC AMERICAN and one copy of +SCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, $7.00. + +A liberal discount to booksellers, news agents, and canvassers. + +MUNN & CO., Publishers, +361 Broadway, New York, N.Y. + + * * * * * + + +USEFUL ENGINEERING BOOKS + +Manufacturers, Agriculturists, Chemists, Engineers, Mechanics, +Builders, men of leisure, and professional men, of all classes, need +good books in the line of their respective callings. Our post office +department permits the transmission of books through the mails at very +small cost. A comprehensive catalogue of useful books by different +authors, on more than fifty different subjects, has recently been +published, for free circulation, at the office of this paper. Subjects +classified with names of author. Persons desiring a copy have only to +ask for it, and it will be mailed to them. Address, MUNN & CO., 361 +Broadway, New York. + + * * * * * + + +PATENTS. + +In connection with the Scientific American, Messrs. MUNN & Co. are +solicitors of American and Foreign Patents, have had 42 years' +experience, and now have the largest establishment in the world. +Patents are obtained on the best terms. + +A special notice is made in the Scientific American of all inventions +patented through this Agency, with the name and residence of the +Patentee. By the immense circulation thus given, public attention is +directed to the merits of the new patent, and sales or introduction +often easily effected. + +Any person who has made a new discovery or invention can ascertain, +free of charge, whether a patent can probably be obtained, by writing +to MUNN & Co. We also send free our Hand Book about the Patent Laws, +Patents, Caveats, Trade Marks, their costs and how procured. Address + +MUNN & Co., + 361 Broadway, New York. +Branch Office, 622 and 624 F St., Washington, D.C. + + + + + + + +End of the Project Gutenberg EBook of Scientific American Supplement, No. +787, January 31, 1891, by Various + +*** END OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + +***** This file should be named 14009.txt or 14009.zip ***** +This and all associated files of various formats will be found in: + https://www.gutenberg.org/1/4/0/0/14009/ + +Produced by Victoria Woosley, Don Kretz, Juliet Sutherland, Charles +Franks and the PG Distributed Proofreading Team + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. Special rules, +set forth in the General Terms of Use part of this license, apply to +copying and distributing Project Gutenberg-tm electronic works to +protect the PROJECT GUTENBERG-tm concept and trademark. Project +Gutenberg is a registered trademark, and may not be used if you +charge for the eBooks, unless you receive specific permission. If you +do not charge anything for copies of this eBook, complying with the +rules is very easy. You may use this eBook for nearly any purpose +such as creation of derivative works, reports, performances and +research. They may be modified and printed and given away--you may do +practically ANYTHING with public domain eBooks. Redistribution is +subject to the trademark license, especially commercial +redistribution. + + + +*** START: FULL LICENSE *** + +THE FULL PROJECT GUTENBERG LICENSE +PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK + +To protect the Project Gutenberg-tm mission of promoting the free +distribution of electronic works, by using or distributing this work +(or any other work associated in any way with the phrase "Project +Gutenberg"), you agree to comply with all the terms of the Full Project +Gutenberg-tm License (available with this file or online at +https://gutenberg.org/license). + + +Section 1. General Terms of Use and Redistributing Project Gutenberg-tm +electronic works + +1.A. By reading or using any part of this Project Gutenberg-tm +electronic work, you indicate that you have read, understand, agree to +and accept all the terms of this license and intellectual property +(trademark/copyright) agreement. If you do not agree to abide by all +the terms of this agreement, you must cease using and return or destroy +all copies of Project Gutenberg-tm electronic works in your possession. +If you paid a fee for obtaining a copy of or access to a Project +Gutenberg-tm electronic work and you do not agree to be bound by the +terms of this agreement, you may obtain a refund from the person or +entity to whom you paid the fee as set forth in paragraph 1.E.8. + +1.B. "Project Gutenberg" is a registered trademark. It may only be +used on or associated in any way with an electronic work by people who +agree to be bound by the terms of this agreement. There are a few +things that you can do with most Project Gutenberg-tm electronic works +even without complying with the full terms of this agreement. See +paragraph 1.C below. There are a lot of things you can do with Project +Gutenberg-tm electronic works if you follow the terms of this agreement +and help preserve free future access to Project Gutenberg-tm electronic +works. See paragraph 1.E below. + +1.C. The Project Gutenberg Literary Archive Foundation ("the Foundation" +or PGLAF), owns a compilation copyright in the collection of Project +Gutenberg-tm electronic works. Nearly all the individual works in the +collection are in the public domain in the United States. If an +individual work is in the public domain in the United States and you are +located in the United States, we do not claim a right to prevent you from +copying, distributing, performing, displaying or creating derivative +works based on the work as long as all references to Project Gutenberg +are removed. Of course, we hope that you will support the Project +Gutenberg-tm mission of promoting free access to electronic works by +freely sharing Project Gutenberg-tm works in compliance with the terms of +this agreement for keeping the Project Gutenberg-tm name associated with +the work. You can easily comply with the terms of this agreement by +keeping this work in the same format with its attached full Project +Gutenberg-tm License when you share it without charge with others. + +1.D. The copyright laws of the place where you are located also govern +what you can do with this work. Copyright laws in most countries are in +a constant state of change. If you are outside the United States, check +the laws of your country in addition to the terms of this agreement +before downloading, copying, displaying, performing, distributing or +creating derivative works based on this work or any other Project +Gutenberg-tm work. The Foundation makes no representations concerning +the copyright status of any work in any country outside the United +States. + +1.E. Unless you have removed all references to Project Gutenberg: + +1.E.1. The following sentence, with active links to, or other immediate +access to, the full Project Gutenberg-tm License must appear prominently +whenever any copy of a Project Gutenberg-tm work (any work on which the +phrase "Project Gutenberg" appears, or with which the phrase "Project +Gutenberg" is associated) is accessed, displayed, performed, viewed, +copied or distributed: + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + +1.E.2. If an individual Project Gutenberg-tm electronic work is derived +from the public domain (does not contain a notice indicating that it is +posted with permission of the copyright holder), the work can be copied +and distributed to anyone in the United States without paying any fees +or charges. If you are redistributing or providing access to a work +with the phrase "Project Gutenberg" associated with or appearing on the +work, you must comply either with the requirements of paragraphs 1.E.1 +through 1.E.7 or obtain permission for the use of the work and the +Project Gutenberg-tm trademark as set forth in paragraphs 1.E.8 or +1.E.9. + +1.E.3. If an individual Project Gutenberg-tm electronic work is posted +with the permission of the copyright holder, your use and distribution +must comply with both paragraphs 1.E.1 through 1.E.7 and any additional +terms imposed by the copyright holder. Additional terms will be linked +to the Project Gutenberg-tm License for all works posted with the +permission of the copyright holder found at the beginning of this work. + +1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm +License terms from this work, or any files containing a part of this +work or any other work associated with Project Gutenberg-tm. + +1.E.5. Do not copy, display, perform, distribute or redistribute this +electronic work, or any part of this electronic work, without +prominently displaying the sentence set forth in paragraph 1.E.1 with +active links or immediate access to the full terms of the Project +Gutenberg-tm License. + +1.E.6. You may convert to and distribute this work in any binary, +compressed, marked up, nonproprietary or proprietary form, including any +word processing or hypertext form. However, if you provide access to or +distribute copies of a Project Gutenberg-tm work in a format other than +"Plain Vanilla ASCII" or other format used in the official version +posted on the official Project Gutenberg-tm web site (www.gutenberg.org), +you must, at no additional cost, fee or expense to the user, provide a +copy, a means of exporting a copy, or a means of obtaining a copy upon +request, of the work in its original "Plain Vanilla ASCII" or other +form. Any alternate format must include the full Project Gutenberg-tm +License as specified in paragraph 1.E.1. + +1.E.7. Do not charge a fee for access to, viewing, displaying, +performing, copying or distributing any Project Gutenberg-tm works +unless you comply with paragraph 1.E.8 or 1.E.9. + +1.E.8. You may charge a reasonable fee for copies of or providing +access to or distributing Project Gutenberg-tm electronic works provided +that + +- You pay a royalty fee of 20% of the gross profits you derive from + the use of Project Gutenberg-tm works calculated using the method + you already use to calculate your applicable taxes. The fee is + owed to the owner of the Project Gutenberg-tm trademark, but he + has agreed to donate royalties under this paragraph to the + Project Gutenberg Literary Archive Foundation. Royalty payments + must be paid within 60 days following each date on which you + prepare (or are legally required to prepare) your periodic tax + returns. Royalty payments should be clearly marked as such and + sent to the Project Gutenberg Literary Archive Foundation at the + address specified in Section 4, "Information about donations to + the Project Gutenberg Literary Archive Foundation." + +- You provide a full refund of any money paid by a user who notifies + you in writing (or by e-mail) within 30 days of receipt that s/he + does not agree to the terms of the full Project Gutenberg-tm + License. You must require such a user to return or + destroy all copies of the works possessed in a physical medium + and discontinue all use of and all access to other copies of + Project Gutenberg-tm works. + +- You provide, in accordance with paragraph 1.F.3, a full refund of any + money paid for a work or a replacement copy, if a defect in the + electronic work is discovered and reported to you within 90 days + of receipt of the work. + +- You comply with all other terms of this agreement for free + distribution of Project Gutenberg-tm works. + +1.E.9. If you wish to charge a fee or distribute a Project Gutenberg-tm +electronic work or group of works on different terms than are set +forth in this agreement, you must obtain permission in writing from +both the Project Gutenberg Literary Archive Foundation and Michael +Hart, the owner of the Project Gutenberg-tm trademark. Contact the +Foundation as set forth in Section 3 below. + +1.F. + +1.F.1. Project Gutenberg volunteers and employees expend considerable +effort to identify, do copyright research on, transcribe and proofread +public domain works in creating the Project Gutenberg-tm +collection. Despite these efforts, Project Gutenberg-tm electronic +works, and the medium on which they may be stored, may contain +"Defects," such as, but not limited to, incomplete, inaccurate or +corrupt data, transcription errors, a copyright or other intellectual +property infringement, a defective or damaged disk or other medium, a +computer virus, or computer codes that damage or cannot be read by +your equipment. + +1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right +of Replacement or Refund" described in paragraph 1.F.3, the Project +Gutenberg Literary Archive Foundation, the owner of the Project +Gutenberg-tm trademark, and any other party distributing a Project +Gutenberg-tm electronic work under this agreement, disclaim all +liability to you for damages, costs and expenses, including legal +fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT +LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE +PROVIDED IN PARAGRAPH F3. YOU AGREE THAT THE FOUNDATION, THE +TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE +LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR +INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH +DAMAGE. + +1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a +defect in this electronic work within 90 days of receiving it, you can +receive a refund of the money (if any) you paid for it by sending a +written explanation to the person you received the work from. If you +received the work on a physical medium, you must return the medium with +your written explanation. The person or entity that provided you with +the defective work may elect to provide a replacement copy in lieu of a +refund. If you received the work electronically, the person or entity +providing it to you may choose to give you a second opportunity to +receive the work electronically in lieu of a refund. If the second copy +is also defective, you may demand a refund in writing without further +opportunities to fix the problem. + +1.F.4. Except for the limited right of replacement or refund set forth +in paragraph 1.F.3, this work is provided to you 'AS-IS' WITH NO OTHER +WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO +WARRANTIES OF MERCHANTIBILITY OR FITNESS FOR ANY PURPOSE. + +1.F.5. Some states do not allow disclaimers of certain implied +warranties or the exclusion or limitation of certain types of damages. +If any disclaimer or limitation set forth in this agreement violates the +law of the state applicable to this agreement, the agreement shall be +interpreted to make the maximum disclaimer or limitation permitted by +the applicable state law. The invalidity or unenforceability of any +provision of this agreement shall not void the remaining provisions. + +1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the +trademark owner, any agent or employee of the Foundation, anyone +providing copies of Project Gutenberg-tm electronic works in accordance +with this agreement, and any volunteers associated with the production, +promotion and distribution of Project Gutenberg-tm electronic works, +harmless from all liability, costs and expenses, including legal fees, +that arise directly or indirectly from any of the following which you do +or cause to occur: (a) distribution of this or any Project Gutenberg-tm +work, (b) alteration, modification, or additions or deletions to any +Project Gutenberg-tm work, and (c) any Defect you cause. + + +Section 2. Information about the Mission of Project Gutenberg-tm + +Project Gutenberg-tm is synonymous with the free distribution of +electronic works in formats readable by the widest variety of computers +including obsolete, old, middle-aged and new computers. It exists +because of the efforts of hundreds of volunteers and donations from +people in all walks of life. + +Volunteers and financial support to provide volunteers with the +assistance they need, is critical to reaching Project Gutenberg-tm's +goals and ensuring that the Project Gutenberg-tm collection will +remain freely available for generations to come. In 2001, the Project +Gutenberg Literary Archive Foundation was created to provide a secure +and permanent future for Project Gutenberg-tm and future generations. +To learn more about the Project Gutenberg Literary Archive Foundation +and how your efforts and donations can help, see Sections 3 and 4 +and the Foundation web page at https://www.pglaf.org. + + +Section 3. Information about the Project Gutenberg Literary Archive +Foundation + +The Project Gutenberg Literary Archive Foundation is a non profit +501(c)(3) educational corporation organized under the laws of the +state of Mississippi and granted tax exempt status by the Internal +Revenue Service. The Foundation's EIN or federal tax identification +number is 64-6221541. Its 501(c)(3) letter is posted at +https://pglaf.org/fundraising. Contributions to the Project Gutenberg +Literary Archive Foundation are tax deductible to the full extent +permitted by U.S. federal laws and your state's laws. + +The Foundation's principal office is located at 4557 Melan Dr. S. +Fairbanks, AK, 99712., but its volunteers and employees are scattered +throughout numerous locations. Its business office is located at +809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887, email +business@pglaf.org. Email contact links and up to date contact +information can be found at the Foundation's web site and official +page at https://pglaf.org + +For additional contact information: + Dr. Gregory B. Newby + Chief Executive and Director + gbnewby@pglaf.org + + +Section 4. Information about Donations to the Project Gutenberg +Literary Archive Foundation + +Project Gutenberg-tm depends upon and cannot survive without wide +spread public support and donations to carry out its mission of +increasing the number of public domain and licensed works that can be +freely distributed in machine readable form accessible by the widest +array of equipment including outdated equipment. Many small donations +($1 to $5,000) are particularly important to maintaining tax exempt +status with the IRS. + +The Foundation is committed to complying with the laws regulating +charities and charitable donations in all 50 states of the United +States. Compliance requirements are not uniform and it takes a +considerable effort, much paperwork and many fees to meet and keep up +with these requirements. We do not solicit donations in locations +where we have not received written confirmation of compliance. To +SEND DONATIONS or determine the status of compliance for any +particular state visit https://pglaf.org + +While we cannot and do not solicit contributions from states where we +have not met the solicitation requirements, we know of no prohibition +against accepting unsolicited donations from donors in such states who +approach us with offers to donate. + +International donations are gratefully accepted, but we cannot make +any statements concerning tax treatment of donations received from +outside the United States. U.S. laws alone swamp our small staff. + +Please check the Project Gutenberg Web pages for current donation +methods and addresses. Donations are accepted in a number of other +ways including including checks, online payments and credit card +donations. To donate, please visit: https://pglaf.org/donate + + +Section 5. General Information About Project Gutenberg-tm electronic +works. + +Professor Michael S. Hart was the originator of the Project Gutenberg-tm +concept of a library of electronic works that could be freely shared +with anyone. For thirty years, he produced and distributed Project +Gutenberg-tm eBooks with only a loose network of volunteer support. + + +Project Gutenberg-tm eBooks are often created from several printed +editions, all of which are confirmed as Public Domain in the U.S. +unless a copyright notice is included. Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + https://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. diff --git a/old/14009.zip b/old/14009.zip Binary files differnew file mode 100644 index 0000000..da3150b --- /dev/null +++ b/old/14009.zip |
