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+The Project Gutenberg EBook of Scientific American Supplement, No. 447,
+July 26, 1884, 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. 447, July 26, 1884
+
+Author: Various
+
+Posting Date: October 10, 2012 [EBook #9266]
+Release Date: November, 2005
+First Posted: September 16, 2003
+
+Language: English
+
+Character set encoding: ASCII
+
+*** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN SUPPL., NO. 447 ***
+
+
+
+
+Produced by Don Kretz, Juliet Sutherland, and Distributed Proofreaders
+
+
+
+
+
+
+
+
+
+[Illustration]
+
+
+
+
+SCIENTIFIC AMERICAN SUPPLEMENT NO. 447
+
+
+
+
+NEW YORK, JULY 26, 1884
+
+Scientific American Supplement. Vol. XVIII, No. 447.
+
+Scientific American established 1845
+
+Scientific American Supplement, $5 a year.
+
+Scientific American and Supplement, $7 a year.
+
+
+       *       *       *       *       *
+
+TABLE OF CONTENTS.
+
+I.    CHEMISTRY.--The Bitter Substance of Hops.--By Dr. H. BUNGENER.
+      --What gives hops their bitter taste?--Processes for obtaining
+      hop-bitter acid.--Analysis of the same.
+
+II.   ENGINEERING AND MECHANICS.--Improvements in the Harbor
+      of Antwerp.--With engraving of caisson for deepening the
+      river.
+
+      Progress of Antwerp.--Recent works in the harbor.
+
+      Bicycles and Tricycles.--By C.V. BOYS.---Advantages of the
+      different machines.--Manner of finding the steepness of a hill
+      and representing same on a map.--Experiments on ball bearings.--
+      The Otto bicycle.
+
+      The Canal Iron Works, London.
+
+      Marinoni's Rotary Printing Press.--With 2 engravings.
+
+      Chenot's Economic Filter Press.--With engraving.
+
+      Steel Chains without Welding.--Method and machines for making
+      same.--Several figures.
+
+III.  TECHNOLOGY.--Some Economic Processes connected with the
+      Cloth Making Industry.--By Dr. WM. RAMSAY.--How to save and
+      utilize soap used in wool scouring.--To recover the indigo from
+      the refuse.--Extraction of potash from _suint_.--Use of
+      bisulphide of carbon.
+
+IV.   PHYSICS. ELECTRICITY, ETC.--Thury's Dynamo Electric Machine.
+      --5 figures.
+
+      Breguet's Telephone.
+
+      Munro's Telephonic Experiments.--9 figures.
+
+      Apparatus for Maneuvering Bichromate of Potassa Piles from a
+      Distance.--2 figures.
+
+      Magnetic Rotations.--By E.L. VOICE.--1 figure.
+
+      Lighton's Immersion Illuminator.--1 figure.
+
+      Foucault's Pendulum Experiments.--By RICHARD A. PROCTOR.
+      --4 figures.
+
+V.    ARCHITECTURE, ART, ETC.--St. Paul's Vicarage, Forest Hill,
+      Kent.--2 engravings.
+
+      Designs for Iron Gates.--An engraving.
+
+VI.   ASTRONOMY.--A New Lunarian.--By Prof. C.W. MACCORD.
+      --With 3 figures.
+
+VII.  GEOLOGY.--Coal and its Uses.--By JAMES PYKE.--Formation
+      of carboniferous rocks and the coal in the same.--Processes of
+      nature.--Greatness of this country due to coal.--Manufacture of
+      gas.--Products of the same.
+
+VIII. NATURAL HISTORY, BOTANY. ETC.--The Wine Fly.--The
+      egg.--Larva.--Pupa and fly.
+
+      The "Potetometer." an Instrument for Measuring the Transpiration
+      of Water by Plants.--1 figure.
+
+      Bolivian Cinchona Forests.
+
+      Ferns.--Nephrolepis Davillioides Furcans and Nephrolepis Duffi.
+      --2 engravings.
+
+IX.   PHYSIOLOGY, HYGIENE, ETC.--The Upright Attitude of Mankind.
+      --Review of a lecture by Dr. S.V. CLEVENGER, in which he
+      tries to prove that man must have originated from a four footed
+      being.
+
+      Our Enemies, the Microbes.--Affections caused by the same.--
+      Experiments of Davaine, Pasteur, and others.--How to prevent
+      bacterides from entering the body.--5 figures.
+
+X.    BIOGRAPHY.--Gaston Plante, the Scientist.--With portrait
+
+      Warren Colburn, the American Mathematician.
+
+       *       *       *       *       *
+
+
+
+
+IMPROVEMENTS IN THE HARBOR OF ANTWERP.
+
+
+The harbor of Antwerp, which, excepting those of London and Liverpool,
+is the largest in Europe, has been improved wonderfully during the last
+decade. Before 1870 it was inferior to the harbor at Havre, but now it
+far surpasses the same. The river Scheldt, which is about 1,500 ft.
+wide, was badgered out up to the vertical walls of the basin, so that
+the largest ships can land at the docks. The river was deepened by the
+use of caissons, in the lower parts of which the workmen operated in
+compressed air. The annexed cut shows that part of one of the caissons
+which projects above the surface of the water. The depth of the river at
+low tide is about 26 ft., and at high tide about 39 ft. Some of the old
+sluices, channels, basins, etc., which were rendered useless by the
+improvements made in the river Scheldt have been filled up, and
+thereby the city has been enriched by several handsome and elegant
+squares.--_Illustrirte Zeitung_.
+
+       *       *       *       *       *
+
+
+
+
+PROGRESS OF ANTWERP.
+
+
+Antwerp is now the chief port on the Continent. Since 1873 the progress
+has continued, and made very rapid advances. In 1883 the tonnage of the
+port reached 3,734,428 registered tons. This marvelous development is
+partly due to the position of Antwerp as the embarking point from the
+Continent of Europe to America, and partly also to the recent additions
+and changes which have been carried out there, and which, now nearly
+completed, have made this cosmopolitan port one of the best organized in
+the world. This is so well known that vessels bound for Switzerland with
+a cargo of corn from Russia pass Marseilles and go two thousand miles
+out of their way for the purpose of unloading at Antwerp. No other port,
+in fact, offers the same facilities. There is not another place in the
+world where fifty vessels of 3,000 tons can come alongside as easily as
+the penny boats on the Thames run into the landing.
+
+[Illustration: CAISSONS FOR DEEPENING THE RIVER AT ANTWERP.]
+
+Since the opening of the St. Gothard Tunnel nearly all the alimentary
+provisions that Italy sends to the British Isles pass through Antwerp.
+In 1882 82,000,000 eggs and 30,000 pounds of fruit were shipped there
+for England. The greater part of these came from Italy. Antwerp has
+become also an important port for emigrants; 35,125 embarked in 1882,
+out of which number 3,055 were bound for New York. The city was always
+destined, from its topographical position, to be at the head of a very
+considerable traffic; political reasons alone for many years prevented
+this being the case. These have happily now disappeared, and, since
+1863, when the "Scheldt was liberated," the progress of commerce has
+been more rapid than even the most ardent Antwerp patriot dared hope. At
+that date the toll of 1s. 11d. on all vessels going up the river, and of
+71/2d. on vessels going down, was abolished, and reforms were introduced
+among the taxes on the general navigation; the tax on tonnage in the
+port itself was abolished, and the pilot tax was lowered. The results of
+these measures became immediately apparent. Traffic increased with
+such rapidity that in 1876 the crowding on the quays was such that the
+relation of the tonnage to the length of the quay was about 270 tons per
+yard, which is four times as great as at Liverpool.
+
+A few words now, briefly, as to the nature of the important works[1]
+completed at Antwerp. They were commenced in 1877, and have opened for
+the port an era of prosperity such as was never experienced even during
+the sixteenth century, the zenith of her splendor. These works have
+cost L4,000,000, and have necessitated the employment of 12,000 tons
+of wrought iron, of 490,000 cubic yards of brickwork and concrete, of
+32,000 cubic yards of masonry, and of more than 3,300,000 cubic yards
+of earthwork in filling and dredging, etc. The quay walls run the whole
+length of the town, a distance of rather more than two miles. It rests
+on a foundation laid without timber footings, and giving a depth of
+twenty-six feet at low water, sufficient drawing for the largest ships
+afloat. Beyond this wall are the real quays, which consists of first a
+line of rails reserved for hydraulic cranes serving to unload vessels
+and deposit their cargo railway trucks; secondly, a second line of rails
+parallel with the first, on which these trucks are stationed; thirdly,
+sheds extending toward the town for a width of one hundred and fifty
+feet, and covered with galvanized iron sheetings. A third line of rails
+parallel with the two others runs from end to end of these sheds, and a
+number of lines placed transversely with this one connect it by means of
+spring bridges with, fourthly, four more lines also parallel with the
+quays, whence the goods start for the different stations, and thence to
+their destinations. The total width of these immense constructions is
+about three hundred and twenty feet. Such is their magnitude that about
+six hundred houses had to be pulled down to make place for them. A
+railing running along their entire length cuts them off from the town.
+
+[Transcribers note 1: changed from 'words']
+
+During the course of last year 4,379 vessels entered the port of
+Antwerp, gauging a total of 3,734,428 tons, which places Antwerp, as I
+have already stated, at the head of European ports. In 1882 the tonnage
+of Havre was only 2,200,000, that of Genoa 2,250,000, and of Bilboa
+315,000, owing to its iron ore exports. Among the English ports a few
+only exceed Antwerp. London is still the first port in the world, with
+a tonnage of 10,421,000 tons, and Liverpool the second, with 7,351,000
+tons; Newcastle follows with 6,000,000 tons, also in excess of Antwerp,
+but both Hull and Glasgow are below, with respectively 1,875,000 and
+2,110,000 tons.--_Pall Mall Gazette_.
+
+       *       *       *       *       *
+
+
+
+
+BICYCLES AND TRICYCLES.
+
+[Footnote: A recent lecture before the Society of Arts, London.]
+
+By C.V. BOYS.
+
+
+The subject of this paper is one of such wide interest, and of such
+great importance, that it is quite unnecessary for me to make any
+apology for bringing it to your notice. Exactly two months ago, I had
+the honor of dealing with the same subject at the Royal Institution. On
+that occasion I considered main principles only, and avoided anything in
+which none but riders were likely to take an interest, or which was in
+any way a matter of dispute. As it may be assumed that the audience here
+consists largely of riders, and of those who are following those matters
+of detail, the elaboration, simplification, and perfection of which
+have brought the art of constructing cycles to its present state of
+perfection, I purpose treating the subject from a totally different
+point of view. I do not intend, in general, to describe anything,
+assuming that the audience is familiar with the construction of the
+leading types of machines, but rather to consider the pros and cons
+of the various methods by which manufacturers have striven to attain
+perfection. As a discussion on the subject of this paper will doubtless
+follow--and I hope makers or riders of every class of machine will
+freely express their opinion, for by so doing they will lend an interest
+which I alone could not hope to awaken--I shall not consider it
+necessary to assume an absolutely neutral position, which might be
+expected of me if there were no discussion, but shall explain my own
+views without reserve.
+
+The great variety of cycles may be grouped under the following heads:
+
+  1. The Bicycle unmodified.
+  2. The Safety bicycle, a modification of 1.
+  3. The Center-cycle.
+  4. The Tricycle, which includes five general types:
+  (a.) Rear steerer of any sort.
+  (b.) Coventry rotary.
+  (c.) Front steerer of any sort (except e).
+  (d.) Humber pattern.
+  (e.) The Oarsman.
+  5. Double machines: sociables and tandems.
+  6. The Otto.
+
+It is perfectly obvious that not one machine is superior to all others
+in every respect, for if that were the case, the rest would rapidly
+become extinct. Not one shows any signs of becoming extinct, and,
+therefore, it may be assumed that each one possesses some points in
+which it is superior to others, the value of which is considered by
+its riders to far outweigh any points in which it may be inferior. The
+widely varying conditions under which, and purposes for which, machines
+are used and the very different degrees of importance which differently
+constituted minds attach to the peculiarities of various machines, will,
+probably, prevent any from becoming extinct. Nevertheless, the very
+great advantages which some of these possess over others will, no doubt,
+in time become evident by the preponderance of the better class of
+machines.
+
+The bicycle, which surpasses all other machines in simplicity,
+lightness, and speed, will probably, for these reasons, always remain a
+favorite with a large class. The fact that it requires only one track
+places it at a great advantage with respect to other machines, for it is
+common for a road which is unpleasant from mud or stones to have a hard,
+smooth edge, a kind of path, where the bicyclist can travel in peace,
+but which is of little advantage to other machines. Again, the bicycle
+can be wheeled through narrow gates or door ways, and so kept in places
+which are inaccessible to tricycles. One peculiarity of the bicycle,
+and to a certain extent of the center-cycle, is that the plane of the
+machine always lies in the direction of the resultant force, that the
+machine leans over to an amount depending on the velocity and the
+sharpness of the curve described. For this reason all lateral strain on
+the parts is abolished, and if we except the slipping away of the wheel
+from under the rider, which can hardly occur on a country road, an upset
+from taking a curve too quickly is impossible. This leaning to either
+side by the machine and rider gives rise to that delightful gliding
+which none but the bicyclist or the skater can experience. In this
+respect the bicycle has an enormous advantage over any machine, tricycle
+or Otto, which must at all times remain upright, and which must,
+therefore, at a high speed, be taken round a curve with discretion.
+
+The perfect and instantaneous steering of the bicycle, combined with
+its narrowness, counteract, to a great extent, the advantage which the
+tricyclist has of being able to stop so much more quickly, for
+the bicyclist can "dodge" past a thing for which the rider of the
+three-wheeler must pull up. In one other respect the bicyclist has an
+advantage which, though of no real importance, has great weight with
+many people. The bicycle well ridden presents a picture of such perfect
+elegance that no one on anything else need expect to appear to advantage
+in comparison.
+
+The chief disadvantage of the bicycle is the fact that a rider cannot
+stop for any purpose, or go back a little, without dismounting. For town
+riding, where a stoppage is frequently necessitated by the traffic, this
+perpetual mounting and dismounting is not only tiresome, but wearying,
+so much so that few bicyclists care to ride daily in town.
+
+The position of the rider on a bicycle, with respect to the treadles,
+is by no means good, for if he is placed sufficiently far forward to be
+able to employ his weight to advantage without bending himself double,
+he will be in so critical a position that a mere touch will send him
+over the handles. He has, therefore, to balance stability and safety
+against comfort and power; the more forward he is, the more furiously he
+can drive his machine, and the less does he suffer from friction and the
+shaking of the little wheel; the more backward he is, the less is he
+likely to come to grief riding down hill, or over unseen stones. The
+bicyclist is no better off than the rider of any other machine with a
+little wheel, the vibration from which may weary him nearly as much as
+the work he does. The little wheel as a mud-throwing machine engine is
+still more effective on the bicycle than it is on any tricycle, for in
+general it is run at a higher speed.
+
+I now come to the usual complaint about the bicycle. There is a fashion
+just now to call it dangerous and the tricycle safe. But the difference
+in safety has been much exaggerated. The bicyclist is more likely to
+suffer from striking a stone than his friend on three wheels, but then
+he should not strike one where the tricyclist would strike a dozen.
+Properly ridden, neither class of machine can be considered dangerous;
+an accident should never happen except it be due to the action of
+others. People, carts, cattle, and dogs on the road are liable to such
+unexpected movements, that the real danger of the cyclist comes from the
+outside; to danger from absolute collapse, due to a hidden flaw in
+the materials employed, every one is liable, but, the bicyclist more
+remotely than the tricyclist, owing to the greater simplicity of his
+machine. The bicyclist, though he has further to fall in case of an
+accident from any of these causes, is in a better position than the
+tricyclist, for he is outside instead of inside his machine; he can in
+an instant get clear.
+
+It would appear that many tricyclists consider accidents of the kind
+next to impossible, for in several machines the rider is so involved
+that an instantaneous dismount without a moment's notice, at any speed,
+is absolutely impossible. There remains one objection, which, however,
+should be of next to no importance--the difficulty of learning the
+bicycle prevents many from taking to the light and fast machine, because
+they are afraid of a little preliminary trouble.
+
+The chief objections to the bicycle, then, are the liability of the
+rider to go over the handles, the impossibility of stopping very
+quickly, and the inability to remain at rest or go backward, and the
+difficulty of learning.
+
+The first two of these are, to a large extent, overcome in the safety
+bicycles, but not without the introduction of what is in comparison a
+certain degree of complication, or without the loss of the whole of the
+grace or elegance of the bicycle. On almost all of these safety bicycles
+the rider is better placed than on the unmodified bicycle, but though
+safer, I do not think bicyclists find them complete in speed, though, no
+doubt, they are superior in that respect to the tricycle. Though they do
+not allow the rider to stop without dismounting, the fatigue resulting
+from this cause is less than it is with a bicycle, owing to the fact
+that with the small machines the rider has so small a distance to climb.
+Of these machines, the Extraordinary leaves the rider high up in the air
+on a full-sized wheel, but places him further back and more over the
+pedals. The motion of these is peculiar, being not circular, but oval, a
+form which has certain advantages.
+
+In the Sun and Planet and Kangaroo bicycles a small wheel is "geared
+up," that is, is made to turn faster than the pedals, so as to avoid the
+very rapid pedaling which is necessary to obtain an ordinary amount
+of speed out of a small wheel. In each of these the pedals move in a
+circular path, and their appearance is in consequence less peculiar than
+that of the Facile, which, in this respect, does not compare favorably
+with any good machine. The pedal motion on the Facile is merely
+reciprocating. Riders of machines where circular motion is employed,
+among them myself, do not believe that this reciprocating motion can
+be so good as circular, but I understand that this view is not held by
+those who are used to it. Of course, the harmonic motion of the Facile
+pedal is superior to the equable reciprocating motion employed in some
+machines where speed is an object, especially with small wheels.
+
+If I have overlooked anything typical in the modified bicycle class,
+I hope some one will afterward supply the omission, and point out any
+peculiarities or advantages.
+
+That very peculiar machine, the center-cycle, seems to combine many of
+the advantages of the bicycle and tricycle. On it the rider can remain
+at rest, or can move backward; he can travel at any speed round curves
+without an upset being possible; he can ride over brickbats, or
+obstructions, not only without being upset, but, if going slowly,
+without even touching them. As this machine is very little known, a few
+words of explanation may be interesting.
+
+In the first place, the rider is placed over the main wheel, as in the
+bicycle, but much further forward. There are around him, on or near the
+ground, four little wheels, two before and two behind, supported in a
+manner the ingenuity of which calls for the utmost admiration. Turning
+the steering handle not only causes the front and rear pairs to turn
+opposite ways, but owing to their swiveling about an inward pointing
+axis, the machine is compelled to lean over toward the inside of the
+curve; not only is this the case, but each pair rises and falls with
+every inequality of the road, if the rider chooses that they run on the
+ground; but he can, if he pleases, arrange that in general they ride in
+the air, any one touching at such times as are necessary to keep him on
+the top of the one wheel, on which alone he is practically riding. He
+can, if he likes, at any time lift the main wheel off the ground and run
+along on the others only. The very few machines of the kind which I have
+seen have been provided with foot straps, to enable the rider to pull as
+well as push, which is a great advantage when climbing a hill, but this
+is on every machine except the Otto, of which I shall speak later,
+considered a dangerous practice.
+
+Some of the objections to the bicycle to which I have referred were
+sufficient to prevent many, especially elderly men, from dreaming of
+becoming cyclists. So long as the tricycle was a crude and clumsy
+machine, there was no chance of cycling becoming a part, as it almost is
+and certainly soon will be, of our national life. The tricycle has been
+brought to such a state of perfection that it is difficult to imagine
+where further progress can be made.
+
+Perhaps it will be well to mention what is necessary in order that a
+three-wheeled machine may be made to roll freely in a straight line, and
+also round curves. At all times each wheel must be able to travel in
+its own plane in spite of the united action of the other two. To run
+straight, the axes of all the wheels must obviously be parallel. To run
+round a curve, the axis of each must, if continued, pass through the
+center of curvature of the curve. If two wheels have a common axis, the
+intersection of the two lines forming the axes can only meet in one
+point. To steer such a combination, therefore, the plane of the third
+wheel only need be turned. If the axis of no two are common, then the
+planes of two of the wheels must be turned in order that the three axes
+may meet in a point.
+
+Not only does free rolling depend on the suitable direction of the
+planes of the wheels, each wheel must be able to run at a speed
+proportional to its distance from the point of intersection of the three
+axes, i.e., from the ever-shifting center of curvature.
+
+The most obvious way, then, of contriving a three wheeler is to drive
+one wheel, steer with another, and leave the third, which must be
+opposite the driver, idle. The next in simplicity is to drive with one
+wheel, and steer with the other two, having one in front and the other
+behind. So far then, the single driving rear-steerer and the Coventry
+rotary pattern are easily understood. The evils of single driving,
+minimized, it is true, to a large extent, in the Coventry rotary, have
+led to the contrivance of means by which a wheel on each side may be
+driven without interfering with their differential motion in turning a
+corner.
+
+Three methods are commonly used, but as only two are employed on
+tricycles, I shall leave the third till I come to the special machine
+for which it is necessary. The most easy to understand is the clutch,
+a model of which I have on the table. If each main wheel is driven by
+means of one of these, though compelled to go forward by the crankshaft,
+it is yet free to go faster without restraint. By this means "double
+driving" is effected in several forms of tricycle.
+
+Differential gear, which is well understood, and of which there are
+several mechanically equivalent forms, divides the applied driving
+power, whether forward or backward, between the main wheels, equally if
+the gear is perfect, unequally if imperfect. To understand the effect
+of the two systems of driving, and of single driving, let us place on
+grooves a block which offers resistance to a moving force. If we wish
+to move it, and apply our force at the end of one side, it will tend to
+turn round as well as move forward, and much friction will be spent on
+the guides by their keeping it straight.
+
+This is the single driver. If, instead of applying force at one side, we
+push the block bodily forward by a beam moving parallel to itself, then
+so long as the guides are straight no strain will be put upon them,
+even though one side of the block is resisted more than the other; if,
+however, the guides compelled the block to travel round a curve, then
+the power, instead of being divided between the two sides in such
+proportion as is necessary to relieve the guides of all strain, is
+suddenly applied only to the inside, and the effect is that of a single
+driver only. This is the clutch. Lastly, if the last-mentioned beam,
+instead of being pushed along parallel to itself, were pivoted in the
+middle, and that pivot only pushed, the same power would be applied to
+each side of the block, and no strain would be thrown on the guides,
+whether straight or curved, so long as the resistance opposed to the
+block on the two sides were equal; if, however, one side met with more
+resistance than the other, then the guides would have to keep the block
+straight. This is the differential gear.
+
+I have assumed that in the last case the force was applied to the middle
+of the beam; this corresponds to every evenly-balanced gear. In the gear
+employed by Singer, which is not evenly balanced, but which derives its
+good qualities from its simplicity, the same effect is produced as
+if the beam were pivoted on one side of the center instead of on the
+center. Thus, though both sides are driven, one is driven more than the
+other. On the whole, there is no doubt that the balanced gear gives a
+superior action to the clutch, for except when the two sides of the
+machine meet with very different resistance, and then only when running
+straight, the clutch will not compare with the other. The clutch also
+gives rise to what is considered by most riders a grave defect, the
+inability to back treadle, while the free pedal, which is an immediate
+consequence, is considered by others a luxury.
+
+On the other hand, this same free pedal can be obtained on
+differentially driven machines to which speed and power gear have been
+applied.
+
+Of the relative merits of different forms of differential gear there is
+little to be said. Perhaps it will not be thought I am unduly thrusting
+myself forward, if I refer to a scheme of my own, in which no toothed
+wheels are employed, but in which two conical surfaces are driven by a
+series of balls lying in the groove between them, and jambed against
+them by a recessed ring.
+
+I have here a large wooden diagrammatic model, and a small working
+model in steel, which shows that the new principle employed is correct,
+namely, that a ball while jambed is free to turn, or if turning is able
+to jamb. All Humbers, and most front steerers, employ differential
+gearing; in some front steerers the clutch of necessity is used.
+
+Neglecting for the present the different modes of transmitting power
+from the pedals to the main wheels, it is possible now to consider the
+four typical builds of tricycle. The only advantage that a rider can
+find in a rear-steerer is the open front, so that in case of accident
+he can more easily clear himself of his machine; as I have already
+remarked, this power of instantly escaping seems to be considered by
+many as of no importance.
+
+In a rear-steerer which has not an open front, whether driven by a
+clutch or by differential gear, I fail to discover any good quality.
+The steering of a rear-steerer is so very uncertain, that such machines
+cannot safely be driven at anything like a high speed, because any wheel
+meeting with an obstruction will, by checking the machine, diminish the
+weight on the steering wheel just at the time when a greater weight than
+usual should be applied. It is for the corresponding reason that the
+steering of a front-steerer is so excellent; the more the machine is
+checked by obstruction, by back treading, or by the brake, the greater
+is the weight on the front wheel.
+
+For shooting hills, or for pulling up suddenly, no machine of any kind
+will compare with a good front-steerer. In all respects it is superior
+to the rear-steerer if we except the open front, but against this may
+be set the fact that on many the rider can mount from behind, or can
+dismount in the same manner while the machine is in motion. Experience
+shows that the front-steerer is for general excellence, safety, easy
+management, and light-running, the best all-round tricycle that is to be
+had.
+
+The Humber build, which departs less from the ordinary bicycle than any
+othar, is far superior to all others for speed; it is, however, somewhat
+difficult to manage, for the steering is not only delicate, but
+critical, requiring constant care lest a stone or other obstruction
+should take the rider unawares, and steer the machine for him.
+
+The control which a skillful rider of the Humber has over his machine is
+wonderful; the elegance of the machine among tricycles is unequaled.
+So great a favorite is this form, especially among the better class of
+riders, that almost every firm have brought out their own Humber, each
+with a distinguishing name.
+
+The only improvement or change, whichever it may be, that has been made
+by others with which I am acquainted, is the triple steering, in which
+the hind wheel moves the opposite way to the others. The corresponding
+change in the bicycle was soon discarded; I do not know what advantage
+can result from the increased delicacy of steering here. I should have
+thought it delicate enough already.
+
+One noticeable change in the front-steering tricycle, which has been
+largely made, lately, is the substitution of central for side gearing,
+in consequence of which bicycle cranks can be employed, instead of
+the cranked axle, with its fixed throw. This gives an appearance of
+lightness which the older types of machine do not possess.
+
+I now come to that very difficult and all-important subject, the method
+of transmitting power from the body of the rider to the main axle. Next
+to the structural arrangement, this is most important in distinguishing
+one type of machine from another.
+
+The first to which I shall refer is the direct action employed on the
+National and the Monarch tricycles. It is obvious that by having no
+separate crank shaft, much greater simplicity and cheapness and less
+friction are attained than can be possible when the extra bearings and
+gear generally used are employed. In this respect the direct action
+machines undoubtedly have an advantage, but an advantage of any kind may
+be too dearly bought, as it certainly is here.
+
+In the first place, the direct action can only be applied to a
+rear-steering, clutch-driven machine, or single driver, for if the
+wheels were not free to run ahead, it would be impossible to go round a
+curve. In the second place, the rider must be placed at such a height
+for his feet to work on the axle that the machine, of necessity, is very
+unstable, and is likely to upset if ridden without great caution round
+a curve. Thirdly, to diminish as far as possible this last objection,
+miserable little wheels must be employed, which cannot be geared up,
+that is, made to travel faster than the treadles, and so be equivalent
+to larger wheels. Therefore, though it is likely that at such low speeds
+only as it is safe to run such a machine it may move more easily than a
+machine of a recognized type, and though direct action would undoubtedly
+be advantageous if it did not entail defects of a most serious order of
+magnitude, we may dismiss this at once from our consideration. It is
+true that in the Monarch a few inches of height are gained by the
+hanging pedals, but I question very much whether one machine is much
+better than the other.
+
+The chain which is used on almost every make of machine cannot be
+considered perfect; it is, on the whole, a dirty and noisy contrivance,
+giving rise to friction where the links take and leave the teeth of
+the pulleys; stretching, or rather lengthening, by wear, and, finally,
+allowing back lash, which is most unpleasant. In spite of all this, it
+affords a convenient and reliable means of transmitting power, which is
+applicable to every type of tricycle, except one.
+
+Instead of a chain, an intermediate or idle wheel has been tried, but
+this has not been found advantageous. The intermediate wheel has been
+removed, and the crank and wheel pulley allowed to gear directly
+together, making reverse motion of the feet necessary, and possibly
+reducing friction.
+
+The crank and connecting rod are employed in some machines. If there are
+two only, they must not be placed in opposite positions, but be fixed at
+an angle, so that there are times when each rod is under compression,
+a strain which delicate rods cannot stand. In the three-throw crank,
+employed in the Matchless tricycle, this objection is obviated, for one,
+at least, is at all times in such a position as to be in tension. The
+objection to the crank is the fact that it weakens the shaft, and that
+it can only be used with a clutch, not with a differential gear.
+
+The most silent, neatest, and cleanest driver, the one of which the
+working friction is least, is the endless steel band, so well known in
+connection with the Otto bicycle. This is not, as far as I am aware,
+employed on any tricycle, makers probably fearing lest it should slip.
+The Otto shows that it can safely be employed.
+
+I have devised a scheme, of which I now show a model, which seems to me
+to be free from the objections which may be urged against other methods;
+but I, of course, cannot be considered in this respect a judge.
+Eccentrics are well known as equivalent to cranks, but if used in the
+same way, with a connecting rod, either fatal friction or enormous
+ball-bearings would be necessary. Instead of these, I connect two pair
+of equal eccentrics by an endless band embracing each, so that the band
+acts like a connecting rod without friction, and, at the same time,
+acts by its turning power as on the Otto, thus making two eccentrics
+sufficient instead of three, and carrying them over the dead points.
+
+There is one more system of transmitting power employed on a few
+machines. In these, a band or line passes over the circumference of a
+sector or wheel, and the power is directly applied to it. The motion of
+the feet in the omnicycle, and of the hands and body in the Oarsman, is
+therefore uniform. There would be no harm in this if it were not for the
+starting and the stopping, which cannot be gradual and at the same time
+effective in machines of this type. For this reason, a high speed cannot
+be obtained; nevertheless, these machines are better able to climb hills
+than are tricycles with the usual rotary motion, for, at all parts of
+the stroke--which may be of any length that the rider chooses--his
+driving power on the wheels is equal. The ingenious expanding drums on
+the omnicycle make this machine exceptionally good in this respect, for
+increased leverage is effected without increased friction, which is the
+result of "putting on the power" in some of the two-speed contrivances.
+
+Having spoken of the Oarsman tricycle, I must express regret that I have
+not been able to find an opportunity to ride on or with the machine, so
+that I cannot from observation form an opinion of its going qualities.
+There can be no doubt that the enormous amount of work that can be got
+from the body in each stroke on a sliding seat in a boat must, applied
+in the same manner on the Oarsman tricycle, make it shoot away in a
+surprising manner; whether such motion, when continued for hours, is
+more tiring than the ordinary leg motion only, I cannot say for certain,
+but I should imagine that it would be. The method by which the steering
+is effected by the feet, and can with one foot be locked to a rigidly
+straight course, is especially to be admired.
+
+There is much difference of opinion with respect to the most suitable
+size for the wheels of machines. Except with certain machines, this has
+nothing to do with the speed at which the machine will travel at a given
+rate of pedaling, for the wheels may be geared up or down to any extent,
+that is made to turn more quickly or slowly than the cranks. Thus the
+most suitable speeding is a separate question, and must be treated by
+itself.
+
+Large wheels are far superior to small wheels in allowing comfortable,
+easy motion, a matter of considerable importance in a long journey. They
+are also far better than small for running over loose or muddy ground,
+for with a given weight upon them they sink in less, from the longer
+bearing they present, and this, combined with their less curvature,
+makes the everlasting ascent which the mud presents to them far less
+than with a smaller wheel. On the other hand, the large wheel is
+heavier, and suffers more from air resistance than the small wheel. For
+racing purposes a little wheel, geared up of course, is certainly better
+than a high wheel; for comfortable traveling, and in general, the high
+wheel is preferable. Though this is certainly the case, it does not
+follow that large wheels are worth having on a machine when there is
+already one little wheel. If the rider is to be worried with the evils
+of a little wheel at all, it is possible that any advantage which large
+wheels would give him would be swamped by the vibration and mud-sticking
+properties of the small steering wheel. One firm, in their endeavors
+to minimize these evils, have designed machines without any very small
+wheels; all three wheels are large, and a steadier and more comfortable
+motion no doubt results.
+
+High and low gearing are the natural sequel to high and low wheels. Of
+course the lower the gearing the greater is the mechanical advantage in
+favor of the rider when meeting with much resistance, whether from wind,
+mud, or steepness of slope. In spite of this, for some reason which I
+cannot divine, the machines with excessively low gear do not seem to
+obtain so great an advantage in climbing hills as might be expected. To
+make such a machine travel at a moderate speed only, excessively rapid
+pedaling is necessary, and the rider is made tired more by the motion of
+his legs than by any work he is doing. The slow, steady stroke by which
+a rider propels a high-geared machine is far more graceful and less
+wearying than the furious motion which is necessary on a low-geared
+machine. The height up to which the driving-wheels are usually geared
+may be taken as an indication of the ease with which any class of
+machines runs. A rider on a low-geared machine can start his machine
+much more quickly than an equal man on one that has high gearing, and
+therefore in a race he has an advantage at first, which he speedily
+loses as his rapid pedaling begins to tell. For ordinary riding the
+slight loss of time at starting is a matter of no importance whatever.
+
+There are several devices which enable us to obtain the advantages of
+high and low gearing on the same machine, which at the same time give
+the rider the benefit of a free pedal whenever he wishes. On some single
+driving rear-steering tricycles the connection on one side is for speed,
+and that on the other for power, either being in action at the wish of
+the rider, or both speed and power combinations are applied on the same
+side. To drive with a power gear a single wheel only seems to me to be
+the height of folly; in my opinion no arrangement of this type is worthy
+of serious attention. Among the better class of machines there are three
+methods by which this change is effected--first, that employed on the
+omnicycle, to which I have already referred; secondly, an epicyclic
+combination of wheelwork which moves as one piece when set for speed,
+thus adding nothing to the working friction except by its weight, but
+which works internally when set for power, thus reducing to a small
+extent, by the additional friction, the gain of power which the rider
+desires; thirdly, a double set of chains and pulleys, each set always in
+movement, so that, whether set for speed or power, there is rather more
+friction than there would be if there were no additional chains, but
+these are free from that increased friction due to toothed wheel
+gearing, from which the epicyclic contrivances suffer only when set
+for power. There is much difference of opinion whether any of these
+arrangements are worth carrying, for perhaps nine miles, for the sake of
+any advantage that may be obtained in the tenth. It is on this account
+that the drums on the omnicycle are so excellent; whether expanded or
+not, there is, on their account, no loss of work whatever, for there is
+no additional friction. The subject of these two speed gears will, I
+hope, be discussed; it is one which, though not new, is coming more to
+the front, and about which much may be said.
+
+Having now dealt with the means by which tricycles are made to climb
+hills more easily, I wish to leave the subject of bicycles and tricycles
+altogether for a few minutes, to say a few words which may specially
+interest those who are fond of trying their power in riding up our best
+known hills. The difficulty of getting up depends to a large extent on
+the surface and on the wind, but chiefly on the steepness. The vague
+manner in which one hill is compared with another, and the wild ideas
+that many hold who have not made any measurements, induces me to
+describe a method which I have found specially applicable for the
+measurement of steepness of any hill on which a cyclist may find
+himself, and also a scheme for the complete representation of the
+steepness and elevation of every part of a hill on a map so as to be
+taken in at a glance. The force required to move the thing up a slope is
+directly proportional not to the angle, but to the trigonometrical sine
+of that angle. To measure this, place the tricycle, or Otto--a
+bicycle will not stand square to the road, and therefore cannot be
+used--pointing in direction at right angles to the slope of the hill, so
+that it will not tend to move. Clip on the top of the wheel a level, and
+mark that part of the road which is in the line of sight. Take a string
+made up of pieces alternately black and white, each exactly as long as
+the wheel is high, and stretch it between the mark and the top of the
+wheel. If there are n pieces of string included, the slope is 1 in n,
+for by similar triangles the diameter of the wheel is to the length of
+the string as the vertical rise is to the distance on the road. This
+gives the average steepness of a piece sufficiently long to be worth
+testing, because an incline only a few feet in length, of almost any
+steepness, can be mounted by the aid of momentum.
+
+There is only one process, with which I am acquainted, which supplies a
+method of representing on a map the steepness of a road at every part.
+Contours, of course, show how far one has to go to rise 50 or 100 feet,
+but as to whether the ascent is made uniformly or in an irregular
+manner, with steep and level places, they tell us nothing. Let the
+course of a road be indicated by a single line where it is level, and by
+a pair of lines where inclined. Let the distance between the lines be
+everywhere proportional to the steepness, then the greatest width will
+show the steepest part, and an intermediate width will show places
+of intermediate steepness; the crossing of the lines, which must be
+distinguishable from one another, will show where the direction of the
+slope changes. Further, the size of the figure bounded by the two lines
+will show the total rise; a great height being reached only by great
+steepness or by great length, a large figure being formed only by great
+width or by great length. Those who are mathematically inclined will
+recognize here that I have differentiated the curve representing the
+slope of the bill, and laid the differential curve down in plan.
+
+Having wandered off my subject, I must return to more mechanical things,
+and give the results of some experiments which I have made on the balls
+of ball bearings. There is no necessity to argue the case of ball vs.
+plain bearings, the balls have so clearly won their case, that it would
+be waste of time to show why. Of the wear of the twelve balls forming
+one set belonging to the bearings of the wheels of my Otto, I have on a
+previous occasion spoken; I may, however, repeat that in running 1,000
+miles, the twelve balls lost in weight only 1/20.8 grain, or each ball
+lost only 1/250 grain. The wear of the surface amounted to only 1/158000
+inch; at the same rate of wear, the loss in traveling from here to the
+moon would amount to only 1/34.3 of their weight. I examined each ball
+every 200 miles, and was surprised to find that on the whole the wear of
+each, during each journey, varied very little. The balls experimented on
+were a new set obtained from Mr. Bown. I also had from him one ball of
+each of each of the following sizes 3, 4, 5, 6, and 7 16ths of an inch
+in diameter, as I was curious to know what weight they would suppport
+without crushing. As as preliminary experiment, I placed a spare 5/16
+ball between the crushing faces of the new testing machine at South
+Kensington, and applied a gradually increasing force up to 7 tons 91/2
+cwt., at which it showed no signs of distress. On removing it I found
+that it had buried itself over an angle of about 60 deg. in the hard steel
+faces, faces so hard that a file would not touch them. Those marks will
+be a permanent record of the stuff of which the ball was made. The ball
+itself is sealed in a tube, so that any one who is curious to see it can
+do so. Finding that the crushing faces were not sufficiently hard, I
+made two anvils of the best tool steel, and very carefully hardened
+them. These, though they were impressed slightly, were sufficiently good
+for the purpose. In the following table are the results of the crushing
+experiments:
+
+3/16 ball at 2 tons 13 cwt. did not break, but crushed on removing part
+of the weight.
+
+1/4 ball at 3 tons 15 cwt. did not break, but crushed on removing part of
+the weight.
+
+5/16 ball at 4 tons 9 cwt. broke.
+
+3/8 ball at 8 tons 6 cwt. did not break, crushed under another 120 lb.
+
+7/16 ball crushed before 3 tons, with which I was starting, had been
+applied. Examination showed that the steel bar of which it was made had
+been laminated.
+
+These experiments do not tell much of importance; they are curious,
+and perhaps of sufficient interest to bring before your notice. The
+fragments are all preserved in tubes, and labeled, so that any one who
+likes to see them can do so.
+
+Of the advantage which a machine which will collapse or fold up when
+desired, but retain its form on the road, offers in convenience, it is
+unnecessary for me to speak.
+
+Of double machines, the Rucker tandem bicycle seems to me to be in every
+respect the best, but I should add that I speak only from imagination
+and not from experience. The independent steering, the impossibility of
+capsizing forward or sideways, the position of the rider over his work,
+the absence of any little wheel with its mud throwing and vibrating
+tendencies, combine to make a machine which ought to be superior in
+almost every desirable quality to any other; what it may be in practice
+I hope to hear in the discussion.
+
+Of double tricycles, the Sociable has been tried by many, and is
+practically a failure in so far as traveling quickly and easily
+is concerned. The Tandem, though it presents so objectionable an
+appearance, seems likely to become a favorite, for it surpasses any
+single tricycle, and rivals the bicycle in speed. How it may compare in
+comfort or in safety with the single machine, perhaps those few who are
+well acquainted with them will say; at any rate, in the case of the
+Humber, greater stability is given to the steering, owing to the weight
+of the front rider.
+
+Time will not allow me to say more of these machines, or to attack the
+subject of steam, electric, or magic tricycles, which I had hoped to do.
+With steam and electricity we are well acquainted; by magic tricycles, I
+mean those driven by a motor which, without any expense, will drive one
+twenty miles an hour, up or down hill, with perfect safety. Highway
+regulations, and certain reasons not well understood, have at present
+prevented these contrivances from making a revolution.
+
+There remains one machine which must be considered separately, for it
+cannot be classed with any other. This is the Otto bicycle. My opinion
+of this machine is so pronounced that I do not care to state it fully. I
+shall merely give the reasons why I prefer it to anything else, and in
+so doing I shall be taking the first step in the discussion, in which it
+will be interesting to hear from riders of other machines the reasons
+for their preference.
+
+In the first place, the evils of a third or little wheel, the cause of
+trouble in all tricycles, are avoided. There is none of the vibration
+which makes all other machines almost unbearable to Ottoists, vibration
+which tricyclists have learnt to consider a necessary accompaniment of
+cycling, but which has, no doubt, been diminished by the use of the
+spring support of the front steering Humber. It would be presumptuous
+in me to make any remarks on the effect of this vibration on the human
+system; we shall all be anxious to hear what our Chairman has to say on
+this point. By having only two wheels, we have only two tracks, so that
+we can travel at a fair speed along those places in the country called
+roads, which consist of alternate lines of ruts and stones, where a
+three-track machine could not be driven, and where, from the quantity
+of loose limestone in the ruts, a little wheel of a two-track tricycle
+would be likely to suffer. By having no little wheel, we can ride in
+dirty weather without having the rest of our machine pelted with mud, so
+that cleaning takes less time than it does with anything else. As I have
+already remarked, the small wheel is the culprit which makes the bicycle
+and tricycle drive so heavily on a soft road. The ease with which the
+Otto can therefore be run through the mud astonishes every one. Having
+no little wheel, we can obtain the full advantage of the high 56
+inch wheel, which almost every one prefers. As I have ridden all
+combinations, from a 50 inch geared up to 60 inch, to a 60 inch geared
+level, I can speak from experience of the increased comfort to be
+derived from these large wheels, though for speed only they do not
+compare with the smaller and lighter wheels geared up. A further point
+gained by the use of two wheels only is the fact that the whole weight
+of machine and rider is on the driving-wheel, as it is also on the
+steering-wheel, so that by no possibility can the wheels be made to slip
+in the driving, or to fail in steering from want of pressure upon them.
+
+The most important consequence, however, is the absence of any fixed
+frame. In all machines, bicycles and tricycles, with the usual fixed
+frame, a position is found for the saddle which is, on the whole, most
+suitable. For some particular gradient it will be perfect; on a steeper
+gradient the treadles will be further in advance, but with a steeper
+gradient the rider should be more over the front of the treadles. To get
+his weight further to the front, he has to double up in the middle, and
+assume a position in which he cannot possibly work to advantage. The
+swinging frame of the Otto carries the treadles, of necessity, further
+back, so that the Ottoist, when working at his hardest, is still
+upright, with his hands in the line between his shoulders, and his feet
+and his arms straight, so that he can hold himself down, and employ his
+strength in a perfectly natural position. On going down a slope, the
+fixed frame of a bicycle or tricycle leans forward, and places the rider
+in such a position that extra weight is thrown on his arms and his
+shoulders, whereas the swing frame of the Otto goes back, and the rider
+of necessity assumes that position in which his arms are relieved of all
+strain. In so far as the general position taken by the automatic Otto
+frame is concerned, nearly the same effect can be obtained by using the
+swing frame of the Devon tricycle, which can be shifted and locked in
+any position which the rider wishes, or by the sliding saddle, which can
+be slid backward or forward and locked so as to place the rider in one
+of three positions. Though the rider can by these devices assume nearly
+that position with respect to the treadles which is most advantageous,
+he cannot obtain that curious fore and aft oscillation made use of by
+the Ottoist in climbing hills, which, as the model on the table shows,
+enables him to get past the dead points without even moving, and which,
+therefore, makes the Otto by far the best hill-climbing machine there
+is, if account is taken of the high speeding with which all Ottoists
+ride. This is a proposition which none who knows the machine will
+question for one moment.
+
+The freedom of motion resulting from the swing of the frame of the Otto
+gives a pleasurable sensation, which those who have only experienced the
+constrained motion of a three-wheeler cannot even understand.
+
+The very peculiar method of driving and steering, which seems so
+puzzling to the novice, especially if he is a good rider of other
+machines--for in that case he is far worse off than one who has never
+ridden anything--give the rider, when he is familiar with them, a
+control over the machine which is still surprising to me. In the first
+place, the machine will run along straight, backward or forward, so
+long as the handles are let alone. This automatic straight running is a
+luxury, for until a deviation has to be made, the steering handles need
+not be touched, and the rider may, if sufficiently confident, travel
+with his arms folded or his hands in his pockets. The rigid connection
+between the cranks and the wheels does away with all the backlash,
+which is so unpleasant with chain or toothed wheel gearing. There is no
+differential gear or clutch, but the machine possesses the advantage
+of the clutch over the differential gear when meeting with unequal
+resistance on a straight course, for each wheel must travel at the same
+speed; but, in turning a corner, instead of driving the inner wheel
+only, which is done by the clutch or both wheels equally, which is the
+case with differential gear, each wheel is driven, but the outer one
+more than the inner. At high speeds, the steering of the Otto has this
+advantage, that whereas, with a given action on a tricyle, the same
+deviation will be effected in the same _space_ at high as at low speeds,
+the same action on the Otto will, at high speeds, produce the same
+deviation in the same _time_ as it does at low speeds; and so instead of
+becoming more sensitive at high speeds, as is the case with the tricyle,
+the steering of the Otto remains the same. This is because the steering
+of the tricycle depends on a kinematical, that of the Otto on a
+dynamical principle.
+
+In another respect, no machine can approach the Otto; at almost any
+speed the rider can, if there is reason, instantly dismount, by which
+action he puts on the brakes, and the machine will save him from
+falling, stopping with him almost instantly. As is well known, we can
+move backward and forward, we can twist around and around in our own
+width, or can ride over bricks with impunity.
+
+One objection to the machine is the difficulty of learning, which is
+considerable, but which presents no danger. This difficulty has been
+much exaggerated, for before the present powerful brake was applied it
+did require considerable skill to ride it down a steep hill. The way
+to do this must still be learnt, but it is now comparatively easy. For
+going down steep hills, the front steering tricycle is without a rival;
+I do not know what other machine will do this better than the Otto.
+Lastly, the foot straps, which would be a great advantage on any
+machine, if only they were safe, are not--though none but riders will
+believe it--in any way a source of danger on the Otto. Having ridden
+this machine for close upon 10,000 miles, I can speak with more
+authority on this point than can those who are not able to sit upon it
+for a moment.
+
+The only disadvantage which the machine presents is the fact that it is
+impossible to remove the feet from the pedals while running, without
+dismounting; but though they must at all times follow the pedals, the
+Ottoist is not, as is generally thought, working when descending a hill.
+
+The enthusiastic terms in which every one who has mastered the
+peculiarities of the Otto speaks of it would be considered as evidence
+in its favor, if we were not all considered by other cyclists to be in
+various stages of lunacy.
+
+       *       *       *       *       *
+
+
+
+
+THE CANAL IRON WORKS, LONDON.
+
+
+Some interest is awakened in engineering circles in London, just now, by
+the approaching close of the old engineering works so well known as the
+"Canal Ironworks," at the entrance to the Isle of Dogs, London, E. This
+notable establishment stands second in priority in London--that of
+Messrs. Maudslay, Sons & Field being the oldest--for the manufacture of
+marine engines. It was founded by the late Messrs. Seawards, above sixty
+years ago. Here was originated Seaward's hoisting "sheers" with the
+traveling back leg, a modern example of which, 100 feet high, in iron,
+stands on the wharf. An interesting tool, also, is the large vertical
+boring machine for largest size cylinders; Seaward spent L5,000 upon
+this, and it is certainly an admirable tool. There is also the large
+vertical slotting machine, with a stroke up to 5 feet 2 inches, a
+wonderfully powerful and compact machine. The extensive collection of
+screwing tackle is, perhaps, unsurpassed, and extends up to 8 inches
+diameter. There is a peculiar erecting shop roof, which will still repay
+examination.
+
+       *       *       *       *       *
+
+
+
+
+MARINONI'S ROTARY PRINTING PRESS.
+
+
+The greatest progress that has been made in recent years in the art
+of printing is in the invention of the high speed press provided with
+continuous paper.
+
+Three French constructors, Messrs. Marinoni, Alauzet, and Derriey, have
+brought this kind of apparatus to such a degree of perfection that
+the majority of foreign journals having a large circulation buy their
+presses in France. We reproduce in Fig. 1 a perspective view of the
+Marinoni press, and in Fig. 2 a diagram showing the parts of the same.
+In order to give a complete description of it, we cannot do better than
+to reproduce the very interesting study that has been made of it by Mr.
+Monet, a civil engineer.
+
+[Illustration: FIG. 1.--MARINONI'S ROTARY PRINTING PRESS.]
+
+The roller, J (Fig. 2), is placed in the machine in the state in which
+it is received from the paper manufactory. The paper unwinds, runs over
+the rollers, e and e', which serve only for tautening it, and then
+passes between the two cylinders, A and B. The cylinder, A, carries the
+form, and B carries the blanket, and the paper thus receives its first
+impression. It afterward passes between the cylinders, A' and B', and
+receives an impression on the other side, the cylinder, A', carrying the
+form, and B' the blanket. Being now printed on both sides, it passes
+between the cylinders, KK', which cut it off and allow the sheet to
+slide between the cords of the rollers. These latter lead the sheets
+over the rollers, g h, on which they wind, one over the other, when the
+rollers, a a', are in the position shown by unbroken lines in the cut.
+
+The part of the machine that holds the rollers, g h, and the different
+cords that wind over them, is the _accumulator_, and it is in this part
+of the press that the sheets accumulate, one over the other, to any
+number desired.
+
+The size of the rollers, g h, and their distance apart are so regulated
+that when the sheet reaches the accumulator, it falls exactly on those
+that have preceded it. When the proper number of sheets is in the
+accumulator (4 or 5 being the number most employed for afterward
+facilitating the separation into packets on the receiving table), the
+two small rollers, a a', advance over the rack, N, and the sheets,
+instead of continuing to roll over into the accumulator, fall on the
+rack and are deposited by it upon the receiving table, O.
+
+[Illustration: FIG. 2.--MARINONI'S PRESS.]
+
+The rack having fallen twenty times, and deposited five sheets each
+time, or one hundred in all, the table moves in such a way as to prevent
+the sheets subsequently deposited from getting mixed with them. When the
+rack has fallen twenty times, the table returns to its initial position.
+
+The distributing rollers, D, come in contact with the inking rollers, I,
+once during each revolution of the printing cylinders, and are mounted
+on racking levers provided with regulating screws that permit of easily
+regulating the amount of ink taken up. The supports of the inking
+rollers are movable and can be made to approach or recede from the
+distributing rollers, so as to still further vary the amount of ink
+taken up by them.
+
+The distributing rollers supply the ink to a roller, E, of large
+diameter, which, having a backward and forward motion, begins to
+distribute the ink and to transmit it to a second roller, F, of the same
+diameter. This latter then spreads it over a metallic cylinder, G, which
+is of the same diameter as the printing cylinders, and against which
+revolve three distributing rollers, H, that have a backward and forward
+motion.
+
+Between the cylindrical inking table, G, and the type cylinder, there
+are situated inking cylinders, T, of large diameter, that constantly
+take up ink from the inking table and distribute it over the types.
+
+The machine here described, when designed for printing large sized
+journals, has cylinders whose circumference corresponds to the size of
+paper for two widths of pages, and whose length is sufficient to allow
+it to receive two forms. Each cylinder, then, carries four forms, or
+eight in all, and prints two complete copies at each revolution.
+
+The large sheet cut off by the cylinders, K K', contains, then, two
+copies; and this sheet, on passing under the roller, f is again cut in
+two by a disk which separates it in a direction perpendicular to the
+cylinders.
+
+To this press there may be added a mechanical folder of Mr. Marinoni's
+invention, capable of folding a journal five times.--_Annales
+Industrielles_.
+
+       *       *       *       *       *
+
+
+
+
+CHENOT'S ECONOMIC FILTER PRESS.
+
+
+Mr. E. Chenot, who is occupied in the manufacture of wine from dry
+grapes, has been led to devise a new style of filter, which by reason of
+its mode of action and its construction, he calls the "Economic Filter
+Press."
+
+The apparatus, which is shown in the accompanying cut, consists of flat
+bags whose mouth may be at the top, as usual, or at the side. Through
+this orifice there is introduced a flat piece of wood or metal, which,
+like the bag, has an aperture through the center. The whole is suspended
+from a distributing pipe that is fixed at one end to the frame and is
+free at the other. This pipe is slotted beneath, and the pieces of wood
+or metal contain, opposite the slot, a number of small apertures that
+put the distributer in communication with the interior of the bags.
+Between these latter there are placed wire cloth frames which hold them
+in position and facilitate the flow of the filtered liquid. The cut
+shows the filter provided with a portion of its bags and frames. When
+all the frames are in place they are locked by causing the movable plate
+to move forward by means of two screws connected with an endless chain
+and actuated by a hand wheel. The pressure of this plate closes up the
+bags hermetically. Then, the feed cock being opened, the liquid flows
+into all the bags, deposits therein what it holds in suspension, and the
+clarified product flows to the inclined bottom of the filter and from
+thence to the exterior.
+
+[Illustration: CHENOT'S ECONOMIC FILTER PRESS.]
+
+The apparatus may be supplied either through an upper reservoir, a juice
+elevator, or a pump. The discharge is proportional to the square root
+of the pressure. When the bags are full of residuum, the feed cock is
+closed, the filter is unscrewed, and the bags and frames are taken out.
+With fresh bags and the same frames, it is possible to at once set the
+apparatus in operation again.
+
+Before the filter is taken apart, the residuum may be exhausted by
+washing it either with water or steam, or by pressure. To effect the
+operation by pressure, the pieces of wood or metal are removed, the
+mouths are closed by making a fold in the top of the bags, and the
+latter are then put back into the apparatus or into an ordinary press
+and submitted to another squeezing.
+
+To render the maneuvering of it easier, the apparatus has been given a
+horizontal position.--_Revue Industrielle_.
+
+       *       *       *       *       *
+
+[American Engineer]
+
+
+
+
+STEEL CHAINS WITHOUT WELDING.
+
+
+We take the following description, together with the illustrations, of
+a method and machine for making steel chain without welding, from our
+valued contemporary, _Le Genie Civil_, of Paris:
+
+When we regard an ordinary oval-linked chain endwise, it presents itself
+in the form of a metal cross, and it was this that gave the cue to M.
+Oury, of the Government Arsenals, to construct chain without welding. By
+a series of matrices and punches, etc., he contrives, with small loss of
+metal, to model a chain out of cross-shaped steel bar.
+
+Steel is the better material for such usage, from its homogeneity, both
+as to composition and strength.
+
+Referring to the plate below, Figs. 1 to 10 explain the successive steps
+from the bar to the finished chain.
+
+Fig. 1 shows in plan and section the steel bar, whose length may be some
+40 feet, and which would make a chain say 50 feet long. The shape of the
+bar presents no difficulties in the way of rolling.
+
+Figs. 2 and 3 give, in side elevations of the two faces and sections,
+the first rough form of the links. These first begin to take the
+exterior shape with the rounding of the angles.
+
+The operations following, represented by Figs. 4 and 5, is the piercing
+of the center of the links, which can later be furnished with a stay for
+such chains as require special strength. The point now is to detach the
+links, which is accomplished by oblique piercings, as shown in Fig. 6.
+In the operation represented by Fig. 7, the oval shape is imparted to
+the link, and the operation finishes as shown in Fig. 8.
+
+Actually, the links are circular and separate. This separation is
+retarded as much as possible, for it is plain that it is easier
+to operate a rigid bar than a chain, above all when the operation
+necessitates its being pushed forward.
+
+By means of a good system of heating, analogous to that employed on the
+large parts entering into ship construction, it is hoped to perform a
+major part of the operations, of which we have given but an idea, at a
+single heat.
+
+[Illustration: MACHINE FOR MAKING CHAIN WITHOUT WELDING.]
+
+These operations require work on both faces alternately--this presents
+no difficulties; but what appears to us most difficult to realize is
+_continuous work_, the bar passing through several machines which
+successively impress upon it the steps of progress toward the finished
+chain. If the machines are end on to each other in a direct line, there
+will necessarily be a fixed place for each tool; the rough cut chain
+must accurately reach the point where another tool is ready to continue
+the modeling. This appears to us practically impossible, the more so as
+the elongation which the bar takes at each stamp varies with its initial
+diameter.
+
+What is more admissible is that with one heat and in the same machine an
+operation could be performed on the two faces perpendicularly. The bar
+could then be taken from one furnace and put in another immediately,
+to pass at once to another machine to again undergo the operations
+following. The work could then be done rapidly, submitting the bar to
+several heats.
+
+A few words on the tools as they exist.
+
+The most important principle to note, and on which the different
+machines employed are designed, is this: The punches or matrices acting
+on the chain at its different points of progress are put in motion by
+spiral springs worked by means of tappets or cams distributed over the
+circumference of a cylinder, having a rotary movement imparted to it by
+pulleys and belts.
+
+The figures on our plate show with sufficient clearness the working of
+one of these machines. It will be seen that the bar traverses through
+and through the machine for stamping, and that it can be disengaged for
+a reheating before passing to subsequent operations.
+
+       *       *       *       *       *
+
+The bog peat of Mexico is now being used on a considerable scale as fuel
+for locomotives, stationary engines, smelting purposes, smiths' fires,
+and househould use. The peat is mixed with a proper proportion of
+bitumen, and is said not only to burn freely, and without smoke in much
+quantity, but to give a higher dynamic equivalent of heat than the same
+amount of wood.
+
+       *       *       *       *       *
+
+
+
+
+THE BITTER SUBSTANCE OF HOPS.
+
+[Footnote: _The Brewers' Guardian_, from the _Zeit. f. d. gesammte
+Brauwesen_.]
+
+By DR. H. BUNGENER.
+
+
+Little that is definite is known of the substance or substances to
+which the hop owes its bitterness. Lermer has succeeded, it is true, in
+separating from hops a crystallized colorless substance, insoluble in
+water, an alkaline solution of which has a marked bitter flavor, and
+which easily changes on exposure to the air, assuming a resinous form.
+According to Lermer, the formula of this substance is C_{32}H_{50}O_{7};
+it possesses the properties of a weak acid and forms a characteristic
+copper salt, which is soluble in ether. This hop bitter is, however,
+produced from the hop by a very roundabout process, by treatment of the
+extract with alkalies; it is not therefore regarded by many as present
+in this form in the hop, and they hold that it is only produced by
+the action of the alkalies. On the other hand, however, Etti, by a
+complicated extracting process, but without using an alkali, succeeded
+in producing a bitter substance from hops, which is, however, soluble in
+water.
+
+Several experiments convinced me that there really existed in hops a
+crystallizable substance, insoluble in water, the alcoholic and alkaline
+solution of which had a bitter flavor, in short, which possessed all
+the properties of Lermer's hop bitter acid. Petroleum ether is the best
+practical solvent in use for its isolation, as it does not dissolve
+the majority of the remaining constituents of the hop, especially the
+hop-resin, which they contain in considerable quantity. Still, the
+extraction of hop-bitter acid from hops is a troublesome and thankless
+job, the petroleum ether taking up certain substances which add greatly
+to the difficulty of purifying the crystals. On the other hand, we can
+readily and quickly attain our object, if we employ for our original
+material fresh lupuline from unsulphured hops.
+
+The following process has furnished me the best results:
+
+The lupuline is first freed from gross impurities (hop-seed leaves,
+etc.), and then covered with petroleum ether boiling at a low
+temperature (40 deg. to 70 deg.) in stoppered flasks. The mixture is shaken up
+from time to time. After twenty-four hours, by means of a Zullowsky
+filter immersed in the mass, and with the aid of a suction-pump, the
+dark brown solution is drawn off; then fresh ether is poured on to the
+lupuline, and it is allowed to stand for another twenty-four hours.
+After this process has been three times repeated, nearly everything the
+petroleum will dissolve has probably been extracted. The solutions are
+put together, and the petroleum ether distilled off _in vacuo_ at a low
+temperature, until there remains in the flask a dark brown sirup, which
+on cooling solidifies into a crystalline mass. This is pulverized and
+turned on to a filter composed of a large funnel, in which a smaller
+funnel covered with muslin is inserted. With the aid of a suction-pump,
+the greater portion of the thick, crude solution can be filtered
+through. There remains on the filter a highly colored crystalline
+"cake," which should be pulverized with a small quantity of petroleum
+ether and again filtered. After this operation has been repeated three
+or four times, we obtain an almost colorless mass, consisting of
+hop-bitter acid, contaminated by small quantities of a fatty substance,
+and a substance which I could not isolate, and which I had at first
+great trouble in separating from the hop-bitter acid.
+
+If we do not wish to utilize this crude substance at once, it will be
+necessary to melt it in the water bath and pour it into a bottle under
+close seal, where it will at once crystallize and solidify. If it
+remains exposed to the atmosphere, it will soon become sticky and
+turn partly into resin. Six kilos of lupuline, which included a large
+proportion of sand, furnished 400 grammes of crude hop-bitter acid. The
+first experiments in crystallization with petroleum ether gave poor
+results; it is difficult to produce the acid pure in large quantities
+by this process, as a small quantity of the above substance obstinately
+clings to it, and it readily assumes a non-crystallizable form. Our
+object is more readily attained if we crystallize it once from alcohol,
+for which purpose we dissolve it in a little lukewarm alcohol, then
+quickly cool the solution; flakes of a fatty substance will be
+separated, which are removed by filtration with the aid of a
+suction-pump. Then we throw a few small crystals of the acid into the
+solution, and after a short time crystallization commences. As soon as
+it appears to be ended, the mother solution is removed with the aid of a
+platinum cone, and the crystals washed with a little cold alcohol. The
+alcoholic mother solution, which still contains the chief part of the
+bitter acid, must be quickly evaporated, and the residue consigned to
+a flask. The acid crystallized from the alcohol is then recrystallized
+several times from petroleum-ether. In order to quickly dissolve the
+bitter substance, it should be carefully melted in a flask, and double
+its volume of ether gradually added; on its cooling, we obtain beautiful
+prismatic crystals, which attain a length of 1 cm., and become perfectly
+pure after four or five crystallizations. The mother solutions must be
+speedily evaporated if we still wish to obtain crystals; after a time
+they will only furnish a resinous residue.
+
+The hop-bitter acid melts at 92 deg. to 93 deg. It is easily soluble in
+alcohol, ether, benzol, chloroform, sulphide of carbon, and vinegar; to
+a lesser extent in cold petroleum ether, and not at all in water.
+
+In the analysis I obtained figures which correspond best with those
+calculated from the formula C_{25}H_{35}O_{4}.
+
+                                     Obtained.
+  Calculated.  ------------------------^-----------------------
+  -----^-----  2. Crystal. 3. Crystal.  5. Crystal. 6. Crystal.
+        p.c.   p.c.    p.c.     p.c.   p.c.    p.c.    p.c.
+    C  75.19   74.79   74.83    74.9   75.04   75.05   75.07
+    H   8.77    8.97    8.90     8.85   8.87    8.83    8.80
+    O  16.04
+
+If we shake up the ether solution of bitter substance with an aqueous
+solution of acetate of copper, the ether will assume a green color, and
+gradually deposits a green crystalline powder, a cupreous combination
+of the bitter acid. It is difficult to obtain in a pure state, as the
+solutions are readily subject to slight decomposition, accompanied by a
+small deposit of copper oxide. This combination is readily soluble in
+alcohol, to a lesser extent in ether, and is insoluble in water.
+
+In the course of analysis, I obtained the following figures:
+
+   C    69.4 per cent.        69.3  per cent.
+   H     7.95     "            7.98     "
+   Cu    7.20     "            7.18     "
+
+If we suppose that the copper combines with two molecules of hop-bitter
+acid, by the decomposition of one of its atoms, H, we obtain the formula
+C_{50}H_{68}O_{8}Cu. This combination will contain 69.87 per cent. C,
+7.91 per cent. H, and 7.33 per cent. Cu. The figures obtained do not
+perfectly coincide with those calculated; it is nevertheless probable
+that the formula is correct, and the combined substance analyzed was not
+perfectly true.
+
+I have already referred to the fact that solutions of hop-bitter acid,
+if left standing too long, assume a yellow color, and on evaporation
+leave only a yellow resinous residue. This, as its reaction shows,
+evinces a complete analogy with the crystallized acid. The dark-colored
+mother solution, from which the crystalline cakes of bitter acid are
+obtained, contains a large proportion of this resinous compound, which
+can be isolated by treatment with a weak soda-lye; this substance, like
+the crystallized acid, is soluble in alkalies, and can be precipitated
+from an alkaline solution by an acid. Old hops furnish far less
+crystallizable acid than new hops; from some samples I have been able to
+obtain only a few crystals; the remainder had been transformed into the
+resinous modification.
+
+If pure hop-bitter acid be pulverized and exposed to the atmosphere, it
+soon turns yellow and the surface assumes a resinous consistency. At
+the same time, a more pronounced odor of fatty acids and aldehydes is
+apparent. Still more rapidly will this oxidation occur if a thin layer
+of an alcoholic solution of the acid is allowed to evaporate in the air.
+On the other hand, we can allow hop-oil to stand for days without its
+odor being perceptibly changed; it appears to me more than probable that
+the peculiar smell of old hops is due far more to the oxidation of the
+bitter substance than to the oxidation of oil.
+
+Hop-bitter acid appears to possess the character of an aldehyde and of
+a weak acid; for the present I am not in a position to state its
+constitution more clearly. Most of the oxidizing processes have an
+energetic effect on it, forming also considerable quantities of
+valerianic acid.
+
+The question as to whether the hop owes chiefly to this acid and its
+resinous modifications the property of imparting a pronounced bitter
+flavor to a solution, I must for the present leave unanswered. The acid
+and its isomer are both insoluble in water; they are, on the other hand,
+very readily dissolved in hop oil; they also furnish a tolerably bitter
+solution, if boiled for a long time in water, probably on their account
+of their gradual decomposition. I will not for the present go further
+into the subject, as I hope soon to be in a position to give more
+definite information.
+
+       *       *       *       *       *
+
+
+
+
+ST. PAUL'S VICARAGE, FOREST HILL, KENT.
+
+
+This vicarage, for the Rev. Frank Jones, has recently been completed
+from the designs of Mr. E.W. Mountford, A.R.I.B.A.; of 22 Buckingham
+Street, Strand, W. C., and Mr. H. D. Appleton, A.R.I.B.A., of the Wool
+Exchange, Coleman Street, E. C., who were the joint architects. The
+builder was Mr. William Robinson, of Lower Tooting, S. W. The walls are
+of yellow stock bricks, with red brick arches, quoins, etc., the gables
+being hung with Kentish tiles and the roofs covered with Broseley tiles.
+The internal joinery is of pitch pine.
+
+[Illustration: ST. PAUL'S VICARAGE, FOREST HILL.--VIEW FROM ROAD.]
+
+[Illustration: ST. PAUL'S VICARAGE, FOREST HILL.--VIEW FROM GARDEN.]
+
+The illustrations are from drawings by Mr. J. Stonier.--_The Architect_.
+
+       *       *       *       *       *
+
+
+
+
+SOME ECONOMICAL PROCESSES CONNECTED WITH THE CLOTHWORKING INDUSTRY.
+
+[Footnote: Read before the Society of Arts, London, May, 1884.]
+
+By Dr. WILLIAM RAMSAY, Professor of Chemistry at University College,
+Bristol.
+
+
+In this present age of scientific and technical activity, there is
+one branch which has, I think, been the subject of an article in the
+_Quarterly Journal of Science_. It is one which deserves attention. It
+was there termed "The Investigation of Residual Phenomena," and I can
+conceive no better title to express the idea. The investigator who
+first explores an unknown region is content if he can in some measure
+delineate its grand features--its rivers, its mountain chains, its
+plains; if he be a geologist, he attempts no more than broadly to
+observe its most important rock formations; if a botanist, its more
+striking forms of vegetation. So with the scientific investigator. The
+chemist or physicist who discovers a new law seldom succeeds in doing
+more than testing its general accuracy by experiments; it is reserved
+for his successors to note the divergence between his broad and sweeping
+generalization and particular instances which do not quite accord with
+it. So it was with Boyle's law that the volume of a gas varies in
+inverse ratio to the pressure to which it is exposed; so it is with the
+Darwinian theory, inasmuch as deterioration and degeneration play a part
+which was, perhaps, at first overlooked; and similar instances may be
+found in almost all pure sciences.
+
+I conceive that the parallel from the technical point of view is a
+double one. For just as every technical process cannot be considered
+to be beyond improvement, there is always scope for technical
+investigation; but the true residual phenomena of which I would speak
+to-night are waste products. There is, I imagine, no manufacture in
+which every substance produced meets with a market. Some products are
+always allowed to run to waste, yet it is evident that every effort
+consistent with economy should be made to prevent such waste; and it has
+been frequently found that an attempt in this direction, though at first
+unsuccessful, has finally been worked into such a form as to remunerate
+the manufacturer.
+
+It is my purpose to-night to bring under your notice methods by which
+saving can be effected in the cloth industry. I am aware that these
+methods have not much claim to novelty; but I also know that there are,
+unfortunately, few works where they are practiced.
+
+The first of these relates to the saving and utilization of the soap
+used in wool scouring and milling. It is, perhaps, hardly necessary to
+explain that woolen goods are scoured by being run between rollers,
+after passing through a bath of soap, and this is continued for several
+hours, the cloth being repeatedly moistened with the lye, and repeatedly
+wrung out by the rollers. The process is analogous to ordinary washing;
+the soap dissolves the greasy film adhering to the fibers, and the
+"dirt" mechanically retained is thus loosened, and washed away. Now, in
+order to dissolve this greasy matter, a considerable amount of soap must
+be employed; and in the course of purification of the fabric, not merely
+what may be characterized as "dirt" is removed, but also short fibers,
+and various dye-stuffs with which the fabric has been dyed, many of
+which are partially soluble in alkaline water; moreover, it invariably
+happens that some dye does not combine with the fiber and mordant, thus
+becoming fixed, but merely incrusts the fiber; hence this portion is
+washed off when the retaining film of grease is removed from the fiber.
+The suds, therefore, after fulfilling this purpose, are no longer a pure
+solution of soap, but contain many foreign matters; and the problem is
+so to treat these suds as to recover the fat in some condition available
+for re-conversion into soap.
+
+For this purpose wooden runnels are placed beneath the rollers, through
+which the cloth passes in the scouring machine, so as to collect the
+suds after they have been spent. These runnels lead to a wooden pipe or
+runnel, which receives the spent suds from all the scouring machines,
+and the whole of the waste, instead of being let off into the stream,
+polluting it, delivers into a tank or trough, which may also be
+constructed of wood, but, as it has to withstand the action of acid, is
+better lined with lead. This tank is necessarily proportioned in size
+to the number of scouring machines and the quantity of spent suds to
+be treated. When a sufficient quantity has collected, oil of vitriol,
+diluted with twice its bulk of water, is added, one workman pouring it
+in gradually while another stirs the contents of the tank vigorously. At
+short intervals, the liquid is tested by means of litmus paper, and
+when it shows a faint acid reaction, by turning the blue paper red, the
+addition of acid is stopped. The acid has then combined with the alkali
+of the soap, while the fatty acids formerly in combination with the
+alkali are liberated, and float to the surface of the liquid, carrying
+with them the impurities in the shape of short fibers and dye stuffs;
+the sand and heavier impurity, should any be present, sinks to the
+bottom.
+
+After standing for some hours, the separation is complete. In order to
+separate the two layers, the tank is provided with an exit in the side,
+near the bottom, closed by a sluice or valve. This valve is opened, and
+the watery portion is allowed to escape into a sand filter bed.
+
+The filter serves to retain any solid impurities which may still remain
+suspended in the water; but it will be found that the escaping water is
+nearly pure.
+
+The dark brown fatty acid is mixed with a large amount of impurity, such
+as short wool fibers, burrs, sand, and dye stuffs washed from the wool.
+To remove water more completely, the semi-fluid mass is pumped from the
+tank, and delivered into hair-cloth filters; the liquid which drains
+from these bags finds its ways to the sand filters joining the drainage
+which formerly passed out from the tank through the sluice. After being
+turned over in the filter several times, the residue is transferred to
+canvas sacks. These sacks are placed in a filter press, where they are
+exposed to pressure while heated to a temperature sufficient to melt
+the fat. The solid impurities remain in the bags, while the fatty acids
+escape, and are received in a barrel or tank for the purpose. The fatty
+acids, when cold, are of a deep brown color, and of the consistency
+of butter. The residue is kept, and the method of treating it for the
+recovery of indigo will afterward be described.
+
+The fatty acids are now ready for conversion into soap. It may here be
+remarked that, on distillation, they yield a nearly white fatty mass,
+which, when treated with soda-lye, is capable of yielding a perfectly
+white soap. But, for the clothworker's purpose, this purification is
+unnecessary.
+
+The conversion into soap is a very simple matter. As the fats are
+acids--a mixture of palmitic, oleic, and stearic acids--and not the
+glycerine salts of these acids, like ordinary fats, soap is made by
+causing them directly to unite with caustic soda. The fats are melted
+in a copper, by means of a steam-jacket, or coil of steam-pipe in the
+copper, and the soda-lye is run in until complete union has taken place.
+The exact point of neutralization can easily be found by taking out
+a small sample after stirring, and dissolving it in some methylated
+spirits. A few drops of alcoholic tincture of phenol-phthalein are then
+added, and as soon as a faint red color appears, addition of soda is
+stopped. This shows that the fatty acids have been over-saturated.
+Addition of a little more fat renders them perfectly neutral, and the
+soap is then ladled out into wooden moulds, lined with loose sheets of
+zinc.
+
+The resulting soap is of a brown color, but is perfectly adapted for the
+purpose of wool-scouring. It should here be mentioned that, in practice,
+the soap is always made somewhat alkaline; in point of fact, it contains
+about 2 per cent. of free alkali. This is found to assist in scouring; I
+presume that the free alkali forms a soap with the oil added to the wool
+during spinning, and if no free alkali be present, this oil would not be
+so thoroughly removed.
+
+It will be noticed that in this simple method of soap-making, there is
+no salting out to separate the true soap from the watery solution of
+glycerine, for no glycerine is present. The apparatus may be of the
+simplest nature, and on any required scale, proportionate to the size of
+the mill. It is a process which requires no specially skilled labor; in
+any works some hand may be told off to conduct the process as occasion
+requires; and as a very large proportion of the fatty matter is
+recovered, the soap-bill is reduced to a very small fraction of the
+amount which would be paid were recovery not practiced. And lastly, the
+streams are not polluted; the only waste is a little sulphate of soda,
+which can hardly be regarded as a nuisance, inasmuch as it is a not
+unfrequent constituent of many natural waters.
+
+Let us now return to the solid matter from which the fatty acids have
+been removed by pressure. This brown, earthly-looking cake consists of
+vegetable impurity washed off from the cloth, of short fibers, and of
+various dye stuffs. It is divided into two lots: That which contains
+indigo, and that which contains none, or which contains too small a
+quantity for profitable extraction. And it may here be remarked, that it
+is advisable to collect the suds from cloth dyed with indigo separate
+from that to dye which no indigo has been employed. The residue from
+indigo-dyed cloth has always a more or less blue shade, and if much
+indigo is present, the well-known copper-color is evident. Of course,
+the amount of indigo must greatly vary, but it may rise to 8 or 10 per
+cent. of the total weight of the refuse.
+
+To recover the indigo from this refuse, the somewhat hard cakes are
+broken up, placed in a tank, and allowed to steep in water. When quite
+disintegrated, they are transferred to another tank--a barrel may be
+used for small quantities--and thus this refuse is exposed to the
+reducing action of copperas and lime. The indigo is converted into
+indigo-white, and is rendered soluble, and it oxidizes on the surface,
+forming a layer of blue froth on the top of the liquid, while the
+remainder of the impurities sinks. This process of reduction may last
+for twenty-four hours, and is helped by frequent stirring.
+
+The indigo scum is preserved, and placed in filter cloths, where it is
+thoroughly washed with water two or three times. The residue which has
+sunk to the bottom is removed, dried, and forms a valuable manure,
+owing to the amount of the nitrogen which it contains. Its value may be
+increased by addition of weak vitriol, which exercises a decomposing
+action on the nitrogenous matter, forming with it sulphate of ammonia.
+The original residue from the filter-press, if it does not contain
+indigo, may be at once put to similar use.
+
+In large works, which dye their own goods, it is well known that the
+"fermentation vat" is in general use for indigo-dyeing. But this vat
+requires constant superintendence, and must be kept in continual action;
+besides, it is successful only on a comparatively large scale. And,
+moreover, it requires skilled labor. Small works, or works in which
+dyeing is only occasionally practiced, find it more convenient to use
+Schuetzenberger and Lalande's process. Although this process is well
+known, a short description of it may not here be out of place.
+
+The process depends on the reduction of indigo to indigo-white, or
+soluble indigo, by means of hyposulphite, or, as it is generally termed
+to avoid confusion with antichlore, rightly named thiosulphate of soda,
+hydrosulphite of soda. The formula of this substance is NaHSO_{2}, as
+distinguished from what is commonly known as hyposulphite of soda,
+Na_{2}S_{2}O_{3}. It is produced by the action of zinc-dust on the acid
+sulphite of soda. The zinc may be supposed to remove oxygen from the
+acid sulphite, NaHSO_{3}, giving hyposulphite, NaHS0_{2}. The reduction
+of the acid sulphite is best performed in a cask, which can be closed at
+the top, so as to avoid entrance of air. The acid sulphite of soda, at a
+strength of 50 or 60 Twaddell (specific gravity 1.26 to 1.3), is placed
+in the cask, and zinc-dust is added, with frequent stirring. The liquid
+is then mixed with milk of lime, and after again thoroughly stirring,
+the liquid is allowed to settle, and the clear is decanted into the
+dyeing-copper. The indigo, in the frothy state in which it is skimmed
+from the purifying barrels or tanks, is then added, with sufficient lime
+to dissolve it when it has been reduced. It is heated gently by a steam
+coil, to about 90 deg. Fahr., and the goods are dyed in it. The colors
+obtained by means of this indigo are light in shade, and the goods must
+be dipped several times if dark shades are required. But it is found
+better in practice not to attempt to dye dark shades by this process;
+the ordinary indigo-vat is better adapted for such work. The object of
+not wasting indigo is sufficiently attained by employing it for the
+purpose to which it is best adapted. Of course the recovered indigo may
+be used in the ordinary manner. I merely mention the most convenient way
+of disposing of it in works where only a small quantity is recovered,
+and which do not practice dyeing on an extensive scale.
+
+I have now to ask you to turn to a different subject, namely, the
+scouring of wool, not by the usual agent, water, but by a liquid,
+bisulphide of carbon, made by the action of sulphur vapor on red hot
+coke or charcoal.
+
+This, again, is not wholly a new process, for various attempts have
+been made to dissolve out the yolk, or _suint_, or greasy matter from
+unwashed wool, as it comes from the back of the sheep. Fusel oil
+has been patented for this purpose. Carbon disulphide has also been
+patented, but, as will afterward be shown, the old method of removing it
+from the wool injured the color and quality of the fiber, so as to make
+the application of this scouring agent a failure.
+
+Wool in its unwashed state contains a considerable proportion of what is
+termed _suint_. This consists of the fatty matter exuded as perspiration
+from the sheep, along with, or in some form of combination with, potash
+derived from the grass on which the sheep feed. _Suint_ was first
+investigated by Vauquelin. He obtained it by evaporating, after
+filtration, the water in which raw fleeces had been washed. The residue
+is of a brown color, and has a saline, bitter taste. On addition of an
+acid to its solution in water, it coagulates, and a fatty matter rises
+to the surface. It is, in fact, a potash soap, to a great extent
+containing carbonate and acetate of potash, along with chloride of
+potassium and lime, probably in combination also with fatty acids. It is
+usually mixed with sand and carbonate of lime.
+
+In 1828, M. Chevreul, who is still alive in Paris, although nearly a
+century old, published an analysis of merino wool. It consisted of:
+
+                                 Per cent.
+  Pure wool                        31.23
+  Soluble _suint_                  32.74
+  Insoluble                         8.57
+  Earthy matter                    27.46
+                                  ------
+                                  100.00
+
+It is easily seen that _suint_ forms a very important constituent of raw
+wool. Its proportion varies, of course, according to the nature of the
+pasture on which the sheep are fed, the climate, etc. Wool from Buenos
+Ayres, for example, contains much less than that analyzed by M.
+Chevreul; its amount is only 12 per cent. of the weight of the raw wool.
+
+This _suint_ contains always about 52 per cent. of residue when ignited.
+The composition of this residue is:
+
+                                 Per cent.
+  Carbonate of potash              86.78
+  Chloride of potassium             6.18
+  Sulphate of potash                2.83
+  Silica, alumina, etc.             4.21
+                                  ------
+                                  100.00
+
+In 1859, MM. Maumene and Rogelet patented the use of the water in
+which wool has been washed as a source of potash, and at present the
+extraction of potash from _suint_ is practiced in France on a large
+scale. The wool is washed in a systematic manner, in casks, with cold
+water, which runs out of the last cask with specific gravity 1.1. These
+washings are evaporated to dryness, and the residue is calcined in iron
+retorts, the gas evolved being used for illuminating purposes. The
+remaining cinder, consisting of a mixture of charcoal and carbonate of
+potash, is treated with water, whereby the latter is dissolved out.
+The residue left on evaporation of this water consists largely--almost
+entirely--of white carbonate of potash. At present there are works at
+Rheims, Elboeuf, Fourmier, and Vervier, which yield about 1,000 tons of
+carbonate of potash annually. Now, only 15,000 tons are made per annum
+by Leblanc's process. In 1868, 62,000 tons of wool were imported into
+Britain from Australia alone, and from this 7,000 to 8,000 tons of
+carbonate of potash might have been recovered, the value of which is
+L260,000. Yet it was all wasted! And this estimate does not include the
+fats of the _suint_, which are worth an even greater sum.
+
+Now, it is evident that there is here a profitable source of economy. So
+far as I am aware, no work in this country saves its washings. The water
+all goes to pollute the nearest river.
+
+The use of carbon disulphide has again been introduced, and it is to be
+hoped with better success, for methods have been devised whereby the
+wool is not injured by it, but is even rendered better than when scoured
+by the old process of washing with carbonate of soda and water, or by
+soap. The process is due to Mr. Thomas J. Mullings. Briefly described,
+it consists in exposing the wool, placed in a hydro-extractor, to the
+action of bisulphide of carbon; the machine is then made to revolve, and
+the excess of solvent is expelled, carrying with it the fatty matters;
+the solvent finds its way into a tank, from which it flows into a still,
+heated with steam; the carbon disulphide, which boils at a very low
+temperature, distills over, and is again ready for use, while the
+residue in the still consists of _suint_ washed from the wool. To
+remove the last trace of carbon disulphide from the wool in the
+hydro-extractor, cold water is admitted, and when the wool is soaked,
+the machine again revolves. On expulsion of the water, the wool is ready
+for washing in the ordinary machines, but with cold water only instead
+of hot soapsuds.
+
+The distinguishing features of Mr. Mullings' process are, method by
+which loss of carbon disulphide is avoided, and the extraction of
+that solvent by means of cold water. The apparatus consists of a
+hydro-extractor or centrifugal machine of special construction, fitted
+with a bell-shaped cover, which can be lifted into and out of position
+by means of a weighted lever. The rim of this cover fits into an annular
+cup filled with water, which surrounds the top of the machine, forming
+an effective seal or joint. Upon the spindle of this machine is
+suspended, as in ordinary forms of the hydro-extractor, a perforated
+basket, and in this basket is placed the wool to be treated. The cover
+being closed, the carbon disulphide is admitted, and passing through the
+wool, the greasy matter is dissolved, and along with the solvent enters
+a reservoir. The machine is now set in motion, and the bulk of the
+solvent is drawn off. Cold water is then admitted, and the machine being
+again caused to rotate, the whole of the bisulphide is expelled. It is
+a curious fact that, although wool soaks remarkably easily with carbon
+disulphide, and at once becomes wet, cold water expels and replaces
+almost all that liquid. This operation takes about twenty minutes, and
+at one operation about 11/2 cwt. of raw wool may be treated. The wool is
+then washed in suitable washing machines of the ordinary type, but with
+cold water, no soap or alkali being employed. The bisulphide of carbon,
+mixed with water, flows into a reservoir, provided with diaphragms to
+prevent splashing, and consequent loss by evaporation. From its gravity
+it sinks, forming a layer below the water; it is then separated and
+recovered by distillation, and may be used in subsequent operations.
+
+The point in which this process differs from the old and unsuccessful
+ones formerly tried, is in the expulsion of the carbon disulphide. It
+was imagined that it was necessary to expel it by means of heat or
+steam. Now, when wool moist with bisulphide is heated, it invariably
+turns yellow. No heat must, therefore, be employed. As already remarked,
+the solvent is expelled with cold water.
+
+The residue, after distillation of the carbon disulphide, is a grayish
+colored, very viscous oily matter, still retaining a little bisulphide,
+as may be perceived from the smell. It has not the composition of
+ordinary _suint_, inasmuch as it contains no carbonate of potash, and
+indeed little mineral matter of any kind. A sample which I analyzed
+lost in drying 36.2 per cent., the loss consisting of water and carbon
+disulphide. It gave a residue on ignition amounting only to 1.6 per
+cent. of the original fatty matter, or 2.5 per cent. of the dried fat.
+The oil appears, from some experiments which I made, to be a mixture of
+a glycerine salt and a cholesterine salt of fatty acids. It distills
+without much decomposition, giving a brown-yellow oil, which fluoresces
+strongly, and has a somewhat pungent smell. The molecular weight was
+determined by saponification with alcoholic potash, and subsequent
+titration of the excess of potash employed. This was found to equal
+546.3. This would correspond to a mixture of 18.7 parts of stearate,
+palmitate, and oleate of glycerine, with 81.3 parts of the same acids
+combined with cholesteryl. But this is largely conjecture. The
+boiling point of the oil is high, much above the range of a mercurial
+thermometer, so that it is difficult to gain an insight into its
+composition.
+
+An objection which has been raised to this process is that the use of
+such an easily inflammable substance as bisulphide of carbon is attended
+by great risk of fire. Were the bisulphide to be exposed to free air,
+there might be force in this objection; but there is no reason why it
+should ever be removed from under a layer of water. The apparatus, to
+make all safe, should not be under the same roof as the mill; and no
+open fire need be used in the building set apart for it. It is easy to
+rotate the centrifugal machine by a belt from the mill, but better by a
+small engine attached, the power for which can be conducted by a small
+steam-pipe, and the distillation of the bisulphide can also be conducted
+without danger by the use of steam, as its boiling point is a very low
+one. The question may be naturally asked, "How do the wool and fabric
+made from the wool scoured by this process, compare with that scoured in
+the usual way?" To answer this question I may refer to a test made by
+Messrs. Isaac Holden & Co., at their works at Roubaix. A sample of wool
+was divided into two portions, one of which was scoured by the usual
+method, and the other by the turbine or Mullings' process. Skilled
+workers then span each sample to as fine a thread as possible. Now
+the thinness to which a wool can be spun is evidence of its power of
+cohesion--in other words, its strength. The weight of 1,000 meters of
+the wool cleaned by the new process bore to that scoured by the old
+process the proportion of 1,015 to 1,085, showing that a considerably
+finer thread had been produced. And in total quantity, 67.53 kilos.
+of the former corresponded to 71.77 kilos. of the latter, showing
+a proportionately less waste. Such fine yarn had never before been
+obtained from similar wool. The yarn of the soap-washed wool could not
+be spun, for it could not withstand the strain; whereas, that scoured by
+the new process gave an admirable thread.
+
+Another test to which it was subjected may be cited. It is the custom in
+France, before the wool is scoured, to put it through a sorting process,
+by which all the short lengths are weeded out. On a quantity exceeding
+11,000 kilogrammes, half of which was scoured by the turbine process,
+and half by the ordinary process, the former in scouring lost in weight
+2 per cent. less than the latter, although the short length extracted
+from the moiety thus treated weighed only 10 kilogrammes, while that
+taken from the other weighed over 150 kilogrammes. This saving, even
+with the unequal treatment, amounted in value to from 30 to 40 centimes
+per kilogramme.
+
+In order that the importance of this application may be realized, I
+shall conclude with some figures:
+
+The raw wool imported into England, in the year 1882, amounted to
+1,487,169 bales, its total value being about L22,000,000. The cost of
+washing this wool by the old process, with carbonate of soda, amounts to
+about 1/2d. per lb. of the raw material. The cost for the total quantity
+of wool imported is at least L1,214,000. But it is customary to wash
+wool with soap, especially for the combing trade, and the cost is then
+about 1d. per lb. The cost of scouring by the new process is about L1
+5s. per ton, or 0.13d. per lb. Taking the least favorable comparison,
+were all the imported wool (home-grown wool is here left out of the
+calculation, for want of sufficient returns) cleansed by the turbine
+process, the actual saving would be L1,214,500 _minus_ L315,700, or
+nearly L900,000 per annum.
+
+It is thus seen that there is room for a very important economy in
+the treatment of wool. I have endeavored to show how economy may be
+practiced in scouring by the old process with soap, and how one dye
+stuff may be profitably recovered. It is to be hoped that means of
+extracting other dyes from the residue may soon follow. Unless the
+process were too costly to repay the trouble of extraction, it would
+be well worth practicing; for it would not merely be a solution of the
+problem of how to avoid waste, but would at the same time prevent the
+pollution of our streams, now, unfortunately, only too rarely pellucid;
+and were the last process to have as successful a future as I hope it
+may have, a very important saving of expense would result, and a large
+quantity of valuable fatty matter would no longer be thrown away.
+
+       *       *       *       *       *
+
+
+[Illustration: SUGGESTIONS IN DECORATIVE ART.--DESIGNS FOR IRON GATES.]
+
+       *       *       *       *       *
+
+
+
+
+COAL AND ITS USES.
+
+[Footnote: From a paper lately read before the Association of Foremen
+Engineers.]
+
+By JAMES PYKE.
+
+
+The records from which geologists draw their information can scarcely be
+compared to written or printed histories. There are, however, nations
+of whom no written account exists, who perhaps never had any written
+history, but about whom we are still able to gather from other sources
+a vast amount of information. Their houses, their monuments, their
+weapons, and their tools have survived, and these tell us the kind of
+life, the state of civilization, and the skill of the men to whom they
+belonged; from the contents of their tombs we learn what manner of men
+they were physically; sometimes a sudden change in the appointments and
+belongings of the folk indicates that tribes which had for a long time
+inhabited a district were driven out and replaced by a new race. Thus,
+then, from waifs and strays we can piece together a fairly connected
+account of the events of a period long antecedent to any written
+history.
+
+The investigations of Dr. Schliemann on the supposed site of the city of
+Troy furnish a good example of this method of research. He found lying,
+one on the top of another, traces of the existence of five successive
+communities of men, differing in customs and social development, and was
+able to establish the fact that some of the cities had been destroyed by
+fire, and that later on other towns had grown up over the buried remains
+of the earlier settlements. The lowest layers were, of course, the
+oldest, and the position of each layer in the pile gives its date, not
+in years, but with regard to the layers above and below it.
+
+Now, from time immemorial nature has been at work building up monuments
+and providing tombs which tell us what were the events going on,
+and what kind of inhabitants the earth had long before man made his
+appearance on its surface. The monuments are the rocks which compose the
+ground under our feet, and these, like many ancient monuments of human
+construction, are the tombs of the creatures that lived while they were
+being built.
+
+Many facts testify that the earth's crust did not come into existence
+exactly as we find it now, but that its rocks have been built up by the
+slow action of natural agencies. These rocks constantly inclose the
+remains of plants and animals, and as it is evident that neither plant
+nor animal could have lived in the heart of a solid rock, this fact
+shows that the rock must in some way have gathered round the remains
+that are now found in it. Again, many of these remains, or fossils,
+belonged to animals that lived in water, the larger part, indeed, to
+marine creatures. This indicates that the rock was formed beneath the
+sea, and when we examine the way in which the constituents of the rock
+are arranged, we frequently find it to correspond exactly with the
+manner in which the sand and mud that rivers sweep down into the sea or
+lakes are spread out over the bottom of the water. In a pile of rocks
+formed in this way it is clear that the lowest is the oldest of all, and
+that any one stratum lying above is younger than the one beneath it.
+Further, the occurrence of rocks inland containing marine fossils far
+above the sea level shows that the sea and land have changed places.
+When, again, we find that the fossils of one group of rocks differ
+entirely from those of a group lying above them, we learn that one race
+of creatures died out and was supplanted by a new assemblage of animal
+forms.
+
+These general remarks will, I trust, give some notion of the evidence
+which is available for reconstructing the history of those remote
+periods with which geology deals, and of the kind of reasoning which the
+geologist employs for interpreting the records that are submitted to
+him.
+
+We will now briefly examine, by aid of these methods, the group of rocks
+in which coal occurs in Great Britain, and see how far we can read the
+story they have to tell.
+
+The group with which we have to deal is called the carboniferous or
+coal bearing system, and it includes four classes of rocks, viz.: 1,
+sandstone; 2, shale or bind; 3, limestone; 4, coal and underclay.
+
+We will take the sandstones and shales first. They are grains of sand
+known to mineralogists as quartz, and consisting of a substance called
+silica by chemists. The grains of sand are bound together by a cement
+which in some few cases is identical in composition with themselves, and
+consists of pure silica, but usually is a mixture of sandy, clayey, and
+other substances. The shales are made up very largely of clay, mixed,
+however, usually with sand and other substances, forming a conglomerate.
+Both sandstones and shales are divided into layers or beds, and are said
+to be stratified. It is this stratified or bedded structure that gives
+us the first clew to the way in which these rocks were formed. Rivers
+are constantly carrying down sand and mud into the sea or lakes, and
+when their flow is slackened on entering the still water the materials
+they bring down with them sink and are spread out in layers over the
+bottom. The structure of the sandstones and shales shows that they were
+formed in this way; they often inclose the remains of plants that have
+been carried down from land, and occasionally of animals that lived in
+the water where they were deposited.
+
+The next we have to consider is limestone, which is mainly made up of a
+substance known to chemists as calcium carbonate, or carbonate of lime.
+
+In some districts, especially in volcanic countries, springs occur very
+highly charged with carbonate of lime. The warm springs of Matlock are
+a case in point; they are probably the last vestige of volcanic action
+which was in operation in that neighborhood during carboniferous times.
+Limestone is chiefly formed by the agency of small marine creatures of
+low organization. By the aid of these animals the carbonate of lime is
+brought back to a solid form; at their death their hard parts fall to
+the bottom and accumulate in a mass of pure limestone, which afterward
+becomes solidified into limestone rock.
+
+The information that limestone gives us is this:
+
+When we find, as is often the case, a mass of limestone hundreds of feet
+thick, and composed of little else but carbonate of lime, we know that
+the spot where it occurs was, at the time it was formed, far out at sea,
+covered by the clear water of mid ocean; and when we find that this
+limestone grows in certain directions earthy and impure, and that layers
+of shale and sandstone, thin at first, but gradually thickening out in
+a wedge-shape form, come in between its beds, we know that in those
+directions we are traveling toward the shore lines of that sea whence
+the water was receiving from time to time supplies of muddy and sandy
+sediment.
+
+The next class of rocks are the clays that are found beneath every
+bed of coal, and which are known as _underclays_, or _warrant_, or
+_spavins_. They vary very much in mineral composition. Sometimes they
+are soft clay; sometimes clay mixed with a certain portion of sand; and
+sometimes they contain such a large proportion of silicious matters that
+they become hard, flinty rock, which many of you know under the name
+of _gannister_. But all underclays agree in two points: they are all
+unstratified. They differ totally from the shales and sandstones in this
+respect, and instead of splitting up readily into thin flakes, they
+break up into irregular lumpy masses. And they all contain a very
+peculiar vegetable fossil called _Stigmaria_.
+
+This strange fossil was for a long time a sore puzzle to fossil
+botanists, and after much discussion the question was fairly solved by
+Mr. Binney by the discovery of a tree embedded in the coal measures,
+and standing erect just as it grew, with its roots spread out into the
+stratum on which it stood. These roots were Stigmaria, and the stuff
+into which they penetrated was an underclay. Sir Charles Lyell mentions
+an individual sigillaria 72 feet in length found at Newcastle, and a
+specimen taken from the Jarrow coal mine was more than 40 feet in length
+and 13 feet in diameter near the base. It is not often these trees are
+found erect, because the action of water, combined with natural decay,
+has generally thrown them down. They are, however, found in very large
+numbers in the roof of the coal, evidently having been tossed over, and
+lying there flat and squeezed thin by the pressure of the measures that
+lie above them.
+
+Lastly, we come to coal itself--a rock which constitutes a small portion
+of the whole bulk of the carboniferous deposits, but which may be fairly
+looked upon as the most important member of that group, both on account
+of its intrinsic value and also from the interest that attaches to its
+history. That coal is little else but mineralized vegetable matter is a
+point on which there has for a long time been but small doubt. The
+more minute investigations of recent years have not only placed this
+completely beyond question, but have also enabled us to say what the
+plants were which contributed to the formation of coal, and in some
+cases even to decide what portions of those plants enter into its
+composition. It is a thing so universally admitted on all hands, that I
+shall take it for granted you are all perfectly convinced that coal has
+been nothing in the world but a great mass of vegetable matter. The only
+question is: How were these great masses of vegetable matter brought
+together? And you must realize that they were very large masses indeed.
+Just to take one instance. The Yorkshire and Derbyshire coal field is
+somewhere about 700 to 800 square miles in area, and Lancashire about
+200. Well, in both these coal fields you have a great number of beds of
+coal that spread over the whole of them with tolerable regularity and
+thickness, and very often with scarcely any break whatever. And this is
+only a very small portion of what must have been the original sheet of
+coal, so that you see we have to account for a mass of vegetable matter
+perfectly free from any admixture of sand, mud, or dirt, and laid down
+with tolerably uniform thickness over many hundreds of square miles.
+
+At one time it was supposed that coal was formed out of dead trees and
+plants which were swept down by rivers into the sea, just in the same
+way as shales and sandstones were formed out of mud and sand so swept
+down. The fatal objection to this theory, however, is that rivers would
+not bring down dead wood alone, but they would bring down sand and mud,
+and other matters, and that in the bottom of the sea the dead wood would
+be mixed with these matters, and instead of getting a perfectly unmixed
+mass of vegetable matter, we should get a mixture of dead plants, sand,
+mud, and other things, which would give rise to something like coal, but
+something very different, as any one who tries to burn such coal will
+soon find out, from really good, pure house coal. So that this theory,
+which is generally known as the "drift" theory, was totally inadequate
+to account for the facts as we know them.
+
+The other theory was that coal was formed out of plants and trees that
+grew on the spot where we now find coal itself. On this supposition it
+is easy to account for the absence of foreign admixtures of sand, mud,
+and clay in the coal; and we can also understand very much better than
+by the aid of the drift theory how the coal had accumulated with such
+wonderful uniformity of thickness over such very large areas. This
+theory was for some time but poorly received; but after the discovery
+of Sir William Logan, that every bed of coal had a bed of underclay
+beneath, and the discovery of Mr. Binney, that these underclays were
+true soils on which plants had undoubtedly grown, there was no doubt
+whatever that this was the real and true explanation of the matter.
+
+I dare say many of you have had occasion to walk across peat bogs.
+The peat bog is a great mass of vegetable matter, which is every year
+growing thicker and thicker; and underneath it there is almost always a
+bed of thin clay, in look very much like the underclays, and this thin
+clay is penetrated by the rootlets of the moss forming the peat, exactly
+the same way as the underclays of the coal measures are penetrated by
+the stigmaria and its rootlets. But you must not suppose that the plants
+out of which coal was formed were exactly the same low type of moss
+which forms our present peat bogs. However, it is pretty certain that
+they were for the most part of a loose, succulent texture, and that they
+grew very rapidly indeed.
+
+You will have noticed that there is one step more wanted to make good
+this theory of the growth of coal on the spot where we now find it.
+The coal is found, as already described, interbedded with shales and
+sandstones. These shales and sandstones, as shown, were formed beneath
+the water of the sea, and as long as they remained there of course no
+plants could grow upon them. The question is, How was the land surface
+formed for the growth of plants? It must have been formed in some way or
+other by the sea bottom having been raised above the level of the water.
+Now, we have distinct proof in many cases that elevation of the sea
+bottom and depression of the land is now going on in many parts of the
+earth's surface. And, therefore, we shall be assuming nothing beyond the
+range of experience if we say that such elevations and depressions went
+on during coal measure times. The coal measure times must have been
+times during which the same spot was now below the sea, and now dry
+land, over and over again. There was a land surface on which plants grew
+fast and multiplied rapidly, and as they died fell and accumulated in
+a great heap of dead vegetable matter. After a time this layer of
+vegetable matter was slowly and gently let down beneath the waters of
+the sea--so slowly that the water flowing over it did not, as a rule,
+disturb the loose, pasty mass; and then, by the method I have described
+to you, shales and sandstones were deposited on the top of this mass
+of dead vegetable matter. By their weight they compressed it, and
+by certain chemical changes (which we have not time to go into this
+evening) this dense mass of vegetable matter became converted into coal.
+After a time the shales and sandstones which had been piled above this
+stuff, which was to form coal for the future, were again elevated to
+form a land surface; upon this another forest sprang up, and by its
+decay produced another mass of vegetable matter fit to form coal. This
+again was let down below the water, more shales and sandstones were
+deposited on the top, and this process went on over and over again till
+the whole mass of our present coal measures was formed. You will now see
+how it is that trees are so seldom found in an upright position in the
+coal beds. As the land went down, they would in very many cases be
+toppled over by the water as it flowed against them, or their base would
+be rotted, and they would then either fall or be blown over; that is the
+reason why in most cases they are found lying flat on the roof of the
+coal bed. But in a few cases, when the depression was very gentle and
+gradual, the trees were not overthrown, and the shales and sandstones
+accumulated round them and preserved them in the position in which they
+grew.
+
+I do not know that I can point out to you anything nowadays that exactly
+resembles the state of things that must have gone on during the times
+these coal measures were being formed; but there are a great many cases
+strikingly analogous to them. I shall not attempt to describe them to
+you, but may just mention the mangrove swamps that very often fringe the
+coasts in the tropics, and the cypress swamps of the Mississippi, which
+are so well described by Sir Charles Lyell in his recent works; also
+the great Dismal Swamp of Virginia, which appears to me to furnish the
+nearest analogue to the state of things that existed during coal measure
+times.
+
+Having explained the way in which coal measures have been formed, we
+will now take a brief sketch of its uses and products. The year 1259 is
+memorable in the annals of coal mining. Hitherto the mineral had not
+been raised by authority, but in that year Henry III. granted a charter
+to the freemen of Newcastle-on-Tyne for liberty to dig coal, and a
+considerable export trade was established with London, and it speedily
+became an article among the various manufacturers of the metropolis. But
+its popularity was but short lived. An impression became general
+that the smoke arising therefrom contaminated the atmosphere and was
+injurious to public health. Years of experience have proved the fallacy
+of the imputation; but in 1306 the outcry became so general that a
+proclamation was issued by Edward I forbidding the use of the offending
+fuel, and authorizing the destruction of all furnaces, etc., of those
+persons who should persist in using it. Prejudice gradually gave way as
+the value of the fossil fuel became better known, and from that time
+downward its use has become more and more extended down to the enormous
+extent of our present trade. The annual increase in the production of
+coal in the British Isles since the year 1854 is over 21/2 million tons.
+In that year the coal produce was about 65 million tons, and it has
+grown up to the year 1880 to the grand total of 135 million tons.
+
+We will now deal with some of the uses that this valuable black diamond
+is now being put to. It is, in the first place, the center of all our
+enterprise and prosperity, and upon it depends our chief success as a
+manufacturing nation for the future. When it is exhausted we shall have
+to look forward to the condition of things which now obtains in those
+regions where there is no coal--that is to say, instead of our being a
+nation full of manufacturing and mercantile enterprise, a great nation
+to which all the people of the earth resort, we shall be merely a people
+who live for ourselves by the cultivation of the ground. The duration of
+our coal fields has been ascertained within certain limits. Mr. Hall, an
+accomplished geologist, tells us that in England at the present time we
+have a stock of coal sufficient for our consumption for no less than
+1,000 years. On the other hand, Professor Jevons, whose opinion is
+worthy of the very greatest weight on such questions, calculates that
+100 years is about the tenure of our coal fields, according to the
+present rate of increase in the consumption. Whichever view we take,
+sooner or later the end must ultimately come when the coal will be
+exhausted; when the great mainspring of our commercial enterprise will
+be gone, and we shall revert to that condition in which we were before
+the coal fields were worked. In this point of view, therefore, coal has
+an especial interest to us as engineers. If coal is important in this
+direction, it is no less important in a purely scientific point of view,
+apart from any mercantile end.
+
+The chemist or physicist will tell you the wondrous story that the black
+substance which you burn is simply so much light and heat and motion
+borrowed from the sun and invested in the tissues of plants. He will
+tell you that when you sit round your firesides the flame which enlivens
+you, and the gas which enables you to read, and which civilizes you, is
+nothing in the world but so much sunlight and so much sunheat bottled up
+in the tissues of vegetables, and simply reproduced in your grates and
+gas burners. Very few persons, I am afraid, realize this, which is one
+of the many stories which science in its higher teachings shows us--one
+of those fairy tales which are the result of the most careful scientific
+investigation. Of the hundred and odd million tons of coal which we in
+this country burn in the course of a year, about 20,000,000 tons are
+thrown on our house fires; 30,000,000 tons find their way into our blast
+furnaces, or are otherwise used in the smelting and manufacture of
+metals; about 48,000,000 are burnt under steam boilers; 6,000,000 are
+used in gas-making; while the remainder is consumed in potteries, glass
+works, brick and lime kilns, chemical works, and other sundries which I
+need not speak of.
+
+To go into the chemistry of coal is quite sufficient to take up more
+time than I have at my disposal this evening, therefore I will briefly
+touch on a few of the main points. Coal gas is made, as you are all
+aware, by heating coal or cannel, which is the special form of coal
+most valued for the purpose, on account of the high quality of gas it
+produces in cylindrical fireclay retorts.
+
+The by-products obtained in the manufacture of coal gas, the tar and the
+ammonia water, are nowadays scarcely less important than the coal gas
+itself. The ammonia water furnishes large quantities of salts to be
+used, among other applications, as food for plants. We thus restore
+to-day to our vegetation the nitrogen which existed in plants of
+primeval times. The tar, black and noisome though it be, is a marvelous
+product, by the reason of scores of beautiful substances which are
+concealed within it.
+
+Coal tar when distilled yields three main products: naphtha, dead oil,
+and pitch or asphalt. The naphtha on redistillation yields benzine, from
+which are prepared some of our most beautiful dyes; the dead oil, as
+the less volatile portion is termed, furnishes carbolic acid, used as a
+disinfectant and antiseptic, together with anthracene and naphthaline;
+all three substances the starting points of new series of coloring
+matters.
+
+This discovery of these coloring matters marks an era in the history
+of chemical science; it exercised an extraordinary influence on the
+development of organic chemistry. Theoretical and applied chemistry were
+knit together in closer union than ever, and dye followed dye in quick
+succession; after mauve came magenta, and in close attendance followed a
+brilliant train of reds, yellows, oranges, greens, blues, and violets;
+in fact, all the simple and beautiful colors of the rainbow.
+
+But there is still another story of coal tar to be told. Among the
+many curious substances that wonderful fluid contains is the beautiful
+wax-like body called paraffine, the development of which chiefly owes
+its origin to the genius and energy of Mr. James Young. As early as
+1848, Mr. Young had worked a small petroleum spring in a coal mine in
+Derbyshire, and had produced oils suitable for burning and lubricating
+purposes, but the spring gave out, and then Mr. Young sought to obtain
+these oils by distilling coal. After many trials, in conjunction with
+other gentlemen connected therewith, he proved successful, and the
+present magnitude of this industry is without parallel in the history of
+British manufactures.
+
+In Scotland alone there are about sixty paraffine oil works, one alone
+occupying a site of nearly forty acres. Here about 120,000 gallons of
+crude oil are produced weekly, and among the various works in Scotland
+about 800,000 tons of shale are distilled per annum, producing nearly
+30,000,000 gallons of crude oil, from which about 12,000,000 gallons of
+refined burning oil are obtained in addition to the large quantities
+of naphtha, solid paraffine, ammonia, and other chemical products.
+Twenty-five years ago scarcely a dozen persons had seen this paraffine,
+and now it is turned out by the ton, fashioned into candles delicately
+tinted with colors obtained from coal tar.
+
+I might dwell on this subject until it becomes wearisome to you,
+therefore I will not trespass too much on your time. But from every
+point we look we reach this fact, that our coal trade is one which
+develops itself according to laws that we are perfectly powerless to
+control; if it seems to promise a less rapid increase here, it is only
+that it may spread abroad with accelerated vigor elsewhere; if it is our
+slave in some aspects, it seems as if it were our master in others.
+
+Finally, we have to ask, What of our export coals? Rapid as has been the
+growth of our total production during the last twenty-three years, the
+growth of our export of coals has been greater still. Beginning at
+4,300,000 tons in '54, we find it reaching 16,250,000 tons in '76, and
+an increase at a corresponding ratio up to the present date as far as
+statistics will carry us. At such a rate of increase it would seem as
+if our whole annual production would be ultimately swallowed up in our
+exports, and it is not, perhaps, impossible that after we have ceased to
+be to any great extent a manufacturing people, a certain export trade
+in coal may still continue. Just the same as the export trade in coal
+preceded by centuries our own uses for it other than domestic, so may
+it also survive these by a period as prolonged. If our descent from
+our present favored position be a gradual one, much may be done in the
+interval to adapt ourselves to the future outcome, but it is certain
+that nothing will be done except under the stern persuasion of
+necessity.
+
+When our coal fields become exhausted, be it soon or late, he would be
+a wise or, perhaps, a rash speculator who fixed himself to a year or a
+generation. Being inevitable, the best philosophy is to make our decline
+more gradual and less bitter. Sentimental regrets that these hills and
+valleys will no longer resound with the din of labor, or be blackened by
+the smoke of the factory, would surely be out of place. What we might
+regret is that Britain, which we know and are proud of, the Britain
+of great achievements in politics and literature, of free thought and
+self-respecting obedience, of a thousand years of high endeavor and
+constant progress, was indeed to perish when these factories and
+furnaces whirled and blazed their last. But, it is not so. This
+country's fortunes are gradually being merged into those of a Greater
+Britain, which largely, through the aid of coal, whose prospective
+loss we are lamenting, has grown beyond the limits of these islands to
+overspread the vastest and richest regions of the earth; and we have no
+reason to fear that the great inheritance that America and Australia
+and New Zealand have accepted from us will in their hands be dealt
+unworthily with in the future.
+
+       *       *       *       *       *
+
+
+
+
+GASTON PLANTE.
+
+
+This eminent scientist was born in Orthez (Department of
+Basses-Pyrenees) on the 22d of April, 1834; at present in his fiftieth
+year. He began his scientific career as assistant to Edmund Becquerel at
+the Conservatoire des Arts et Metiers at Paris. In the year 1859, after
+resigning his position at the above named institution, he entered upon
+his researches in electricity, and has continued them ever since.
+His work entitled "Recherches sur l'Electricite" is a model of clear
+language and elegant demonstration, and contains all the papers
+presented by Plante to the Paris Academy of Sciences since 1859.
+
+[Illustration: GASTON PLANTE.]
+
+At the Paris Electrical Exhibition in 1881, Plante received a Diploma
+of Honor, the highest distinction conferred, while in the same year the
+Academy of Sciences voted him the "Lacaze" prize, and the Society for
+the Encouragement of National Industry presented him with the "Ampere"
+medal, its highest award.
+
+Plante deserves not only the honors conferred upon him by his own
+country, but those of the world on account of his cosmopolitan
+character--a rarity among his countrymen. He sends his apparatus to all
+exhibitions of any consequence; they appeared at Munich and Vienna,
+where their interpretation by the attendant added considerably to the
+renown of their author.--_Zeitch f. Elektrotechnik_.
+
+       *       *       *       *       *
+
+
+
+
+WARREN COLBURN.
+
+
+Warren Colburn, the eminent American mathematician, was born in Dedham,
+Mass., March 1, 1793.
+
+He was the eldest son of a large family of children. His parents were
+poor, and "Warren" was, during his childhood, frequently employed in
+different manufacturing establishments to aid the family by his small
+earnings.
+
+In early boyhood he manifested an unusual taste for mathematics, and
+in the common district school was regarded as remarkable in this
+department. He learned the trade of a machinist, studying winters, until
+he was over twenty-two years of age, when he began to fit for Harvard
+College, which he entered in 1817 and graduated with high honors in
+1820. He taught school in the winter months, while in college, in
+Boston, Leominster, and in Canton, Mass. From 1820 to 1823 he taught a
+select school in Boston.
+
+While in college he was regarded as by far the best mathematician in his
+class, and during this period thought there was the necessity for such a
+book as his "First Lessons in Intellectual Arithmetic." This conviction
+had been forced upon his mind by his experience in teaching. In the
+autumn of 1821 he published his "first edition." His plan was well
+digested, although he was accustomed to say that "the pupils who were
+under his tuition made his arithmetic for him;" that the questions they
+asked and the necessary answers and explanations which he gave in reply
+were embodied in the book, which has had a sale unprecedented for
+any book on elementary arithmetic in the world, having reached over
+2,000,000 copies in this country, and the sale still continues, both in
+this country and in Great Britain. It has been translated into most of
+the European languages and by missionaries into many Asiatic languages.
+
+After teaching in Boston about two and one-half years, he was chosen
+superintendent of the Boston Manufacturing Company's works at Waltham,
+Mass., and accepted the position; and in August, 1824, owing to the
+mechanical genius he displayed in applying power to machinery, combined
+with his great administrative ability, he was appointed superintendent
+of the Lowell Merrimac Manufacturing Co., at Lowell, Mass. Here he
+projected a system of lectures of an instructive character, presenting
+commerce and useful subjects in such a way as to gain attention and
+enlighten the people.
+
+For several years he delivered gratuitous lectures on the Natural
+History of Animals, Light, Electricity, the Seasons, Hydraulics,
+Eclipses, etc. His knowledge of machinery enabled him admirably to
+illustrate these lectures by models of his own construction; and his
+successful experiments and simple teaching added much to the practical
+knowledge of his operatives.
+
+He proposed to occupy the space between the common schools and the
+college halls by carrying, so far as might be practicable, the design of
+the Rumford Lectures of Harvard into the community of the actual workers
+of common life.
+
+In the mean time he discharged his official duties efficiently, and the
+superintendence of the schools of Lowell was also added to his labors.
+He never relinquished, during these busy years, the design formed in his
+college days of furnishing to the children of the country a series of
+text-books on the _inductive plan_ in mathematics.
+
+His "Algebra upon the Inductive Method of Instruction," appeared in
+1825, and his "Sequel to Intellectual Arithmetic" in 1836. He regarded
+the "Sequel" as a book of more merit and importance than the "First
+Lessons."
+
+He also published a series of selections from Miss Edgeworth's stories,
+in a suitable form for reading exercises for the younger classes of
+the Lowell schools, in the use of which the teachers were carefully
+instructed.
+
+In May, 1827, he was elected a Fellow of the American Academy of
+Sciences. For several years he was a member of the Examining Committee
+for Mathematics at Harvard College.
+
+He was a member of the Superintending School Committee of Lowell; and so
+busy were he and his coworkers that they were repeatedly obliged to hold
+their meetings at six o'clock in the morning.
+
+Warren Colburn was ardently admired--almost revered--by the teachers who
+were trained to use his "Inductive Methods of Instruction" in teaching
+elementary mathematics.
+
+In personal appearance Mr. Colburn was decidedly pleasing. His height
+was five feet ten, and his figure was well proportioned. His face
+was one not to be forgotten; it indicated sweetness of disposition,
+benevolence, intelligence, and refinement. His mental operations were
+not rapid, and it was only by great patience and long continued thought
+that he achieved his objects. He was not fluent in conversation; his
+hesitancy of speech, however, was not so great when with friends as
+with strangers. The tendency of his mind was toward the practical in
+knowledge; his study was to simplify science, and to make it accessible
+to common minds.
+
+Mr. Colburn will live in educational history as the author of "Warren
+Colburn's First Lessons," one of the very best books ever written, and
+which, for a quarter of a century, was in almost universal use as a
+text-book in the best common schools, not only in the primary and
+intermediate grades, but also in the grammar school classes.
+
+In accordance with the method of this famous book, the pupils were
+taught in a natural way, a knowledge of the fundamental principles of
+arithmetic. By its use they developed the ability to solve mentally and
+with great facility all of the simple questions likely to occur in the
+every day business of common life.
+
+Undoubtedly Pestalozzi first conceived the idea of the true "inductive
+method" of teaching numbers; but it was Mr. Colburn who adapted it to
+the needs of the children of the common elementary schools. It has
+wrought a great change in teaching, and placed Warren Colburn on the
+roll as one of the educational benefactors of his age.
+
+He died at Lowell, Mass., Sept. 13, 1883, at the age of 90
+years.--_Journal of Education_.
+
+       *       *       *       *       *
+
+
+
+
+THURY'S DYNAMO-ELECTRIC MACHINE.
+
+
+Thury's dynamo-electric machine, which presents some peculiarities,
+has never to our knowledge been employed outside of Sweden and a few
+neighboring regions; but this is doubtless due to some personal motive
+or other of its constructors, since it has, it would seem, given
+excellent results in every application that has been made of it. It is
+represented in perspective in Fig. 1, and in longitudinal section and
+elevation in Figs. 2 and 3.
+
+As may be seen, it is a multipolar (6-pole) machine in which an attempt
+has been made to utilize magnetically, as far as possible, all the iron
+used in the frame. For this reason the system has been given the form of
+a hexagonal prism, whose faces are formed of flat electro-magnets, A, A,
+xxx, constituting the inductors.
+
+The internal angles of this prism are filled by polar expansions, P, P,
+xxx, alternately north and south, that thus form in the interior of the
+apparatus an inscribed cylinder designed to receive the armature. This
+latter belongs to the kinds that are wound upon a cylinder in which the
+wire is external thereto.
+
+The conductors are placed upon the iron drum longitudinally and parallel
+with its axis. But instead of being connected with each other at the
+posterier end of the armature, as in the Siemens system, they are
+connected according to chords that correspond to a fourth, a sixth,
+or any equal fraction whatever of the circumference. Fig. 4 gives a
+perspective view of the cylinder, upon which the conductors 1, 2, 3,
+4, and so on, are placed according to generatrices. The armature is
+supposed to be divided into six parts, each conductor passing over the
+bases of the drum through a chord equal to the radius, that is to say,
+corresponding to a sixth of the circumference.
+
+Three conductors are all connected together in such a way as to form
+but a single circuit closed upon itself. Conductor 1, for example, is
+connected with No. 6 in such a way that the end issuing from 1 becomes
+the end that enters No. 6. Conductor No. 3 is connected in the same way
+with No. 8, and so on, up to the last conductor, which is connected in
+its turn with the end that enters the first.
+
+As the figure shows, the conductor before passing from 3 to 8, for
+example, returns several times upon itself in following 6 and 3, and the
+same is the case with all the rest of the winding.
+
+[Illustration: FIG. 1. PERSPECTIVE VIEW OF THE THURY MACHINE.]
+
+In this way the cylinder becomes inclosed within nine rectangular wire
+frames, each of which is connected with the following one by a conductor
+that is at the same time connected with one of the nine plates of
+the collector. The number of the rubbers corresponds to that of the
+inducting poles. They may be coupled in different ways, but they are in
+most cases united for quantity.
+
+It will be seen that the Thury armature resembles, in the system of
+winding, those of the Siemens machines and their derivatives. But it
+differs from these, however, in the details connected with the coupling
+of the wires, from the very fact that the features of a two-pole machine
+are not found exactly in a multipolar one.
+
+[Illustration: FIGS. 2 AND 3.]
+
+This latter kind of machine is considered advantageous by its inventors,
+in that there is no need of revolving it with much velocity. It must not
+be forgotten, however, that although we reduce the velocity by this mode
+of construction, we are, on another hand, obliged to increase the size
+of the machine, so that, according to the circumstances under which we
+chanced to be placed, the advantage may now be on the one side and now
+on the other.
+
+[Illustration: FIGS. 4 AND 5.]
+
+It goes without saying that Fig. 4 is essentially diagrammatic, and is
+designed to give a clearer idea of the mode of winding the armature. In
+practice the number of the frames, and consequently that of the plates
+of the conductor, is much greater, and the arrangement that we have
+described is repeated a certain number of times, the conducter always
+forming a circuit that is closed upon itself.
+
+The Thury machines are constructed in different styles. No. 1 is a
+100-lamp (16 candles and 100 volts) machine, and Nos. 2 and 3 are
+nominally 250-lamp ones, but may be more. Their weight is 1,100
+kilogrammes, and their velocity, for 100 volts, is from 400 to 500
+revolutions, according to the mode of coupling.
+
+A later type, now in course of construction, is to furnish from 750 to
+2,000 lamps, with 250 revolutions, for 100 volts, and is not to weigh
+more than 2,000 kilogrammes. Let us add that Messrs. Meuron and Cuenod,
+the manufacturers, have likewise applied their mode of winding to
+conductors arranged radially upon the surface of a circle. Fig. 5 shows
+this arrangement.
+
+In this case the inductors will, it is unnecessary to say, be arranged
+laterally as in all flat ring machines. The arrangement will recall, for
+example, that of the Victoria machines (Brush-Mordey).
+
+We do not think that the inventors have applied this radial arrangement
+practically, for it does not appear to be advantageous. The parts of
+conductors which are perpendicular to the radius, and which can be only
+inert (even if they do not become the seat of disadvantageous currents),
+have, in fact, too great an importance with respect to the radial
+parts.--_A. Guerout, in La Lumiere Electrique_.
+
+       *       *       *       *       *
+
+
+
+
+BREGUET'S TELEPHONE.
+
+
+Prof. G. Forbes gives the following description: The instrument which
+I call Breguet's telephone is founded upon the instrument which was
+described by Lipmann, called the capillary electrometer. The phenomenon
+may be shown in a variety of ways. One of the easiest methods to show it
+is by taking a long glass tube and bending it into two glasses of dilute
+acid, and, the tube being filled with acid itself, a piece of mercury
+is placed in the center of the tube. Then if one pole of a battery is
+connected with one vessel of acid, and the other pole of the battery is
+connected with the other vessel of acid, at the moment of connection the
+bit of mercury will be seen to travel to the right or left, according to
+the direction of the current. M. Lipmann explained the action by showing
+that the electro-motive force which is generated tends to alter the
+convexity of the surface of the mercury. The surface of the mercury,
+looked at from one side, has a convex form, which is altered by the
+electro-motive force set up when connection is made with the battery.
+The equilibrium of the mercury is dependent upon the convexity, and
+consequently when the convexity is disturbed the mercury moves to one
+side or the other. Lipmann also showed that if a tube containing a bit
+of mercury, and tapering to a point, is taken and dipped into acid, and
+then the tube filled with acid, on one pole of a battery being dipped
+into the tube and another into the acid the mercury will move up or
+down, showing similar action to that which I have just described.
+
+Lipmann further showed the reverse effect, that if a piece of mercury be
+forcibly pressed, so as to alter the convexity of its surface, such
+as by bringing it into a narrower part of the tube, then there is an
+electro-motive force produced.
+
+It occurred to me, and no doubt it did to Breguet also, that if we speak
+either against the surface of the glass tube, and caused the tube to
+vibrate, or if the mercury were caused to vibrate in the manner I have
+shown, we ought to be able to introduce a varying current in the wires
+which might have sufficient electro-motive force to produce audible
+speech in a Bell telephone. Further, the same instrument, since varying
+electro-motive force affected the drop of mercury and produced varying
+displacement, ought also to act as a receiving instrument, and should
+vibrate in accordance with the currents that arrive. My experiments
+have only been in the way of using the instrument as a transmitter; but
+Breguet, I find, used it as a receiver as well as a transmitter, though
+I am not aware that M. Breguet made any actual experiments so as to
+produce articulate speech. I presume that this was done, although I have
+not come across any description of the experiments, and it was for that
+reason that I thought possibly some account of my own experiments might
+be interesting to the members of the Society. The first tubes that I
+used were bits of glass tube about a centimeter diameter, and simply
+drawn out to a tapering point. I have the tubes here. The first
+experiment I tried was by tapping the glass tube so as to mechanically
+shift the position of the mercury, and by listening on the telephone for
+the effect. For a long time, at least an hour, I could get no effect at
+all. At last I got a sound, but could not understand how it was that at
+one time of tapping I could not hear, while at another time it was quite
+loud.
+
+At the top I always got sound, but at the side I got no sound, although
+the mercury was shaking. I then tried to see how feeble a current was
+audible in the telephone. An assistant tapped the tube while I stood out
+of the way, and where I could not see. I got him to tap it gentler and
+gentler, and could hear the most feeble tap. A pellet of paper was next
+dropped from various heights down to an inch, and each tap was perfectly
+audible in the telephone. I tried many methods, and one, purely
+accidentally chosen, was a piece of glass tube which I had drawn out
+into a tube about 2 mm. diameter, and then nearly closed the end of
+it. I have that tube here, and you will see what an ill-shapen and
+ugly-looking tube it is, but it is one of the best tubes I ever got; and
+finally, I found that small bits of thermometer tube, which were simply
+closed at their ends with a blow-pipe, gave very good results, and I was
+able to make them useful for various purposes. I then tried mounting a
+tube on the end of a speaking-trumpet and speaking to the mercury, but
+got no effect. In every place where I attached the glass tube itself
+to a sounding-board I got a very accurate reproduction. I put one on a
+piece of ferrotype plate, and that gave really the best result I ever
+got. The tube was fastened with sealing-wax, and with it I got excellent
+speech heard in a Bell receiver. I tried putting in a large number of
+these tubes, all in quantity, on the bottom of a ferrotype plate, but
+with no advantage. I have not yet tried putting them in series, one
+behind the other, so as to increase the electro-motive force, but I
+think that probably would be an improvement; of course it would require
+many vessels of acidulated water to dip into. The most distinct
+articulate speech was obtained from an ordinary ferrotype telephone
+plate, secured at the edges, and one of the glass tubes you see here
+attached to it.
+
+       *       *       *       *       *
+
+
+
+
+MUNRO'S TELEPHONIC EXPERIMENTS.
+
+
+Mr. J. Munro, whose name is well known not only as a very clear writer
+upon electrical subjects, but as an original investigator, has recently,
+with the assistance of Mr. Benjamin Warwick, been conducting a most
+interesting experimental investigation of the action of the microphone
+as a telephonic transmitter, with the result of proving that metals may
+advantageously be employed in the place of carbon in a transmitting
+instrument, a practical development of one of the very earliest of
+Professor Hughes' microphones. The fact that metallic electrodes can
+practically be employed in microphonic transmitters has been denied of
+late with so much assurance and in such high quarters, that Mr. Munro's
+successful applications of that portion of Professor Hughes' discovery
+possess an especial interest, and must to a considerable extent affect
+the aspect of litigation in future contests in which the discovery of
+the microphone and the invention of the carbon transmitter are vital
+points at issue.
+
+In investigating the properties of metallic conductors employed in the
+construction of microphones, Mr. Munro's first experiments were made
+with wires. These, in some cases, were caused by the action of a
+diaphragm, to rub the one on the other in such a manner as to make the
+point of contact vary (under the influence of the vibrations of the
+diaphragms) on one side or other of a position of normal potential, so
+that by the movement of a wire attached to a vibrating tympan along a
+fixed wire conveying a current from a battery, and thereby shunting the
+current at various positions along the length of the fixed wire, the
+strength of the current in the derived circuit, in which was included a
+suitable receiver, was varied accordingly. In other experiments mercury
+was employed, either as a sliding-drop, inclosing the fixed wire, or as
+an oscillating column; but these experiments, though instructive and
+interesting, did not for various reasons give encouraging results with a
+view to the practical application of the principle.
+
+They, however, led Mr. Munro to proceed with compound wire structures,
+such as gratings resting upon or rubbing against one another, and one of
+the first experiments in this direction proved very successful, and led
+Mr. Munro to the construction of his gauze telephone, which is the most
+characteristic and efficient of his practical apparatus.
+
+This instrument consists essentially of two pieces of iron-wire gauze,
+the one fixed in a vertical plane, and the other resting more or less
+lightly against it, the pressure between them being regulated by an
+adjustable spring or weight. These gauze plates are so connected in a
+telephonic circuit as to constitute the electrodes of a microphone; for
+touching one another lightly in several points, they allow the current
+to be transmitted between them in inverse proportion to the resistance
+offered to it in its passage from one to the other. Under the influence
+of sonorous vibrations the one plate dances more or less on the other,
+thus varying the resistance; and very perfect articulation is produced
+in a telephonic receiver included in the circuit. The gauze transmitter
+so constructed may be fixed within a wall-box with or without a
+mouthpiece; but as the sound waves acting directly upon the gauze plates
+set them into agitation through their sympathetic vibration or by direct
+impact, no sort of diaphragm or equivalent device is necessary, and none
+is employed.
+
+[Illustration: FIG. 1.]
+
+A convenient form of this apparatus is shown in Fig. 1, and to which the
+name of "The Lyre Telephone" has been given from its resemblance to that
+impossible musical instrument. In this apparatus, G1 is a plate of iron
+wire gauze stretched vertically between two horizontal wires attached to
+a lyre-shaped framework of mahogany; against the plate rests the smaller
+plate, G squared, the normal pressure between them being regulated by an
+adjustable spring acting in opposition to a weighted lever, W. The two
+plates are connected respectively with the attachment screws, X and
+Y, by which the instrument is placed in a circuit with a battery and
+telephonic circuit.
+
+[Illustration: FIG. 2.]
+
+A modification of this apparatus is shown in the diagram sketch, Fig.
+2, which will probably be a more practical form. In this instrument the
+electrodes consist of two circular disks of iron wire gauze of different
+diameters, the larger disk, G1, which is fixed, being pierced with holes
+of smaller diameter than the smaller disk, G squared. In the diagram the two
+disks are shown separated for the purpose of explanation, but in reality
+they rest the one against the other; the smaller and movable disk,
+G squared, is held up against G1 with greater or less pressure by the spiral
+spring, S, the tension of which can be adjusted by a screw or other
+suitable device at N. This form of the apparatus is more suitable for
+inclosure in a wall box with or without a mouthpiece, but it does not
+require the employment of any kind of diaphragm or tympan. Mr. Munro
+can employ with all his instruments an induction coil for installations
+where the resistance of the line wire makes it desirable to do so; the
+microphone and battery being included in the primary circuit and the
+telephones in the secondary.
+
+[Illustration: FIG. 3.]
+
+Fig. 3 is an ingenious arrangement devised by Mr. Munro, in which the
+adjusting spring or weight is substituted by a magnet which may be
+either a permanent or an electro-magnet. The figure shows an arrangement
+in which the fixed gauze, g1, is perforated as in the apparatus
+illustrated in Fig. 2, and the movable electrode, g, is bent or dished
+so as to press upon g1 around its edge. E is a magnet which by its
+attractive influence upon g holds t up against g1 with a pressure
+dependent upon its magnetic intensity and upon its distance from the
+gauze. By making E an electro-magnet, and including its coil in the
+telephonic circuit, an instrument may be constructed in which the normal
+pressure between the electrodes can be automatically adjusted to the
+strength of the current, and in cases where an induction coil is
+employed the magnet, E, may be the core of such a coil.
+
+[Illustration: FIG. 4.]
+
+Fig. 4 illustrates an apparatus devised by Mr. Munro, and to which the
+name thermo-microphone might be given, as it is a microphone in which
+thermo-electric currents are employed in the place of voltaic currents,
+its special feature of interest lying in the fact that the heated
+junction of the thermo-electric couple is identical with the microphone
+contacts of the two electrodes. In this very elegant experiment a piece
+of iron wire gauze, G, is supported in a horizontal position by a light
+metallic support, B. To another support. A, is loosely hinged a frame,
+which at its further extremity carries a little coil of German silver
+wire, C, which by its weight rests upon the center of the gauze plate,
+G; and in contact therewith, and to increase the pressure of contact, a
+little bar weight is laid within the convolutions of the core. The
+two electrodes, the gauze, and the coil are connected, as shown, to a
+receiving telephone, T. Upon the application of heat, as from the flame
+of a spirit lamp placed below, a thermo-electric current is set up
+throughout the circuit; in this condition the apparatus becomes a very
+perfect microphone, and when the pressure between the electrodes is
+properly adjusted it is a very efficient telephonic transmitter,
+transmitting articulate speech and musical sounds with remarkable
+clearness and fidelity.
+
+[Illustration: FIG. 5]
+
+Mr. Munro is, with the aid of Mr. Warwick's manipulative skill,
+extending this portion of his investigation further by experimenting
+with gauzes and coils of various metals forming other couples in
+the thermo-electric series, as well as with iron and other gauzes
+electrotyped with bismuth and other metals, and we hope in due time to
+lay the results of those experiments before our readers.
+
+Mr. Munro has, moreover, observed that if two pieces of gauze of
+identical material and in microphonic contact be heated, a peculiar
+sighing sound is heard in a telephone connected with them and with a
+battery, and he attributes this phenomenon to the electrical discharge
+between the gauze plates being facilitated and increased by the
+action of heat, but we are rather inclined to trace the effect to the
+mechanical action of the one gauze moving over the other under the
+influence of expansion and contraction of the metals by the variable
+temperature of the flame and convection currents of heated air, such
+movement producing the sounds just as would be produced if one of the
+electrodes of an ordinary microphone were as delicately moved by the
+hand or other agent.
+
+[Illustration: FIG. 6]
+
+Figs. 5 and 6 illustrate another and distinct form of metallic
+microphone transmitter designed by Mr. Munro and Mr. Warwick, in which
+a small chain, preferably of iron, forms the microphonic portion of the
+apparatus. In Fig. 5, A is a plate of sonorous wood forming a diaphragm
+or collector of the sonorous waves; to the back of this is attached a
+short length of chain, C, the opposite ends of which are by the wires, X
+and Y, included in the telephonic circuit. The points of junction of the
+links with one another constitute the variable microphonic contacts, and
+the normal pressure between them is adjusted by the spiral spring, S,
+the tension of which may be varied by the cord and winding pin, B. Fig.
+6 is the section of a transmitter constructed upon this principle, and
+in which two chains, c and c', are employed attached at one end by a
+wire, f, to a diaphragm mouthpiece, N, and at their opposite extremities
+to the adjusting springs, s and s'; an induction coil, D, may be
+employed if the resistance of the line render it advantageous.
+
+[Illustration: FIG. 7]
+
+Fig. 7 is a form of pencil microphone experimented with by Mr. Munro,
+which differs from some of the Hughes' transmitters adopted by Crossley,
+Gower, Ader, and many others only in the material of which it is
+composed, Mr. Munro's being of cast iron, while the others to which we
+have referred are of carbon rods such as are used in electric lighting.
+In Fig. 7 a light cast-iron bar, i squared, of the form shown, is supported in
+holes drilled in two blocks of cast iron, i i', and the pressure between
+the bar and the blocks can be adjusted by a regulating spring, s. In
+connection with this apparatus Mr. Munro has observed that rust has no
+appreciable effect upon the efficiency of the instrument unless it be
+to such an extent as to cause the two to adhere, or to be "rusted up"
+together.
+
+[Illustration: FIG. 8]
+
+We now come to another class of metallic transmitters with which Mr.
+Munro and his associate have been making experiments, and to which he
+has given the name "Grain transmitter," since it consists of a box
+having metallic sides, e e', to which terminal screws, t t', are
+attached and filled in between with iron or brass filings, granules of
+spongy iron, or indeed small metallic particles in any form; one of the
+most efficient transmitters being a box such as is shown in Fig. 8,
+filled with a quantity of 1/4 in. screws.
+
+[Illustration: FIG. 9]
+
+The results of Mr. Munro's experiments have led him to the opinion
+that the action of the microphone must be attributed to the action
+of sonorous vibrations upon the air or gaseous medium separating the
+so-called contact-points of the electrodes, and that across these
+spaces, or films of gaseous matter, silent electrical discharges take
+place, the strengths of which, being determined by the thickness of the
+gaseous strata through which they pass, vary with the motion of the
+electrodes; and as, according to this hypothesis, the distances of the
+electrodes from one another is determined by the sound-waves, the sound
+in that way controls the current.--_Engineering_.
+
+       *       *       *       *       *
+
+
+
+
+APPARATUS FOR MANEUVRING BICHROMATE OF POTASSA PILES FROM A DISTANCE.
+
+
+Bichromate of potassa piles, especially those single liquid ones that
+are applied to domestic lighting, all present the grave defect of
+consuming almost as much zinc in open as in closed circuit, and of
+becoming rapidly exhausted if care be not taken to remove the zinc from
+the liquid when the battery is not in use. This operation, which is a
+purely mechanical one, has hitherto required the pile to be located near
+the place where it was to be used, or to have at one's disposal a system
+of mechanical transmission that was complicated and not very ornamental.
+
+In order to do away with this inconvenience, which is inherent to all
+bichromate piles, Mr. G. Mareschal has invented and had constructed an
+ingenious system that we shall now describe.
+
+[Illustration: FIG. 1.--BICHROMATE OF POTASSIUM PILE, WITH MANEUVERING
+APPARATUS.]
+
+Mr. Mareschal's plan consists in suspending the frame that carries all
+the battery zincs (Fig. 1) from the extremity of a horizontal beam, and
+balancing them by means of weights at the other extremity.
+
+The system, being balanced, the lifting or immersion of the zincs then
+only requires a slight mechanical power, such as may be obtained from
+an ordinary kitchen jack through a combination that will be readily
+understood upon reference to Fig. 2. The axis, M, of the jack,
+on revolving, carries along a crank, MD, to which is fixed a
+connecting-rod, A, whose other extremity is attached to the horizontal
+beam that supports the zincs and counterpoises. If the axle, M, be given
+a continuous revolution, it will communicate to the rod, A, an upward
+and downward motion that will be transmitted to the beam and produce an
+alternate immersion and emersion of the zincs.
+
+Upon stopping the jack at certain properly selected positions of the
+rod, MD, the zincs may, at will, be kept immersed in the liquids, or
+_vice versa_. This is brought about by Mr. Mareschal in the following
+way: The jack carries along in its motion a horizontal fly-wheel, V,
+against whose rim there bears an iron shoe, F, placed opposite an
+electro-magnet, E. In the ordinary position, this shoe, which is fixed
+to a spring, bears against the felly of the wheel and stops the jack
+through friction. When a current is sent into the electro-magnet, E, the
+brake shoe, F, is attracted, leaves the fly wheel, and sets free the
+jack, which continues to revolve until the current ceases to pass into
+the electro.
+
+[Illustration: FIG. 2.--PRINCIPLE OF THE APPARATUS.]
+
+The problem, then, is reduced to sending a current into the electro and
+in shutting it off at the proper moment. This result is obtained very
+simply by means of an auxiliary Leclauche pile. (The piles got up for
+house bells will answer.) The current from this pile is cut off from
+the electro, F, by means of a button, B, when it is desired to light or
+extinguish the lamps. In a position of rest, for example, the crank, MD,
+is vertical, as shown in the diagram to the right in Fig. 2. The circuit
+is open between M and N through the effect of the small rod, C, which
+separates the spring, R, from the spring, R'. As soon as the circuit has
+been closed, be it only for an instant, the crank leaves its vertical
+position, the rod, C, quits the bend, S, and the spring, R, by virtue of
+its elasticity, touches the spring, R', and continues its contact until
+the crank, MD, having made a half revolution, the rod, C', repulses the
+spring, R, and breaks the circuit anew. The brake then acts, and the
+crank stops after making a revolution of 180 deg., and immersing the
+zincs to a maximum depth. In order to extinguish the lamp, it is only
+necessary to press the button, B, again. The axle, M, will then make
+another half revolution, and, when it stops, the zinks will be entirely
+out of the liquid. The depth of immersion is regulated by fixing the
+crank-pin. D, in the apertures, T1, or T2, of the connecting rod. This
+permits the travel, and consequently the degree of immersion, to be
+varied.
+
+The device requires three wires, two for connecting the lamp with the
+battery, and one for maneuvering the apparatus through a closing of the
+contact, B.
+
+With Mr. Mareschal's system, bichromate of potassa piles may be utilized
+in a large number of cases where a light of but short duration is
+required until the battery is exhausted, without the tedious maneuvering
+of a winch and without inconvenience. The jack permits of a large number
+of lightings and extinctions being effected before it becomes necessary
+to wind up its clockwork movement. This operation, however, is very
+simple, and may be performed every time the battery is visited in order
+to see what state it is in.
+
+We regard Mr. Mareschal's apparatus as an indispensable addition to
+every case of domestic electric lighting in which bichromate of potassa
+piles are used, and, in general, to all cases where the pile becomes
+uselessly exhausted in open circuit. It will likewise find an
+application in laboratories, where the bichromate pile is in much demand
+because of its powerful qualities, and where it is often necessary to
+order it from quite a distant point.--_La Nature_.
+
+       *       *       *       *       *
+
+
+
+
+MAGNETIC ROTATIONS.
+
+By E. L. VOICE.
+
+
+The remarkable researches and experiments of Professor Hughes clearly
+show that magnetism is totally independent of iron, and that its
+molecules, particles, or polarities are capable of rotation in that
+metal. It would also appear that by reason of the friction between
+magnetism and iron, the molecules of the latter are only partially
+moved, such movement being the result of the tendency of iron to retard
+magnetic change.
+
+I have found that the magnetic molecules also possess inertia, that they
+are capable of acquiring momentum, and that their rotation continues
+for a considerable time after the exciting cause of their rotation has
+ceased.
+
+These facts may be proved in a very evident manner, inasmuch as induced
+electric currents are generated by this _after_ rotation, which may be
+made to light incandescent lamps.
+
+In this case the magnetic rotations are produced in an electro magnet by
+means of alternate currents supplied by alternating Gramme machine.
+
+In order to better explain the action, it will be necessary to refer
+to a new electro-motor, which was the subject of an article in the
+_Electrical Review_ of February 19 last. It is of that type of motor in
+which the field magnet and armature poles are alternately arranged, and
+which requires a periodical reversibility of magnetism in the armature
+to cause the latter to revolve, as in the Griscom motor. The insulating
+strips in the commutator are sufficiently wide to demagnetize the whole
+of the machine before reversibility in the armature takes place, and
+this demagnetization sets up a _direct_ induced current, which is caught
+in a shunt circuit by the aid of a second commutator, which only comes
+into action when the first commutator goes out.
+
+When this motor is supplied by a continuous current, it is easy to
+understand that the induced current which passes through the shunt
+circuit, and which is caused by the demagnetization, is proportional
+to the mass of iron and wire of which the machine is composed, or
+proportional to its inductive capacity. This current is purely a
+secondary effect, of short duration, and only occurs once at each break
+of the commutator.
+
+The motor is of such a size that when supplied with a continuous current
+of proper strength the induced electrical effect in the shunt circuit
+will light one incandescent lamp. If, however, it is supplied with an
+alternating current of the same power, it will light eight lamps, and
+the mechanical power given off is even more than with a continuous
+current, provided that the alternations from the dynamo do not exceed
+6,000 a minute.
+
+At first I was considerably puzzled by this great difference, because in
+both cases it is impossible for the lamp circuit to be acted upon by the
+main current. It occurred to me, however, that the rapid alternations
+of the exciting current from the dynamo, and the consequent speed of
+magnetic molecular rotation, gave the latter a certain momentum, and
+that by widening the insulating strips of the first or main current
+commutator, and proportionately increasing the width of conducting
+surface in the shunt commutator up to certain limits, this effect would
+be increased. I found such to be the case, from which I inferred that
+the increase of induced current in the shunt circuit was on account of
+its longer duration, by reason of the acquired momentum of the magnetic
+molecular rotations _after_ the alternating exciting current had ceased.
+
+[Illustration]
+
+Those who have facilities for carrying out experiments may prove it in
+the following manner:
+
+E, in the inclosed drawing, is an electro-magnet whose brushes press on
+two metallic bands, B and B1, fixed to but insulated from the spindle,
+A. The band, B, is in electrical circuit with the shunt commutator, S,
+and the main commutator, M; while the band, B1, is in contact with
+shunt commutator, S1, and main commutator, M1. This contact is made
+by conducting rods, as indicated. The commutators, as regards their
+brushes, are so arranged that when M and M1 are in action, S and S1 are
+out of action, and _vice versa_. The spindle and commutators are rotated
+by the pulley, P. L is an incandescent lamp in the shunt circuit.
+
+Let us now suppose the apparatus at rest, and the brushes in electrical
+contact with the main commutators, M and M1. The current from an
+alternating dynamo passes into the magnet, E, and rapidly reverses its
+polarity. By actuating the pulley, P, the commutators are rotated, when
+M and M1 go out of, and the shunt commutators, S and S1, come into
+action, enabling the _after_ current set up in the magnet to light the
+lamp, L, in the shunt circuit.
+
+In order to make comparative tests, the same apparatus may be supplied
+with continuous instead of alternating currents. The after current in
+the former case, however, is much smaller, consisting of one electrical
+impulse only at each break of the commutator, whereas in the alternating
+system these impulses are practically continued; the result being that,
+all things being equal, a far greater number of lamps may be used in the
+shunt than when supplied by continuous current only, and it would
+appear that this difference can only be attributed to the fact that the
+rotatory motion of magnetic molecules, or polarity of the magnet, E,
+acquires momentum when acted upon by a suitable physical cause, such as
+alternating currents of electricity; this momentum lasting a sensible
+time after the cessation of the acting cause.
+
+If we had the gift of magnetic sight, and could see what is going on in
+the electro-magnet when it is excited by alternating currents, we should
+probably see the molecules or polarities tumbling over each other at an
+enormous rate. I do not think, however, that we should see anything but
+a vibratory motion as regards the iron molecules.--_Elec. Review_.
+
+       *       *       *       *       *
+
+[AMER. MICROSCOP. JOUR.]
+
+
+
+
+LIGHTON'S IMMERSION ILLUMINATOR
+
+
+The following extremely simple plan for an immersion illuminator was
+first brought to the notice of microscopists a few years ago, and,
+in the absence of the inventor, was kindly described by Prof. Albert
+McCalla, at the meeting of the American Society of Microscopists, at
+Columbus, O. It consists of a small disk of silvered plate glass, c,
+about one-eighth of an inch thick, which is cemented by glycerine
+or some homogeneous immersion medium to the under surface of the
+glass-slide, s. Let r represent the silvered surface of the glass disk,
+b, the immersion objective, f, the thin glass cover. It will be easily
+seen that the ray of light, h, from the mirror or condenser above the
+stage will enter the slide and thence be refracted to the silvered
+surface of the illuminator, r, whence it is reflected at a corresponding
+angle to the object in the focus of the objective. A shield to prevent
+unnecessary light from entering the objective can be made of any
+material at hand, by taking a strip one inch long and three-fourths
+of an inch wide and turning up one end. A hole not more than
+three-sixteenths of an inch in diameter should be made at the angle. The
+shield should be placed on the upper surface of the slide, so that the
+hole will cover the point where the light from the mirror enters the
+glass. With this illuminator Moeller's balsam test-plate is resolved
+with ease, with suitable objectives. Diatoms mounted dry are shown in
+a manner far surpassing that by the usual arrangement of mirror,
+particularly with large angle dry objectives.
+
+Ottumwa, Ia.
+
+WM. LIGHTON.
+
+[Illustration: LIGHTON'S ILLUMINATOR.]
+
+       *       *       *       *       *
+
+
+
+
+FOUCAULT'S PENDULUM EXPERIMENTS.
+
+By RICHARD A. PROCTOR.
+
+
+Science owes to M. Foucault the suggestion that the motions of a
+pendulum so suspended as to be free to swing in any vertical plane
+might be made to give ocular demonstration of the earth's rotation. The
+principle of proof may be easily exhibited, though, like nearly all of
+the evidences of the earth's rotation, the complete theory of the
+matter can only be mastered by the aid of mathematical researches of
+considerable complexity. Suppose A B (Fig. 1) to be a straight rod in a
+horizontal position bearing the free pendulum C D suspended in some such
+manner as is indicated at C; and suppose the pendulum to be set swinging
+in the direction of the length of the rod A B, so that the bob D remains
+throughout the oscillations vertically under the rod A B. Now, if A B be
+shifted in the manner indicated by the arrows, its horizontality being
+preserved, it will be found that the pendulum does not partake in this
+motion. Thus, if the direction of A B was north and south at first, so
+that the pendulum was set swinging in a north and south direction, it
+will be found that, the pendulum will still swing in that direction,
+even though the rod be made to take up an east and west position.
+
+[Illustration: Fig. 1.]
+
+Nor will it matter if we suppose B (say) fixed and the rod shifted by
+moving the end A horizontally round B. Further, as this is true whatever
+the length of the rod, it is clear that the same fixity of the plane
+of swing will be observed if the rod be shifted horizontally as though
+forming part of a radial line from a point E in its length. In these
+cases the plane of the pendulum's swing will indeed be shifted _bodily_,
+but the direction of swing will still continue to be from north to
+south.
+
+Now, let P O P' represent the polar axis of the earth; a b a horizontal
+rod at the pole bearing a pendulum, as in Fig. 1. It is clear that if
+the earth is rotating about P O P' in the direction shown by the arrow,
+the rod a b is being shifted round, precisely as in the case first
+considered. The swinging pendulum below it will not partake in its
+motion; and thus, through whatever arc the earth rotates from west to
+east, through the same arc will the plane of swing of the pendulum
+appear to travel from east to west under a b.
+
+But we cannot set up a pendulum to swing at the pole of the earth. Let
+us inquire, then, whether the experiment ought to have similar results
+if carried out elsewhere.
+
+Suppose A B to be our pendulum-bearing rod, placed (for convenience of
+description merely) in a north and south position. Then it is clear that
+A B produced meets the polar axis produced (in E, suppose), and when,
+owing to the earth's rotation, the rod has been carried to the position
+A' B', it still passes through the point E. Hence it has shifted through
+the angle A E A', a motion which corresponds to the case of the motion
+of A B (in Fig. 1) about the point E,[1] and the plane of the pendulum's
+swing will therefore show a displacement equal to the angle A E A'. It
+will be at once seen that for a given arc of rotation the displacement
+is smaller in this case than in the former, since the angle A E A' is
+obviously less than the angle A K A'.[2] In our latitude a free pendulum
+should seem to shift through one degree in about five minutes.
+
+[Footnote 1: In reality A E moves to the position A' E over the surface
+of a cone having E P' as axis, and E as vertex; but for any small part
+of its motion, the effect is the same as though it traveled in a plane
+through E, touching this cone; and the sum of the effects should clearly
+be proportioned to the sum of the angular displacements.]
+
+[Footnote 2: In fact, the former angle is less than the latter, in the
+same proportion that A K is less than A E, or in the proportion of the
+sine of the angle A E P, which is obviously the same as the sine of the
+latitude.]
+
+It is obvious that a great deal depends on the mode of suspension. What
+is needed is that the pendulum should be as little affected as possible
+by its connection with the rotating earth. It will surprise many,
+perhaps, to learn that in Foucault's original mode of suspension the
+upper end of the wire bearing the pendulum bob was fastened to a metal
+plate by means of a screw. It might be supposed that the torsion of
+the wire would appreciably affect the result. In reality, however, the
+torsion was very small.
+
+[Illustration: Fig. 2.]
+
+Still, other modes of suspension are obviously suggested by the
+requirements of the problem. Hansen made use of the mode of suspension
+exhibited in Fig. 3. Mr. Worms, in a series of experiments carried out
+at King's College, London, adopted a somewhat similar arrangement, but
+in place of the hemispherical segment he employed a conoid, as shown in
+Fig. 4, and a socket was provided in which the conoid could work freely.
+From some experiments I made myself a score of years ago, I am inclined
+to prefer a plane surface for the conoid to work upon. Care must be
+taken that the first swing of the pendulum may take place truly in one
+plane. The mode of liberation is also a matter of importance.
+
+[Illustration: Fig.3.]
+
+Many interesting experiments have been made upon the motions of a
+free pendulum, regarded as a proof of the earth's rotation, and when
+carefully conducted, the experiments have never failed to afford the
+most satisfactory results. Space, however, will only permit me to dwell
+on a single series of experiments. I select those made by Mr. Worms in
+the Hall of King's College, London, in the year 1859:
+
+"The bob was a truly turned ball of brass weighing 40 lb.; the
+suspending medium was a thick steel wire; the length of the pendulum was
+17 feet 9 inches. The amplitude of the first oscillation was 6 deg. 42', and
+during the time of the experiment--about half an hour--the arcs were
+not much diminished. As I had to demonstrate to a large number of
+spectators, I encountered considerable difficulty," says Mr. Worms, "in
+rendering the small deviations of the plane of oscillation visible to
+all. I accomplished it in three different ways." These he proceeds
+to describe. He had first a set of small cones set up, which were
+successively knocked down as the change in the plane of the pendulum
+slowly brought the pointer under the bob to bear on cone after cone.
+Secondly, a small cannon was so placed that the first touch of the
+pendulum pointer against a platinum wire across the touch-hole completed
+a galvanic circuit, and so fired the cannon. Lastly, a candle was placed
+so as to throw the shadow of the pendulum bob upon a ground-glass
+screen, and so to exhibit the gradual change of the plane of swing.
+
+The results accorded most satisfactorily with the deductions from the
+theory of the earth's rotation.
+
+[Illustration: Fig.4.]
+
+       *       *       *       *       *
+
+
+
+
+A NEW LUNARIAN.
+
+By Prof. C. W. MACCORD, Sc.D.
+
+
+The construction of apparatus for illustrating the motions of the
+heavenly bodies has often occupied the attention of both mathematicians
+and mechanicians, who have produced many very ingenious, and in some
+cases very complicated, combinations. These may be divided into two
+classes; the object of the first being to represent _exactly_ what
+occurs--to reproduce the precise movements of the various bodies
+represented in their true proportions and relations to each other, in
+respect to distances, magnitudes, times, and phases. When the absolute
+complexity of the movements of the bodies composing the solar system
+is considered, it is not so much a matter of wonder that a planetarium
+which shall thus imitate them is a very delicate and complicated machine
+as that it should lie within the limits of human ingenuity.
+
+In the second class, the object is to show the nature and the causes
+of specific phenomena, without regard to others perhaps, and without
+necessarily paying attention to exact proportions of distances and
+dimensions. Indeed, it is often the case that the illustration is made
+clearer by exaggerating some of these and reducing others; thus, for
+example, the causes of the variation in the lengths of the days and
+nights, and of the changes in the seasons, can be exhibited to much
+better advantage by an apparatus in which the diameter of the sun and
+its distance from the earth are enormously reduced than they possibly
+could be were they of their proper proportionate magnitudes; nor is the
+presence of any other planet, or the attendance of a satellite, at all
+necessary or even desirable for the purpose named.
+
+It is apparent that machines of this class can be made much more simple
+than those of the first, while at the same time it may safely be
+asserted that for educational purposes they are far more useful.
+
+In both classes, the action involves the use of some sort of epicyclic
+train, since the motions to be explained are both orbital and axial. The
+planetary body is carried round by a train-arm, and its rotation about
+its axis is usually given it by a train of gearing, the inner or
+central wheel of which is stationary, being fastened to the fixed frame
+supporting the whole.
+
+[Illustration: AN IMPROVED LUNARIAN.]
+
+The lunarian which we herewith present belongs to the second of the
+classes above named; in its construction an attempt has been made to
+show by as simple means and in as clear a manner as possible the nature
+of the following phenomena, viz.:
+
+1. Apogee and perigee.
+
+2. The moon's phases.
+
+3. The rotation on her axis, by reason of which she always presents
+nearly the same face to the earth.
+
+4. The inclination of her axis to the plane of her orbit, and her
+consequent libration in latitude.
+
+5. Her varying angular velocity, and consequent libration in longitude.
+
+The mechanism consists of a train-arm, T, which turns upon the vertical
+pivot, P, fixed in the stand. In this arm, T, are the bearings of two
+cranks, B and C. equal in length to each other and to a third crank, A,
+which is stationary, being fixed to the pivot, P, by a pin, p. To the
+crank-pin of A is secured a reverted arm, A', which supports the earth,
+E, and keeps it also stationary. The three cranks are connected by the
+rod, R, like the parallel rod of a locomotive: to which is fastened by a
+steady-pin, o, the bevel wheel, D, concentric with the crank-pin, b. The
+head of this crank-pin is first made spherical, then faced off at an
+angle with the axis of b, and in the sloping face is firmly fixed the
+long screw, S, forming the support for the moon, M, which is caused
+to rotate about the axis of S, by means of the wheel, F, equal to
+and engaging with D. The upper end of S projects slightly through a
+perforation in the moon, and to it the hemispherical black shell or cap,
+G, is fixed by the screw, K; this cap represents the unilluminated part
+of the moon, and since G, s, b, and B, are in effect but one piece, the
+cap moves precisely as the crank does.
+
+Now as the train-arm, T, is carried round, the cranks, B and C, will
+turn in their bearings; but by their connection with A, they are
+compelled to remain always parallel to themselves, and thus the axis of
+the moon receives a motion of translation. But since during this action
+the wheel D turns relatively to the pin b, the moon evidently rotates
+about its axis with an angular velocity precisely equal to that of its
+orbital motion.
+
+The black shell however has the motion of translation only, and thus
+exhibits the phases of the moon, on the supposition that the source
+of light is infinitely remote and the rays come always in the same
+direction, which is not strictly true, of course; but the reasons of the
+varying appearance are as clearly shown as if it were absolutely exact.
+The same may be said in regard to the phenomena of libration; the
+inclination of the moon's axis to the plane of her orbit is really
+small, but is purposely exaggerated in this apparatus in order to make
+the results apparent; in the position represented, it is quite obvious
+that an observer upon the earth can see a little past one pole, and
+cannot quite see the other, as well as that this condition will be
+reversed after half a revolution.
+
+The action in reference to the phases is clearly shown in the small
+diagram on the right. The one on the left illustrates the manner in
+which the libration in longitude is made apparent. It will be noted that
+the center of M is not directly over the axis of the bearing of the
+crank, B, so that after half a revolution the moon will be farther from
+the earth than she is here shown. Her orbit here is circular, whereas,
+in fact, it is an ellipse; but the earth not being in the center, her
+angular velocity in relation to the earth is variable, the result
+of which is that, when she is near her quadrature, the actual force
+presented to the earth is slightly different from that presented when in
+conjunction or opposition.
+
+Thus these various peculiarities of the motion of our satellite are
+exhibited by comparatively simple means--the number of moving parts
+being, it is believed, as small as it can be made; and the substitution
+of a crank motion for the usual train of wheels, we think, is a new
+device.
+
+       *       *       *       *       *
+
+
+
+
+THE UPRIGHT ATTITUDE OF MANKIND.
+
+
+Every one must have heard or have read of the supposed perfect
+adaptation of the human frame to bipedal locomotion and to an upright
+attitude, as well as the advantages which we gain by this erect
+position. We are told, and with perfect truth, that in man the occipital
+foramen--the aperture through which the brain is connected with the
+spinal cord--is so placed that the head is nearly in equilibrium when he
+stands upright. In other mammalia this aperture lies further back, and
+takes a more oblique direction, so that the head is thrown forward,
+and requires to be upheld partly by muscular effort and partly by the
+ligamentum nuchae, popularly known in cattle as the "pax-wax."
+
+Again, the relative lengths of the bones of the hinder extremities in
+man form an obstacle to his walking on all-fours. If we keep the legs
+straight we may touch the ground in front of our feet with the tips of
+the fingers, but we cannot place the palms of the hands upon the ground
+and use them to support any part of our weight in walking. Not a few
+other points of a similar tendency have been so often enlarged upon, in
+works of a teleological character, that there can be no need even to
+specify them at present.
+
+But till lately it has never been asked, "Is man's adaptation to
+an upright posture perfect?" and "Is this posture attended with no
+drawbacks?" These questions have been raised by Dr. S. V. Clevenger in a
+lecture delivered before the Chicago University Club, on April 18, 1882,
+and recently published in the _American Naturalist_. This lecture,
+we may add, cost the speaker the chair of Comparative Anatomy and
+Physiology at the Chicago University!
+
+Dr. Clevenger first discusses the position of the valves in the veins.
+The teleologists have long told us that the valves in the veins of
+the arms and legs assist in the return of blood to the heart against
+gravitation. But what earthly use has a man for valves in the
+intercostal veins which carry blood almost horizontally backward to the
+azygos veins? When recumbent, these valves are an actual obstacle to
+the free flow of the blood. The inferior thyroid veins which drop their
+blood into the innominate are obstructed by valves at their junction.
+Two pairs of valves are situate in the external jugular, and another
+pair in the internal jugular, but they do not prevent regurgitation of
+blood upward.
+
+An anomaly exists in the absence of valves from parts where they are
+most needed, such as the venae cavae, the spinal, iliac, haemorrhoidal, and
+portal veins.
+
+But if we place man upon all-fours these anomalies disappear, and a law
+is found regulating the presence or absence of valves, and, according to
+Dr. Clevenger, it is applicable to all quadrupeds and to the so-called
+Quadrumana. Veins flowing toward the back, i.e., against gravitation in
+the all-fours posture--are fitted with valves; those flowing in
+other directions are without. For the few exceptions a very feasible
+explanation is given.
+
+Valves in the haemorrhoidal veins would be useless to quadrupeds; but to
+man, in his upright position, they would be very valuable. "To their
+absence in man many a life has been and will be sacrificed, to say
+nothing of the discomfort and distress occasioned by the engorgement
+known as piles, which the presence of valves in their veins would
+obviate."
+
+A noticeable departure from the rule obtaining in the vascular system of
+mammalia also occurs to the exposed situation of the femoral artery in
+man. The arteries lie deeper than the veins, or are otherwise protected,
+for the purpose--as a teleologist would say--of preventing serious loss
+of blood from superficial cuts. Translating this view into evolutionary
+language, it appears that only animals with deeply placed arteries can
+survive and transmit their structural peculiarities to their offspring.
+The ordinary abrasions to which all animals are exposed, not to mention
+their onslaughts upon each other, would quickly kill off species with
+superficially placed arteries. But when man assumed the upright posture
+the femoral artery, which in the quadrupedal position is placed out of
+reach on the inner part of the thigh, became exposed. Were not this
+defect greatly compensated by man's ability to protect this part in ways
+not open to brutes, he, too, might have become extinct. As it is, this
+exposure of so large an artery is a fruitful cause of trouble and death.
+
+We may here mention some other disadvantages of the upright position
+which Dr. Clevenger has omitted. Foremost comes the liability to fall
+due to an erect posture supported upon two feet only. Four-footed
+animals in their natural haunts are little liable to fall; if one foot
+slips or fails to find hold, the other three are available. If a fall
+does occur on level ground, there is very little danger to any mammal
+nearly approaching man in bulk and weight. Their vital parts, especially
+the heart and the head, are ordinarily so near the ground that to them
+the shock is comparatively slight. To human beings the effects of a
+fall on smooth, level ground are often serious, or even deadly. We need
+merely call to mind the case of the illustrious physicist whom we have
+so recently and suddenly lost.
+
+The upright attitude involves a further sourge of danger. In few parts
+(if any) of the body is a blow more fatal than over what is popularly
+called the "pit of the stomach." In the quadruped this part is little
+exposed either to accidental or intentional injuries. In man it is quite
+open to both. A blow, a kick, a fall among stones, etc., may thus easily
+prove fatal.
+
+Another point is the exposure and prominence of the generative organs,
+which in most other animals are well protected. Leaving danger out of
+the question, it may be asked whether we have not here the origin of
+clothing? The assumption of the upright posture may have made primitive
+man aware of his nakedness.
+
+Returning to the illustrations furnished by Dr. Clevenger, we are
+reminded that another disadvantage which occurs from the upright
+position of man is his greater liability to inguinal hernia. In
+quadrupeds the main weight of the abdominal viscera is supported by the
+ribs and by strong pectoral and abdominal muscles. The weakest part of
+the latter group of muscles is in the region of Poupart's ligament,
+above the groin. Inguinal hernia is rare in other vertebrates because
+this weak part is relieved by the pressure of the viscera. In man the
+pelvis receives almost the entire load of the intestines, and hence Art
+is called in to compensate the deficiencies of nature, and an immense
+number of trusses have to be manufactured and used. It is calculated
+that 20 per cent. of the human family suffer in this way. Strangulated
+hernia frequently causes death. The liability to femoral hernia is in
+like manner increased by the upright position.
+
+Now, if man has always been erect from his creation--or, if that term be
+disliked, from his origin--we have evidently nothing to hope from the
+future in the way of an amendment of this and other defects. But if we
+have sprung from a quadrupedal animal, and have by degrees adopted
+an upright position, to which we are as yet imperfectly adapted, the
+muscular tissues of the abdomen will doubtless in the lapse of ages
+become strengthened to meet the demand made upon them, so that the
+liability to rupture will decrease. In like manner the other defects
+above enumerated may gradually be rendered less serious.
+
+A most important point remains; the peritoneal ligaments of the uterus
+fully subserve suspensory functions. The anterior, posterior, and
+lateral ligaments are mainly concerned in preventing the gravid uterus,
+in quadrupeds, from pitching too far forward toward the diaphragm. The
+round ligaments are utterly unmeaning in the human female, but in the
+lower animals they serve the same purpose as the other ligaments.
+Prolapsus uteri, from the erect position and the absence of supports
+adapted to the position, is thus rendered common, destroying the health
+and happiness of multitudes.
+
+As a simple deduction from mechanical laws, it would readily follow that
+any animal or race of men which had for the longest time maintained an
+erect position would have straighter abdomens, wider pelvic brims with
+contracted pelvic outlets, and that the weight of the spinal column
+would force the sacrum lower down. This, generally speaking, we find to
+be the case. In quadrupeds the box-shaped pelvis, which admits of easy
+parturition, is prevalent. Where the position of the animal is such as
+to throw the weight of the viscera into the pelvis, the brim necessarily
+widens, these weighty organs sink lower, and the beads of the
+thigh-bones acting as fulcra permit the crest of the ilium to be
+carried outward, while the lower part of the pelvis is at the same time
+contracted.
+
+In the innominate bones of a young child the box-shape exists, while its
+prominent abdomen resembles that of the gorilla. The gibbon exhibits
+this iliac expansion through the sitting posture which developed his
+ischial callosities. Similarly iliac expansion occurs in the chimpanzee.
+The megatherium had wide iliacal expansions due to its semi-erect
+habits; but as its weight was in great part supported by the huge tail,
+and as the fermora rested in acetabula placed far forward, the leverage
+necessary to contract the lower portion of the pelvis was absent.
+
+Prof. Weber, of Bonn, quoted in Karl Vogt's "Vorlesungen ueber den
+Mensohen," distinguishes four chief forms of the pelvis in mankind--the
+oval in Aryans, the round among the Red Indians, the square in the
+Mongols, and the wedge-shaped in the Negro. Examining this question
+mechanically it would seem that the longer a race had remained in
+an upright position the lower is the sacrum, and the greater is the
+tendency to approximate to the larger lateral diameter of the European
+female. The front to back diameter of the ape's pelvis is usually
+greater than the measurement from side to side. A similar condition
+affords the cuneiform, from which it may be inferred that the erect
+position in the Negro has not been maintained so long as in the Mongol,
+whose pelvis has assumed the quadrilateral shape owing to persistence
+of spinal axis weight for a greater time. This pressure has finally
+culminated in forcing the sacrum of the European nearer the pubes, with
+consequent lateral expansion and contraction of the diameter from
+front to back. From the marsupials to the lemurs the box-shaped pelvis
+remains. With the wedge-shape occasioned in the lowest human types there
+occurs a further remarkable phenomenon in the increased size of the
+foetal head accompanying the contraction of the pelvic outlet. While the
+marsupial head is about one-sixth the size of the narrowest part of the
+bony parturient canal, the moment we pass to erect animals the greater
+relative increase is there seen in cranial size, with a coexisting
+decrease in the area of the outlet. This altered condition of things
+has caused the death of millions of otherwise perfectly healthy and
+well-formed human mothers and children. The palaeontologist might tell us
+if some such case of ischial approximation by natural mechanical causes
+has not caused the probable extinction of whole genera of vertebrates.
+"If we are to believe that for our original sin the pangs and labor
+of childbirth were increased, and if we also believe in the
+disproportionate contraction of the pelvic space being an efficient
+cause of the same difficulties of parturition, the logical inference is
+that man's original sin consisted in his getting upon his hind legs."
+
+This subject is not without direct applications. Accoucheurs cause their
+patients to assume what is called the knee-chest position, a prone one,
+for the purpose of restoring the uterus to something near a natural
+position. Brown-Sequard recommends, in myelitis, or spinal congestion,
+drawing away the blood from the spine by placing the patient on his
+abdomen or side, with hands and feet somewhat hanging down. The
+liability to _spina bifida_ is greatest in the human infant, through
+the stress thrown on the spine. The easy parturition in the lower human
+races is due to the discrepancy between cranial and pelvic sizes not
+having been as yet reached by those races. The Sandwich Island mother
+has a difficult delivery only when her child is half white, and has
+consequently a longer head than the unmixed native strain.
+
+At present the world goes on in its blindness, apparently satisfied
+that everything is all right because its exists, ignorant of the evil
+consequences of apparently beneficial pecularities, vaunting man's
+erectness and its advantages, while ignoring the disadvantages.
+
+The observation that the lower the animal the more prolific (not
+universally true!) would warrant the belief that the higher the animal
+the more difficulties encompass its propagation and development. The
+cranio-pelvic difficulty may perhaps settle the Malthusian question as
+far as the higher races of men are concerned by their extinction.
+
+[If the facts brought forward by Dr. Clevenger cannot be controverted,
+they seem to prove that man must have originated by gradual development
+from a four-footed being. Had he been created an erect, bipedal animal,
+as we find him, his structure would have been not in partial, but in
+perfect, adaptation to the conditions of that attitude. That some of the
+peculiarities of his structure are better in harmony with a horizontal
+than a vertical position of the spinal column, is perhaps the strongest
+argument against the theory of direct creation and the radical _toto
+coelo_ distinction between man and beast that has yet been advanced. We
+cannot at the moment lay our hands upon any thorough and trustworthy
+account of the valves in the veins of the sloth: as that animal spends
+its life hanging, back downward, the structure of the veins would be
+interesting in this connection.--ED. J. S.]--_Journal of Science_.
+
+       *       *       *       *       *
+
+
+
+
+OUR ENEMIES, THE MICROBES.
+
+
+We have seen the microbes, as our servants[1], often performing,
+unbeknown to us, the work of purifying and regenerating the soil and
+atmosphere. Let us now examine our enemies, for they are numerous.
+Everywhere frequent--in the air, in the earth, in the water--they only
+await an occasion to introduce themselves into our body in order to
+engage in a contest for existence with the cells that make up our
+tissues; and, often victorious, they cause death with fearful rapidity.
+When we have named charbon, septicaemia, diphtheria, typhoid fever, pork
+measles, etc., we shall have indicated the serious affections that
+microbes are capable of engendering in the animal organism.
+
+[Footnote 1: SUPPLEMENT, No. 446, page 7125.]
+
+We call those diseases "parasitic" that are occasioned by the
+introduction of a living organism into the bodies of animals. Although a
+knowledge of such diseases is easy where it concerns parasites such as
+acari and worms, it becomes very difficult when it is a question of
+diseases that are caused by the Bacteriaceae. In fact, the germs of these
+plants exist in the air in large quantities, as is shown by the analysis
+of pure air by a sunbeam, and we are obliged to take minute precautions
+to prevent then from invading organic substances. If, then, during an
+autopsy of an individual or animal, a microscopic examination reveals
+the presence of microbes, we cannot affirm that the latter were the
+cause of the affection that it is desired to study, since they might
+have introduced themselves during the manipulation, and by reason of
+their rapid vegetation have invaded the tissues of the dead animal in
+a very short time. The presumption exists, nevertheless, that when
+the same form of bacteria is present in the same tissue with the same
+affection, it is connected with the disease. This was what Davaine was
+the first to show with regard to _Bacillus anthracis_, which causes
+charbon. He, in 1850, having examined the blood of an animal that had
+died of this disease, found therein amid the globules (Fig. 1), small,
+immovable, very narrow rods of a length double that of the blood
+corpuscles. It was not till 1863 that he suspected the active role of
+these organisms in the charbon malady, and endeavored to demonstrate it
+by experiments in inoculation. Is the presence of these little rods in
+the blood of an animal that has died of charbon sufficient of itself to
+demonstrate the parasitic nature of the affection? No; in order that
+the demonstration shall be complete, the bacteria must be isolated,
+cultivated in a state of purity in proper liquids, and then be used
+to inoculate animals with. If the latter die with all the symptoms
+of charbon, the demonstration will be complete. Davaine did, indeed,
+perform some experiments in inoculation that were successful, but his
+results were contradicted by the experiments of Messrs. Jaillard and
+Leplat, and those of Mr. Bert concerning the toxic influence of oxygen
+at high tension upon microbes. As Davaine was unable to explain the
+contradiction between his results and those of Messrs. Jaillard, Leplat,
+and Bert, minds were not as yet convinced, notwithstanding the support
+that his ideas received from Mr. Koch's researches.
+
+In 1877 Mr. Pasteur took up Davaine's experiments, and confirmed his
+affirmations step by step by employing the method of culture that he had
+used with such success in his studies upon fermentation. He isolated
+Davaine's bacterium by cultivating it in a decoction of beer yeast that
+had been previously sterilized (Fig. 2); and after from ten to twenty
+cultures, he found that a portion of the liquid containing a few
+bacteria, when used for inoculating a rabbit, quickly caused the latter
+to die of charbon, while the same liquid, when filtered through plaster
+or porcelain, became harmless.
+
+Davaine's bacterium develops exclusively in the blood, and is never
+found at any depth in the tissues. This is due to the fact that the
+alga, having need of oxygen in order to live, borrows its flow from the
+blood, and thus extracts from the globules that which they should have
+carried to the tissue. The animal therefore dies asphyxiated. It is on
+account of the absence of oxygen in the blood that the latter assumes
+the blackish-brown color that characterizes the malady, and that has
+given its name of _charbon_ (coal).
+
+The parasitic nature of charbon was therefore absolutely demonstrated,
+first, by the constant presence of _Bacillus anthracis_ in the blood of
+anthracoid animals, and second, by the pure culture of the parasite and
+the inoculation of animals with charbon by means of it.
+
+Davaine began the demonstration in 1863, and Pasteur finished it in
+1877. These facts are now incontestable; yet, to show how slowly truth
+is propagated, even in these days of telegraphs and telephones, there
+might have been read a few months ago, in an interesting article on
+microbes, by Dr. Fol, a distinguished savant, the statement that charbon
+and tuberculosis were discovered by Dr. Koch!
+
+New parasitic affections, whose existence was suspected, were soon
+discovered and scientifically demonstrated, such, for example, as
+septicaemia, or the putrefaction which occurs in living animals, which in
+ambulances causes so fearful havoc among the wounded, and which proceeds
+from _Bacillus septicus_. This parasite exhibits itself under the form
+of little articulated rods that live isolated from oxygen in the mass of
+the tissues, and disorganize the latter in disengaging a large quantity
+of putrid gas. Other parasites of this class are the _micrococcus_ of
+chicken cholera (Fig. 3), the _micrococcus_ of hog measles, and the
+_Spirochoete Obermeieri_ of recurrent fever, discovered by Obermeier
+(Fig. 5).
+
+Besides these, there are a certain number of maladies that seem as if
+they must be due to the Bacteriaceae, although a demonstration of the
+fact by the method of cultures and inoculation has not as yet been
+attempted. Among such, we may cite typhoid fever, diphtheria, murrain,
+tuberculosis (Fig. 4), malarial fever (Fig. 6), etc.
+
+As may be seen, the list is already a long one, and it tends every day
+to still further increase. All the progress that has been made in so
+few years in our knowledge of contagious or epidemic diseases is due
+exclusively to M. Pasteur and the scientific method that he introduced
+through his remarkable labors on fermentation. Now that we know our most
+formidable enemies, how shall we defend ourselves against them?
+
+As we have seen, bacteria exist everywhere, mixed with the dust that
+interferes with the transparency of the air and covers all objects; and
+they are likewise found in water.
+
+Under normal conditions, our body is closed to these organisms through
+the epidermis and epithelium, and, as has been shown by Mr. Pasteur, no
+bacteria are found in the blood and tissues of living animals. But let a
+rupture or wound occur, and bacteria will enter the body, and, when once
+the enemy is in place, it will be too late. One sole chance of safety
+remains to us, and that is that in the warfare that it is raging against
+our tissues the enemy may succumb. M. Pasteur has shown that the blood
+corpsucles sometimes engage in the contest against bacterides and
+come off victorious. In fact, chickens are proof against poisoning by
+charbon, because, owing to the high temperature of their blood, the
+bacterides are unable to extract oxygen from the corpuscles thereof.
+But, if the chickens be chilled, the conditions are changed, and they
+will die of charbon just as do cattle and sheep; but, as the result of
+the contest cannot always be foreseen, it is necessary at any cost to
+prevent bacterides from entering the body.
+
+[Illustration: I. Bacteria of charbon (_Bacillus antracis_.) II. The
+same cultivated in yeast. III. The _Micrococcus_ of chicken cholera. IV.
+The _Bacillus_ of tuberculosis. V. The _Spirillun_ of recurrent fever.
+VI. The _Bacillus_ of malaria.]
+
+Under ordinary circumstances a severe hygiene will suffice to preserve
+us; if a wound is received it should be washed with water mixed with
+antiseptics, such as phenic acid, borax, or salicylic acid. If water is
+impure, it must be boiled and then aerated before it is drunk. If the
+air is the vehicle of the germs of the disease, it will have to be
+filtered by means of a muslin curtain kept wet with a hygroscopic
+solution, glycerine for example. Finally, when, after an epidemic,
+contaminated apartments are to be occupied, the walls and floor and the
+clothing must be washed with antiseptic solutions whose nature will vary
+according to circumstances--steam charged with phenic acid, water mixed
+with a millionth part of sulphuric acid, boric acid, ozone, chlorine,
+etc.
+
+These preventives only prove efficient on condition that they be used
+persistently. Let our vigilance be lacking for an instant, and the enemy
+will enter to work destruction, for it only requires a spore less than
+a hundredth of a millimeter in diameter to produce the most serious
+affections.
+
+Fortunately, and it is again to Mr. Pasteur that we owe these wonderful
+discoveries, the parasitic microbes themselves, which sow sickness and
+death, may, through proper culture, become true vaccine viri that are
+capable of preserving the organism against any future attack of the
+disease that they were capable of producing; such vaccine matters have
+been discovered for charbon, chicken cholera, the measles of swine, etc.
+
+When the _micrococcus_ of chicken cholera (Fig. 3.) is cultivated, it
+is seen that the activity of the microbe in cultures exposed to the air
+gradually diminishes. While a drop of the liquid would, in twenty-four
+hours, have killed all the chickens that were inoculated with it, its
+effect after two, three, or four days considerably diminishes, and an
+inoculation with it produces nothing more than a slight indisposition in
+the animal, and one that is never followed by a serious accident. It is
+then said that the virulence of the microbe is attenuated.
+
+The air is the agent of this transformation that gradually renders the
+bacteria benign, for in cultures made under the same circumstances as
+the preceding, but with the absence of air, the activity of these algae
+is preserved for days or weeks, and they will then cause death just as
+surely as they would have done at the end of one day.
+
+What is remarkable is that animals inoculated with the attenuated
+_micrococcus_ become for a varying length of time refractory to the
+action of the most formidable parasites of this kind. Mr. Pasteur has
+discovered two such vaccine viri--one for chicken cholera and the other
+for charbon. His results have not been accepted without a struggle, and
+it required nothing less than public experiment in vaccination, both in
+France and abroad, to convince the incredulous. There are still people
+at the present time who assert that Mr. Pasteur's process of vaccination
+has not a great practical range! And yet, here we have the results; more
+than 400,000 animals have been vaccinated since 1881, and it has been
+found that the mortality is ten times less in these than in those that
+have not been vaccinated!
+
+An impetus has now been given, and we can look to the future with
+confidence, for, if our enemies are numerous, the use of a severe
+hygiene and preventive vaccination will permit us to gradually free
+humanity from the terrible scourges that sap the sources of fortune and
+life.--_Science et Nature_.
+
+       *       *       *       *       *
+
+
+
+
+THE WINE FLY.
+
+
+At the last meeting of the New York Microscopical Society, a paper
+was read by Dr. Samuel Lockwood, secretary of the New Jersey State
+Microscopical Society. His subject was the Wine Fly, _Drosophila
+ampelophila_. The paper was a contribution to the life-history of this
+minute insect. He had given in part three years to its study, beginning
+in September, 1881, when nothing whatever of its life-history seemed to
+have been known. In October the flies attacked his Concords. He found
+upon a grape which he was inspecting with a pocket-lens an extremely
+small white egg; but lost it. The grapes when brought on the table were
+infested by the flies, which proved to be the above mentioned species.
+When driven from the grapes they would fly to the window, where he
+captured two of them These were placed in a jar with a grape for food.
+In two days he found one egg on the outer skin of the grape. The laying
+was kept up for four or five days, until there were about thirty, some
+on the outside of the grape and some at an opening where the two flies
+had fed. The egg had a pair of curious suspenders near the end where
+the mouth of the larva would develop. These suspenders were attached at
+their ends to the grape, but where the egg was laid in the soft part of
+the fruit the suspenders were spread out at the surface; thus the larva
+would emerge clean from the shell. The egg was 0.5 mm. in length, and
+about a fourth of that in width. The larva when grown was at least four
+times as long as the egg. As the larva burrowed in the juices of the
+fruit, two quite prominent breathing tubes at the posterior end were
+kept in the air. Between these cardinal tubes were several teat-like
+points, much smaller, but having a similar function.
+
+The larvae appeared in five days after the eggs were laid. In about as
+many more days the puparium state would be entered, and in about six
+days more the fly or imago would appear. In ovipositing the suspensors
+would leave the oviparous duct last. The paper claimed that the curious
+shape of the egg compelled the female to oviposit slowly, as it took
+time for the egg to assume its form; hence, the eggs were not laid in
+strings or masses, but singly and at considerable intervals.
+
+The flies are very hairy, especially the females. The neck and even the
+eyes are very hirsute. The eyes are red, quite large and pretty, though
+somewhat _outre_ under the microscope, for from between the little
+lenses are projecting, straight, stiff hairs. As the insect is quite
+active, it must be that this fringing of the tiny eyelets with hair does
+not materially obscure its vision. When the minuteness of this singular
+arrangement is considered, it is surely remarkable. This general
+hairiness of the female especially, and that about the head, neck, and
+forward part of the thorax, stands correlated to a beautiful structure
+found only in the male, which has on the tarsus of each leg in the
+forward pair what the lecturer called a sexual comb. It is a beautiful
+comb of a very dark brown color, each comb having ten pointed and strong
+teeth. In the nuptial embrace these combs are fixed in the hairy front
+of the thorax of the female, thus becoming little grapnels.
+
+The flies love any vegetable substance in fermentation, whether acetic
+or vinous. Hence it will abound about cider mills, swarm on preserves in
+the pantry, and in cellars or places where wine is being made or stored.
+The paper showed the tendency of the glucose in the over-ripe grape
+to the vinous ferment, and that the fly delighted in it. A singular
+accident showed how they loved even the very high spirits. In making
+some of the mounts shown to the society, Dr. Lockwood had left a bottle
+of 90 per cent. alcohol uncorked over night. Next morning he was
+astonished to find his alcohol of a beautiful amethystine color, and the
+cork out. Inspection showed a number of these tiny creatures, which,
+when filled with the purple juice of the grape, had smelt the alcohol
+in the open bottle, and had gone in to drink. They had ignominiously
+perished, and had given color to the liquid.--_Micro. Journal_.
+
+       *       *       *       *       *
+
+[NATURE.]
+
+
+
+
+THE "POTETOMETER," AN INSTRUMENT FOR MEASURING THE TRANSPIRATION OF
+WATER BY PLANTS.
+
+
+In view of the interest now attaching to recent advances in vegetable
+physiology, it seems not unlikely that a description of the instrument
+bearing the above name, lately published by Moll (_Archives
+Neerlandaises_, t. xviii.), will serve as useful purpose. The apparatus
+was designed to do away with certain sources of error in Sachs'
+older form of the instrument, described in his "Experimental
+Physiologie"--errors chiefly due to the continual alteration of pressure
+during the progress of the experiment.
+
+As shown in the diagram, the "potetometer" consists essentially of a
+glass tube, a d, open at both ends, and blown out into a bulb near the
+lower end; an aperture also exists on either side of the bulb at or
+about its equator. The two ends of the main tube are governed by the
+stopcocks, a and d, and the greater length of the tube is graduated. A
+perforated caoutchouc stopper is fitted into one aparture of the bulb,
+e, and the tube, g k, fits hermetically to the other. This latter tube
+is dilated into a cup at h to receive the caoutchouc stopper, into which
+the end of the shoot to be experimented upon is properly fixed.
+
+The fixing of the shoot is effected by caoutchouc and wire or silk, as
+shown at i, and must be performed so that the clean-cut end of the
+shoot is exactly at the level of a tube passing through the perforated
+stopper, e, of the bulb; this is easily managed, and is provided for by
+the bending of the tube, g h. The tube, f, passing horizontally through
+the caoutchouc stopper, e, is intended to admit bubbles of air, and so
+equalize the pressure and at the same time afford a means of measuring
+the rapidity of the absorption of water by the transpiring shoot. This
+tube (see Fig. 2, f) is a short piece of capillary glass tubing, to
+which is fixed a thin sheath of copper, b', which slides on it, and
+supports a small plate of polished copper, a', in such a manner that the
+latter can be held vertically at a small distance from the inner opening
+of the tube, and so regulate the size of the bubble of air to be
+directed upward into the graduated tube, a b.
+
+[Illustration]
+
+The apparatus is filled by placing the lower end of the main tube under
+water, closing the tubes, f and i (with caoutchouc tubing and clips),
+and opening the stopcocks, a and d. Water is then sucked in from a, and
+the whole apparatus carefully filled. The cocks are then turned, and the
+cut end of the shoot fixed into i, as stated; care must be taken that no
+air remains under the cut end at i, and the end of the shoot must be at
+the level, k l. This done, the tube, f, may then be opened.
+
+The leaves of the shoot transpire water, which is replaced through the
+stem at the cut end in i from the water in the apparatus. A bubble of
+air passes through the tube, f, and at once ascends into the graduated
+tube, a c. The descent of the water-level in this tube--which may
+conveniently be graduated to measure cubic millimeters--enables the
+experimenter at once to read off the amount of water employed in a given
+time.
+
+It is not necessary to dwell on obvious modifications of these
+essentials, nor to speak of the slight difficulties of manipulation
+(especially with the tube, f). Of course the apparatus might be mounted
+in several ways; and excellent results for demonstration in class could
+be obtained by arranging the whole on one of the pans of a sensitive
+balance. H. MARSHALL WARD.
+
+Botanical Laboratory, Owens College.
+
+       *       *       *       *       *
+
+
+
+
+BOLIVIAN CINCHONA FORESTS.
+
+
+The great progress made in the acclimation of cinchona trees in India,
+Ceylon, and elsewhere has awakened the governments of countries where
+the plants are indigenous to the necessity of conserving from reckless
+destruction, and replanting denuded forests, so as to be able to keep up
+the supply of this valuable product.
+
+In Bolivia, since 1878, according to the report of the Netherlands
+Consul, private individuals and land owners have taken up the question
+with great earnestness, and at the present time on the banks of the
+Mapiri, in the department of La Paz, there are over a million of young
+trees growing.
+
+New plantations have also sprung up in various other localities, either
+on private ground or that owned by Government. The competition of India
+and Ceylon in supplying the markets has had also the effect of inducing
+more care in collecting and also of revisiting old spots, often with the
+result of a rich harvest of bark which had been left on partly denuded
+trunks, and the opening up of new localities. The new shoots springing
+up from the old stumps have yielded much quill bark, and the root bark
+of the old stumps has also been utilized.
+
+The replanting entails very little expense. The Indian tenant on an
+estate has a house and land from the owner (hacienda) of the estate. For
+this he binds himself to work for two to four days a week, at from 28 to
+36 cents per day, women and children obtaining 16 to 21 cents per day.
+Thus the planting, weeding, etc., during the first two years is
+but nominal in expense; after this period the trees may be left to
+themselves.
+
+On Government land the expense is greater, as, after an application
+being made, the land is put up to public auction, and may fetch a
+very low or higher price according to the bidding. The land secured,
+contracts are made with natives of the lower class to clear the forest
+and plant cinchona. The contracts are often sublet to Indians. The
+young plants are planted from five to six feet apart, with banana trees
+between, on account of their rapid growth and the shade the latter
+afford. From March to June, after the wet season is over, is the best
+time for planting, and the contractor keeps the plantation free from
+weeds and in good order for twelve months, when it is handed over to the
+owner. The following is given as the cost of the Mapiri River plantation
+of an area from 60 or more miles in extent:
+
+  Ground.                                   $1,200
+  300,000 plants at $0.14.                  42,000
+  Superintendent, buildings, etc.            4,400
+  Interest.                                  4,800
+                                           -------
+  Total.                                   $52,400
+
+Till the plants are above two years of age, they are liable to die from
+drought or the attacks of ants, and during 1878 many thousands died from
+these causes. At the end of the fourth year some proprietors begin to
+collect the quill bark by the method of coppicing.
+
+It is feared by some that, should this new venture be successful, it
+will prove a dangerous rival to the plantations of India, Ceylon, and
+Java, and lower the price of bark considerably.--_Jour. Society of
+Arts_.
+
+       *       *       *       *       *
+
+
+
+
+FERNS.
+
+
+_N. Davallioides Furcans._--Among the many crested ferns in cultivation,
+this, of which the annexed is an illustration, is one of the most
+distinct; so different indeed it is from the type, that it is
+questionable if it really is a form of it; the most essential
+characteristic, that of the fructification at the extreme edge of the
+lobes of the pinnae, is altogether absent, and the whole habit of the
+plant is also thoroughly distinct. It is of equally robust growth,
+but its handsomely arching fronds, which are from 3 feet to 4 feet
+in length, are produced in great abundance from a central tuft or
+agglomeration of crowns. Its most distinct characteristic is the
+furcation of the pinnae, which are all of the same dimensions, whether
+sterile or fertile; they are all opposite and closely set along the
+mid-rib, whereas those of N. davallioides are set much further apart.
+In the barren pinnae which are only situated on the lower portion of the
+frond, and which generally are only few in number, the furcation is
+rudimentary; in the fertile pinnae it is twice and even three times
+repeated in the extremities of the first division, becoming more complex
+toward the point of the frond, where it often forms quite a large
+tassel, whose weight gives the fronds quite an elegant, arching habit.
+On that account this plant is valuable for growing in baskets of large
+dimensions, in which it shows itself off to good advantage, and never
+fails to prove attractive. Although it produces spores freely, it is
+best to propagate it by means of the young plants produced from rhizomes
+in the ordinary way, on account of the extreme variations which take
+place among the seedlings, a small percentage only of which are
+possessed of the true character of the parent plant. Stove.--_The
+Garden._
+
+[Illustration: NEPHROLEPIS DAVALLIOIDES FURCANS.]
+
+_N. Duffi_.--This pretty, neat-habited species, of which an
+illustration, kindly lent us by Mr. Bull, appears in another place, is a
+native of the Duke of York's Island, in the South Pacific Ocean, and is
+undoubtedly one of the most interesting of the whole genus. Its compact
+habit, its comparatively small dimensions, and the bright, glossy color
+of its beautifully tasseled fronds render it a most welcome addition to
+a group of ferns naturally rich in decorative plants. Its curiously and
+irregularly pinnate fronds are borne on slender stalks, terete toward
+the base, and covered with reddish brown, downy scales, instead of being
+produced loosely, as in most other Nephrolepises; these are densily
+crowded, and the outcome of closely clustered crowns. They measure from
+15 inches to 18 inches long, and are terminated by very handsome massive
+crests, which vary in size according to the temperature in which the
+plant is grown. We have at different times heard complaints of these
+fronds being simply furcate, when the same plant, after being subjected
+to a greater amount of heat and moisture, produced fronds very heavily
+tasseled, and partaking of an elegant vase-shaped appearance. In fact,
+nothing short of the moist heat of a stove will induce it to show its
+characters in their best condition. The pinnae, which are small, of
+different sizes, rounded and serrated at the edges, are produced in
+pairs, one overlying the other, and, curiously enough, those on the top
+are the largest. The pairs are sometimes opposite, but mostly alternate,
+distant toward the base, approximate higher up, and crowded and
+quite overlapping in the crested portion of the frond. This, being
+a thoroughly barren kind, can only be propagated by division of the
+crowns, an operation easily done at any time of the year, but most
+safely in early spring and by young plants produced from the rhizomes,
+which, however, are produced much more sparingly than in any other
+species. It is also one of the best adapted for pot or pan culture, its
+somewhat upright habit making it less suitable for baskets, brackets,
+and wall covering than other species. Stove.--_The Garden_.
+
+[Illustration: NEPHROLEPIS DUFFI.]
+
+       *       *       *       *       *
+
+
+
+
+FORMATION OF SUGAR.
+
+
+A paper on "The Formation of Sugar in the Sugar-cane" was recently read
+by M. Aime Girard before the Paris Academy of Sciences. By comparative
+investigations of the amount of cane sugar and grape sugar in different
+parts of the sugar-cane in the afternoon and before sunrise, the author
+has found that only in the substance of the leaves does this quantity
+vary, and that the quantity of cane sugar sinks during the night to
+one-half, while the quantity of reducing sugar remains almost unaltered.
+He finds further that the quantity of sugar-cane in the leaves increases
+with the illumination, on very bright days reaching nearly one per
+cent., considerably less on dull ones, and in either case diminishing
+during the night by one-half. From this the author concludes that the
+formation of saccharose from glucose takes place entirely in the leaves
+under the influence of sunlight, and that the saccharose thereupon
+ascends the cane through the petioles, etc., and collects there.
+
+       *       *       *       *       *
+
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+End of the Project Gutenberg EBook of Scientific American Supplement, No.
+447, July 26, 1884, by Various
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