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| author | Roger Frank <rfrank@pglaf.org> | 2025-10-15 04:50:05 -0700 |
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| committer | Roger Frank <rfrank@pglaf.org> | 2025-10-15 04:50:05 -0700 |
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diff --git a/.gitattributes b/.gitattributes new file mode 100644 index 0000000..6833f05 --- /dev/null +++ b/.gitattributes @@ -0,0 +1,3 @@ +* text=auto +*.txt text +*.md text diff --git a/16972-8.txt b/16972-8.txt new file mode 100644 index 0000000..628b6ef --- /dev/null +++ b/16972-8.txt @@ -0,0 +1,4772 @@ +The Project Gutenberg EBook of Scientific American Supplement, No. 711, +August 17, 1889, 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. 711, August 17, 1889 + +Author: Various + +Release Date: October 31, 2005 [EBook #16972] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + + + + +Produced by Juliet Sutherland and the Online Distributed +Proofreading Team at www.pgdp.net + + + + + +[Illustration] + + + + +SCIENTIFIC AMERICAN SUPPLEMENT NO. 711 + + + + +NEW YORK, AUGUST 17, 1889 + +Scientific American Supplement. Vol. XXVIII., No. 711. + +Scientific American established 1845 + +Scientific American Supplement, $5 a year. + +Scientific American and Supplement, $7 a year. + + * * * * * + + + + +TABLE OF CONTENTS. + + +I. AGRICULTURE.--How to Raise Turkeys.--A collection of hints + and suggestions on the raising of the delicate fowls, so + often the cause of trouble to farmers. 11364 + + Pear Duchesse D'Angouleme.--The history of the famous pear + tree, with hints as to its culture and general treatment. 11362 + + +II. BIOLOGY.--Development of the Embryo.--A note of some + interesting biological researches.--By Prof. PREYER, + of Berlin. 11365 + + The "Hatchery" of the Sun Fish.--A curious incident in the + life history of the common sunfish.--1 illustration. 11363 + +III. CHEMISTRY.--On Allotropic Forms of Silver.--By M. CAREY + LEA.--A continuation of this paper, containing one of the + most important researches in the history of silver, with + statement of interesting results attained. 11361 + + On the Occurrence of Paraffine in Crude Petroleum.--A + valuable contribution to the history of paraffine, with + reference to petroleum and ozokerite. 11361 + + Turpentine and its Products.--By EDWARD DAVIES.--A resume + of the work done by chemists in the turpentine products. + --The different compounds produced therefrom. 11361 + +IV. ELECTRICITY.--Electric Lighting at the Paris Exhibition. + --The Oerlikon works.--A very exhaustive exhibition of + electric apparatus described and illustrated.--12 + illustrations. 11356 + + Magnetism in its Relation to Induced Electromotive Force + and Current.--By ELIHU THOMSON.--A most impressive paper, + bringing the obscure laws of magnetic induction within the + understanding of all without the application of + mathematics.--12 illustrations. 11354 + + The Ader Flourish of Trumpets.--One of the curiosities in + telephony from the Paris exhibition, by which sounds are + transmitted to a large audience.--4 illustrations. 11358 + + The Electric Motor Tests on the New York Elevated + Railroad.--Abstracts of tests which were recently made of + the Daft motor on the elevated railroad of this city. 11353 + +V. ETHNOLOGY.--Ancient Lake Dwellings.--Interesting abstract + of what is known about lake dwellings, the history of + their construction, and the "finds" made on the sites by + archæologists. 11363 + +VI. FORESTRY.--Succession of Forest Growths.--A valuable paper + on forestry, treating of the evils done by man and a plea + for the necessity of intelligent treatment of our woods. 11362 + +VII. HYGIENE AND MEDICINE.--Acetic Acid as a Disinfectant.--Use + of acetic acid in septic medical cases as a substitute + for carbolic acid and bichloride of mercury. 11365 + + Counter-Irritation in Whooping Cough.--By G.F. INGLOTT, + M.D.--Application of irritants to the skin for curing the + paroxysms of whooping cough. 11365 + + On the Health Value to Man of the So-called Divinely + Beneficent Gift, Tobacco.--By J.M.W. KITCHEN, M.D.--The + evils to man and to the soil.--A formidable series of + accusations well expressed. 11365 + + Water as a Therapeutical Agent.--By F.C. ROBINSON, + M.D.--An interesting resume of different applications of + water in therapeutics.--Suggestions of use for all + households. 11364 + +VIII. MILITARY ENGINEERING.--Gibraltar.--A history of this + important strategic position and of the different sieges + the fortress has undergone. 11352 + + Gibraltar and Neighborhood.--A consular report on the + statistics of the famous military station. 11352 + + The Defense of Gibraltar--Experimental Naval and Military + Operations.--Interesting series of operations recently + carried out under the shadow of the historic rock.--1 + illustration. 11352 + +IX. NAVAL ENGINEERING.--Clark's Gyroscopic Torpedoes.--A + recent torpedo, in which all the possible parts are made + to rotate.--2 illustrations. 11353 + + The First Steamboat on the Seine.--The Marquis de + Jouffroy's steamer of 1816.--1 illustration. 11353 + + The Franz Josef I., New War Ship.--Details of the + dimensions of the new Austrian ship.--Her armament, + speed, armor, etc. 11353 + +X. PHOTOGRAPHY.--Orthochromatic Photography.--By OSCAR O. + LITZKOW.--The last developments in this interesting + branch of photographic art, with formulæ. 11360 + + Platinotype Printing.--A description of the most advanced + method of conducting the platinum print process. 11360 + +XI. PHYSICS.--Iridescent Crystals.--By LORD RAYLEIGH.--An + abstract of a lecture by the distinguished physicist, + detailing some interesting experiments applicable to the + colored reflection observed in crystals of chloride of + potash.--1 illustration. 11366 + + Transmission of Pressure in Fluids.--By ALBERT B. + PORTER.--An apparatus for illustrating the laws of + transmission of pressure in fluids, suitable for lecture + purposes.--1 illustration. 11362 + + XII. TECHNOLOGY.--Notes on Dyewood Extracts and Similar + Preparations.--By LOUIS SIEBOLD.--The recent development + in the preparation of dyewood extracts, with notes of + their adulterations. 11359 + + * * * * * + + + + +THE DEFENSE OF GIBRALTAR: EXPERIMENTAL NAVAL AND MILITARY +OPERATIONS. + + +[Illustration: THE DEFENSE OF GIBRALTAR--EXPERIMENTAL NAVAL AND +MILITARY OPERATIONS.] + +A novel and interesting series of operations was carried out at +Gibraltar a few weeks ago, with a view to test the promptitude with +which the garrison of the famous Rock could turn out to resist a +sudden attack by a powerful iron-clad fleet. The supposed enemy was +represented by the Channel Squadron, under the command of Vice-Admiral +Baird, and consisting of H.M.S. Northumberland (flag ship), the +Agincourt, Monarch, Iron Duke, and Curlew. The "general idea" of the +operations was that a hostile fleet was known to be cruising in the +vicinity, and that an attack on the Rock might be made. The squadron +left Gibraltar and proceeded to the westward, returning to the +eastward through the Straits under cover of the night. + +The Governor of Gibraltar, General the Hon. Sir Arthur Hardinge, +issued orders for the whole garrison to stand to their arms at dawn, +and subsequent days, until the attack should be made; but by his +express command no batteries were to be manned, or any troops moved +from their alarm posts, until the signal was given that an attack was +imminent. The alarm signal ordered was that of three guns fired in +rapid succession from the Upper Signal Station on the summit of the +Rock, to be followed, after a short pause, by two more shots. It was a +matter of complete uncertainty as to the direction from which the +attack would be made. + +Every detail was carefully carried out, as if the impending attack was +a real affair. The telegraphic communication between the various parts +of the Rock was supplemented by signalers; arrangements were made for +the ready supply of reserve ammunition for all arms; and the medical +authorities established dressing stations, at numerous points of the +Rock, to render "first aid" to those who might chance to be numbered +among the "wounded." Day broke with a "Levanter," and the heavy clouds +hanging about rendered any distant view a matter of difficulty. +However, before it had become actually daylight the alarm guns gave +notice that the enemy had been sighted. The troops turned out with +great promptitude, being all at their assigned stations in less than a +quarter of an hour, and were shortly ordered to various points +commanding the east side of the Rock. As day broke, the hostile ships +were to be discerned steaming in single line ahead, from the northeast, +along the back of the Rock, and about 5,000 yards from it. The flag +ship, followed by the Monarch and the Agincourt, proceeded toward +Europa Point, while the Iron Duke and the Curlew stood close in to the +eastern beach, so as to engage the northern defenses of the fortress. +The first shot was fired by the flag ship, shortly before six o'clock +in the morning, at the southern defenses. It was replied to, in less +than three minutes, by the Europa batteries, and very shortly the +engagement became general. The plan of tactics employed by the +squadron was that of steaming rapidly up and down, and concentrating +their fire in turn on the various shore batteries. Later on, the whole +squadron assembled off Europa Point, and fired broadsides by +electricity as they steamed past at speed. The spectacle at this +moment was a very fine one, the roar of the heavy guns of the ships +being supplemented by the sharp, rapid report of the quick-firing +guns, which were supposed to be sending a storm of small shell among +the defenders of the Rock. The incessant rattle of the ships' machine +guns was also heard in the intervals between the thundering broadsides +of heavy ordnance. All the ships were, of course, cleared for action, +with topmasts and yards sent down, and it is needless to say they +looked exceedingly workmanlike and formidable. + +The various batteries on the Rock replied with great vivacity, and the +general effect produced as gun after gun was brought to bear on the +ships, and the white smoke wreathed itself round the many crags and +precipices of the grim old Rock, was a sight long to be remembered. +The exercise afforded to both branches of the service was undoubtedly +most instructive. Our illustration is a sketch by Captain Willoughby +Verner from one of the batteries above the Europa Flats, at which +point the governor took up his position to watch the operations. +--_Illustrated London News._ + + * * * * * + + + + +GIBRALTAR AND NEIGHBORHOOD. + +REPORT BY CONSUL SPRAGUE. + + +Notwithstanding that the political situation of Europe seems to be +less threatening among its leading powers, still the uncertainty +prevalent among those who are generally considered the arbiters of +public affairs has had its influence in contracting the limits of +speculative adventure, thereby circumscribing the general course of +trade throughout the Mediterranean. + +In renewing to the department my reports upon the navigation and +general commerce of Gibraltar, I beg to state that there has been a +tolerably fair current business prevailing in American produce during +the past quarter, consisting chiefly in flour, tobacco, and refined +petroleum in cases, imported direct from New York. + +The steady demand for American petroleum confirms the fact that +Russian petroleum so far receives but little attention in this market +from the regular traders and consumers, so long as supplies from the +United States can be regularly imported at reasonable prices. It, +however, remains an open question, in the event of lower prices ruling +in the Russian petroleum regions, whether American supplies may not +later on experience some greater competitive foreign interference. + +According to the statistical data, steam vessels of all nationalities +have continued to make Gibraltar their port of call, not only for +orders, but also for replenishing their stock of fuel and provisions, +and in larger numbers than ever before, the number in 1888 having +reached 5,712 steam vessels, measuring in all 5,969,563 tons, while in +1887 the number was only 5,187 steam vessels, with an aggregate +tonnage of 5,372,962. This increase cannot but result in considerable +benefit to the coal and maritime traffic, which now forms the most +important portion of the general commerce of Gibraltar, in spite of +the keen competition it experiences from other British and foreign +coaling ports. + +Freights have also advanced in favor of steamship interests, which, +with higher prices in England for coal, have also caused an advance in +the price of coal at this port, to the benefit of the coal merchants +and others interested in this important trade. At present the ruling +price for steam coal is 24s. per ton, deliverable from alongside of +coal hulks moored in the bay. As near as I have been able to +ascertain, the quantity of coal sold in this market during the past +year for supplying merchant steam vessels has amounted to about +508,000 tons, which is an increase of about 20,000 tons over the year +1887. + +Notwithstanding that plans have already been submitted to the British +government for the construction of a dry dock in Gibraltar, the matter +remains somewhat in suspense, since it meets with some opposition on +the part of the British government, which, in face of the European +fever for general arming, seems more inclined to utilize in another +form the expense which such a work would entail upon the imperial +government, by replacing the obsolete ordnance recently removed from +this fortress and substituting new defenses and guns of the most +approved patterns, a matter which has evidently been receiving, for +some time past, the special attention of the British military +authorities, not doubting that the recent visit to the fortress of the +Duke of Cambridge has had some connection with it. In fact, it is +reported that the duke has already expressed the opinion that this +fortress requires a larger number of artillerymen than are quartered +here at present to man its batteries, and it would seem that this +recommendation is likely to be carried out. + +It is yet somewhat too early to venture an opinion regarding the +growing crops of cereals in this Spanish neighborhood, but the +agricultural and manufacturing interests in Spain have suffered so +much in the past years that the general feeling in Spain continues to +tend toward establishing increased restrictions against foreign +competition in her home markets. There is every probability that the +provinces of Malaga and Granada may shortly be granted the privilege +of cultivating the tobacco plant under government supervision, as an +essay. If properly managed, it may form an important and lucrative +business for those interested in land and agricultural pursuits. + +After many consecutive years of heavy outlays, difficulties, and +constant disappointments, a new English company has recently succeeded +in commencing the construction of a railway from the neighboring +Spanish town of Algeciras to join, via Ronda, the railway station of +Bobadilla, on the railroad line toward Malaga. It is presumed that +when this railroad will be in running order it will greatly benefit +this community, especially if the Spanish government should decide to +establish custom houses at Algeciras and the Spanish lines outside the +gates of this fortress, similar to those existing on the frontiers of +France and Portugal. + +That some idea may be formed of the constant important daily +intercourse which exists between this fortress and Spain, I may state +that late police statistics show that 1,887,617 passes were issued to +visitors entering this fortress on daily permits during the year 1888, +1,608,004 entering by the land route and 279,613 by sea. I must, +however, observe that the larger portion of these visitors consists of +laborers, coal heavers, market people, and others engaged in general +traffic. + +A new industry in cork has lately sprung up, in which leading Spanish +and native commercial firms in Gibraltar are directly interested to a +considerable extent. Extensive warehouses for the storing of cork wood +and machinery for the manufacture of bottle corks have recently been +established at the Spanish lines, about a mile distant from this +fortress, in Spanish territory, where large quantities of cork have +already been stored. The cork is obtained and collected from the +valuable trees, which are owned by the representatives of some of the +oldest nobility of Spain, who have sold the products of their +extensive woods to private individuals for periods reaching as far on +as ten years, for which concession large cash advances have already +been made. The woods commence at a distance of about twelve miles from +Gibraltar, and are of considerable extent. + +The railway now in course of construction passes through these woods, +which may ere long offer quite picturesque scenery for travelers, +especially when the cork trees are bearing acorns, which form the +principal food for the fattening of large herds of swine during +certain seasons of the year, in this way, also, contributing to the +value of this tree, which, like the other kinds of oak trees, is of +long and tardy growth. The tree from which the cork is obtained is +somewhat abundant in the mountainous districts of Andalusia. It grows +to a height of about 30 feet, and resembles the _Quercus ilex_, or +evergreen oak, and attains to a great age. After arriving at a certain +state of maturity it periodically sheds its bark, but this bark is +found to be of better quality when artificially removed from the tree, +which may be effected without injury to the tree itself. After the +tree has attained twenty-five years it may be barked, and the +operation is afterward repeated once in every seven years. The quality +of the cork seems to improve with the increasing age of the tree, +which is said to live over one hundred and fifty years. The bark is +taken off during July and August. + +Cork dust is also obtained from this cork wood, and is much used in +the packing of grapes, which fruit is largely shipped from the eastern +coast of Spain, especially from Almeria, during the vintage seasons, +for the American and British markets.--_Reports of U.S. Consuls._ + + * * * * * + + + + +GIBRALTAR. + + +The point or rock known as Gibraltar is a promontory two and one-half +miles long and from a quarter to three-quarters of a mile wide. It +rises abruptly from the sandy shore to a height at its highest point +of 1,408 ft. It is composed of gray limestone, honeycombed with caves +and subterranean passages, some of which contain most beautiful +stalactites in the form of massive pillars. + +Gibraltar is emphatically a fortress, and in some respects its +fortifications are unique. On the eastern side the rock needs no +defense beyond its own precipitous cliffs, and in all other directions +it has been rendered practically impregnable. Besides a sea wall +extending at intervals round the western base of the rock, and +strengthened by curtains and bastions and three formidable forts, +there are batteries in all available positions from the sea wall up to +the summit, 1,350 feet above the sea, and a remarkable series of +galleries has been hewn out of the solid face of the rock toward the +north and northwest. These galleries have an aggregate length of +between two and three miles, and their breadth is sufficient to let a +carriage pass. Portholes are cut at intervals of twelve yards, so +contrived that the gunners are safe from the shot of any possible +assailants. At the end of one of the galleries hollowed out in a +prominent part of the cliff is St. George's Hall, 50 feet long by 85 +feet wide, in which the governor was accustomed to give fetes. +Alterations, extensions, and improvements are continually taking place +in the defensive system, and new guns of the most formidable sort are +gradually displacing or supplementing the old fashioned ordnance. + +The whole population of Gibraltar, whether civil or military, is +subjected to certain stringent rules. For even a day's sojourn the +alien must obtain a pass from the town major, and if he wish to remain +longer, a consul or householder must become security for his good +behavior. Licenses of residence are granted only for short +periods--ten, fifteen, or twenty days--but they can be renewed if +occasion require. Military officers may introduce a stranger for +thirty days. A special permit is necessary if the visitor wishes to +sketch. + +Though the town of Gibraltar may be said to date from the fourteenth +century, it has preserved very little architectural evidence of its +antiquity. Rebuilt on an enlarged and improved plan after its almost +complete destruction during the great siege, it is still, on the +whole, a mean-looking town, with narrow streets and lanes and an +incongruous mixture of houses after the English and the Spanish types. +As a proprietor may at any moment be called upon to give up his house +and ground at the demand of the military authorities, he is naturally +deterred from spending his money on substantial or sumptuous +erections. The area of the town is about one hundred acres. + +Gibraltar was known to the Greek and Roman geographers as Calpe or +Alybe, the two names being probably corruptions of the same local +(perhaps Phenician) word. The eminence on the African coast near +Ceuta, which bears the modern English name of Apes' Hill, was then +designated Abyla; and Calpe and Abyla, at least according to an +ancient and widely current interpretation, formed the renowned pillars +of Hercules (Herculis columnæ), which for centuries were the limits of +enterprise to the seafaring peoples of the Mediterranean world. + +The strategic importance of the rock appears to have been first +discovered by the Moors, who, when they crossed over from Africa in +the eighth century, selected it as the site of a fortress. From their +leader, Tarik Ibn Zeyad, it was called Gebel Tarik or Tarik's Hill; +and, though the name had a competitor in Gebel af Futah, or Hill of +the Entrance, it gradually gained acceptance, and still remains +sufficiently recognizable in the corrupted form of the present day. +The first siege of the rock was in 1309, when it was taken by Alonzo +Perez de Guzman for Ferdinand IV. of Spain, who, in order to attract +inhabitants to the spot, offered an asylum to swindlers, thieves, and +murderers, and promised to levy no taxes on the import or export of +goods. The attack of Ismail Ben Ferez, in 1315 (second siege), was +frustrated; but in 1333 Vasco Paez de Meira, having allowed the +fortifications and garrison to decay, was obliged to capitulate to +Mahomet IV. (third siege). Alphonso's attempts to recover possession +(fourth siege) were futile, though pertinacious and heroic, and he was +obliged to content himself with a tribute for the rock from Abdul +Melek of Granada; but after his successful attack on Algeciras in 1344 +he was encouraged to try his fortune again at Gibraltar. In 1349 he +invested the rock, but the siege (fifth siege) was brought to an +untimely close by his death from the plague in February, 1350. The +next or sixth siege resulted simply in the transference of the coveted +position from the hands of the King of Morocco to those of Yussef III. +of Granada; and the seventh, undertaken by the Spanish Count of +Niebla, Enrico de Guzman, proved fatal to the besieger and his forces. +In 1462, however, success attended the efforts of Alphonso de Arcos +(eighth siege), and in August the rock passed once more under +Christian sway. The Duke of Medina Sidonia, a powerful grandee who had +assisted in its capture, was anxious to get possession of the +fortress, and though Henry IV. at first managed to maintain the claims +of the crown, the duke ultimately made good his ambition by force of +arms (ninth siege), and in 1469 the king was constrained to declare +his son and his heirs perpetual governors of Gibraltar. In 1479 +Ferdinand and Isabella made the second duke Marquis of Gibraltar, and +in 1492 the third duke, Don Juan, was reluctantly allowed to retain +the fortress. At length, in 1501, Garcilaso de la Vega was ordered to +take possession of the place in the king's name, and it was formally +incorporated with the domains of the crown. After Ferdinand and +Isabella were both dead the duke, Don Juan, tried in 1506 to recover +possession, and added a tenth to the list of sieges. Thirty-four years +afterward the garrison had to defend itself against a much more +formidable attack (eleventh siege)--the pirates of Algiers having +determined to recover the rock for Mahomet and themselves. The +conflict was severe, but resulted in the repulse of the besiegers. +After this the Spaniards made great efforts to strengthen the place, +and they succeeded so well that throughout Europe Gibraltar was +regarded as impregnable. + +In the course of the war of the Spanish succession, however, it was +taken by a combined English and Dutch fleet under Sir George Rooke, +assisted by a body of troops under Prince George of Hesse-Darmstadt. +The captors had ostensibly fought in the interests of Charles Archduke +of Austria (afterward Charles III.), but, though his sovereignty over +the rock was proclaimed on July 24, 1704, Sir George Rooke on his own +responsibility caused the English flag to be hoisted, and took +possession in name of Queen Anne. It is hardly to the honor of England +that it was both unprincipled enough to sanction and ratify the +occupation and ungrateful enough to leave unrewarded the general to +whose unscrupulous patriotism the acquisition was due. The Spaniards +keenly felt the injustice done to them, and the inhabitants of the +town of Gibraltar in great numbers abandoned their homes rather than +recognize the authority of the invaders. In October, 1704, the rock +was invested by sea and land; but the Spanish ships were dispersed by +Sir John Leake, and the Marquis of Villadarias fared so ill with his +forces that he was replaced by Marshal Tesse, who was at length +compelled to raise the siege in April, 1705. During the next twenty +years there were endless negotiations for the peaceful surrender of +the fortress, and in 1726 the Spaniards again appealed to arms. But +the Conde de la Torres, who had the chief command, succeeded no better +than his predecessors, and the defense of the garrison under General +Clayton and the Earl of Portmore was so effectual that the armistice +of June 23 practically put a close to the siege, though two years +elapsed before the general pacification ensued. The most memorable +siege of Gibraltar, indeed one of the most memorable of all sieges, +was that which it sustained from the combined land and sea forces of +France and Spain during the years 1779-1783. The grand attack on the +place was made on the 13th September, 1782, and all the resources of +power and science were exhausted by the assailants in the fruitless +attempt. On the side of the sea they brought to bear against the +fortress forty-six sail of the line and a countless fleet of gun and +mortar boats. But their chief hope lay in the floating batteries +planned by D'Arcon, an eminent French engineer, and built at the cost +of half a million sterling. They were so constructed as to be +impenetrable by the red hot shot which it was foreseen the garrison +would employ; and such hopes were entertained of their efficiency that +they were styled invincible. The Count D'Artois (afterward Charles X.) +hastened from Paris to witness the capture of the place. He arrived in +time to see the total destruction of the floating batteries and a +considerable portion of the combined fleet by the English fire. +Despite this disaster, however, the siege continued till brought to a +close by the general pacification, February 2, 1783. The history of +the four eventful years' siege is fully detailed in the work of +Drinkwater, who himself took part in the defense, and in the life of +its gallant defender Sir George Augustus Eliott, afterward Lord +Heathfield, whose military skill and moral courage place him among the +best soldiers and noblest men whom Europe produced during the 18th +century. + +Since 1783 the history of Gibraltar has been comparatively uneventful. +In the beginning of 1801 there were rumors of a Spanish and French +attack, but the Spanish ships were defeated off Algeciras in June by +Admiral Saumarez. Improvements in the fortifications, maintenance of +military discipline, and legislation in regard to trade and smuggling +are the principal matters of recent interest. + + * * * * * + + + + +THE FRANZ JOSEF I., NEW WAR SHIP. + + +Another addition was made to the Austrian navy by the launching on May +18 of the ram cruiser Franz Josef I. from the yards of S. Rocco in the +Stabilimento Tecnico Triestino. Her dimensions are: Length (over all), +103.7 meters; length (between perpendiculars), 97.9 meters; greatest +breadth (outside), 14.8 meters; draught (bow), 5.28 meters; draught +(stern), 6.05 meters; displacement on the construction water line, +4,000 tons. The armament consists of two 24-centimeter and six +15-centimeter Krupp breech loaders of 35 caliber length, two +7-centimeter Uchatius guns as an armament for the boats and for +landing purposes, eleven Hotchkiss quick-firing guns, and several +torpedo-launching ports; indicated horse power with natural draught +6,400, speed 17.5 knots; with forced draught 9,800, speed 19 knots. + +The ship is built of steel, and constructed according to the "double +bottom" system along the engine, boiler, and ammunition rooms. The +vaulted armor deck, extending 1.25 meters below the water line and +protecting the most vital parts of the ship, is 0.057 meter thick. +There are more than 100 water tight compartments below and above the +deck. A protecting belt of "cellulose" is provided for the engines and +boilers, extending from the armor deck downward. + +The two main guns, placed on Krupp's hydraulic carriages, occupy +positions in front and rear, and are protected by stands 0.09 meter +thick and 1.60 meters high. They fire _en barbette_ with a lateral +range each of 260 degrees at bow and stern--i.e., 130 degrees on +either of the broadsides. The weight of the barrel of the gun is 25 +tons, that of the steel shell 215 kilogrammes (about 430 lb.), that of +the brown powder charge 100 kilogrammes; initial velocity of +projectile, 610 meters; penetration, 0.524 meter iron; longest range, +17 kilometers (about 10½ English miles); range at 15 deg. elevation, +10 kilometers. The six 15-centimeter guns are placed in a kind of +machicouli arrangement in two tiers on each of the broadsides, so that +always four guns can fire in the direction of the keel to the front +and rear. The weight of the barrel of the gun is each six tons, that +of the steel shells 51 kilogrammes, that of the charge 22 kilogrammes; +initial velocity, 610 meters. + +The 11 quick-firing guns are partly placed along the broadsides, +partly in the masts, of which there are two. The triple expansion +engines, having each a bronze screw of 4.42 meters diameter, with +three blades and a rise of 6.3 meters, make with natural draught 105 +revolutions, and with forced draught 120. The pumping apparatus are +able to lift in one hour 400 tons of water. The front boiler room +contains a special cylindrical boiler for the working of the +electrical apparatus, for hydraulic pumps of the artillery service, +for anchor windlasses, ventilators, fire engines, etc. The whole +engines weigh 890 tons. The bunkers have a capacity for 660 tons of +coal, which allows for a run of 4,500 sea miles. + + * * * * * + + + + +CLARK'S GYROSCOPIC TORPEDOES. + + +Figs. 1 and 2 represent, upon a scale of about 1/10, two types of +torpedoes, the greatest number possible of the parts of which are made +revolvable, so as to render the torpedoes as dirigible as the gyrating +motion permits of. + +Fig. 1 represents an electric torpedo actuated by accumulators, A A, +keyed upon the shaft, and revolving along with the gearings. At the +beginning of the running, the accumulators are not all coupled, but +under the action of a clockwork movement which is set in motion at the +moment of starting, metallic brushes descend one after another upon +the collectors, B, and set in action new batteries for keeping +constant or, if need be, accelerating the speed at the end of the +travel. + +[Illustration: Fig. 1.] + +[Illustration: Fig. 2. CLARK'S GYROSCOPIC TORPEDOES.] + +Fig. 2 represents an air torpedo proposed by the same inventor. The +air reservoir, C, revolves along with the gearings under the action +of the pneumatic machine, D. The central shaft is hollow, so as to +serve as a conduit. The admission of air into the slide valve of the +machine is regulated by a clockwork which actuates a slide in an +aperture whose form and dimensions are so calculated that the speed +remains as constant as possible toward the end of the travel. + +The trajectory of the two torpedoes is regulated by a cylindrical +bellows, F, which gives entrance to the sea water. The springs shown +in the figure balance the hydraulic pressure. The tension of these +springs is regulated by the rod, H, according to the indications of +the scale of depths, I. + +When the torpedo reaches too great a depth, the action of the springs +can no longer balance the increase of the hydraulic pressure, and the +accumulation of the charge in the rear causes the front to rise toward +the surface. When the torpedo reaches the surface, a contrary action +is produced.--_Revue Industrielle._ + + * * * * * + + + + +THE FIRST STEAMBOAT ON THE SEINE. + + +[Illustration: FIRST STEAMBOAT BUILT ON THE SEINE.] + +The accompanying engraving represents the remarkable steamboat that +the unfortunate Marquis de Jouffroy constructed at Paris in 1816, +after organizing a company for the carriage of passengers on the +Seine. De Jouffroy, as well known, made the first experiment in steam +navigation at Lyons in 1783, but the inventor's genius was not +recognized, and he met with nothing but deception and hostility. With +the obstinacy of men of conviction, he did not cease to prosecute his +task. He assuredly had an inkling of the future in store for the +invention that he was offering to humanity. + +The paddle wheel boat that he constructed at Paris in 1816 did not +succeed any better than its predecessors; it was remarkable +nevertheless in appearance and structure. + +The engine was forward, as shown in the engraving, which is copied +from a composition of Dubucourt's. + +The company organized by the marquis was ruined, and, as well known, +the unfortunate inventor himself died in poverty in 1832, at the age +of eighty-one years.--_La Nature._ + + * * * * * + + + + +THE ELECTRIC MOTOR TESTS ON THE NEW YORK ELEVATED RAILROAD. + + +The American Institute of Electrical Engineers at its last meeting of +the season, held June 25, again considered the subject of electrical +traction, the paper presented by Mr. Leo Daft being based upon some +recent electrical work on the elevated railroads and its bearing on +the rapid transit problem. The _Railroad Gazette_ gives the following +abstract: + + He introduced the subject with a tribute to the efficiency of + the elevated railroad system as it is now operated by steam, + with special reference to that section of it known as the Ninth + Avenue line, upon which his experiments with the electric motor + have been conducted, over which passengers are now conveyed a + distance of five miles in 26 minutes for five cents, which he + considered the best and cheapest municipal rapid transit in the + world, and which is operated with a higher degree of safety than + any other railroad in the world making an equal number of stops + per 100 miles. On a recent holiday, April 30 last, 835,720 + passengers were carried upon the entire system without + noticeable detention or accident. The rapidly increasing traffic + makes the demand for better facilities a pressing one, and as + the average half million now carried daily will soon become a + million, it appears doubtful if any method can be devised of + providing for the growth by the use of steam motors on the + present structures, which are now taxed to their utmost. To the + mind of the mechanical engineer, having in view the ordinary + coefficients of tractive ability, there is no remedy for this. + The speaker stated that these coefficients were not entirely + trustworthy. He reiterated his previously expressed opinion, + based on frequent experiments, that there is a decided increase + in traction gained by the passage of the electric current from + the wheels to the rails, giving the details of one test where a + motor with a load making a total of 600 lb. climbed a gradient + of 2,900 ft. per mile, starting from a state of rest. He stated + that some of those people who had ridiculed his statements had + finally admitted that they were true. + + The motor Ben Franklin, which had been used in making these + tests on the elevated roads, weighed 10 tons, and performed + service nearly equal to the steam motors weighing 18 tons. The + object of these tests was the determination of coal economy. + Tests with a Prony brake showed that the motor developed 128 + H.P. The piece of track on which the experiments were conducted + embraced 2,200 ft. of level track and 1-8/10 miles of gradients, + varying from 11-3/10 to 98-7/10 ft. per mile, while at Thirtieth + street the station is at the foot of the steepest grade, thus + testing to the utmost the tractive capacity of the motor. The + experiments were begun in October, 1888, and carried on between + the hours of 9 P.M. and 4 A.M., beginning with one or two cars, + the load being increased nightly until it was finally made up of + eight coaches of 12 tons each, which were hauled up the 98 ft. + grade at a speed of 7½ miles per hour, the entire distance being + covered at the rate of 14-6/10 miles per hour. The maximum speed + obtained on level with that train was 16.36 miles per hour. + Seventy trips were subsequently made with a 70 ton train + operated between the steam trains under 3 minutes headway, but + the work was considered too critical on account of the absence + of suitable brakes. A number of experiments made about this time + showed that the mean speed with a three-car train running + express on the up-town track was about 24 miles per hour, + although the ability of the motor on a level with a similar + train was nearly 28 miles per hour. This, however, was not the + maximum speed, as the level track was not long enough to permit + of its attaining the highest rate. It was the opinion of the + speaker, however, that the speed attained could not be exceeded + with prudence on the elevated structure. + + The measurements of speed were made by dividing the track into + 19 sections of 500 ft., each section being provided with a + circuit-closing plate connected with a chronograph which was + carefully tested. The indicator cards were taken at the central + station by Mr. Idell and his assistants, and the dynamometer + used was of the liquid type made by Mr. Shaw, of Philadelphia. + The diagrams prepared from the data obtained were then explained + by the speaker, who stated that there was not a marked + difference between the 10 ton motor and the 18 ton locomotive in + the initial effort on the level, as will be seen by comparing a + run observed by a railroad officer on March 9 with a steam motor + and a load of about 57½ tons. The steam motor required 1 min. + and 29 sec. to make the distance from 14th to 23d streets, while + the electric motor with a train of 70 tons made the same trip in + 1 min. and 50 sec.; the absence of power brakes compelled the + current to be taken off at 19th street, while it was probable + that the throttle of the steam locomotive was not closed until + it reached 23d street, this being the usual practice. The data + obtained in these experiments shows that 29,940 h.p. is required + to operate the Ninth avenue railroad for the 16 hours' service, + or an average of 1,871 h.p. per hour, or 2,181 h.p., adding + station friction. The varying requirements of the traffic during + the day shows that the service could be advantageously divided + up between four stationary engines of 800 h.p. each, there being + but five hours of the day when all of them would be required. + The fuel consumption per day, allowing 22 lb. of coal per h.p. + per hour at $2.25 per ton, would make a total of $92.25 per diem + for fuel, the coal being a mixture deliverable at the dock for + about $1.80 per ton. The weight of coal used for the present + locomotives is about the same, viz., 40 tons per day, but + practice has shown it to be most economical to use coal of the + best quality, costing $5 per ton, making the cost of fuel about + double that required for the electric system. Without entering + into other economies which the speaker claimed were in favor of + electricity, and ignoring the plan suggested by Sir William + Siemens of braking the train by converting the motor into a + dynamo and thus utilizing the energy of momentum, he believed + that the economy in fuel alone was sufficient to prove that the + application of power by electricity was preferable to direct + steam propulsion for the elevated railroad service. + + * * * * * + + + + +MAGNETISM IN ITS RELATION TO INDUCED ELECTROMOTIVE FORCE AND +CURRENT.[1] + + [Footnote 1: A paper read before the American Institute of + Electrical Engineers, New York, May 22, 1889.] + +By ELIHU THOMSON. + + +There is perhaps no subject which at the present time can have a +greater interest to the physicist, the electrician, and the electrical +engineer than the one which heads this paper. The advances which have +been made in the study from its purely theoretical or scientific side, +and the great technical progress in the utilization of the known facts +and principles concerning magnetic inductions, can but deepen and +strengthen that interest. + +On the side of pure theory we find the eager collection of +experimental data to be submitted to the scrutiny of the ablest and +brightest minds, to be examined and reasoned upon with the hope of +finding some clew to satisfying explanations, and on the side of +practice we find the search for new facts and relations no less +diligent, though often stimulated by practical problems presented for +solution. Indeed, the urgency for results is often the greater on the +practical side, for theory can wait, practice cannot, at least in the +United States. + +We must look for continued triumphs in both directions, and the most +welcome of all will be the framing of a theory or explanation which +will enable us to interpret magnetic and electric phenomena. The +recent beautiful experiments of Hertz on magnetic waves have opened a +fertile region for investigation. + +It would seem that the study of magnetism and electricity will give us +the ability to investigate the ether of space, which medium has been +theorized upon at great length, with the result of leaving it very +much where it was before, a mysterious necessity. + +Faraday says, speaking of magnetism: + + "Such an action may be a function of the ether, for it is not at + all unlikely that if there be an ether it should have other uses + than simply the conveyance of radiations." 3,075. Vol. III., + Exp. Res. + + "It may be a vibration of the hypothetical ether, or a state of + tension of that ether equivalent to either a dynamic or a static + condition," etc. 3,263. Vol. III., Exp. Res. + +Faraday again says, speaking of the magnetic power of a vacuum: + + "What that surrounding magnetic medium deprived of all material + substance may be I cannot tell, perhaps the ether." 3,277. Vol. + III., Exp. Res. + +Modern views would seem to point that through a study of magnetic +phenomena we may take a feeble hold upon the universal ether. +Magnetism is an action or condition of that medium, and it may be that +electrical actions are the expression of molecular disturbances +brought about by ether strains or interferences. The close relations +which are shown to exist between magnetism and light tend to +strengthen such views. Indeed, it would not be too much to expect that +if the mechanics of the ether are ever worked out, we should find the +relation between sensible heat and electric currents to be as close as +that of light to magnetism, perhaps find ultimately the forms of +matter, the elements and compounds to be the more complex +manifestations of the universal medium--aggregations in stable +equilibrium. It is a difficult conception, I confess, and a most +shadowy and imperfect one, yet facts and inferences which favor such +views are not wanting. + +Our science of electricity seems almost to be in the same condition +that chemistry was before the work of Lavoisier had shed its light on +chemical theory. Our store of facts is daily increasing, and +apparently disconnected phenomena are being brought into harmonious +relation. Perhaps the edifice of complete theory will not be more than +begun in our time, perhaps the building process will be a very gradual +one, but I cannot refrain from the conviction that the intelligence of +man will, if it has time, continue its advance until such a structure +exists. + +I have been led to make these general allusions to electrical theory +in order to emphasize the fact that in the present paper no unraveling +of the mystery is to be attempted, but rather the presentation of some +few considerations upon a subject of absorbing interest. + +The conception of Faraday in regard to the existence of lines of +magnetic force representing directions of magnetic strain or tension +in a medium has not only lost nothing of its usefulness up to the +present time, but has continually been of great service in the +understanding of magnetic phenomena. We need spend no time in showing, +as Faraday and others have done, that these lines are always closed +circuits, polarized so that the direction of the lines cannot be +reversed without reversal of the actions. Nor need we take time to +show that in any medium the lines are mutually repellent laterally if +of the same direction of polarization. Opposing this tendency to +separation or lateral diffusion of magnetic force is the strong +apparent tendency of the lines to shorten themselves in any medium. +These actions are distributed by the presentation of a better medium, +as iron instead of space or air. Lines of force will move into the +better medium, having apparently the constant tendency to diminish the +resistance in their paths. + +The peculiar and mysterious nature of media, such as iron, is to +permit an extraordinary crowding of lines on account of slight +resistance to their passage through it. We need not, in addition, do +more than refer to the other well-known facts of an electric current +developing magnetic lines encircling the conductor, as being the +general type, which includes all forms of magnetic field or +electro-magnets, sustained by currents, and the fact of a development +when magnetic lines or circuits and material masses are in relative +movement of electromotive forces transversely to the direction of the +lines of magnetism, and also transversely to the direction of relative +movement, as in the case of electric conductors traversing or cutting +through a field, or of a field traversing or being moved across a +conductor. We must not forget that even insulators, as well as +conductors, cutting lines of force, have the electromotive force +developed in them. The action simply develops potential difference, +and this generates the current where a circuit exists. While we are in +the habit of saying that a conductor moved across a field of lines, or +_vice versa_, generates electric current, I think the statement +incomplete. The movement only sets up a potential difference, and the +power expended in effecting the movement generates C × E. The current +is energy less the potential, or the energy expended gives the two +effects of potential or pressure and current or rate of movement. +Consequently an insulator, or an open-circuited conductor, traversing +a field, consumes no energy, potential difference only being produced. +Nevertheless, as will be shown, the magnetic circuits or lines +themselves may furnish the energy for their own movement across a +conductor, and so develop current as well as potential. + +This occurs in the effort of lines to shorten their paths, to lessen +their density, to pass to better media. Indeed, a close examination +will show that wherever power is expended in developing current in a +circuit, cutting lines of force, the energy expended is first employed +in stretching the lines, which thus receive the energy required to +permit them, in shortening, to cut the conductor and set up currents +in the electric circuit in accordance with the potential difference +developed in that circuit and its resistance. + +I think we may also say, though I do not remember to have seen the +statement so put, that whenever electric potential is set up +inductively, as in self-induction, mutual induction, induction from +one circuit to another, and induction from magnets or magnetic field, +it is set up by the movement of lines of force laterally across the +body, mass or conductor in which the potential is developed, and that +whenever current is set up in a wire or an existing current prolonged, +or an existing current checked by induction, self-induction, or +induction from magnets, the action is a transfer of energy, +represented by strained lines of force shortening or lessening their +resistance, or lengthening and increasing the resistance in their +paths. The magnetic field is like an elastic spring--it can in one +condition represent stored energy--it can be strained and will store +energy--it can be made to relieve its strain and impart energy. + +[Illustration: Fig. 1.] + +Let us examine some known phenomena in this light. Take the case of a +simple wire, conveying current, say, in a line away from observer, +Fig. 1. There exists a free field of circular magnetism (so called), +shading off away from the wire, and which is represented by concentric +circles of increased diameter. The superior intensity or strength of +the lines near the wire may also be represented by their thickness. +This is often shown also by crowding the lines near the wire, though I +am disposed to regard Fig. 1 as more nearly expressing the condition, +unless we are to regard the lines as simply indicating a sort of +atmosphere of magnetic effect whose density becomes less as we proceed +outward from the wire, in which case either form of symbol suffices. +The direction of polarization of the lines may be indicated by an +arrow head pointing in a direction of right-handed rotation in the +path of the lines. This is the typical figure or expression for all +forms of simple magnetic circuit--the form of the lines, their length, +position, density, will depend on the shape of the conductor or +conductors (when more than one) and the materials surrounding or in +proximity to the wire or wires. + +If the current traversing the conductor is constant, the magnetic +field around it is stable and static, unless other influences come in +to modify it. The cutting off of the current is followed by +instability of the field whereby it can and must produce dynamic +effects. I say _must_ because the field represents stored energy, and +in disappearing _must_ give out that energy. To throw light on this +part of the subject is one of the objects of the present paper. +Cutting off the current supply in the case assumed leaves the +developed magnetic lines or strains unsupported. They at once shorten +their paths or circuits, collapsing upon the conductor as it were, and +continuing this action, cut the section of the conductor, and +apparently disappear in magnetic closed circuits of infinitesimal +diameter but of great strength of polarization. It appears to me that +we must either be prepared to give up the idea of lines of force or +take the position that the magnetic circuits precipitate themselves in +shortening their circuits and disappearing upon and cut the conductor. +It was Hughes who put forward the idea that an iron bar in losing its +apparent magnetism really short-circuits the lines in itself as +innumerable strongly magnetized closed circuits among the molecules. +In becoming magnetic once more these short circuits are opened or +extended into the air by some source of energy applied to strain the +lines, such as a current in a conductor around the bar. + +May not this idea be extended, then, to include the magnetic medium, +the ether itself? Does it contain intensely polarized closed circuits +of magnetism which are ready to be stretched or extended under certain +conditions by the application of energy, which energy is returned by +the collapse of the extended circuits? This is doubtless but a crude +expression of the real condition of things, for the lines are only +symbols for a condition of strain in a medium which cannot be +represented in thought, as we know nothing of its real nature. There +is one point in this connection which I must emphasize. The strained +lines, Fig. 1, are indications of stored energy in the ether, and the +lines _cannot_ disappear without giving out that energy. Ordinarily, +it makes its appearance as the extra current, and adds itself so as to +prolong the current which extended the lines when an attempt is made +to cut off such current. Were it conceivable that the current could be +cut off and the wire put on open circuit while the lines still +remained open or strained, the energy must still escape when the field +disappears. It would then produce such a high potential as to be able +to discharge from the ends of the conductor, and if the conductor were +of some section, part of the energy would be expended in setting up +local currents in it. The field could not disappear without an outlet +for the energy it represents. But we cannot cut off a current in a +wire so as to leave the wire on open circuit with the lines of the +magnetic circuit remaining around it without iron or steel or the like +in the magnetic circuit. We can approach that condition, however, by +breaking the circuit very quickly with a condenser of limited capacity +around the break. This is done in the Ruhmkorff coil primary; the +condenser forms a sort of blind alley for the extra current on its +beginning to flow out of the primary coil. But the condenser charges +and backs up and stops the discharge from the primary, even giving a +reverse current. The lines of magnetic force collapse, however, and +have their effect in the enormous potential set up in the secondary +coil. + +Take away the secondary coil so as to stop that outlet, the energy +expends itself on the iron core and the primary coil. Take away the +iron core, and the energy of magnetization of the air or ether core +expends itself on the wire of the primary and, possibly, also on the +dielectric of the condenser to some extent. The extra current becomes +in this instance an oscillatory discharge of very high period back and +forth through the primary coil from the condenser, until the energy is +lost in the heat of C2 × R. This conversion is doubtless rendered +all the more rapid by uneven distribution of current and eddy current +set up in the wire of the coil. + +The considerations just given concern the loss of field or the +shortening and apparent disappearance of the magnetic lines or +circuits, as giving rise to the self-induction or increased potential +on breaking. Where the energizing current is slowly cut off or +diminished the energy is gradually transferred to the wire in +producing elevation of potential during the decrease; and the collapse +and cutting of the wire by the collapsing circuits or lines is then +only more gradual. + +Let the current be returned to the wire after disappearance of +magnetism, and the lines again seem to emanate from the wire and at +the same time cut it and produce a counter potential in it, which is +the index of the abstraction of energy from the circuit, and its +storing up in the form of elastically strained lines of magnetism +around the conductor. The effect is that of self-induction on making +or upon increase of current, the measure of the amount being the +energy stored in the magnetic circuits which have been extended or +opened up by the current. The greater the current and the shorter the +path for the lines developed around the axis of the conductor, the +greater the energy stored up. Hence, a circular section conductor has +the highest self-induction, a tube of same section less as its +diameter increases, a flat strip has less as its width increases and +thickness diminishes, a divided conductor much less than a single +conductor of same shape and section. Separating the strands of a +divided conductor increases the length of magnetic paths around it, +and so diminishes the self-induction. A striking instance of this +latter fact was developed in conveying very heavy alternating currents +of a very low potential a distance of about three feet by copper +conductors, the current being used in electric welding operations. + +The conductors were built up of flat thin strips of copper for +flexibility. When the strips were allowed to lie closely together, the +short conductor showed an enormous self-induction, which cut down the +effective potential at its ends near the work. By spreading apart the +strips so as to lengthen a line around the conductor, the +self-induction could be easily made less than 35 per cent. of what it +had been before. The interweaving of the outgoing and return conductor +strands as one compound conductor gets rid almost entirely of the +self-inductive effects, because neither conductor has any free space +in which to develop strong magnetic forces, but is opposed in effect +everywhere by the opposite current in its neighbor. + +Where a number of conductors are parallel, and have the same direction +of current, as in a coil or in a strand, it is evident that statically +the conductor may be considered as replaceable by a single conductor +with the same external dimensions and same total current in the area +occupied, the magnetic forces or lines surrounding them being of same +intensity. But with changing current strength the distribution of +current in the conductor has also a powerful effect on the energy +absorbed or given out in accordance with the magnetism produced. Hence +the self-induction of a strand, coil or conductor of the same section +varies with the rapidity of current changes, owing to the conduction +being uneven. + +The uneven distribution of current, or its tendency to flow on the +outer parts of a conductor when the rate of variation or alternation +is made great, is in itself a consequence of the fact that less energy +is transferred into magnetism in this case than when the current flows +uniformly over the section, or is concentrated at the center. In other +words, when a uniform current traverses a conductor of the same +section, the circular magnetism, or surrounding magnetic lines, are to +be found not only outside the conductor, but also beneath its +exterior. Since in forming these lines on passage of current the +middle of section would be surrounded by more lines than any other +part of the conductor, the current tends to keep out of that part and +move nearer the exterior in greater amount. Hence, in rapidly +alternating currents the conductor section is practically lessened, +being restricted largely to the outer metal of the conductor. If the +round conductor, Fig. 2, were made of iron, the magnetism interior to +it and set up by a current in it would be very much greater, the +section of the conductor being filled with magnetic circuits or lines +around the center. The total magnetism, external and internal, would +be much greater in this case for a given current flow, and the energy +absorbed and given out in formation and loss of field or the +self-induction would be much increased. This could, however, be +greatly diminished by slitting the conductor radially or making it of +a number of separate wires out of lateral magnetic contact one with +the other, Fig. 3. In these cases the resistance of the interior +magnetic circuits would be increased, as there would be several breaks +in the continuity around the center of the conductor. The total +magnetism which could be set up by a current would be lessened, and +the self-induction, therefore, lessened. + +[Illustration: Fig. 2.] + +[Illustration: Fig. 3.] + +The moment we begin the bringing of iron into proximity with an +electric conductor conveying current, we provide a better medium for +the flow or development of magnetic lines or circuits. In other words, +the lines may then be longer, yet equally intense, or more lines may +be crowded into a section of this metal than in air or space. Figs. +4a, 4b, 4c show the effect brought about by bringing iron of +different forms near to the conductor. + +[Illustration: Fig. 4a.] + +[Illustration: Fig. 4b.] + +[Illustration: Fig. 4c.] + +It shows, in other words, the development of the ordinary +electro-magnet of the horseshoe form, and the concentration of the +lines in the better medium. The lines also tend to shorten and +diminish the resistance to their passage, so that attraction of the +iron to the conductor takes place, and if there is more than one piece +of iron, they tend to string themselves around the conductor in +magnetic contact with one another. + +When copper bars of 1 inch diameter are traversed by currents of +40,000 to 60,000 amperes, as in welding them, the magnetic forces just +referred to become so enormous that very heavy masses of iron brought +up to the bar are firmly held, even though the current be of an +alternating character, changing direction many times a second. + +[Illustration: Fig. 5] + +[Illustration: Fig. 6] + +When a conductor is surrounded by a cast iron ring, as in Fig. 5, the +current in such conductor has an excellent magnetic medium surrounding +it. A large amount of energy is then abstracted on the first impulse +of current, which goes to develop strong and dense magnetic lines +through the iron ring and across the gap in it. On taking off the +current the energy is returned as extra current, and its force is many +times what would be found with air alone surrounding the conductor. We +have then greatly increased the self-induction, the storing of energy +and opposition to current flow at the beginning, the giving back of +energy and assistance to the current flow on attempting to remove or +stop the current. Let us now complete the ring, by making it of iron, +endless, Fig. 6, with the conductor in the middle. + +We now find that on passing current through the conductor it meets +with a very strong opposing effect or counter potential. The evolution +of magnetic lines, or the opening out of magnetic circuits, goes on at +a very rapid rate. Each line or magnetic circuit evolved, and cutting +the conductor, flies at once outward, and locates itself in the iron +ring. This ring can carry innumerable lines, and they do not crowd one +another. It permits the lines even to lengthen in reaching it, and +yet, on account of its low resistance to their passage, the +lengthening is equivalent to their having shortened in other media. We +will suppose the current not sufficient to exhaust this peculiar +capacity for lines which the iron has. Equilibrium is reached, the +conductor has opened up innumerable closed circuits, and caused them +to exist in the ring still closed; but in iron, not space or ether +merely. The current passing has continued its action and storage of +energy until to emit another line in view of the resistance now found +in the crowded iron ring is impossible. + +Now let us cut off the current. We are surprised to find a very weak +extra current, a practical absence of self-induction on breaking, or, +at least, a giving out of energy in nowise comparable to that on +making. Let us put on the current as it was before. Another curious +result. But little self-induction now on making energy not absorbed. + +Now cut off the current again. Same effect as before. Now let us put +on the current reversed in direction. At once we find a very strong +counter potential or opposing self-induction developed. + +The ring had been polarized, or retained its magnetic energy, and we +are now taking out one set of lines and putting in reversely polarized +lines of force. This done, we break the reversed current without much +effect of self-induction. The ring remains polarized and inert until +an opposite flow of current be sent through. Iron is then a different +medium from the ether. + +The ring once magnetized must, in losing its magnetism, permit a +closure of the lines by shortening. This involves their passage from +the iron across the space in the center of the ring, notwithstanding +its great resistance to the lines of force. As passage from iron to +air is equivalent to lengthening of the lines, it is readily seen that +such lengthening may oppose more effect than a slight shortening due +to leaving iron, for air or space may give in provoking a closure and +disappearance of the lines. Looked at from another standpoint, the +lines on the iron may actually require a small amount of initial +energy to dislodge them therefrom, so that after being dislodged they +may collapse and yield whatever energy they represent. + +I must reserve for the future further consideration of the iron ring, +but in thinking upon this matter I am led to think that the production +of a magnetic line in an iron ring around a conductor may represent a +sort of wave of energy, an absorption of energy on the evolution of +the line from the conductor, and a slight giving out of energy on the +line reaching that position of proximity to the iron ring, that its +passage thereto may be said to be a shortening process or a lessening +of its resistance. + +The magnetism in air, gases, and non-magnetic bodies, being assumed to +be that of the ether, this medium shows no such effects as those we +get with the ring. It does not become permanently polarized, as does +even soft iron under the condition of a closed ring. The iron +possesses coercive force, or magnetic rigidity, and a steel ring would +show more of it. The molecules of the iron or steel take a set. If we +were to cut the soft iron ring, or separate it in any way, this +introduction of resistance of air for ether in the magnetic circuit +would cause the lines to collapse and set up a current in the +conductor. The energy of the ring would have been restored to the +latter. The curious thing is that physically the polarized ring does +not present any different appearance or ordinary properties different +from those of a plain ring, and will not deflect a compass needle. Its +condition is discoverable, however, by the test of self-induction to +currents of different direction. As a practical consideration, we may +mention in this connection that a self-inductive coil for currents of +one direction must be constructed differently from one to be used with +alternating currents. The former must have in its magnetic circuit a +section of air or the like, or be an imperfectly closed circuit, as it +were. The latter should have as perfectly closed a magnetic circuit as +can be made. We see here also the futility of constructing a Ruhmkorff +core coil on the closed iron magnetic circuit plan, because the +currents in the primary are interrupted, not reversed. + +The considerations just put forward in relation to the closed iron +ring, and its passive character under the condition of becoming +polarized, are more important than at first appears. It has been found +that the secondary current wave of a closed iron circuit induction +coil or transformer, whose primary circuit receives alternating +current, is lagged from its theoretical position of 90 degrees behind +the primary wave an additional 90 degrees, so that the phases of the +two currents are directly opposed; or the secondary current working +lamps only in its circuit is one half a wave length behind a primary, +instead of a quarter wave length, as might have been expected. + +But when it is understood that the iron core polarized in one +direction by the primary impulse does not begin to lose its magnetism +when that impulse simply weakens, but waits until an actual reversal +of current has taken place, it will be seen that the secondary +current, which can only be produced when magnetic lines are leaving +the core and cutting the secondary coil, or when the lines are being +evolved and passing into the core from the primary coil, will have a +beginning at the moment the primary reverses, will continue during the +flow of that impulse, and will end at substantially the same time with +the primary impulse, provided the work of the secondary current is not +expended in overcoming self-induction, which would introduce a further +lag. Moreover, the direction of the secondary current will be opposite +to that of the primary, because the magnetic circuits which are opened +up by the primary current in magnetizing the core, or which are closed +or collapsed by it in demagnetizing the core, will always cut the +secondary coil in the direction proper for this result. Transformers +of the straight core type with very soft iron in the cores and not too +high rates of alternation should approximate more nearly the +theoretical relation of primary and secondary waves, because the +magnetic changes in the core are capable of taking place almost +simultaneously with the changes of strength of the primary current. +This fact also has other important practical and theoretical bearings. + +Let us assume a plain iron core, Fig. 7, magnetized as indicated, so +that its poles, N, S, complete their magnetic circuits by what is +called free field or lines in space around it. Let a coil of wire be +wound thereon as indicated. Now assume that the magnetism is to be +lost or cease, either suddenly or slowly. An electric potential will +be set up in the coil, and if it has a circuit, work or energy will be +produced or given out in that circuit, and in any other inductively +related to it. Hence the magnetic field represents work or potential +energy. But to develop potential in the wire the lines must cut the +wire. This they can do by collapsing or closing on themselves. The bar +seems, therefore, to lose its magnetism by gaining it all, and in +doing so all the external lines of force moving inward cut the wire. +The magnetic circuits shorten and short-circuit themselves in the bar, +perhaps as innumerable molecular magnetic circuits interior to the +iron medium. To remagnetize the bar we may pass an electric current +through the coil. The small closed circuits are again distended, the +free field appears, and the lines moving outward cut across the wire +coil opposite to the former direction and produce a counter potential +in the wire, and consequent absorption of the energy represented in +the free field produced. As before studied, the magnetism cannot +disappear without giving out the energy it represents, even though the +wire coil be on open circuit, and therefore unable to discharge that +energy. The coil open-circuited is static, not dynamic. In such +assumed case the lines in closing cut the core and heat it. Let us, +however, laminate the core or subdivide it as far as possible, and we +appear to have cut off this escape for the energy. This is not really +so, however. We have simply increased the possible rate of speed of +closure, or movement of the lines, and so have increased for the +divided core the intensity of the actions of magnetic friction and +local currents in the core, the latter still receiving the energy of +the magnetic circuit. This reasoning is based on the possibility in +this case of cutting off the current in the magnetizing coil and +retaining the magnetic field. This is of itself probably impossible +with soft iron. That the core receives the energy when the coil cannot +is shown in the well known fact that in some dynamos with armatures of +bobbins on iron cores, the running of the armature coils on open +circuit gives rise to dangerous heating of the cores, and that under +normal work the heating is less. In the former case the core +accumulates the energy represented in the magnetic changes. In the +latter the external circuit of the machine and its wire coils take the +larger part of the energy which is expended in doing the work in the +circuit. In this case, also, the current in the coils causes a +retardation of the speed of change and extent of change of magnetism +in the iron cores, which keeps down the intensity of the magnetic +reaction. In fact, this retardation or lag and reduction of range of +magnetic change may in some machines be made so great by closing the +circuit of the armature coils themselves or short-circuiting them that +the total heat developed in the cores is much less than under normal +load. + +[Illustration: Fig. 7.] + +I wish now, in closing, to refer briefly to phenomena of moving lines +of force, and to the effects of speed of movement. In order to +generate a given potential in a length of conductor we have choice of +certain conditions. We can vary the strength of field and we can vary +the velocity. We can use a strong field and slow movement of +conductor, or we can use a weak field and rapid movement of the +conductor. But we find also that where the conductor has large section +it is liable to heat from eddy currents caused by one part of its +section being in a stronger field than another at the same time. One +part cuts the lines where they are dense and the other where they are +not dense, with the result of difference of potential and local +currents which waste energy in heat. We cannot make the conductor move +in a field of uniform density, because it must pass into and out of +the field. The conditions just stated are present in dynamos for heavy +current work, where the speed of cutting of lines is low and the +armature conductor large in section. + +But we find that in a transformer secondary we can use very large +section of conductor, even (as in welding machines) 12 to 15 square +inches solid copper, without meeting appreciable difficulty from eddy +currents in it. The magnetic lines certainly cut the heavy conductor +and generate the heavy current and potential needed. What difference, +if any, exists? In the transformer the currents are generated by +magnetic field of very low density, in which the lines are moving +across the conductor with extreme rapidity. The velocity of emanation +of lines around the primary coil is probably near that of light, and +each line passes across the section secondary conductor in a +practically inappreciable time. There is no cause then for differences +of potential at different parts of the section heavy secondary. Then +to avoid eddy currents in large conductors and generate useful +currents in them, we may cause the conductor to be either moved into +and out of a low density field with very great speed, or better, we +must cause the lines of a very low or diffused field to traverse or +cut across the conductor with very high velocity. + +It is a known fact that, in dynamos with large section armature +conductors, there are less eddy currents produced in the conductors +when they are provided with iron cores or wound upon iron cores than +when the conductors are made into flat bobbins moved in front of field +poles. Projections existing on the armature between which the +conductors are placed have a like effect, and enable us to employ +heavy bars or bundles of wire without much difficulty from local +currents. The reason is simple. In the armatures with coils without +iron in them, or without projections extending between the turns, the +conductor moves into and out of a very dense field at comparatively +low velocity, so that any differences of potential developed in the +parts of the section of conductor have full effect and abundant time +to act in setting up harmful local currents. In the cases in which +iron projects through the coil or conductor, the real action is that +the lines of the magnetic circuits move at high speeds across the +conductor, and the conductor is at all times in a field of very low +density. Figs. 8 and 9 will make this plain. In Fig. 8 we have shown a +smooth armature surface, having a heavy conductor laid thereon, and +which is at a just entering a dense field at the edge of the pole, +N, and at b leaving such field. It will be seen that when in such +position the conductor, if wide, is subjected to varying field +strength, and moves at a low speed for the generation of the working +potential as it passes through the field, thus giving rise to eddy +currents in the conductor. + +[Illustration: Fig. 8.] + +In Fig. 9 the conductors are set down between projections, in which +case both armature and field poles are laminated or subdivided. As +each projection leaves the edge of field pole, N, the lines which it +had concentrated on and through it snap backward at an enormous speed, +and cross the gap to the next succeeding projection on the armature, +cutting the whole section of the heavy armature conductor at +practically the same instant. This brisk transfer of lines goes on +from each projection to the succeeding one in front of the field pole, +leaving a very low density of field at any time between the +projections. The best results would be obtained when the armature +conductor does not project beyond or quite fill the depth of groove +between the projections. Of course there are other remedies for the +eddy current difficulty, notably the stranding and twisting of the +conductor on the armatures so as to average the position of the parts +of the compound conductor. + +[Illustration: Fig. 9.] + +Perhaps the most extreme case of what may be called dilution of field +by projections and by closed magnetic circuits in transformers would +be that of a block of iron, B, Fig. 10, moved between poles, N and S, +and having a hole through it, into and through which a conductor is +carried. The path through the iron is so good that we can scarcely +consider that any lines cross the hole from N to S; yet as B moves +forward there is a continual snapping transfer of lines from the right +forward side of the hole to the left or backward side, cutting the +conductor as they fly across, and developing an electromotive force in +it. I have described this action more in detail because we have in it +whatever distinction in the manner of cutting the lines of the field +is to be found between wire on smooth armatures and on projection +armatures and modifications thereof; and also between flat, open coils +passing through a field and bobbins with cores of iron. The +considerations advanced also bring out the relation which exists +between closed iron circuit transformers and closed iron circuit +(projection) dynamos, as we may call them. + +[Illustration: Fig. 10.] + +I had intended at the outset of this paper to deal to some extent with +the propagation of lines of magnetism undergoing retardation in +reference to alternating current motor devices, transformers with +limited secondary current, or constant average current, an alternating +motor working with what I may term a translation lag, etc.; but it was +soon found that these matters must remain over for a continuation of +this paper at some future time. My endeavor has been in the present +paper to deal with the lines of force theory as though it were a +symbol of the reality, but I confess that it is done with many +misgivings that I may have carried it too far. Yet, if we are to use +the idea at all it has seemed but right to apply it wherever it may +throw any light on the subject or assist in our understanding of +phenomena. + + * * * * * + + + + +ELECTRIC LIGHTING AT THE PARIS EXHIBITION--THE OERLIKON +WORKS. + + +Immediately on entering the Machinery Hall by the _galerie_ leading +from the central dome, and occupying a prominent position at the +commencement of the Swiss section, is a very important plant of +dynamos, motors, and steam engines, put down by the Oerlikon Works, of +Zurich. During the time the machinery is kept running in the hall, +power is supplied electrically to drive the whole of the main shafting +in the Swiss section and part of that in the Belgian section, +amounting in all to some 200 ft., a large number of machines of +various industries deriving their power from these lines of shafting, +while during the evening a portion of the upper and lower galleries +adjoining this section is lit by some twenty-five arc lamps run from +this exhibit. Steam is supplied from the Roser boilers in the motive +power court. The whole of the generating plant is illustrated in one +view, and a separate view is given of the motor employed to drive the +main shafting, this latter view showing the details of connection to +the same. On the extreme right hand side of the first view is a direct +coupled engine and dynamo of 20 horse power, a separate cut of which +is given in Fig. 3. The engine is of the vertical single cylinder +type, standing 5 ft. high, and fitted, as are the other two engines +exhibited, with centrifugal governor gear on the fly wheel, acting +directly on the throw of the cutoff valve eccentric. The two +standards, supporting the cylinder and forming the guide bars, +together with the entire field magnets and pole pieces of the dynamo, +and the bed plate common to both, are cast in one piece. + +[Illustration: FIG. 3 ENGINE AND DYNAMO FOR STEAMSHIPS.] + +The machine is specially designed for ship lighting, and with the view +of preventing any magnetic effect upon the ship's compass, the field +is arranged so that the armature, pole pieces, and coils are entirely +inclosed by iron. Any tendency to leakage of magnetic lines will +therefore be within the machine, the iron acting as a shield. This +build of field--shown in Fig. 3A--is also advantageous as a mechanical +shield to the parts of the machine most likely to suffer from rough +handling in transport, and it will be seen that the field coils are +easily slipped on before the armature is mounted in its bearings. + +[Illustration: FIG. 3A] + +The winding is compound, and in such a direction that the two opposite +horizontal poles have the same polarity; it follows from this that +there will be two consequent poles in the iron, these being opposite +in name to the horizontal poles and at right angles to them, viz., +above and below the armature. Opposite sections of the commutator are +connected together internally as in most four-pole machines, so that +only two brushes are necessary, at 90 deg. apart. + +The section of iron in the field is 60 square inches and rectangular +in form, and the whole machine measures 4 ft. 3 in. in length, and 2 +ft. in height, without including the height of the bed plate. The +armature is 17 in. in length and the same in diameter, measured over +the winding, and develops at the machine terminals 70 volts and 200 +amperes at 480 revolutions. The moving parts of the engine are well +balanced, and run remarkably well and without noise at this high rate +of speed. + +This dynamo serves to develop power to run a motor in an adjoining +inclosure, containing some fine specimens of lathes and machine tools +constructed by the Oerlikon Works. These are driven by the motor +through the medium of a countershaft, and the power and speed are +controlled from the switch board seen at the left of the exhibit, and +in Fig. 11. The resistance, R1, serves to vary the intensity of the +shunt field of the dynamo, the volts being indicated by the voltmeter +V1, and a resistance separate from the switch board is inserted in +the main circuit of the two machines. The ammeter, A2, is directly +connected to the dynamo, and therefore indicates the current, whatever +circuit this machine is running. + +[Illustration: Figs. 5-9, 11 plus THE PARIS EXHIBITION--STAND OF THE +OERLIKON WORKS.] + +A larger combined engine and dynamo, seen in the center of the stand, +serves to run the lighting of the galleries. The engine is a 60 horse +power compound, running at 350 revolutions, and fitted with a governor +on the fly wheel, like that described above. + +The dynamo is a two-pole machine, the upper pole and yoke being cast +in one, and the lower pole, yoke, and combined bed plate forming a +separate casting. The two vertical cores, over which the field bobbins +are slipped, are of wrought iron, and are turned with a shoulder at +either end, the yokes being recessed to fit them exactly. The cores +are then bolted to the yokes vertically from the top and horizontally +below. The field of this machine is shunt-wound, and in order to +maintain the potential constant a hand-regulated resistance--R2 on +the switch board--is added in circuit with the shunt field. The +voltmeter, V2, immediately above this resistance, serves to +indicate the difference of potential at the machine terminals. Both +voltmeters are fitted with keys, so that they are only put in circuit +when the readings are taken. + +The main terminals of this machine are fitted on substantial +insulating bases, fixed one at each end of the top yoke. These connect +to the external circuit by a heavy cable--the machine being capable of +developing 500 amperes--and to the shunt circuit, and regulating +resistance by small wires; while the two connections to the brushes +are by four covered wires in parallel on each side. This mode of +connection is more flexible than a short length of heavy cable, and +looks well, the wires being held neatly together by vulcanized fiber +bridges. The dynamo is a low tension machine, the field being +regulated to give 65 volts when running the lamp circuits. + +[Illustration: Fig. 10.] + +The illustration, Fig. 10, represents the automatic +re-regulator--C.E.L. Brown's patent. Motion is imparted to the cores +of two electro-magnets at the ends by the pulleys, W W1. The cores +have a projection opposite to the spindle, ab, which latter is +screw-threaded. By a relay one or other electro-magnet is put in +action, and the rotating core, which is magnetized, causes rotation of +the spindle by attraction, resulting in the movement of the contact +along the resistance stops. The relay is acted upon directly by the +potential of the dynamo, and the variable resistance is included in +the shunt field of the machine, so that changes in the potential, +resulting from changes in load or speed, are compensated for. + +The arrangements of the lamp circuits and the lamp itself may now be +described. The lamps are all run in parallel circuit, but are divided +into groups of five, each group being controlled by a separate switch +on the board--Figs. 11 and 11A. These switches are not in +direct communication with the dynamo, but make that connection through +a large central switch, S2, which therefore carries the whole +current. The returns from each group are brought to the connections +seen between the two resistances, where the circuits may be +disconnected if desired, and the main current then passes through the +ammeter, A3, to the other terminal of the machine. One of the smaller +switches at the top, Fig. 11A, is directly connected with one terminal +of the 20 horse power dynamo before mentioned, and the other side of +the switch to the motor in the machine tool exhibit. Also one of the +switches in connection with the central switch, S2, is connected to +the same motor, and therefore the latter may be run by either machine, +or, in fact, any combination of machines, lamps, and motor be made as +required. + +The form of switch made by the Oerlikon Works is illustrated in Fig. +7. Two thick semicircular bands of copper are screwed at one end to +opposite sides of a square block which is turned round by the switch +handle. The block has a projection at each corner, and two strong, +flat, stationary springs are attached to the framework of the switch +and press on opposite sides of the block. The ends of the springs +engage in the projections and prevent the switch being turned round +the wrong way, while the pressure of the springs on opposite sides +forces the copper bands to take up a position exactly in line with the +terminal contacts when the switch is closed, or at right angles to +them when it is opened. + +[Illustration: FIG. 4A] + +[Illustration: FIGS. 4, 4B and 4C] + +Further, each lamp has its own separate adjustable resistance, fuse, +and switch. These are of special construction, combined in one, and +are illustrated in Figs. 4 and 4A; the other figures, 4B and 4C, +showing some of the details of the same. The wires, W W, lead from and +to one lamp. The current enters at one wire, passes through the fuse, +f--Figs. 4C and 4A--down the center of the cylinder to a divided +contact, into which a switch arm can be shot. When this is so, a +connection is made to the upright brass rod, T, which serves to grip +the band, R, passing round the body of the cylinder. The current then +passes through all the turns of wire above the band, and out at the +other terminal. The resistance can be varied by raising or lowering +the band. Fig. 4B shows the manner of tightening the band against the +wires on the cylinder. The upright rod, T, is seen in section, and is +fixed in one position to the frame of the apparatus. Abutting against +this, and working in the block to which the two ends of the band are +screwed, is a thumb screw, S, by turning which the band may be +loosened for adjusting, and tightened when the right position is +found. The cylinder is covered with asbestos sheet, and the wire, +which is of nickel, and measures altogether from 3 to 4 ohms, is wound +helically round this. The switch arm, to which the handle is attached +below, does not itself make and break the circuit, but carries a +spring, as shown, which, when the arm is at the end of its movement, +pulls over the contact lever with a rapid action, shooting the same +between the divided contact piece, and making a perfect contact. The +switchboard forms one side of a closed wooden case or cupboard, with +sufficient room for a man to enter and adjust the resistances or +switches for each lamp. These are screwed to the inside of the case in +rows, to the number of twenty-five. The greatest care has been taken +in the fixing of the connections to the inside of this case, and no +leading wires of different potential are allowed to cross each other. + +[Illustration: FIG. 11A] + +The Oerlikon lamp, which is designed to work with constant potential, +is shown partly in section in Fig. 8. There is only one solenoid, A, +through which all the current passes, and whose action is to strike +the arc and maintain the current constant. The soft iron core, C, is +suspended from the inside of the tube, T, in which it has an up and +down movement checked by an air piston in the tube. An end elevation +of the brake wheels and solenoid is given in Fig. 9, where it will be +seen that the spindle carrying these wheels also carries between them +a pinion engaging with the rack rod, R. The top carbon attached to the +rack rod falls by its own weight, and is therefore in contact with the +lower carbon before the lamp is switched in circuit. When this is done +the core is instantly magnetized, and attracted to the soft iron brake +wheels, which it holds firmly. The air cushion in the tube prevents +the core being drawn up until it has fairly gripped the sides of the +wheels. The subsequent raising of the core therefore turns the wheels, +raises the rack rod, and strikes the arc. The feed is operated by the +weakening of the magnetic field of the coil, which causes the core to +lose its grip of the wheels, and allows the top carbon to descend. The +catch, L, Fig. 8, has a lateral play, and serves to engage in the +teeth of the rack rod, so as to prevent its falling when being +trimmed. Each carbon when in position is held against two rectangular +guide bars by the pressure of a wire spring--see figure. In this way +the carbon is pressed against two parallel knife edges, and is +therefore always in true alignment. The action of the lamp is very +simple, the working parts are few and solidly constructed, and the +regulation, as exhibited by the lamps running in the galleries, is +exceptionally steady. + +The transmission of power plant consists of two 250 horse power +dynamos--C.E.L. Brown's patent--the generator being driven by a +vertical compound condensing engine of the same power, running at 180 +revolutions. The dynamo generator is a four-pole 600 volt direct +current machine, series wound, and may be distinguished in the +engraving next to the switch board; while the motor receiver +connected to it, and erected in another portion of the Swiss section, +is of exactly the same size and type. The field, which is hexagonal in +shape, is cast in two pieces, bolted together horizontally, the +cross-sectional area of iron being 170 square inches. The armature is +cylindrical, and built up of flat rings stamped out of soft sheet +iron, eight notches in the same being provided to fit over the arms of +the spider keyed to the shaft. The spider is in halves, which are +bolted together longitudinally after the rings are in position. It is +Gramme wound, and measures over the winding 7 in. radial depth, 37 in. +outside diameter, and 22 in. in length. The current is collected by +four brushes. The fitting and mechanical build of the dynamos leaves +nothing to be desired. All the working parts of the dynamos and +engines are turned up to gauge and template, so as to be +interchangeable. As an instance of this, the armature of the generator +was built in the works, while the field magnets were being erected in +the exhibition, and, on arrival, fitted in position perfectly, and ran +at once without trouble. + +The energy taken off on the motor shaft is close on 200 horse power, +but varies according to the machines at work; the speed of the motor +does not, however, vary more than 3 per cent., and the brushes need no +adjustment. About 6 ft. of shafting is coupled on in line with the +motor shaft, and an extra plummer block fixed at the end. This +shafting carries at its extremity an additional 2 ft. pulley, the +power being delivered by belting from these pulleys to two large +pulleys on the main shaft. + +The machines run by this transmission consist of the looms of Rieter & +Co., of Winterthur; the large flour mill and lift of A. Millot & Co.; +the flour milling machinery of Frederick Wegmann & Co., of Zurich; the +brick and tile making machines of the Rorschach foundries; and the +looms of Messrs. Houget & Teston, of Verviers, in the Belgian section. +A 15 horse power two-pole Oerlikon dynamo is also run by a belt from +the main shaft, and generates power to drive a motor of similar type +in the Swiss section of the upper gallery. This runs a length of +countershafting supplying power to three silk-weaving machines +constructed by Benninger Frères; six weaving machines from the Ruti +works, near Zurich; and one knitting machine exhibited by Edward +Dubied & Co., of Couvet. + +The dynamo and motor are connected to the main cable by switches of +the type shown in Fig. 5. These are specially designed to destroy the +extra current on breaking circuit by the formation of an arc which +gradually increases the resistance till the break occurs, rendering it +less sudden. One wire passes through the handle and makes contact with +the springs, and the other is attached to the clamp in which the +carbon rod is held. The current is made to enter at the carbon rod, so +that the arcs formed cause consumption of the carbon. A magnetic +cut-out--Fig. 6--is also provided to each machine; this consists of an +electro-magnet, through which the main current passes, provided with +side pole pieces. A flat soft iron plate armature is hinged so as to +come up against the pole pieces when attracted. When the current is +not sufficiently strong to cause the plate to be attracted, a hole in +the center of the latter engages over a small projection in the top of +a weighted arm hinged in the center of the board, and keeps it +upright. If now the current exceeds the limits of safety to the +machine, due to a too heavy load being thrown on, the armature is +attracted and releases the vertical arm, which falls over and enters +with considerable force between the two spring contacts below. These +contacts are connected to the field terminals, which are, therefore, +short-circuited, and prevent the dynamo generating any current. A +retractile spring can be adjusted to cause cut-off at any required +current. These details are indicated in our illustrations mounted on +their respective switch boards. + +Since the erection of plant by these works at Solothurn for +transmitting 50 horse power five miles distant, which attracted so +much interest some time ago, several important works have been carried +out. Among these we may mention a 280 horse power transmission at 1½ +kilom. distance to a cotton mill at Derendingen in Switzerland, a 250 +horse power transmission at ½ kilom. distance, carried out for Gaetano +Rossi at Piovene in Italy, and a 300 horse transmission at 6 kilom. +distance installed for Giovanni Rossi, in which the power is given off +at two different stations.--_The Engineer._ + + * * * * * + + + + +THE ADER FLOURISH OF TRUMPETS. + + +Although telephonic novelties are not numerous at the Universal +Exposition, telephony--that quite young branch of electric science--is +daily the object of curious and interesting experiments which we must +make known to our readers, a large number of whom were not yet born to +scientific life when the experiments were made for the first time at +Paris in 1881; and it is proper to congratulate the Société Générale +des Téléphones on having repeated them in 1889 to the great +satisfaction of the rising generation. + +We allude to the Ader system of telephonic transmissions of sounds in +such a way that they can be heard by an audience. + +The essential parts of this mode of transmission consist of two +distinct systems--transmitters and receivers. + +[Illustration: FIG. 1.--THE ADER FLOURISH OF TRUMPETS] + +The transmitters are four in number, and are actuated by the same +number of musicians, each humming into them his part of the quartet +(Fig. 1). This transmitter, represented apart in elevation and section +in Fig. 2, is identical with the one used in the curious experiment +with the singing condenser. At A is a mouthpiece before which the +musician hums his part as upon a reed pipe. He causes the plate, B, to +vibrate in unison with the sound that he emits, and this produces +periodical interruptions of varying rapidity between the disk, B, and +the point, C. The button, D, serves to regulate the distance in such a +way that the breakings of the circuit shall be very complete and +produce sounds in the receivers as pure as allowed by this special +mode of transmission, in which all the harmonics are systematically +suppressed in order to re-enforce the fundamental. + +[Illustration: FIG. 2.--DETAILS OF THE TRANSMITTER.] + +This transmitter interrupter is interposed in the circuit of a battery +of accumulators, with the five receivers that it actuates, in such a +way that the four transmitters and five receivers form in reality four +groups of distinct autonomous transmission, the accordance of which is +absolutely dependent upon that of the artists who make them vibrate. + +The five receivers are arranged over the front door of the telephone +pavilion, near the Eiffel tower (Fig. 3). Each consists of a horseshoe +magnet provided, between its branches, with two small iron cores +having a space of a few millimeters between them (Fig. 4). Each of +these soft iron cores carries a copper wire bobbin, N, the number of +spirals of which is properly calculated for the effect to be produced. +Opposite the vacant space left by the two cores, there is a small +piece, t, of rectangular form, and also of soft iron, fixed to a +vibrating strip of firwood, L, of about 4 inches section. The +periodical breaking of the circuit produced by the transmitter causes +a variation in the magnetization of the iron cores of the five +receivers and makes the firwood strips vibrate energetically. These +vibrations are received and poured forth as it were in front of the +telephone pavilion, by large brass trumpets arranged in front of each +receiver, as shown in Fig. 3. + +[Illustration: FIG. 3.--THE ADER FLOURISH OF TRUMPETS] + +It would be difficult for us to pass any judgment whatever upon the +musical and artistic value of these transmissions of trumpet music to +a distance; we prefer to confess our incompetency in the matter. But +it is none the less certain that these experiments are having the same +success that they had at their inception in 1881 at the Universal +Exposition of Electricity, and they allow us to foresee that there is +a time coming in which it will be possible to transmit speech to a +distance with the same intensity that the present trumpet flourishes +have. Although all the tentatives hitherto made in this direction have +not given very brilliant results, we must not despair of attaining the +end some day or other. Less than fifteen years ago the telephone did +not exist; now it covers the world with its lines.--_La Nature._ + +[Illustration: Fig. 4.--DETAILS OF THE RECEIVER.] + + * * * * * + + + + +NOTES ON DYEWOOD EXTRACTS AND SIMILAR PREPARATIONS. + +By LOUIS SIEBOLD, F.I.C., F.C.S. + + +During the last ten years there has been an enormous increase in the +production of these preparations, and the time will come when their +application in dyeing and calico printing will become so general as to +completely supersede the employment of the raw materials. The +manufacture of these extracts, to be thoroughly successful, requires +to be so conducted as to secure the perfect exhaustion of the dyewoods +without the slightest destruction or deterioration of the coloring +matters contained in them; and though nothing like perfection has been +reached in the attainment of these objects, it is certain that the +processes of extraction and evaporation now employed by the best +makers are a very great improvement on the older methods. Indeed, +there is no difficulty nowadays in procuring dyewood extracts of high +excellence if the consumer is willing to pay a price for them +corresponding to their quality, and knows how to avail himself of the +aid of chemical skill to control his purchases. Unfortunately, +however, there is so much hankering after cheap articles, and so +little care is taken to ascertain their real quality, that every scope +is afforded to the malpractices of the adulterer. There are many dye +and print works in which large quantities of these extracts are used +without being subjected to trustworthy tests. Moreover, much of the +testing is done by fallacious methods and often by biased hands. So +fallacious, indeed, are some of these tests, that grossly adulterated +extracts are often declared superior to the purer ones, the cause of +this being the application of an insufficient proportion of mordant in +the dyeing or printing trials, and the consequent waste of the excess +of coloring matter in the case of the purer preparation. + +Professional analytical chemists have hitherto given but little +attention to these preparations, and the employment of experienced +chemists in works is as yet far from general. The testing of dyewood +extracts in such a manner as to throw full light on their purity, the +quality of raw material from which they are prepared, their exact +commercial value their suitability for special purposes, and the +proportion and nature of any adulterants they may contain, is of +course a difficult and tedious task, and must be left to the expert +who is in possession of authentic specimens prepared by himself of all +the different extracts made from every variety and quality of raw +materials, and who combines a thorough knowledge of experimental +dyeing and printing with a large experience in the chemical +investigation of these preparations. But when the object of the +testing is merely careful comparison of the sample in question with an +original sample or previous deliveries, the case is much simplified, +and comes within the scope of the general chemist or the laboratory +attached to works. A few years ago I recommended carefully conducted +dyeing trials on woolen cloth mordanted with bichromate of potash as +the best and simplest mode adapted to such cases, and my subsequent +experience enables me to confirm that observation to the fullest +extent. Most of these extracts contain the coloring matter in two +states, the developed and the undeveloped, and an oxidizing mordant +such as bichromate of potash causes the latter as well as the former +to enter completely into combination with a metallic base; whereas +many of the other mordants, such as alumina or tin compounds, merely +take up the developed portion of the coloring matter together with +such small and variable proportions of the undeveloped as might +undergo oxidation during the process of dyeing. I would therefore +suggest dyeing trials with alumina, tin, iron, etc., only as +subsidiary tests indicating the suitability of an extract for certain +special purposes, while recommending the trial with bichromate of +potash as the one giving the best information respecting the actual +strength of the extract in relation to the raw material from which it +was obtained, and as giving a fair idea of the money value of the +sample. Cotton dyeing does not, as a general rule, afford a good means +of assaying extracts, as it is generally done under conditions which +do not admit of complete exhaustion of the dye bath, but it might +often with advantage be resorted to as an additional trial throwing +further light on the degree of oxidation or development of the +coloring matter. Printing trials are apt to give fallacious results +unless the proportion of mordant is carefully adjusted to the amount +of coloring matter present, and several trials with different +proportions would be necessary to prevent erroneous conclusions. For +the trials with bichromate of potash on wool I would recommend pieces +of cloth weighing about 150 grains, and the most suitable proportion +of bichromate of potash is 3 per cent. of the weight of the cloth. The +requisite number of pieces (equal to the number of samples to be +tested) should be thoroughly scoured and then heated in the bichromate +solution at or near the boiling point for not less than 1½ hours, +after which they should be well washed and then dyed separately in the +solutions of equal weights of the extracts at the same temperature and +for the same length of time; 15 grains of extract is a suitable +quantity for a first trial under these conditions. These trials can +then be repeated with different relative proportions of extract in +order to ascertain what weight of a sample would give the same depth +of color as 15 grains of the standard example. Many precautions are +required both in the mordanting and dyeing processes in order to +obtain trustworthy results; and though the trials with bichromate of +potash give the most reliable information of any single test, they +should be supplemented by the subsidiary tests already alluded to, and +also by a chemical examination, in order to obtain a knowledge, not +merely of the wood strength, but also of the general nature of the +extract. An adulteration with molasses or glucose can be best +determined by fermentation in comparison with a pure sample. Mineral +adulterants may, of course, be detected by an estimation and analysis +of the ash, after making due allowances for variations due to +differences in different kinds of the same dyewoods. The estimation of +the individual coloring matters in these extracts by means of a +chemical analysis is under all circumstances a task requiring much +experience, especially as the coloring principles are associated in +different qualities of each class of dyewood with different +proportions of other constituents which often give much trouble to the +unpracticed experimenter. Extracts made from logwood roots are now +largely manufactured and often substituted or mixed with the extracts +of real logwood, and have in some instances been palmed of as logwood +extracts of high quality. The correct determination of such +admixtures, like the fixing of anything like the exact commercial +value of dyewood extracts, requires nothing less than a complete +chemical investigation coupled with numerous dyeing trials in +comparison with standard preparations, and should be left to an +expert. + +The presence in dyewood extracts of coloring matters in various stages +of development has hitherto militated against their use in place of +the raw materials by many dyers and printers who are still employing +inherited and antiquated processes in which the whole of the coloring +matter is not rendered available. It is often asserted by these that +even the best of extracts fail to give anything like the results +attained by the use of well-prepared woods, and that, indeed, their +application proves a complete failure. Such failure, however, is +simply due to the want of chemical knowledge on the part of the dyers, +for there is no real difficulty in making any good and pure extract +serve all the purposes for which the woods were used. It is to be +hoped that in this branch of industry, as well as in many others, the +employment of chemists will become more general than at present, and +not be restricted, as is often the case, to young men without +experience and without the trained intellect so essential to success +in chemical investigations. High class chemical skill is of course +available to the manufacturer, but the man of science who brings +matured knowledge and valuable brain work into the business required +social as well as pecuniary recognition, and the sooner and more +fuller this fact is appreciated the better it will be for the +maintenance and progress of our industries. + +With regard to the astringent extracts, such as sumac, myrabolam, +divi, valonia, quebracho, oak, etc., it is the aim of the +manufacturer, whenever such extracts are intended for the purposes of +dyeing and printing, to obtain the tannin in a form in which it is +best calculated to fix itself upon the fiber. The case is somewhat +different when the same extracts are required for tanning. For this +purpose it is necessary that the extract shall have considerable +permeating power, and that the tannin contained in it shall readily +yield leather of the desired texture, color, and permanency. Extracts +specially suited for this purpose are by no means always the most +suitable for the dyer, and _vice versa_. + +A brief description of the processes by which the astringent extracts +may be tested with particular reference to their fitness for definite +purposes concluded the paper. + +With regard to the question as to whether experimental dyeing with +bichromate of potash should be employed as a test even in works where +all the dyeing was done with other mordants, he was decidedly of +opinion that it should always be resorted to as one of the tests, +inasmuch as it was the only simple and expeditious method giving a +fair idea of the actual wood strength and money value of the extract. +The test should, in such cases, be supplemented by dyeing trials with +the mordants used at the works, and, if necessary, also by a chemical +analysis. Printing trials were not necessarily bad tests, since +oxidizing was usually added in these where it was necessary, and any +undeveloped coloring matter would thus be oxidized during the steaming +process: but, as he had stated before, it was essentially necessary in +such cases to have a fair idea of the amount of actual coloring matter +in the extract and to adjust the proportion of mordant accordingly. +Such trials should therefore be preceded by carefully conducted dyeing +trials with bichromate of potash. Mr. Thomson had raised the question +whether it would not be well for the manufacturer to prepare these +extracts in such a manner that they would contain all the coloring +matter in one condition only, in order to insure greater uniformity in +their quality and mode of application. This would, no doubt, be a +desirable step to take if the owners of dye and print works were more +in the habit of availing themselves of the service of competent +chemists experienced in this branch, for then they would be able to +make any extract do its full work irrespective of the state of +development of the coloring matter. Such, however, was not the case, +and it was a very common thing for the consumer of dyewood extracts to +require the manufacturer to prepare them specially for him so as to +suit his own dyeing recipes, or in other words to give exactly the +same shades, weight for weight, by his own method of dyeing as the +article he was in the habit of using. The manufacturer was thus often +compelled to make many different qualities of the same extract to suit +different customers. For the same reason adulterated articles were +often preferred to the pure ones. There was, perhaps, no branch of +industry in which chemical skill of a high order could be applied with +greater advantage than in dyeing, and nowhere was this fact less +recognized. Some of the processes of dyeing were exceedingly wasteful +and stood in much need of improvement. He (Mr. Siebold) knew a large +works in which a ton of logwood extract was used daily for black +dyeing only, and he might safely assert that of this enormous quantity +only a very small proportion would be fixed on the fiber, while by far +the greater proportion was utterly wasted. Such a waste could only be +prevented by a searching investigation of its causes by trained skill. +Mr. Thomson had further alluded to the color obtained with logwood or +logwood extract and wool mordanted with bichromate of potash, and +seemed to be under the impression that the color thus obtained was not +black, but blue. This was undoubtedly the case in dyeing trials +performed as tests, as these were conducted purposely with a very +small proportion of coloring matter in order to admit of a better +comparison of the resulting depth of shades. But with larger +proportions of logwood the color obtained was a fine bluish-black, and +with the addition of a small proportion of fustic or quercitron bark +to the logwood a jet black was readily produced. With regard to Mr. +Watson Smith's observation as to fractional dyeing, he (Mr. Siebold) +did not regard this method as a suitable trial for ascertaining the +strength of an extract, but he admitted it was occasionally very +valuable for detecting an admixture of extracts of other dyewoods, +such as quercitron bark extract in logwood extract. It was also a good +method of ascertaining the speed of dyeing and hence the relative +proportion of fully developed coloring matter of an extract.--_Jour. +Soc. Chem. Industry._ + + * * * * * + + + + +ORTHOCHROMATIC PHOTOGRAPHY.[1] + + [Footnote 1: Read before the Photographic Association of + Brooklyn.] + +By OSCAR O. LITZKOW. + + +What I want to show is the manner in which the process has been +tested. My employer, Mr. Bierstadt, has given me permission to show +you some samples, and also his chart containing the spectrum colors: +violet, indigo blue, green, yellow, orange, red, and black. This chart +has been photographed in the orthochromatic and also in the ordinary +way. + +There are many ways of producing an orthochromatic effect; one is the +use of a glass tank placed behind or in front of the lens, in which a +coloring matter from either a vegetable or mineral product is placed; +this tank or cell is, however, only for use in the studio, as for +outdoor photography we have a colored glass screen, so as not to be +bothered with carrying colored solution. + +The tank is constructed as follows: Procure two pieces of best white +plate glass, about 6 inches square; between these place a piece of +rubber of the same size square, and about 3/8 of an inch thick. In the +center of this rubber cut out a circle about 4 inches diameter, and +from one of the corners to the center of the circle cut out a narrow +strip ¼ inch wide; this serves as the mouth of the tank. The two +pieces of glass and the rubber are cemented together with rubber +cement; then, to hold it firmly together, two brass flanges are used +as a clamp, with four screws at an equal distance apart; a thin sheet +of rubber is on the glass side of the flanges to prevent direct +contact with the glass, the center remaining clear for the rays of +light to pass through solution and glass. + +One of the best orthochromatic effects made through this tank is with +a three-grains-to-the-ounce solution of bichromatic of ammonia or +bichromate of potassium. In this method there is no preparation used +on the plate. A common rapid dry plate is exposed through this +solution; the exposure, however, is about twenty times longer than it +would be if you removed the tank with the yellow solution, or, in +other words, if a dry-plate is exposed one minute without the yellow +solution it would have to be exposed twenty minutes through a +three-grain solution of bichromate of potassium or ammonia. It +produces wonderful results on an oil painting or any highly colored +object. + +Another method, and the one best adapted for landscapes, is to bathe +the plate in erythrosine and then expose it through a yellow glass +screen. + +As an illustration, suppose we have before us a beautiful landscape. +In the foreground beautiful foliage, in the center a lake, in the +distance hills, with a bluish haze appearing pleasing to the eye, also +a nice sky with light clouds. Now make a plain negative, and see what +has become of your clouds, hills, and the distance--not visible! Some +photographers have been led to think that by underexposing they retain +the distance, but they sacrifice the foreground; besides, it does not +produce an orthochromatic effect. + +But it is a good idea to expose longer on the foreground than you do +on the distance. This can be done by raising the cap of the lens +skyward and gradually shut off, giving the foreground more exposure. + +Plates are prepared for orthochromatic work as follows: Take any +ordinary rapid dry plate, place it in a bath containing + + Distilled water 200 c.c. + Strong liquid ammonia 2 c.c. + +Rock it for two minutes, work as dark as you possibly can. Now take it +out, and place it in the second bath for one and one-fourth minutes +and keep it rocking. Have on hand for use a stock solution of + + Distilled water 1,000 parts. + Erythrosine "Y" brand 1 part. + +Prepare second bath as follows: + + Erythrosine stock solution 25 c.c. + Distilled water 175 c.c. + Strong water ammonia 4 c.c. + +After removing the plate, dip it again face down to rinse off any +particles of scum, etc., that may get in the bath accidentally. This +bath may be used for one dozen 8 by 10, when it should be thrown away +and fresh bath used. + +After the plates come out of the last bath, they should be stood on +clean blotting paper to absorb the excess of solution. I would also +advise to use clean fingers. Pyro. or hypo. on the fingers is a +drawback to success. + +After plates have been drained, place them in a cleaned rack in an +absolutely light-tight closet, with air holes so constructed as to +admit air but no light; the plates will dry in from eight to twelve +hours. They are best prepared in the evening, and, if the closet is +good, will be dry in the morning. + +After the plates are dry they may be packed face to face with nothing +between them, in a double-cover paper box, and put in a dark closet +free from sulphureted hydrogen gas, until ready for use. I have kept +plates for three months in this way, and they were in good condition. +Great care should be used in developing these plates, as they are +sensitive to the red; get used to developing in a dark part of the +dark room; occasionally you may look at the process of development in +a little stronger light. + +The exposure through the yellow screen with an erythrosine plate is +about the same as if you had no orthochromatic plate--a plain plate +instead--provided you are not using too dark a yellow on your screen. +This can only be determined by experience. I will give to a common +plate about four seconds, an orthochromatic plate under the same +conditions five seconds. + +The yellow glass screen is prepared as follows: Take a piece of best +plate glass--common cannot be used--clean it nicely; take another +large plate glass, or anything that is level and true, level it with a +small spirit-level. Now take the cleaned piece of glass and coat it +with + +AURENTIA COLLODION. + + Ether 5 oz. + Alcohol 5 oz. + Cotton 60 grs. + +The aurentia to be added to suit your judgment; it takes a very small +quantity to make an intense yellowish-red collodion. Pour it on the +center of the glass, flow it to the edges, and before it sets place it +on the level glass and allow it to set; when set put it in a rack to +dry. + +Should it dry in ridges, the collodion may be too thick, and it must +be thinned down with equal parts of alcohol and ether. A single piece +of plate glass, about one-eighth inch thick, coated with aurentia +collodion, is all that is required with an erythrosine plate. Or, +after a piece has been successfully coated, another piece of the same +plate glass, and the same size, may be cemented together with balsam, +having the coated aurentia side between the two glasses; the edges may +then be bound with paper. + +In using different colored solutions, collodion, etc., I have found +that one will change the focus and the other not. With some screens +you must focus with them in their positions; take away the screen, and +the picture appears out of focus. I cannot fully explain why it is, +and for this reason will not make the attempt; experience alone can +teach it. + +Another thing that has been tried lately is to do away with the yellow +screen by substituting a yellow coating direct on the plate. No doubt +the focus on an object that requires absolute sharpness is somewhat +affected by the use of a glass. We have been successful, on a small +scale, to coat the plate with the following yellow solution: + +Place in a tray enough of a saturated solution of tropæolin in wood +alcohol to cover the plate; allow it to remain ten seconds. It is +necessary that the plate should be bathed previously in erythrosine +and dried. Before applying the tropæolin, which, being in alcohol, +dries in a few minutes, have some blotting paper on hand, as the +solution gathers in a pool and leaves bad marks on the end of the +plate. + +The plate can be developed in the usual way. Try it and see the +results.--_Reported in the Beacon._ + + * * * * * + + + + +PLATINOTYPE PRINTING.[1] + + [Footnote 1: A communication to the North London Photographic + Society.] + + +Platinotype, which may be considered to be the most artistic of +photographic printing processes, may be separated into its three +modifications--the hot bath and cold bath, in which a faintly visible +image is developed, and the Pizzighelli printing-out paper. The hot +bath process, again, may be divided into the black and white and sepia +papers. I intend to give you a rough outline of the preparation of the +paper and working of these modifications, concluding by demonstrating +the hot bath method, and handing around prints by it. + +Platinotype may almost be styled an iron printing process, for, while +no trace of iron or its salts is found in the finished print, certain +salts of iron are mixed with the platinum salt, which is platinum +combined with two atoms of chlorine (PtCl2), as a means for readily +reducing it; this, however, cannot be effected without the presence of +neutral oxalate of potash, hence the use of the oxalate bath. There is +no platinum in the paper for the cold bath process, it being coated +with ferric oxalate mixed with a very small quantity of chloride of +mercury--somewhere about one grain to an ounce of ferric oxalate +solution. When dry it is ready for exposure, which is about three +times less than with silver printing. + +It is absolutely necessary to store all papers for platinum printing +in an air-tight tin containing chloride of calcium, which must be +dried by heating from time to time. For the cold bath, however, it is +important to have moisture present during printing, or it may be after +printing and before development. If the paper is left in a dampish +room for fifteen minutes, it should be sufficient. Prints made by +exposing damp paper, or damping dry paper just before development, +must be developed within one hour if the maximum of vigor is desired; +by delaying the development some hours, the prints in the meantime +being stored in a drawer so that they may retain their moisture, an +increase of half tone and warmth of color will be obtained. If it +should be necessary to delay development for a day or two, the prints +must be dried before a fire soon after being removed from the frames, +and then stored in a calcium tube until wanted for development. + +While printing, the lemon color of the paper receives a grayish +colored image, which, although faint, can, with practice, be judged as +easily as silver printing. + +The developer consists of oxalate of potash and potassic +chloro-platinite--about thirty grains of the platinum salt to half an +ounce of oxalate forming about six ounces of solution; a great many +variations, however, may be made in the proportions of platinum salt +and oxalate, and different effects secured. Development is effected by +sliding the print face downward on to the developer, which must be +rocked after the development of each print to avoid scum marks. To +clear the prints they are washed in three or four baths of a weak +solution of hydrochloric acid after leaving the developer, to remove +all traces of the iron salts, and finally washed for a quarter of an +hour in three changes of water; they are then finished, and may be +dried between clean blotting paper. + +Pizzighelli's process differs from the above in being one that prints +fully out in the frame without development; the paper contains the +platinum and iron salts as well as the developer, and so prints and +develops at the same time. Although excellent prints can be produced +with it, for general work the results of the paper, as at present +made, will not compare with the hot and cold bath processes. It is, +however, excellent for printing from very dense negatives, and +occasional negatives that seem extremely suitable for it. The paper +should be breathed on before printing, as if it is quite dry the +printing will be very slow and irregular. The best conditions for the +preparation of the paper have scarcely been decided upon yet, and it +is not quite fair to judge the process. The prints are cleared in the +acid baths and washed for about a quarter of an hour. + +The sepia and black hot bath processes are much alike in the general +treatment. There are, however, some special precautions to be observed +with the sepia paper, the chief being to protect it from any but the +faintest rays of light; the prints, unlike the black ones, may be +affected by light when in the acid bath. A special solution must be +added to the developer to keep the lights pure. Over-exposure cannot +be corrected by using a cooler bath, as is the case with the black +prints, and the paper does not remain good so long. + +The paper for the black prints by the hot bath process is washed with +a mixture of potassic platinous chloride and ferric oxalate, the +proportion being about sixty grains of the platinum salt to one ounce +of the iron solution. It will not keep good longer than twenty minutes +or so, and must be applied to the paper directly after mixing. The +ferric oxalate in the paper is reduced by the action of light to +ferrous oxalate, which forms the faint visible image; this, when the +paper is floated on the oxalate of potash bath, is capable of reducing +the platinum salt in contact with it into metallic platinum; but the +ferric salt, which remains unaltered, has no action on the platinum +salt, leaving these parts, which represent the high lights of the +print, untouched. The ferric oxalate is removed by the acid baths +which follow the development. A good temperature for development is +150° Fahr., and when using this so much detail should not be apparent +as when printing for the cold bath process, in which all the detail +desired should be very faintly visible. There are, however, many +methods of exposing the paper and developing it, and no fixed rule can +be made, but the development must in every case be suited to the +exposure or the result will be a failure. For instance, the paper may +be printed until all detail is visible, but a very much cooler +development must be used, say 80° or 90°; on the other hand, a +slightly short exposure may be given, and a temperature of 180° to +200° used. 150° should be taken as the normal temperature, and kept to +until some experience has been gained, as employing all temperatures +will lead to confusion, and nothing will be learned. Some negatives +require a special treatment, and both printing and development must be +altered, while for a very dense negative the paper may be left out in +a dampish room for some time. It will then print with less contrast +and more half tone. A thin negative is better printed by the cold bath +process, but negatives should be good and brilliant for platinotype +printing. Any one taking up platinotype and getting only weak prints +would do well to look to his negatives instead of blaming the paper, +as the high lights should be fairly dense, and the deep shadows nearly +clear glass. + +Time for complete development should always be allowed; with a hot +bath fifteen seconds will be sufficient, but if a cooler development +is used, or the prints are solarized in the shadows, more time should +be allowed. When the deep shadows are solarized, or appear lighter +than surrounding parts, a hot and prolonged development is required to +obtain sufficient blackness, as they have a tendency to look like +brown paper. I have found breathing on solarized shadows useful, as in +the presence of slight moisture they begin to print out and become +dark before development, getting black almost directly the print is +floated on the oxalate. Three or four acid baths of about ten minutes +each are used, and the prints are washed as before. The process +throughout takes much less time than silver printing, and can be kept +on all the winter, when it is nearly impossible to print in silver. +Prints can be developed in weak daylight or gaslight, and prolonged +washing is dispensed with.--_N.P. Fox, reported in Br. Jour. of +Photo._ + + * * * * * + +[Continued from Supplement, No. 706, page 11283.] + + + + +ON ALLOTROPIC FORMS OF SILVER. + +By M. CAREY LEA. + + +In the first part of this paper were described certain forms of +silver; among them a lilac blue substance, very soluble in water, with +a deep red color. After undergoing purification, it was shown to be +nearly pure silver. During the purification by washing it seemed to +change somewhat, and, consequently, some uncertainty existed as to +whether or not the purified substance was essentially the same as the +first product; it seemed possible that the extreme solubility of the +product in its first condition might be due to a combination in some +way with citric acid, the acid separating during the washing. Many +attempts were made to get a decisive indication, and two series of +analyses, one a long one, to determine the ratio between the silver +and the citric acid present, without obtaining a wholly satisfactory +result, inasmuch as even these determinations of mere ratio involved a +certain degree of previous purification which might have caused a +separation. + +This question has since been settled in an extremely simple way, and +the fact established that the soluble blue substance contains not a +trace of combined citric acid. + +The precipitated lilac blue substance (obtained by reducing silver +citrate by ferrous citrate) was thrown on a filter and cleared of +mother water as far as possible with a filter pump. Pure water was +then poured on in successive portions until more than half the +substance was dissolved. The residue, evidently quite unchanged, was, +of course, tolerably free from mother water. It was found that by +evaporating it to dryness over a water bath, most of the silver +separated out as bright white normal silver; by adding water and +evaporating a second time, the separation was complete, and water +added dissolved no silver. _The solution thus obtained was neutral._ +It must have been acid had any citric acid been combined originally +with the silver. This experiment, repeated with every precaution, +seems conclusive. The ferrous solution, used for reducing the silver +citrate, had been brought to exact neutrality with sodium hydroxide. +After the reduction had been effected, the mother water over the lilac +blue precipitate was neutral or faintly acid. + +A corroborating indication is the following: The portions of the lilac +blue substance which were dissolved on the filter (see above) were +received into a dilute solution of magnesium sulphate, which throws +down insoluble allotropic silver of the form I have called B (see +previous paper). This form has already been shown to be nearly pure +silver. The magnesia solution, neutral before use, was also neutral +after it had effected the precipitation, indicating that no citric +acid had been set free in the precipitation of the silver. + +It seems, therefore, clear that the lilac blue substance contains no +combined citric acid. Had the solubility of the silver been due to +combination with either acid or alkali, the liquid from which it was +separated by digestion at or below 100° C. must have been acid or +alkaline; it could not have been neutral. + +We have, therefore, this alternative: In the lilac blue substance we +have either pure silver in a soluble form or else a compound of +silver, with a perfectly neutral substance generated from citric acid +in the reaction which leads to the formation of the lilac blue +substance. If this last should prove the true explanation, then we +have to do with a combination of silver of a quite different nature +from any silver compounds hitherto known. A neutral substance +generated from citric acid must have one or more atoms of hydrogen +replaced by silver. This possibility recalls the recent observations +of Ballo, who, by acting with a ferrous salt on tartaric acid, +obtained a neutral colloid substance having the constitution of +arabin, C6 H10 O6. + +To appreciate the difficulty of arriving at a correct conclusion, it +must be remembered that the silver precipitate is obtained saturated +with strong solutions of ferric and ferrous citrate, sodium citrate, +sulphate, etc. These cannot be removed by washing with pure water, in +which the substance itself is very soluble, but must be got rid of by +washing with saline solutions, under the influence of which the +substance itself slowly but continually changes. Next, the saline +solution used for washing must be removed by alcohol. During this +treatment, the substance, at first very soluble, gradually loses its +solubility, and, when ready for analysis, has become wholly insoluble. +It is impossible at present to say whether it may not have undergone +other change; this is a matter as to which I hope to speak more +positively later. It is to be remarked, however, that these allotropic +forms of silver acquire and lose solubility from very slight causes, +as an instance of which may be mentioned the ease with which the +insoluble form B recovers its solubility under the influence of sodium +sulphate and borate, and other salts, as described in the previous +part of this paper. + +The two insoluble forms of allotropic silver which I have described as +B and C--B, bluish green; C, rich golden color--show the following +curious reaction. A film of B, spread on glass and heated in a water +stove to 100° C. for a few minutes becomes superficially bright +yellow. A similar film of the gold colored substance, C, treated in +the same way, acquires a blue bloom. In both cases it is the surface +only that changes. + +_Sensitiveness to Light._--All these forms of silver are acted upon by +light. A and B acquire a brownish tinge by some hours' exposure to +sunlight. With C the case is quite different, the color changes from +that of red gold to that of pure yellow gold. The experiment is an +interesting one. The exposed portion retains its full metallic +brilliancy, giving an additional proof that the color depends upon +molecular arrangement, and this with the allotropic forms of silver is +subject to change from almost any influence. + +_Stability._--These substances vary greatly in stability under +influences difficult to appreciate. I have two specimens of the gold +yellow substance, C, both made in December, 1886, with the same +proportions, under the same conditions. One has passed to dazzling +white, normal silver, without falling to powder, or undergoing +disaggregation of any sort; the fragments have retained their shape, +simply changing to a pure frosted white, remaining apparently as solid +as before; the other is unchanged, and still shows its deep yellow +color and golden luster. Another specimen made within a few months and +supposed to be permanent has changed to brown. Complete exclusion of +air and light is certainly favorable to permanence. + +_Physical Condition._--The brittleness of the substances B and C, the +facility with which they can be reduced to the finest powder, makes a +striking point of difference between allotropic and normal silver. It +is probable that normal silver, precipitated in fine powder and set +aside moist to dry gradually, may cohere into brittle lumps, but these +would be mere aggregations of discontinuous material. With allotropic +silver the case is very different, the particles dry in optical +contact with each other, the surfaces are brilliant, and the material +evidently continuous. That this should be brittle indicates a totally +different state of molecular constitution from that of normal silver. + +_Specific Gravities._--The allotropic forms of silver show a lower +specific gravity than that of normal silver. + +In determining the specific gravities it was found essential to keep +the sp. gr. bottle after placing the material in it for some hours +under the bell of an air pump. Films of air attach themselves +obstinately to the surfaces, and escape but slowly even in vacuo. + +Taken with this precaution, the blue substance, B, gave specific +gravity 9.58, and the yellow substance, C, specific gravity 8.51. The +specific gravity of normal silver, after melting, was found by G. Rose +to be 10.5. That of finely divided silver obtained by precipitation is +stated to be 10.62.[1] + + [Footnote 1: Watts' Dict., orig. ed., v. 277.] + +I believe these determinations to be exact for the specimens employed. +But the condition of aggregation may not improbably vary somewhat in +different specimens. It seems, however, clear that these forms of +silver have a lower specific gravity than the normal, and this is what +would be expected. + +Chestnut Hill, Philadelphia, May, 1889. + +--_Amer. Jour. of Science._ + + * * * * * + + + + +TURPENTINE AND ITS PRODUCTS.[1] + + [Footnote 1: Read at a meeting of the Liverpool Chemists' + Association.] + +By EDWARD DAVIES, F.C.S., F.I.C. + + +In treating this subject it is necessary to limit it within +comparatively narrow bounds, for bodies of the turpentine class are +exceedingly numerous and not well understood. In this definite class +turpentine means the exudation from various trees of the natural order +Coniferæ, consisting of a hydrocarbon, C10 H16, and a resin. The +constitution of the hydrocarbons in turpentine from different sources, +though identical chemically, varies physically, the boiling point +ranging from 156° C. to 163° C., the density from 0.855 to 0.880, and +the action on polarized light from -40.3 to +21.5. They are very +unstable bodies in their molecular constitution, heat, sulphuric acid, +and other reagents modifying their properties. The resins are also +very variable bodies formed probably by oxidation of the hydrocarbons, +and as this oxidation is more or less complete, mixtures are formed +very difficult to separate and study. + +Turpentine as met with in commerce is mainly derived from _Pinus +maritima_, yielding French turpentine, and _Pinus australis_, +furnishing most of the American turpentine. The latter is obtained +from North and South Carolina, Georgia and Alabama. In Hanbury and +Fluckiger's Pharmacographia there is a full description of the manner +in which the trees are wounded to obtain the turpentine. Besides these +there are Venice turpentine from the larch, _Pinus Larix_, Strassburg +turpentine from _Abies pectinata_, and Canada balsam from _Pinus +balsamea_. + +The crude American turpentine is a viscid liquid of about the +consistence of honey, but varying to a soft solid, known as gum, thus, +according to the amount of exposure which it has undergone, it +contains about 10 to 25 per cent. of "spirits," to which the name of +turpentine is commonly given, the rest being resin, or as it is +usually called, rosin. + +In Liverpool almost all the spirits of turpentine comes from America, +so that it is almost impossible to get a sample of French. + +The terpene from American turpentine is called austraterebenthene. It +possesses dextro-rotatory polarization of +21.5. Its density is 0.864. +Boiling point 156° C. + +In taking the boiling point of a commercial sample of spirits it is +necessary to wait until the thermometer becomes steady. Not more than +5 per cent. should pass over before this takes place, and then there +is not more than two or three degrees of rise until almost all is +distilled over. + +The liquids of lower boiling point do not appear to have been much +studied. In French spirits they seem to be of the same composition as +the main product, but with more action on polarized light. + +French spirits of turpentine is mainly composed of terebenthene. The +boiling point and sp. gr. are the same as those of the austraterebenthene, +but the polarization is left handed and amounts to -40.5. + +Isomeric modifications. Heated to 300° C. in a sealed tube for two +hours, it becomes an isomeric compound, boiling at 175° C., while the +density is lowered, being only 0.8586 at 0° C. The rotatory power is +only -9°. It oxidizes much more rapidly. It is called isoterebenthene +and has a smell of essential oil of lemons. + +By the action of a small quantity of sulphuric acid, among other +products terebene is formed. It has the same boiling point and sp. gr. +as terebenthene, but is without action on polarized light. +Austraterebenthene forms similar if not identical bodies. + +Polymers. One part of boron fluoride BF3 instantly converts 160 +parts of terebenthene into polymers boiling above 300° C., and +optically inactive. H2 SO4 does the same on heating and forms +diterebene C20 H32. + +Terchloride of antimony does the same, and also produces tetraterebene +C40H64, a solid brittle compound formed by the union of four +molecules of C10 H16. It does not boil below 350° C. and +decomposes on heating. + +Compound with H2O. Terpin C10 H18 2HO is formed when 1 volume +of spirits of turpentine is mixed with 6 of nitric acid and 1 of +alcohol, and exposed to air for some weeks. Crystals are formed which +are pressed, decolorized by animal charcoal, and recrystallized from +boiling water. + +Compounds with HCl. When a slow current of HCl is passed through +cooled spirits of turpentine, two isomeric compounds are formed, one +solid, and one liquid. The lower the temperature is kept, the more of +the solid body is produced. To obtain the solid body pure it is +pressed and recrystallized from ether or alcohol. It is volatile and +has the odor of camphor. It is called artificial camphor, and has the +composition C10 H16 HCl. There is also a compound with 2HCl. + +Oxidation products. By passing air into spirits of turpentine oxygen +is absorbed. It was thought at one time that ozone was produced, but +Kingzett's view is that camphoric peroxide is formed C10 H14 O4, +and that in presence of water it decomposes into camphoric acid and +H2 O2. This liquid constitutes the disinfectant known as +"sanitas," which possesses the advantages of a pleasant smell and +non-poisonous properties. C10 H18 O2 may be obtained by +exposing spirits of turpentine in a flask full of oxygen with a little +water. + +Camphor C16 H16 O has been made in small quantity by oxidizing spirits +of turpentine. Terebenthene belongs to the benzene or aromatic series, +which can be shown from its connection with cymene. Cymene is +methylpropyl-benzene, and can be made from terpenes by removing two +atoms of H. It has not yet been converted again into terpene, but the +connection is sufficiently proved. The presence of CH3 in terpenes is +shown by their yielding chloroform when distilled with bleaching +powder and water. The resin is imperfectly known. It was supposed to +consist of picric and sylvic acids. It is also stated to contain +abietic anhydride C44 H62 O4, but it is difficult to understand how a +compound containing C44 can be produced from C10 H16. The most +probable view is that it is the anhydride of sylvic acid, which is +probably C20 H30 O2. + +The dark colored resin which is obtained when the turpentine is +distilled without water can be converted into a transparent slightly +yellow body by distillation with superheated steam. A small portion is +decomposed, but the greater part distills unchanged. It is used in +making soap which will lather with sea water. + +When distilled alone, various hydrocarbons, resin oil and resin pitch, +are obtained. + +I find that commercial spirits of turpentine varies in sp. gr. from +0.865 to 0.869 at 15° C. The higher sp. gr. appears to be connected +with the presence of resinous bodies, the result of oxidation. The +boiling point is very uniform, ranging from 155° C. to 157° C. at 760 +mm. Taking these two points together, it is hardly possible to +adulterate spirits of turpentine without detection. I give the figures +for a few imitations or adulterations: + + Sp. gr. B.P. + No. 1 0.821 137° C. + No. 2 0.884 165° C. + No. 3 0.815 150° C. + No. 4 0.895 156° C. + +There is a considerable difference in the flashing point, no doubt due +to the longer or shorter exposure of the crude turpentine, by which +more or less of the volatile portion escapes. + + * * * * * + + + + +ON THE OCCURRENCE OF PARAFFINE IN CRUDE PETROLEUM.[1] + + [Footnote 1: An abstract of thesis by E.A. Partridge, class of + '89, Univ. of Pa. Read before the Chemical Section of the + Franklin Institute by Prof. S.P. Sadtler.] + + +It is well known that the paraffine obtained by the distillation of +petroleum residues is crystalline, while that obtained directly (as in +the filtration of residuum) is amorphous. Ozokerite or ceresine +differs but slightly from paraffine, the principal distinction being +want of crystalline structure in it as found. Other characteristics, +such as the melting point, specific gravity, etc., vary in both, and +so are not of importance in a comparison. Hence it has been asked, Is +the paraffine occurring in petroleum and ozokerite identical with that +which is produced by their distillation? As crystalline paraffine +could be obtained from ozokerite by distillation alone, many persons +have supposed that it was engendered in the process. Recently, +however, crystalline paraffine has been obtained from ozokerite by +dissolving the latter in warm amyl alcohol; on cooling the greater +part separates out in crystals having the luster of mother-of-pearl. +By repetition of this process, a substance is obtained that is +scarcely to be distinguished from the paraffine obtained by +distillation. Apparently there exists then in ozokerite, together with +paraffine, other substances not capable of crystallization which keep +the paraffine from crystallizing. These colloids appear to be +separated by amyl alcohol in virtue of their greater solubility in +that menstruum. It is also reasonable to suppose that they undergo +change or decomposition by distillation. + +So as petroleum residues are amorphous, and the crystalline paraffine +is first produced by distillation, it has been argued that the +paraffine present in crude petroleum is approximately the same thing +as ozokerite. + +This, however, is not sufficient to establish the pyrogenic origin of +all crystallized paraffine, as crystals can be obtained from the +amorphous residues by distillation at normal or reduced pressure or in +a current of steam. To explain these facts two assumptions are +possible. Either the chemical and physical properties of all or some +of the solid constituents are changed by the distillation, and the +paraffine is changed from the amorphous into the crystalline variety, +or the change produced by the distillation takes place in the medium +(i.e., the mother liquid) in which the paraffine exists. The change +effected in ozokerite and in petroleum residues when crystalline +paraffine is obtained by distillation is to be regarded as a +purification, and can be effected partially by treatment with amyl +alcohol. In the same way, by repeated treatment of petroleum residuum +with amyl alcohol, a substance of melting point 59° C. can be +obtained, which cannot be distinguished from ordinary paraffine. + +The treatment with amyl alcohol has therefore accomplished the same +results as was obtained by distillation, and the action is probably +the same, i.e., a partial separation of colloid substance. These +facts point to the conclusion that crystallizable paraffine exists +ready formed in both petroleum and in ozokerite, but in both cases +other colloidal substances prevent its crystallization. By +distillation, these colloids appear to be destroyed or changed so as +to allow the paraffine to crystallize. + +It is a generally known fact that liquids always appear among the +products of the distillation of paraffine, no matter in what way the +distillation be conducted. This shows that some paraffine is +decomposed in the operation. + +The name _proto-paraffine_ has been given to ozokerite and to the +paraffine of petroleum in contradistinction to _pyro-paraffine_, the +name that has been applied to the paraffine obtained by distillation +from any source. + +According to Reichenbach, paraffine may crystallize in three forms: +needles, angular grains, and leaflets having the luster of +mother-of-pearl. Hofstadter, in an article on the identity of +paraffine from different sources, confirmed this statement, and added +further that at first needles, then the angular forms, and then the +leaflets are formed. Fritsche found, by means of the microscope, in +the ethereal solution of ozokerite, very fine and thin crystal +leaflets concentrically grouped, and in the alcoholic solution fine +irregular leaflets. Zaloziecki has recently developed these +microscopic investigations to a much greater extent. According to this +observer, the principal part of paraffine, as seen under the +microscope, consists of shining stratified leaflets with a darker +edge. The most characteristic and well developed crystals are formed +by dissolving paraffine in a mixture of ethyl and amyl alcohols and +chilling. The crystals are rhombic or hexagonal tablets or leaves, and +are quite regularly formed. They are unequally developed in different +varieties of paraffine. The best developed are those obtained from +ceresine. Their relative size and appearance give an indication as to +the purity of the paraffine, and, as they are always present, they are +to be counted among the characteristic tests for paraffine. +Reichenbach observed that mere traces of empyreumatic oil prevented +their formation. + +The old method of determining the amount of paraffine in petroleum was +to carry out the refining process on a small scale; that is, to +distill the residue from the kerosene oils to coking, chill out the +paraffine, press it thoroughly between filter paper, and weigh the +residue. The sources of error in this procedure are manifold; the +principal one is the solubility of paraffine in oils, which depends +upon the character of both the paraffine and the oil, and also upon +the temperature. The next greatest source of error is variation in the +process of distillation and the difference between working on the +small scale and on the large scale. + +In most cases, where a paraffine determination is to be carried out, +one has to deal with a mixture of paraffine with liquid oils. Now, +paraffine is not a substance defined by characteristic physical +properties which distinguish it from the liquid portions of petroleum. +It consists of a mixture of homologous hydrocarbons, which form a +solid under ordinary conditions. The hydrocarbons of this mixture show +a gradation in their properties, and gradually approximate to those +which are liquid at ordinary temperatures. It is a well known fact +that a separation of these homologues is entirely impossible by +distillation. It has also been ascertained that the liquid +constituents of petroleum do not always possess boiling points that +are lower than those of the solid constituents. This shows that we +have to deal not merely with hydrocarbons of one, but of several +series. + +When determinations of the amount of paraffine are to be made, then it +becomes necessary to specify with exactness what is to be called +paraffine. The most definite property that can be made use of for this +purpose is the melting point. For several reasons it is convenient to +include under this name hydrocarbons of melting point as low as +35°-40° C. + +The method proposed by Zaloziecki for the determination of paraffine +is the following: The most volatile portions of the petroleum are +separated by distillation, until the thermometer shows 200° C. These +portions are separated, as they exert great solvent action upon +paraffine. At the same time he finds that no pyro-paraffine is formed +under this temperature. A weighed portion of the residue is taken and +mixed with ten parts by weight of amyl alcohol and ten parts of +seventy-five per cent. ethyl alcohol: the mixture is then chilled for +twelve hours to 0° C. It is then filtered cold, washed first with a +mixture of amyl and ethyl alcohols, and then with ethyl alcohol alone. +The paraffine is transferred to a small porcelain evaporating dish and +dried at 110° C. It is then heated with concentrated sulphuric acid to +150°-160° C. for fifteen to thirty minutes with constant stirring. The +acid is then neutralized and the paraffine extracted by petroleum +ether. On evaporation of the solvent, the paraffine is dried at 100° +C. and weighed. Zaloziecki found, according to this method, in three +samples of Galician petroleums, 4.6, 5.8 and 6.5 per cent., +respectively, of proto-paraffine. The method was carried out as above +with four samples of American petroleums, Colorado oil from Florence, +Col.; Warren County oil from Wing Well, Warren, Pa.; Washington oil +from Washington County, Pa.; Middle District oil from Butler County, +Pa., all furnished by Professor Sadtler. + +They were very different in physical properties and in appearance, the +Colorado oil being a much heavier oil than the others and the +Washington oil being an amber oil, while the other two were of the +ordinary dark green color and consistence. The losses on distillation +to 200° C. were very different, being about one-tenth in the case of +the Colorado oil and nearly one-half in the case of the others. The +percentages of partially refined proto-paraffine in the four reduced +oils (all below 200° C. off) were as follows: for the Colorado oil, +23.9 per cent.; for the Warren oil, 26.5 per cent.; for the Washington +oil, 26.6 per cent.; and for the Middle District oil, 28.2 per cent. + +The question now arises, What value has this determination of the +proto-paraffine which may exist in an oil? As before said, a portion +of the paraffine is always decomposed in distillation at temperatures +sufficiently high to drive over the paraffine oils, so the yield of +pyro-paraffine is always less than the proto-paraffine shown to be +present originally. Zaloziecki found this in the case of the several +Galician oils he examined. Corresponding to the 4.6, 5.8 and 6.5 per +cent. of proto-paraffine in the several oils he obtained 2.18, 2.65 +and 2.35 per cent., respectively, of pyro-paraffine. + +For the present, however, the extraction of proto-paraffine on a large +scale by means of such solvents as amyl and ethyl alcohols is out of +the question on account of their cost. A distillation, under reduced +pressure and with superheated steam, would, however, prevent much of +the decomposition of the original proto-paraffine and increase the +yield of pyro-paraffine. + +This study of Zaloziecki's method and the examination of American oils +was suggested by Professor Sadtler and carried out in his laboratory. + + * * * * * + + + + +TRANSMISSION OF PRESSURE IN FLUIDS. + +By ALBERT B. PORTER. + + +The young student of physics occasionally has difficulty in grasping +the laws of pressure in fluids. His every day experience has taught +him that a push against a solid body causes it to push in the same +direction, and he often receives with some doubt the statement that +pressure applied to a fluid is transmitted equally in every direction. +The experiments ordinarily shown in illustration of this principle +prove that pressure is transmitted in all directions, but do not prove +the equality of transmission, and in spite of all the text books may +tell him, the student is apt to cling to the idea that a downward +pressure applied to a liquid is more apt to burst the bottom than the +side of the containing vessel. + +[Illustration: Figs. 1. and 2.] + +The little piece of apparatus shown in Fig. 1 was designed to furnish +a clear demonstration of the principle under consideration. It is +essentially an arrangement by which a downward pressure is applied to +a confined mass of air or water, and the resultant pressures measured +in the three directions, down, up, and sideways. By means of a broken +rat tail file kept wet with turpentine three holes are bored through a +bottle, one through the bottom, one through the side, and one through +the shoulder, as near the neck as may be convenient. The operation is +quick and easy, the only precaution to be observed being to work very +slowly and use but a slight pressure when the glass is nearly +perforated. The holes may be enlarged to any size required by careful +filing with the wet file. From each of the holes a rubber tube leads +to one of the glass manometer tubes at the right in the figure, the +joints being made air tight by slipping into each rubber tube a piece +of glass tubing about half an inch long in order to swell it to the +size of the hole it is to fit. The ends of these glass tubes must be +well rounded by partial fusion in a gas flame, that there may be no +sharp edges to cut the rubber. The bottle rests in a depression in the +turned wood base, the lower rubber tube passing out through a hole in +the wood. Fig. 2 shows the shape of the manometer tubes. They are made +of quarter inch glass tubing bent to shape in a flame and left open at +both ends. They are mounted on a scale board which has several +equidistant horizontal lines running across it. The two bent wires +which support the scale board fit loosely in holes in it and in the +base. This method of mounting is very handy, since it permits the +scale board to be swung to right or left as may be convenient, or +turned round so as to show the fittings on its back, without moving +the bottle. The three manometers are filled to the same level with +mercury, the quantity being adjusted by means of a pipette. A +perforated rubber stopper, fitted with a glass tube on which is +slipped a rubber syringe bulb, completes the apparatus. + +When the bulb is pinched between the fingers, the mercury is forced up +to the same height in each of the manometers, thus proving that the +pressure is exerted equally in the three directions, up, down, and +sideways. With the bottle filled with water the same effect follows, +the law being the same for liquids and gases. When using water in the +apparatus it is essential that the rubber tubes, as well as the +bottle, be filled, and when used in the class room it is better to +show the experiment with water first, it being easier and quicker to +empty the bottle and tubes than to fill them. + + * * * * * + + + + +PEAR DUCHESSE D'ANGOULEME. + + +Although well known to fruit growers and generally represented in all +parts of Britain, this noble French pear has not become a universal +favorite. If the quality of the fruit, independently of its fine, +handsome appearance, was bad, or even indifferent, it might be +exterminated from our lists, but this we know is not the case, as any +one who has tasted good samples grown in France, the Channel Islands, +and upon favorable soils in this country will bear out the statement +that the flavor is superb. Some fruits, we know, are quite incapable +of being good, as they have no quality in them; but here we have one +of the hardiest of trees, capable of giving us quantity as well as +quality, provided we cultivate properly. Pears, no doubt, are +capricious, like our seasons, but given a good average year, soils and +stocks which suit them, a light, warm, airy aspect, and good culture, +a great number of varieties formerly only good enough for stewing are +now elevated, and most deservedly so, to the dessert table. But, +assuming that some sorts known to be good do not reach their highest +standard of excellence every year, they are infinitely superior to +many of the old stewers, as they carry their own sugar, a quality +which fits them for consumption by the most delicate invalids. Indeed, +so prominently have choice dessert pears, and apples too for that +matter, come to the front for cooking purposes, that a new demand is +now established, and although Duchesse d'Angoulême, always juicy and +sweet, from bad situations does not always come up to the fine quality +met within Covent Garden in November, it is worthy of our skill, as we +know it has all the good points of a first rate pear when properly +ripened. + +The original tree of this pear was observed by M. Anne Pierre +Andusson, a nurseryman at Angers, growing in a farm garden near +Champigne, in Anjou, and having procured grafts of it, he sold the +trees, in 1812, under the name of Poire des Eparannais. In 1820, he +sent a basket of the fruit to the Duchesse d'Angoulême, with a request +to be permitted to name the pear in honor of her. The request was +granted, and the pear has since borne its present name. + +That such a fine pear, which does so well in France, would soon find +its way to England there exists little doubt, as we find that within a +few years it became established and well known throughout the United +Kingdom. All the earliest trees would be worked upon the pear or free +stock, and as root pruning until recently was but little practiced, we +may reasonably suppose that the majority of them are deeply anchored +in clay, marl, and other subsoils calculated to force a crude, gross +growth from which high flavored fruit could not be expected. These +defects under modern culture upon the quince and double grafting are +giving way, as we find, on reference to the report of the committee of +the pear conference, held at Chiswick in 1885, that twenty counties in +England, also Scotland, Ireland, and Wales, contributed no less than +121 dishes to the tables, and thirty-eight growers voted in favor of +the Duchesse being recognized as one of our standard dessert +varieties. This step looks like progress, as it is a record of facts +which cannot be gainsaid, and it now remains to be seen whether the +English grower, whose indomitable will has brought him to the front in +the subjugation of other fruits, will be successful with the fine +Duchesse d'Angoulême. Although this remarkable pear cannot easily be +mistaken, for the benefit of those who do not know it, the following +description may not be out of place. Fruit large, often very large, 3½ +inches wide and 3 inches to 4 inches high, roundish obovate, uneven, +and bossed in its outline. Skin greenish yellow, changing to pale dull +yellow, covered with veins and freckles of pale brown russet, and when +grown against a south wall it acquires a brown cheek. Eye open, with +erect dry segments, set in a deep irregular basin. Stalk 1 inch long, +inserted in a deep irregular cavity. Flesh white, buttery, and +melting, with a rich flavor when well ripened; otherwise rather coarse +grained and gritty. + +As to culture, experienced fruitists say the tree grows vigorously and +well. It bears abundantly, and succeeds either on the pear or quince +stock, forming handsome pyramids, but is better on the quince. Here, +then, we have the key to the secret of success: The cordon on the +quince; roots near the surface; loam, sound, sandy, and good; and good +feeding. Aspect, a good wall facing south or west--the latter, +perhaps, the best. Those who have not already done so, should try +trees on the quince as pyramids and bushes, as this, like some other +capricious pears, although the fruit be smaller, may put in better +flavor than is met with in fruit from hot walls.--_The Garden._ + + * * * * * + + + + +SUCCESSION OF FOREST GROWTHS. + + +The following is from an address delivered by Mr. Robert Douglas +before the Association of American Nurserymen at the meeting in +Chicago recently. + +It is the prevailing and almost universal belief that when native +forests are destroyed they will be replaced by other kinds, for the +simple reason that the soil has been impoverished of the constituents +required for the growth of that particular tree or trees. This I +believe to be one of the fallacies handed down from past ages, taken +for granted, and never questioned. Nowhere does the English oak grow +better than where it grew when William the Conqueror found it at the +time he invaded Britain. Where do you find white pines growing better +than in parts of New England where this tree has grown from time +immemorial? Where can you find young redwoods growing more thriftily +than among their giant ancestors, nearly or quite as old as the +Christian era? + +The question why the original growth is not reproduced can best be +answered by some illustrations. When a pine forest is burned over, +both trees and seeds are destroyed, and as the burned trees cannot +sprout from the stump like oaks and many other trees, the land is left +in a condition well suited for the germination of tree seeds, but +there are no seeds to germinate. It is an open field for pioneers to +enter, and the seeds which arrive there first have the right of +possession. The aspen poplar (_Populus tremuloides_) has the advantage +over all other trees. It is a native of all our northern forests, from +the Atlantic to the Pacific. Even fires cannot eradicate it, as it +grows in moist as well as dry places, and sprouts from any part of the +root. It is a short-lived tree, consequently it seeds when quite young +and seeds abundantly; the seeds are light, almost infinitesimal, and +are carried on wings of down. Its seeds ripen in spring, and are +carried to great distances at the very time when the ground is in the +best condition for them. Even on the dry mountain sides in Colorado, +the snows are just melting and the ground is moist where they fall. + +To grow this tree from seed would require the greatest skill of the +nurseryman, but the burnt land is its paradise. Wherever you see it on +high, dry land you may rest assured that a fire has been there. On +land slides you will not find its seeds germinating, although they +have been deposited there as abundantly as on the burned land. + +Next to the aspen and poplars comes the canoe birch, and further north +the yellow birch, and such other trees as have provision for +scattering their seeds. I have seen acorns and nuts germinating in +clusters on burned lands in a few instances. They had evidently been +buried there by animals and had escaped the fires. I have seen the red +cherry (_Prunus Pennsylvanica_) coming up in great quantities where +they might never have germinated had not the fires destroyed the +debris which covered the seed too deeply. + +A careful examination around the margin of a burned forest will show +the trees of surrounding kinds working in again. Thus by the time the +short-lived aspens (and they are very short-lived on high land) have +made a covering on the burned land, the surrounding kinds will be +found re-established in the new forest, the seeds of the conifers, +carried in by the winds, the berries by the birds, the nuts and acorns +by the squirrels, the mixture varying more or less from the kinds +which grew there before the fire. + +It is wonderful how far the seeds of berries are carried by birds. The +waxwings and cedar birds carry seeds of our tartarean honeysuckles, +purple barberries and many other kinds four miles distant, where we +see them spring up on the lake shore, where these birds fly in flocks +to feed on the juniper berries. It seems to be the same everywhere. I +found European mountain ash trees last summer in a forest in New +Hampshire; the seed must have been carried over two miles as the crow +flies. + +While this alternation is going on in the East, and may have been +going on for thousands of years, the Rocky Mountain district is not so +fortunate. When a forest is burned down in that dry region, it is +doubtful if coniferous trees will ever grow again, except in some +localities specially favored. I have seen localities where short-lived +trees were dying out and no others taking their places. Such spots +will hereafter take their places above the timber line, which seems to +me to be a line governed by circumstances more than by altitude or +quality of soil. + +There are a few exceptions where pines will succeed pines in a +burned-down forest. _Pinus Murrayana_ grows up near the timber line in +the Rocky Mountains. This tree has persistent cones which adhere to +the trees for many years. I have counted the cones of sixteen years on +one of these trees, and examined burned forests of this species, where +many of the cones had apparently been bedded in the earth as the trees +fell. The heat had opened the cones and the seedlings were growing up +in myriads; but not a conifer of any other kind could be seen as far +as the fire had reached. + +In the Michigan Peninsula, northern Wisconsin and Minnesota, _P. +Banksiana_, a comparatively worthless tree, is replacing the valuable +red pine (_P. resinosa_), and in the Sierras _P. Murrayana_ and _P. +tuberculata_ are replacing the more valuable species by the same +process. + +In this case, also, the worthless trees are the shortest lived. So we +see that nature is doing all that she can to remedy the evil. Man only +is reckless, and especially the American man. The Mexican will cut +large limbs off his trees for fuel, but will spare the tree. Even the +poor Indian, when at the starvation point, stripping the bark from the +yellow pine (_P. ponderosa_), for the mucilaginous matter being formed +into sap wood, will never take a strip wider than one third the +circumference of the tree, so that its growth may not be injured. + +We often read that oaks are springing up in destroyed forests where +oaks had never grown before. The writers are no doubt sincere, but +they are careless. The only pine forests where oaks are not intermixed +are either in land so sandy that oaks cannot be made to grow on them +at all, or so far north that they are beyond their northern limit. In +the Green Mountains and in the New England forests, in the pine +forests in Pennsylvania, in the Adirondacks, in Wisconsin and +Michigan--except in sand--I have found oaks mixed with the pines and +spruces. In northwestern Minnesota and in northern Dakota the oaks are +near their northern limit, but even there the burr oak drags on a bare +existence among the pines and spruces. In the Black Hills, in Dakota, +poor, forlorn, scrubby burr oaks are scattered through the hills among +the yellow pines. In Colorado we find them as shrubs among the pines +and Douglas spruces. In New Mexico we find them scattered among the +piñons. In Arizona they grow like hazel bushes among the yellow pines. +On the Sierra Nevada the oak region crosses the pine region, and +scattering oaks reach far up into the mountains. Yet oaks will not +flourish between the one hundredth meridian and the eastern base of +the Sierras, owing to the aridity of the climate. I recently found +oaks scattered among the redwoods on both sides of the Coast Range +Mountains. + +Darwin has truly said, "The oaks are driving the pines to the sands." +Wherever the oak is established--and we have seen that it is already +established whereever it can endure the soil and climate--there it +will remain and keep on advancing. The oak produces comparatively few +seeds. Where it produces a hundred, the ash and maple will yield a +thousand, the elm ten thousand, and many other trees a hundred +thousand. The acorn has no provision for protection and transportation +like many tree seeds. Many kinds are furnished with wings to float +them on the water and carry them in the air. Nearly every tree seed, +except the acorn, has a case to protect it while growing, either +opening and casting the seeds off to a distance when ripe or falling +with them to protect them till they begin to germinate. Even the +equally large seeds of other kinds are protected in some way. The +hickory nut has a hard shell, which shell itself is protected by a +strong covering until ripe. The black walnut has both a hard shell and +a fleshy covering. The acorn is the only seed I can think of which is +left by nature to take care of itself. It matures without protection, +falls heavily and helplessly to the ground, to be eaten and trodden on +by animals, yet the few which escape and those which are trodden under +are well able to compete in the race for life. While the elm and maple +seeds are drying up on the surface, the hickories and the walnuts +waiting to be cracked, the acorn is at work with its coat off. It +drives its tap root into the earth in spite of grass, and brush, and +litter. No matter if it is shaded by forest trees so that the sun +cannot penetrate, it will manage to make a short stem and a few leaves +the first season, enough to keep life in the root, which will drill in +deeper and deeper. When age or accident removes the tree which has +overshadowed it, then it will assert itself. Fires may run over the +land, destroying almost everything else, the oak will be killed to the +ground, but it will throw up a new shoot the next spring, the root +will keep enlarging, and when the opportunity arrives it will make a +vigorous growth, in proportion to the strength of the root, and throw +out strong side roots, and after that care no more for its tap root, +which has been its only support, than the frog cares for the tail of +the tadpole after it has got on its own legs. + +There is no mystery about the succession of forest growths, nothing in +nature is more plain and simple. We cannot but admire her wisdom, +economy, and justness, compensating in another direction for any +disadvantage a species may have to labor under. Every kind of tree has +an interesting history in itself. Seeds with a hard shell, or with a +pulpy or resinous covering which retards their germination, are often +saved from becoming extinct by these means. + +The red cedar (_Juniperus Virginiana_) reaches from Florida to and +beyond Cape Cod; it is among the hills of Tennessee, through the +Middle States and New England. It is scattered through the Western +States and Territories, at long distances apart, creeping up the +Platte River, in Nebraska. (I found only three in the Black Hills, in +Dakota, in an extended search for the different trees which grow +there. Found only one in a long ramble in the hills at Las Vegas, New +Mexico.) Yet this tree has crept across the continent, and is found +here and there in a northwesterly direction between the Platte and the +Pacific Coast. It is owing to the resinous coating which protects its +seeds that this tree is found to-day scattered over that immense +region. + + * * * * * + +[NATURE.] + + + + +THE "HATCHERY" OF THE SUN-FISH. + + +I have thought that an example of the intelligence (instinct?) of a +class of fish which has come under my observation during my excursions +into the Adirondack region of New York State might possibly be of +interest to your readers, especially as I am not aware that any one +except myself has noticed it, or, at least, has given it publicity. + +The female sun-fish (called, I believe, in England, the roach or +bream) makes a "hatchery" for her eggs in this wise. Selecting a spot +near the banks of the numerous lakes in which this region abounds, and +where the water is about 4 inches deep, and still, she builds, with +her tail and snout, a circular embankment 3 inches in height and 2 +thick. The circle, which is as perfect a one as could be formed with +mathematical instruments, is usually a foot and a half in diameter; +and at one side of this circular wall an opening is left by the fish +of just sufficient width to admit her body, thus: + +[Illustration] + +The mother sun-fish, having now built or provided her "hatchery," +deposits her spawn within the circular inclosure, and mounts guard at +the entrance until the fry are hatched out and are sufficiently large +to take charge of themselves. As the embankment, moreover, is built up +to the surface of the water, no enemy can very easily obtain an +entrance within the inclosure from the top; while there being only one +entrance, the fish is able, with comparative ease, to keep out all +intruders. + +I have, as I say, noticed this beautiful instinct of the sun-fish for +the perpetuity of her species more particularly in the lakes of this +region; but doubtless the same habit is common to these fish in other +waters. + +William L. Stone. + +Jersey City Heights, N.J. + + * * * * * + + + + +ANCIENT LAKE DWELLINGS. + + +Among the many traces which man has left of his existence in long past +ages on the face of the earth, says a correspondent of the _Scotsman_, +none are more interesting and instructive than the lake dwellings of +Switzerland and other countries, which have been discovered within the +last fifty years or so. Although these relics of the past are far more +modern than those which we referred to in a late article on "Primeval +Man," and are probably included within the range of Egyptian and +other chronologies, yet they stretch far beyond the historic period, +so far as Europe is concerned, and throw a flood of light on the +habits of our ancestors, or at any rate predecessors, in these +regions. We are tolerably well acquainted with the history of the Jews +when David worked his way up from the shepherd's staff to the royal +scepter, or when Joshua drove out the Canaanites and took possession +of their land, but of what was going on in Europe in these times we +have hitherto had no knowledge whatever. These lake dwellings, +however, were in all probability inhabited by human beings somewhere +about the time when the events we have referred to took place, and may +have been inhabited before the earlier of them. + +The first hint we had of the existence of these remarkable dwellings +was obtained in 1829, when an excavation was being made on the shore +of a Swiss lake. Some wooden piles, apparently very old, and other +antiquities were found by the workmen. Not much attention, however, +was paid to this discovery till 1854, when a Mr. Aeppli drew attention +to some remains of human handiwork found near his house, in part of +the bed of a lake which had been left dry during a season of great +drought. The workmen employed in recovering some land from the lake +found the heads of a great many wooden piles protruding through the +mud, and also a number of stags' horns, and implements of various +descriptions. Stimulated by this discovery, search was made in various +lakes, and the result was truly astonishing. In every direction +remains of the habitations of prehistoric man were discovered, and +relics were found in such abundance that the history of this unknown +past could be traced through long ages, and the habits of the people +ascertained with a very considerable amount of probability. The +details are so numerous that it would be impossible in the space at +our disposal to go into them all. + +Of course, during the long time that has elapsed since these +structures were erected, their remains have been reduced to mere +ruins, and it is only by comparing one with another that we are able +to picture to ourselves what they were originally like and what sort +of life was led by the men who inhabited them. The oldest of these +dwellings belong to the stone age, when man had not acquired any +knowledge of the use of metal; when all his instruments were merely +sharpened stones, fixed in wooden handles, or pieces of bone, horn, or +other natural material. They are therefore somewhat roughly finished, +but at the same time exhibit considerable ingenuity and skill. The +method of construction seems to have been somewhat as follows: A +suitable situation, not far from the shore, where the water was not +very deep, having been fixed upon, these prehistoric builders drove +into the muddy bottom of the lake a number of piles or long stakes, +arranged generally pretty close together, and in some sort of regular +order. These piles were formed generally from stems of trees, with the +bark on, but occasionally from split wood. The ends were sharpened to +a point by the aid of fire or by cutting with stone axes. On a +sufficient number being driven in, and their upper ends brought to a +level above the surface of the water, platform beams were laid across, +fastened by wooden pegs, or in some cases fixed into notches cut in +the heads of the vertical piles. The platform was generally very +roughly made, just a series of unbarked stems placed side by side and +covered with layers of earth or clay, with numerous openings through +which refuse of all kinds fell into the water beneath. In many cases +connection with the shore was made by means of a narrow bridge or +gangway, constructed in the same manner. On this rude platform huts +were erected by driving small piles or stakes which projected above +the floor, and to these were fastened boards standing edgeways like +the skirting of our ordinary rooms, and marking out the size of each +building. The walls of the huts were formed of small branches of twigs +interwoven and plastered over with clay. The roof was made of straw or +reeds like a thatched cottage. In size these huts were probably +eighteen to twenty feet long, eight or ten feet broad, and about six +feet high. They may have been divided into rooms, but there is no +evidence of this. Each was provided with a hearth formed of three or +four slabs of stone. The number of huts in each settlement must have +been considerable, in fact, they must have formed villages of no mean +extent, for as many as forty, fifty, or even a hundred thousand piles +have been found spread over a large extent of ground, forming the +foundation of one such settlement. It is probable, however, that these +were not so numerous when first erected, but were gradually added to +as the population increased. This fact, along with many others, shows +that these dwellings were inhabited for long periods of time, during +which the population pursued their ordinary life in comparative peace +and quietness in their island homes. + +Such is, in brief, a general account of these remarkable structures. +Of course there were several variations in the methods of fixing these +piles, one of which may be mentioned as showing the ingenuity of the +builders. Where the piles did not get a firm hold of the lake bottom, +they carried out in boats or rafts loads of stones, which they threw +down between the piles, thus firmly fixing them, just as modern +engineers sometimes do for a similar purpose. As to the habits of the +people who dwelt in these lake dwellings, we get a considerable amount +of information from the various implements, refuse, etc., which fell +through the imperfectly closed platforms into the lake, and which have +been preserved in the mud at the bottom. They were fishers, hunters, +shepherds, and agriculturists. Skeletons of fish are found in large +abundance, and in some settlements even the fishing nets, and hooks +made of boar's tusks, have been discovered. Then again there is an +abundance of remains of the hunter's feast; bones of the stag, wild +boar, bear, wolf, otter, squirrel, and many other wild animals are +found in rich profusion, and often these are split and the marrow +extracted. These ancient men, however, did not entirely rely on such +precarious provision for their wants, but were so far advanced in +civilization that they kept cattle and domestic animals of various +kinds. They possessed dogs in great numbers, as well as cows, sheep, +goats, and pigs, and in winter time had these housed on their +settlements, as among the remains found are litters of straw, etc., +which had evidently served as bedding for these animals. This, of +course, necessitated the gathering of grass or other material for +their food. They also cultivated wheat, barley, flax, and a number of +other vegetable products. Their methods of cultivation were no doubt +very rude, consisting of a mere scratching of the ground with crooked +branches of trees or with simple instruments made of stags' horn; but, +nevertheless, they succeeded in getting very good results. Among the +relics which they have left are found stones for crushing corn, the +grain which they used, and even the very cakes or bread which they +made. There are also fruits, such as the apple, pear, nut, etc.; so +that the bill of fare of prehistoric man was by no means contemptible. +He had fish, game, beef, mutton, pork, bread, and fruit, besides a +plentiful supply of water from the lake at his door. He was acquainted +with the potter's art, and manufactured earthen vessels of various +kinds. He seems to have produced two kinds--a coarser and a finer; the +former made from clay mixed with a quantity of grains of stone, and +the latter of washed loam. These he ornamented in an elementary +fashion with certain lines and marks. Some of the vessels he used have +been found with a burnt crust of the porridge which he had been making +adhering. As to his clothes, these were probably formed in great part +from the skins of wild or domestic animals, but he also used fabrics +made from flax, which he had learned to weave, as remains of cloth, +twine, rope, etc., are not infrequently found in his dwellings. + +One prominent feature in the history of these lake dwellers is their +gradual advance in the arts of civilization. While the main features +of their settlements remain very much the same during the whole period +of their residence, there is a gradual improvement in the details; the +settlements become larger, and the implements, etc., better finished. +And this is especially observable in the change of material which the +dweller uses. In the earlier stages of his existence stone is the +predominant feature, all his knives, saws, chisels, axes, etc., are +made from this substance; but as time rolls on, one or two implements +are found made of bronze, which is a mixture of tin and copper, and +requires for its production a certain amount of knowledge and +mechanical skill. Gradually the number of bronze implements increases +until eventually stone is superseded altogether, and improved forms of +weapons of war make their appearance, and his work has a more finished +look, arising from his improved implements. Whether the manufacture of +bronze was an original discovery of his own, or whether it was an +importation from some more advanced race, is not certainly known; but +as he undoubtedly had intercourse with the East, it is probable that +the first bronze was imported, and that afterward he discovered the +way to manufacture it himself. However this may be, it seems evident +that the introduction of this material greatly aided his development. +As stone gave place to bronze, so in the course of time this latter +gave place to iron, probably introduced in the same manner some +considerable time before the dawn of history; and this metal held its +place until these habitations were finally abandoned. + +With regard to the religion of these lake dwellers, if they had any, +nothing is known. From some curious objects formed somewhat like the +crescent of the moon, which are found in considerable numbers, it has +been supposed that they worshiped that body; but there seems to be +really no evidence for this supposition, and these objects may only +have been ornaments, or perhaps charms, fixed above the doors of their +huts something after the manner of the horse shoe nailed over the door +in modern times to keep away evil spirits. So far as can be inferred +from the remains that have been examined, the same race seems to have +inhabited these dwellings from their commencement to their end. There +is no appearance of invasion from without; all seems continuous. +Probably his race came in early time from the East, and were a +pastoral people, with flocks, herds, and domestic animals, and built +their peculiar habitations to protect themselves from human enemies. +Certainly the arrangements were well fitted for the purpose in those +days, when the club and the spear were almost the only weapons of +offense. Dr. Keller, who has investigated this subject with great +care, is of the opinion that these lake dwellers were a branch of the +great Celtic race. + + * * * * * + +[New England Farmer.] + + + + +HOW TO RAISE TURKEYS. + + +The best feed for young turkeys and ducks is yelks of hard-boiled +eggs, and after they are several days old the white may be added. +Continue this for two or three weeks, occasionally chopping onions +fine and sometimes sprinkling the boiled eggs with black pepper; then +give rice, a teacupful with enough milk to just cover it, and boil +slowly until the milk is evaporated. Put in enough more to cover the +rice again, so that when boiled down the second time it will be soft +if pressed between the fingers. Milk must not be used too freely, as +it will get too soft and the grains will adhere together. Stir +frequently when boiling. Do not use water with the rice, as it forms a +paste and the chicks cannot swallow it. In cold, damp weather, a half +teaspoonful of Cayenne pepper in a pint of flour, with lard enough to +make it stick together, will protect them from diarrhea. This amount +of food is sufficient for two meals for seventy-five chicks. Give all +food in shallow tin pans. Water and boiled milk, with a little lime +water in each occasionally, is the best drink until the chicks are two +or three months old, when loppered and buttermilk may take the place +of the boiled milk. Turkeys like best to roost on trees, and in their +place artificial roots may be made by planting long forked locust +poles and laying others across the forks.--_American Agriculturist._ + + +HOW TO RAISE TURKEYS. + +Keep the turkey hens tame by feeding them close to the house. Have two +or three barrels in sheltered corners containing plenty of straw or +leaves for them to lay in. Gather the eggs every evening, as turkey +eggs are very easily chilled. Keep the eggs in a woolen cloth on end +and turn them every three days. Set the first seven eggs under a +chicken hen, as they get too old before the turkey hen will go to +sitting. Make a board pen ten or twelve feet square and twelve or +fourteen inches high. Put a coop in it and put your hen and turkeys in +it. Feed the hen with corn and the turkeys soaked wheat bread (corn +meal will kill them), until they are a week old (I feed five or six +times a day). Then feed wheat until they are big enough to eat corn. +Give plenty of fresh water in a shallow vessel. Keep the mother in +the pen until they are large enough to fly over the top of the boards. +Let them out awhile about the middle of the day. Shut them in at +night. A turkey hen does not like to be shut up, but have a good big +coop for her and she will go in. Don't let the little turkeys get +their backs wet until they are feathered. The turkey hen will sit down +when night comes just where she happens to be, but if you drive her +home a few times she will come herself after that. Always feed them +when they come home, no matter if they are full of "hoppers." Have +your No. 2 pen in the orchard under an apple tree where it is shady. +Have the turkey hen's pen close to the chicken hen's pen, so that when +the chicken hen weans her turkeys, they will soon learn to go with the +turkey hen. Give them a dose of black pepper in their feed every cold +rain. And never, no never, get excited and in a hurry while working +with turkeys if you don't want them to get wild and fly all over the +plantation. Three or four weeks before selling, feed all the corn they +will eat. + + +FOOD HINTS. + +Restrain your desire to count your young turkeys, and let them alone +for twenty-four hours after they get into this world. Remove them to a +clean, airy, roomy coop, and give them boiled eggs, stale wheat bread +crumbs just moistened with milk or water, "Dutch" cheese, or a mixture +of all these. + +For the first two weeks feed entirely with the eggs, bread, curds, +cooked rice and cooked oatmeal. About the third week commence feeding +cooked cornmeal; and from that on they may have any cooked food that +would be suitable for chickens of the same age. Season all food +slightly with salt and pepper, and twice a week add a level +tablespoonful of bone meal to a pint of feed. Never feed any sour food +or sloppy food of any kind, except sour milk, and never feed any +uncooked food of any kind until after they have thrown out the red on +their heads. Feed often, five or six times a day, until after they are +three months old; then, if insects are numerous, you may gradually +reduce the number of meals per day to three or even two. + +After they are three months old they may be given wheat, cracked corn, +etc., but not whole corn until they are five months old. Keep the +coops dry and clean, and the turkeys out of the dew and rain until +they are fully feathered, and have thrown out the red. Dampness and +filth will kill young turkeys as surely as a dose of poison. For the +first few days confine the poults to the limits of the coop and safety +run; then, if all appear strong and well, give the mother hen and her +brood liberty on pleasant days after the dew is off. + +If they get caught out in a shower, get them to shelter as soon as +possible; and if they are chilled take them to the house and +thoroughly dry and warm them. See that the little turkeys come home +every night. The turkey mother must, for the first few nights, be +hunted up and driven home. After they are three months old, turkeys +are quite hardy, and may be allowed range at all times. If turkeys +that are well cared for, and have always seemed all right, show signs +of drooping when about six weeks or two months old, give Douglas +mixture in the drink or food, and add a little cooked meat to the food +once a day.--_The Practical Farmer._ + + +ABOUT SITTING. + +For an ordinary place, select from a good breed (I prefer the bronze) +a large gobbler and two or three hens. As soon as the warm weather +comes, place about the barn in sheltered places two or three barrels +on their sides, and in them make nice nests. In these the hens will +lay. Gather the eggs every day, keeping them in a cool place. When a +box contains 23 eggs mark it No. 1 and begin to fill a second box, and +when it contains 23 eggs mark it No. 2 and so continue. It is well to +leave turkey hens on the nest two or three days, for they often lay +one or two eggs after they begin to show signs of sitting. + +When you have decided to sit a hen, give her a good nest and 15 eggs +and at the same time give a common hen eight eggs. These, when +hatched, are all to be given to the turkey hen. Never try to raise +turkeys with a domestic fowl. If you have no place free of grass, you +can start turkeys with difficulty. Feeding is of the greatest +importance. For the first week I have found wheat bread moistened in +water the most satisfactory. If you can feed them by sunrise for the +first three or four weeks, you need lose hardly a bird. Each evening +try and call them nearer and nearer home, so that you will not be +troubled with their wandering to the neighbors'. As early as possible +train them to roost high, so as to be out of danger at night. Bird +dogs are often very destructive to turkeys, at times destroying a +whole flock in a single night. Fatten with corn. The turkey crop ought +to be one of the most profitable on our farms. + +Dr. G.G. GROFF. +Pennsylvania. + + +GRAHAM. + +Turkeys want care, especially for the first two or three weeks. I feed +graham and wheat bread, made by scalding the flour, making a very +stiff dough, and baking in a hot oven; soak over night in cold water. +I also give them plenty of young onions, cutting them up with +scissors. Be careful not to let young turkeys out in the morning while +the grass is wet. After the birds are two weeks old I feed wheat, but +no corn until they are about a month old. I like hen mothers best, for +turkey mothers are rangers, and do not take kindly to being kept in a +coop. The bread will keep a week if made right, but do not soak more +than will be wanted in a day, as it soon sours. I feed scraps from the +table, such as potatoes and bits of meat cut very fine, but not much +of the latter to young birds. I rarely lose a bird.--_Mrs. E. Reith, +in Homestead._ + + +CARE AND GENERAL MANAGEMENT. + +In turkey raising the one who is the most careful and attentive to the +small things is the most successful. The first laying of eggs should +be set under a chicken hen. The turkey hen will, after a few days' +confinement, lay another batch of eggs. A good-sized hen will cover +and care for ten eggs; a turkey hen, seventeen. Make a large, roomy +nest of soft, fine hay--straw is too brittle and slippery. If there is +danger of lice in the nest-box, sprinkle with water in which carbolic +acid has been mixed in the proportion of eight drops to a half gallon +of water. Don't wet the eggs with this. After the eggs have been sat +on one week, sprinkle with warm water every other day, until the last +week; then every day, until they hatch. Have the water clear, and use +a flower or fine rose sprinkler. Let the water be of the same +temperature as the eggs, which can be ascertained by slipping a +thermometer under the hen for a few minutes. This softens the shells, +and as a little turkey is very weak, it is helped out easily, and is +stronger than if working long to get out. + +Let the little turkeys get well dried and strong enough to climb +around the edges of their nest before taking them off. Have a pen, say +six feet square, built for them, and made tight at the sides clear +down to the ground, to keep them from getting out and being chilled. +Put sand and fine gravel over the ground, and cover enough of it to +afford shelter at night and when it rains. They may be kept in this +pen the first four or five days, then let out after dew is off, and +shut up before night. + +For the first few days' feed, nothing is better than clabber cheese or +curd made by scalding clabbered milk until the curd separates and is +cooked, then skimmed out and fed. Mix a little black pepper with this +every other day. Meal must not be fed raw for several weeks, and then +should be mixed with sour milk instead of water. Bake the meal into +bread by mixing it, unsifted, with sour milk, and adding a little soda +and pepper. Spinach, lettuce, onion tops and any other tender greens, +chopped fine, are excellent food. From the time a turkey is hatched +until it is ready for market it should have plenty of milk. Give them +clear water to drink, for milk is a food. See that the very young ones +have milk and water in quite shallow dishes, for they are in danger of +getting wet if the dish is deep. + + +GATHER THE LITTLE TURKEYS IN + +at the first signs of rain, and they will soon learn to run and fly to +their coop at the first drops. Always shut them up at night, for they +are early risers and will be out long before the dew is dried off. +Don't pen them too near the house. Feed them at or near the same place +all the time and they will learn to go there when hungry. Give them a +good feed at night and they will remember to come home for it. If the +morning is dry, feed lightly and let them hunt the rest in the orchard +and fields. Keep the grass and weeds mowed around their pen and +feeding places. Mix slaked lime in the dust for them to take their +dust bath in, and sprinkle the carbolic acid and water over and around +their roosting pen. Keep pails and kettles covered, for they will get +drowned if they have half a chance, as they begin to fly so young. Of +course a turkey hen will take her young off, and care for them after a +fashion, but the safest way to make them tame is to raise them where +they may be cared for. Even if the turkey hen hatches her last batch +of eggs, it is a good plan to have a hen ready to take the little +turkeys and slip them away at night. If she still stays on her nest +give her 20 or 25 hen's eggs, and if she hatches them let her run with +the chickens. They are not so tender or so easily led astray as +turkeys are, nor as valuable.--_Mrs. Jas. R. Hinds, in Orange Judd +Farmer._ + + * * * * * + + + + +WATER AS A THERAPEUTICAL AGENT. + +By F.C. ROBINSON, M.D. + + +My experience in the use of water in almost every disease occurring in +this climate has long since satisfied me that it is less objectionable +and produces quicker and better results than any other treatment, and +can be used when all other medication is contra-indicated. Drinking +water should be pure, uncontaminated by animal or vegetable +impurities, and given _ad libitum_, unless, in rare instances, it +should cause vomiting or interfere with the capability of digesting +food. If children are comatose or delirious, as they frequently are in +typhoid fever, give water to them regularly, or force it upon them, if +they refuse to take it, as I was obliged to do with a child of six +years just recovering from that fever. + +It is my custom to allow cold drinks of water in all cases of measles +whenever patients desire it, and I am satisfied that it aids the early +appearance of the rash, and certainly is cooling and grateful to the +patient. Hot drinks or vile and nauseous teas are unnecessary in this +disease, and should be discarded as useless, odious, and disgusting. +If congestion of the lungs or any intercurrent inflammation occurs, or +the rash is much delayed, a hot water bath or the old reliable corn +sweat will break up the complication with amazing rapidity, and if the +head is kept cool, will not generally be unacceptable to the patient. + +Hot baths reduce temperature by causing free perspiration afterward, +and cold packs reduce it by cooling the surface sufficiently long to +reduce the heat of the blood, and, if used judiciously, seldom fail of +success. I have reduced the temperature four degrees in two hours by +wrapping around a child a sheet wet with tepid water, and no other +covering. Cold packs are sometimes objectionable, because of their +depressing effects, and should only be used to reduce high temperature +and when there is no congestion or inflammation of any of the vital +organs of the body. + +Cold water poured in a small stream from a pitcher upon the head for +five or ten minutes will often relieve headache, and is a benefit in +all inflammatory brain diseases, if, at the same time, you can put the +feet into hot water containing mustard or pepper. + +Large enemas of warm water will care for spasmodic colic, and I have, +in one instance, relieved strangulated hernia by the same method, and +at another time the same result was accomplished by a large injection +of warm linseed oil. I have often applied a cloth wet with cold water +upon the throats of children suffering with spasmodic croup, with +satisfactory results. + +I have seen infants suffering with diarrhea or summer complaint, +sleepless, worrying, fretting, or crying from thirst, begging for +water, and the mother or nurse afraid to give it more than a +teaspoonful or two at a time, saying that it vomited everything it +drank as soon as taken. I have often, when visiting such cases, called +for a glass of cold water, and, to the surprise of the mother, would +allow it to take all it could drink, which usually would be retained, +and the child would soon be wrapped in a refreshing sleep. Without +medicine, a proper regulation of the child's diet would soon restore +it to health again. + +The spasms of children, from whatever causes, or the eclampsia from +uræmic poisoning, are often readily controlled when immersed in hot +water or given a hot vapor bath or corn sweat. If the convulsions of +children are accompanied by a high temperature, put them into water of +100° and then gradually cool it down to 68° or 70°, and then keep them +in a room of the same temperature, with little covering. If the +temperature rises, repeat the treatment as frequently as necessary, +and I think you will not be disappointed in the results. + +Scarlet fever and diphtheria, two of the most dreaded and formidable +diseases of children, are largely shorn of their terrors when, in +addition to an early and thorough medicinal treatment, the little +patients are bathed in as warm water as the surface will allow +frequently, or for thirty minutes wrapped in a warm, wet blanket, +followed by warm, dry coverings, to maintain the perspiration that +such treatment usually produces. It has proved to me a valuable aid in +eliminating from the blood the specific poison which causes these +diseases, and I can safely recommend it to your notice and trial. + +There is no disease more favorably influenced by this treatment than +pneumonia, and in mild cases one daily warm bath or sweat, without +medicine, will be sufficient to arrest this disease, and it is among +the first things I usually order. If I find a child or infant with a +temperature of 103° to 105°, short, dry, and painful cough, +dyspnoea, rapid pulse, great thirst, or vomiting, with dry +crepitation in any part of the lung tissue, I order it rolled up in a +blanket or sheet coming out of hot water, and in thirty minutes change +it to warm, dry blankets, and soon the little fretful, worrying +sufferer would rest in a quiet, peaceful sleep.--_Peoria Med. Mo._ + + * * * * * + + + + +ON THE HEALTH VALUE TO MAN OF THE SO-CALLED DIVINELY BENEFICENT +GIFT, TOBACCO. + +By J.M.W. KITCHEN, M.D., New York. + + +With perhaps the exception of heredity, the question of stimulants and +narcotics in their relation to the physical welfare of the race is +second to none in importance. With trifling exceptions, the whole +world is addicted to their use. The universality of such use has led +many to consider them a necessity to man, and that they are God's +gifts to him, and, if rightly used, are of physical benefit. It may +not be a perversion of judgment to consider that their widespread +popular use is greatly due to the efforts of the race to gain +anæsthesia for, and distraction from, those pains and punishments that +are the inevitable sequence of departure from hygienic and social law +on the part of the individual, his ancestry, and society in general. + +The taste for these things is acquired, not natural, though the +acquisition may be through hereditary influence. An idea is held by a +majority of even fairly intelligent individuals that there is a +justifiable, harmless, and even beneficial use of these substances by +the general public, though acknowledging that beyond a certain +indefinite line this use becomes an abuse. + +I believe that there may occasionally be cases in which the physical +benefits derived from their use outweigh the injury they inflict, but +I think this use is very much less than is generally supposed, and if +we can judge from the preponderance of evil effected by such use, +these substances ought to be considered as the materialized curses of +God rather than as beneficent gifts. The prevalent idea as to the +beneficent nature of these substances I consider to be a delusion that +can only be explained upon the hypothesis that there is a widespread +lack of appreciation of the fact that, though they may have an +immediate pleasant and agreeable effect upon the body, their injurious +effects are cumulative, and are usually ultimate, and so distant as to +be difficult of direct connection with their cause to ordinary +observation. The more moderate the use of these substances, the more +remotely is the effect removed from the cause and more difficult of +detection. That the ordinary habitual, so-called moderate use of +stimulants and narcotics, such as tea, coffee, tobacco, and alcohol, +is, in the vast majority of cases, really an abuse, is a proposition +that I think should be admitted by all who have given the subject an +unbiased study. + +The idea that the user of tobacco and other injurious substances will +be cognizant of the injury inflicted by habitual use in moderate or +even excessive amounts is an undoubted fallacy. The daily, weekly, or +monthly injurious effect may be entirely unobservable to even trained +physicians, and yet the ultimate cumulative effect may be fatal. I can +instance numerous cases of physicians directly fatally injured by the +use of alcohol, who have never had the slightest cognizance of the +fact; and I can also instance cases of grave disease from the use of +tobacco where the patients never have believed that tobacco has been +the cause of their troubles, even after a unanimous opinion to that +effect has been expressed by a number of competent medical advisers. +The habitual consumption of opium, in doses of any amount, is +generally admitted by most people to be physically injurious outside +of its strict medicinal application. Moderate indulgence in alcohol as +a beverage is beginning to acquire a very widespread evil reputation. +But how about tobacco? Tea and coffee we can confidently leave to the +consideration of a somewhat remote posterity of a considerably +advanced intelligence and elevated hygienic ideals. + +The relation of tobacco to the physical welfare of man can only be +fairly estimated by viewing the subject in its broadest aspect; by +considering its effects upon the race as a whole rather than in +individual cases; by taking into consideration economical and other +social conditions that at first sight might be considered as having +little relevancy to the medical side of the subject. But there can be +no just consideration of the matter otherwise. The direct deleterious +effects of the immoderate use of tobacco are readily observable; but +the great bulk of the evil physical effects due to the moderate use of +this plant are of an intermediate nature and not directly noticeable; +nevertheless, they are real, and worthy of medical attention. The +plainly marked results following the use of tobacco in relatively +large amounts seem to be due to quick and extreme interference with +nutrition, and a diminution of function of all kinds, which may be +represented by anything from a slight decrease of appetite and +digestive ability up to a complete loss of function of almost any +important organ. Tobacco has stimulating as well narcotic properties, +but as ordinarily used its stimulating effect appears to be slight as +compared with its narcotic influence. In this respect it differs from +alcohol, the use of which, owing to the usual method of introduction +in large amounts through the stomach, produces directly, by +stimulation, readily noticeable structural changes. But with tobacco +the direct evil results are mostly of a functional character, and are +more generally diffused, owing to the usual slow manner of +introduction into the body. These two properties have an effect upon +the body in moderate use as well as in immoderate use, the effect +being simply in proportion to the quantity used, though the effects of +moderate use may not be measurable by ordinary means. It is easy to +see the effects of large amounts of tobacco in the stunted growth of +adolescents; in functional cardiac disorders; in intellectual +sluggishness, loss of memory, and color blindness; in loss of +appetite, and other neuroses of motion, and marked blunting of various +functions of sensation, and in degeneracy of descendants; but that +lesser evils are produced must be proved mostly by inference, +circumstantial collateral evidence, and analogy. + +The greater evils that are the outcome of a moderate use of tobacco +are probably due to prolonged slight interference with nutrition, and +consequent general decrease of vitality, which renders the individual +more susceptible through indirect influence to the invasion of +disease, and which lessens the capacity for productive effort. + +It is of course difficult, and perhaps even impossible, to accurately +estimate the value of tobacco to the race; but let us glance at the +pros and cons, and then each one can roughly estimate for himself. +Tobacco may be used medicinally, but it is a dangerous and uncertain +remedy, and it probably has not one medicinal use that cannot be more +suitably met by other remedies. One can readily imagine easier +digestion as the result of the sedative influence of the after-dinner +cigar upon a disquieted nervous system, especially if the coincident +irritation of alcohol and coffee have need of correction; but it can +also be imagined that in most of such cases the remedy has been the +cause of and will further increase the disordered condition, and that +nutrition of deficiently nourished nerve tissue is rationally +indicated rather than partial narcotization. There then remains, so +far as I can see, the solace of moderate anæsthesia and, occasionally, +of occupation for idlers, as the only items that can be placed to the +credit of tobacco. There certainly are individual cases where such +usage may be more provocative of physical benefit than evil, but, +before judging for the race as a whole, compute the other side of the +question. + +Tobacco injures the general health of the public through the economic +loss caused by its consumption. The people of our country spend +annually over seven hundred millions of dollars for tobacco--twenty +per cent. more than is spent for bread. This sum represents only a +minor part of the cost of the tobacco habit to the country. The crop +is immensely exhaustive to the soil. Its culture has blighted whole +sections of fertile territory. In the time consumed by the producer +and the trader in its production, manufacture, and sale, and by the +consumer in its use, and by the general interference with vital +activity and consequent decreased productive capacity, there is +represented an almost unimaginable sum of money. Certainly the people +at large are not so well fed both as to quantity and quality, or so +thoroughly clothed, or so hygienically housed that they can afford +this gigantic economic waste. + +There can be little doubt that if the people had sufficient +intelligence and moral strength to taboo tobacco, this comparatively +senseless outgo would be largely devoted to supplying these and other +necessities of an exalted health status. + +Tobacco injures health through its moral effects. The tobacco habit is +certainly a dirty and frequently a disgusting habit, and encourages +other dirty practices. Its use tends to make men cowardly, irritable +in temper, and low in spirits. It blunts ideas of purity and courtesy, +leading to invasion of the rights of others. It is presumed that few +medical men would visit a delicate, sensitive patient after saturation +with the "fragrant" effluvia of onions, but thousands whose systems +are saturated with nicotine and who reek with nauseating odor do not +hesitate to inflict their presence on sick or well. The time will come +when the tobacco user will not be allowed to poison the atmosphere +that is the common property of the public--will not be allowed to +force the inhalation of nicotine upon the general public, to say +nothing of being allowed to poison the infants and women in his own +family. What would be said of a man who introduced poison in any +degree into the food or drink of his child? Is the poisoning of the +household atmosphere by the ignorant, thoughtless, or selfish smoker +morally more defensible? Tobacco injures health through hereditary +influence. The tobacco user begets, more certainly than the non-user, +puny children with disordered nervous conditions. Luckily for our +race, the women, who have the most important prenatal influence in +guarding its physical well-being, are practically non-users of the +plant. The general health status of the race is improving, not because +the use of tobacco or the indulgence in other questionable practices +is harmless, but because, among other things, of the great advance in +general intelligence and knowledge of hygienic law. + +A person, or the public in general, may practice an injurious habit, +and yet more than counteract its influence by opposing beneficial +practices. + +Horace Greeley said, "Show me a drunkard who does not use tobacco, and +I will show you a white blackbird." In this country, where dietetic +drinking habits are not common in the family, the weakening of moral +fiber by indulgence in tobacco is usually the introduction into the +round of vicious indulgences, and thus directly or indirectly affects +health. Smoking induces dryness of the mucous membrane of the mouth +and consequent thirst. The partially paralyzed nerve terminals want +something more stimulating than water to afford relief. Furthermore, +blunted appetite induces deficient nutrition, and consequently there +is a call for some "pick-me-up;" hence we find that the use of tobacco +tends to the habitual use of alcoholic beverages, and there are very +few habitual users of alcohol who escape without structural injuries +to the body as well as perversion of its functions. Decrease of vital +activity in all the tissues of the body marks the use of tobacco. The +tendency is toward functional paralysis, though occasional signs of +stimulative irritation are to be noticed, especially in the +respiratory passages. The interference with intellectual activity is +marked. It is said that during a period of fifty years no tobacco user +stood at the head of his class in Harvard. The accumulated testimony +of investigating observers is conclusive that, other things being +equal, users of tobacco, in schools of all grades, never do so well in +their studies as non-users. + +One head of a public school said he could always tell when a boy +commenced to use tobacco by the record of his recitations. Professor +Oliver, of the Annapolis Academy, said he could indicate the boy who +used tobacco by his absolute inability to draw a clean, straight line. +The deleterious effects of tobacco have become so clearly apparent +that we find its sale to minors is prohibited in France, Germany, and +various sections of this country. It is somewhat a question if, at the +present time, the race is not doing itself more injury by its use of +tobacco than it is with alcohol, because of its more universal use, +particularly by youth, and because of the respectability of the habit, +which comes of its use by a certain intelligent part of the race, +including teachers of morals and physics, and even temperance +reformers. There is a widespread sentiment in existence that it is not +a respectable thing to be even partly paralyzed by alcohol, but how +few there are who consider narcosis as in any way connected with the +use of tobacco. Its effect is more diffused and masked, and is not so +acutely serious in individual cases, but through its interference with +vital activity, tobacco is probably more generally injurious to the +race than alcohol. + +The editorial fiat of "too long" prevents a full exposition of the +subject, but, in closing, let me say I hear millions of tobacco users +ask, "Why, then, was this plant given to man, if its general effects +are so decidedly evil?" The question presupposes design in creation. +Without subscribing to this theory, or pretending to have solved the +mystery of the presence of evil in the world, the answer may be +suggested that the overcoming of many seductive evils becomes to man a +means of his progressive higher development. Of one thing I am +convinced, that the physical development and welfare of man is +interfered with in strict sequence to his consumption of substances +that are unnecessary for his nutrition--stimulants and narcotics +inclusive.--_Medical Record._ + + * * * * * + + + + +ACETIC ACID AS A DISINFECTANT. + + +Dr. F. Engelmann, in _Cent. f. Gyn._, claims that acetic acid +possesses equally as good antiseptic properties as carbolic acid; in +fact, that it is to be preferred, as it is completely harmless, even +if used in concentrated solutions, and that it is a valuable +hæmostatic, an advantageous addition particularly in obstetrics. +Another important property is its ease of transition into the tissues, +which, according to Engelmann's experiments, is by far greater than +that of all the other antiseptics. Of bichloride it is well known that +it forms an insoluble combination with albumen, and can therefore act +only on the surface, while acetic acid extends into the deeper tissues +with ease. + +Acetic acid also affects the metal of the instruments, but not as +severely as the bichloride; the forceps, for instance, may be placed +for a quarter of an hour in an irrigator filled with a three per cent. +solution of acetic acid without being injured. + +A pleasant effect of acetic acid is that it softens and lubricates the +skin. The author generally used a three per cent. solution; at times +he has made use of a five per cent. solution, which would easily cause +a painful burning at sore places, so that he only used the latter +strength in septic cases, as the three per cent. solution proved to be +a satisfactory antiseptic for general purposes. + + * * * * * + + + + +COUNTER-IRRITATION IN WHOOPING COUGH. + +By G.F. INGLOTT, M.D. + + +To combat this often distressing disease I have tried the +administration of several medicines, namely, bromide of potassium, +asafoetida, valerian, morphine, belladonna, etc., and I have very +closely watched their effects, but none of them proved of much use. +Having observed, however, that during the late cholera epidemic some +of the patients admitted into the hospital under my medical charge +slept well, had their anxiety improved, and some of them ultimately +recovered, after the application of a strong counter-irritation of the +pneumogastric nerves in the neck, namely, between the mastoid process +and the angle of the lower jaw, I tried the same treatment on whooping +patients, and I have no hesitation in stating that the result was very +satisfactory. I may quote one single case of the many I have had under +treatment. + +A boy, aged twelve years, of weak constitution, was suffering from +frequent and intense attacks of whooping cough. At a time the fits +were so vehement that blood came out of his eyes and mouth. The case +was a severe one, and I thought it would very likely end fatally. I +prescribed several medicines, and even subcutaneous injections of +morphine, but without any avail. I then tried for the first time the +counter-irritation on both sides of the neck, and this means acted +like magic. In four or five days the patient recovered, and was able +to go to school. Since that time I have been applying the same +treatment, either on the right side only or on both, with the greatest +benefit.--_Br. Med. Jour._ + + * * * * * + + + + +DEVELOPMENT OF THE EMBRYO. + + +At a recent meeting of the Physical Society, Berlin, Prof. Preyer +spoke on reflexes in the embryo. His researches extended over many +classes of animals. As representing mammals, guinea pigs were chiefly +used; and for reptiles, snakes; while in addition the embryos of +fishes, frogs, mollusks, and other lower animals were also employed. +But of all animals birds are most suitable for embryological +observations, inasmuch as with due precautions the development of one +and the same individual can be followed for a considerable time. +Birds' eggs can be incubated in a warm chamber, and by removing a +portion of the shell and replacing it by an unbroken piece from +another egg, it becomes possible to follow the daily development of +the chick and to experiment upon it. As early as the ninetieth hour of +incubation, spontaneous "impulsive" movements may be observed, taking +place apparently without any external stimulus as a cause, and at a +time when no muscles or nerves have as yet been developed. After the +occurrence of these spontaneous movements, and at the earliest on the +fifth day of incubation, movements are observed to result from the +application of mechanical, chemical, and electrical stimuli. In order +to observe these the eggs must be allowed to cool down until all +spontaneous movements have ceased. From the tenth to the thirteenth +day more complicated and reflex actions occur on the application of +stimuli, as, for instance, movements of the eyelids, beak, and limbs; +and if the stimuli are strong, reflex respiratory movements. These +reflexes make their appearance before any ganglia have become +differentiated. Prof. Preyer considered himself justified in +concluding from this that ganglia are not essential for the liberation +of reflex actions. He intends, on some future occasion, to give a more +detailed account of these experiments, and of the conclusions which +may be drawn from them. In the discussion which ensued the conclusions +of the speaker were contested from many sides. + + * * * * * + + + + +IRIDESCENT CRYSTALS.[1] + + [Footnote 1: Abstract of the Friday evening lecture delivered by + Lord Rayleigh, F.R.S., at the Royal Institution, on April 12, + 1889.] + +By LORD RAYLEIGH. + + +The principal subject of the lecture is the peculiar colored +reflection observed in certain specimens of chlorate of potash. +Reflection implies a high degree of discontinuity. In some cases, as +in decomposed glass, and probably in opals, the discontinuity is due +to the interposition of layers of air; but, as was proved by Stokes, +in the case of chlorate crystals the discontinuity is that known as +twinning. The seat of the color is a very thin layer in the interior +of the crystal and parallel to its faces. + +The following laws were discovered by Stokes: + + (1) If one of the crystalline plates be turned round in its own + plane, without alteration of the angle of incidence, the + peculiar reflection vanishes twice in a revolution, viz., when + the plane of incidence coincides with the plane of symmetry of + the crystal. [Shown.] + + (2) As the angle of incidence is increased, the reflected light + becomes brighter and rises in refrangibility. [Shown.] + + (3) The colors are not due to absorption, the transmitted light + being strictly complementary to the reflected. + + (4) The colored light is not polarized. It is produced + indifferently, whether the incident light be common light or + light polarized in any plane, and is seen whether the reflected + light be viewed directly or through a Nicol's prism turned in + any way. [Shown.] + + (5) The spectrum of the reflected light is frequently found to + consist almost entirely of a comparatively narrow band. When the + angle of incidence is increased, the band moves in the direction + of increasing refrangibility, and at the same time increases + rapidly in width. In many cases the reflection appears to be + almost total. + +[Illustration: FIG. 1 GENERAL SCHEME + FIG. 2 DETAIL OF LAZY-TONGS] + +In order to project these phenomena a crystal is prepared by cementing +a smooth face to a strip of glass whose sides are not quite parallel. +The white reflection from the anterior face of the glass can then be +separated from the real subject of the experiment. + +A very remarkable feature in the reflected light remains to be +noticed. If the angle of incidence be small, and if the incident light +be polarized in or perpendicularly to the plane of incidence, the +reflected light is polarized in the _opposite_ manner. [Shown.] + +Similar phenomena, except that the reflection is white, are exhibited +by crystals prepared in a manner described by Madan. If the crystal be +heated beyond a certain point the peculiar reflection disappears, but +returns upon cooling. [Shown.] + +In all these cases there can be little doubt that the reflection takes +place at twin surfaces, the theory of such reflection (_Phil. Mag._, +Sept., 1888) reproducing with remarkable exactness most of the +features above described. In order to explain the vigor and purity of +the color reflected in certain crystals, it is necessary to suppose +that there are a considerable number of twin surfaces disposed at +approximate equal intervals. At each angle of incidence there would be +a particular wave length for which the phases of the several +reflections are in agreement. The selection of light of a particular +wave length would thus take place upon the same principle as in +diffraction spectra, and might reach a high degree of perfection. + +In illustration of this explanation an acoustical analogue is +exhibited. The successive twin planes are imitated by parallel and +equidistant disks of muslin (Figs. 1 and 2) stretched upon brass rings +and mounted (with the aid of three lazy-tongs arrangements) so that +there is but one degree of freedom to move, and that of such a +character as to vary the interval between the disks without disturbing +their equidistance and parallelism. + +The source of sound is a bird call, giving a pure tone of high pitch +(inaudible), and the percipient is a high-pressure flame issuing from +a burner so oriented that the direct waves are without influence upon +the flame (see _Nature_, xxxviii., 208; Proc. Roy. Inst., January, +1888). But the waves reflected from the muslin arrive in the effective +direction, and if of sufficient intensity induce flaring. The +experiment consists in showing that the action depends upon the +distance between the disks. If the distance be such that the waves +reflected from the several disks co-operate,[2] the flame flares, but +for intermediate adjustments recovers its equilibrium. For full +success it is necessary that the reflective power of a single disk be +neither too great nor too small. A somewhat open fabric appears +suitable. + + [Footnote 2: If the reflection were perpendicular, the interval + between successive disks would be equal to the half wave-length, + or to some multiple of this.] + +It was shown by Brewster that certain natural specimens of Iceland +spar are traversed by thin twin strata. A convergent beam, reflected +at a nearly grazing incidence from the twin planes, depicts upon the +screen an arc of light, which is interrupted by a dark spot +corresponding to the plane of symmetry. [Shown.] A similar experiment +may be made with small rhombs in which twin layers have been developed +by mechanical force after the manner of Reusch. + +The light reflected from fiery opals has been shown by Crookes to +possess in many cases a high degree of purity, rivaling in this +respect the reflection from chlorate of potash. + +The explanation is to be sought in a periodic stratified structure. +But the other features differ widely in the two cases. There is here +no semicircular evanescence, as the specimen is rotated in azimuth. On +the contrary, the colored light transmitted perpendicularly through a +thin plate of opal undergoes no change when the gem is turned round in +its own plane. This appears to prove that the alternate states are not +related to one another as twin crystals. More probably the alternate +strata are of air, as in decomposed glass. The brilliancy of opals is +said to be readily affected by atmospheric conditions. + + * * * * * + + +A NEW CATALOGUE OF VALUABLE PAPERS + +Contained in SCIENTIFIC AMERICAN SUPPLEMENT during the past +ten years, sent _free of charge_ to any address. MUNN & CO., 361 +Broadway, New York. + + * * * * * + + +THE SCIENTIFIC AMERICAN + +ARCHITECTS AND BUILDERS EDITION. + +$2.50 a Year. Single Copies, 25 cts. + +This is a Special Edition of the SCIENTIFIC AMERICAN, issued +monthly--on the first day of the month. 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Thus, we do not necessarily +keep eBooks in compliance with any particular paper edition. + + +Most people start at our Web site which has the main PG search facility: + + https://www.gutenberg.org + +This Web site includes information about Project Gutenberg-tm, +including how to make donations to the Project Gutenberg Literary +Archive Foundation, how to help produce our new eBooks, and how to +subscribe to our email newsletter to hear about new eBooks. diff --git a/16972-8.zip b/16972-8.zip Binary files differnew file mode 100644 index 0000000..fa31a63 --- /dev/null +++ b/16972-8.zip diff --git a/16972-h.zip b/16972-h.zip Binary files differnew file mode 100644 index 0000000..922524c --- /dev/null +++ b/16972-h.zip diff --git a/16972-h/16972-h.htm b/16972-h/16972-h.htm new file mode 100644 index 0000000..7ff6653 --- /dev/null +++ b/16972-h/16972-h.htm @@ -0,0 +1,5029 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> + +<html xmlns="http://www.w3.org/1999/xhtml"> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" /> + +<title> +The Project Gutenberg eBook of Scientific American Supplement, August 17, 1889 +</title> + +<style type="text/css"> +<!-- + body {margin-left: 15%; margin-right: 15%; background-color: white} + img {border: 0;} + p { text-align: justify;} + h1,h2,h3 {text-align: center;} + + hr {text-align: center; width: 50%;} + hr.short {width: 25%;} + hr.long {width: 75%;} + hr.full {width: 100%;} + + .note {margin-left: 2em; margin-right: 2em; margin-bottom: 1em;} + .ind {margin-left: 10%; margin-right: 10%;} + .caption {font-weight: bold; + font-size: smaller;} + .longcaption {margin-left: 10%; + margin-right: 10%; + text-align: left; } + + .center {text-align: center; + margin-left: auto; + margin-right: auto; } + .center table { + margin-left: auto; + margin-right: auto; } + + .signature {font-variant: small-caps; + text-align: right;} + .smcap {font-variant: small-caps;} + + .figcenter {margin: auto; text-align: center;} + + .figleft {float: left; clear: left; margin-left: 0; margin-bottom: 1em; + margin-top: 1em; margin-right: 1em; padding: 0; text-align: center;} + + .figright {float: right; clear: right; margin-left: 1em; margin-bottom: 1em; + margin-top: 1em; margin-right: 0; padding: 0; text-align: center;} + + +--> +</style> +</head> + +<body> + + +<pre> + +The Project Gutenberg EBook of Scientific American Supplement, No. 711, +August 17, 1889, 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. 711, August 17, 1889 + +Author: Various + +Release Date: October 31, 2005 [EBook #16972] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + + + + +Produced by Juliet Sutherland and the Online Distributed +Proofreading Team at www.pgdp.net + + + + + + +</pre> + +<div class="center"><a href="./images/title.png"><img src="./images/title_th.png" alt="Issue Title" /></a></div> +<h1>SCIENTIFIC AMERICAN SUPPLEMENT NO. 711</h1> +<h2>NEW YORK, AUGUST 17, 1889.</h2> +<h4>Scientific American Supplement. Vol. XXVIII., No. 711.</h4> +<h4>Scientific American established 1845</h4> +<h4>Scientific American Supplement, $5 a year.</h4> +<h4>Scientific American and Supplement, $7 a year.</h4> +<hr /> + +<table summary="Contents" border="0" cellspacing="5"> +<tr> +<th colspan="2" align="center">TABLE OF CONTENTS.</th> +</tr> +<tr><td colspan="2"> </td><td>PAGE.</td> +</tr> + +<tr><td valign="top" align="left">I.</td><td align="left"><a href="#art01">AGRICULTURE.—How to Raise Turkeys.—A collection of hints +and suggestions on the raising of the delicate fowls, so often the +cause of trouble to farmers.</a></td><td>11364</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art02">Pear Duchesse D'Angouleme.—The history of the famous pear +tree, with hints as to its culture and general treatment.</a></td><td>11362</td> +</tr> + + +<tr><td valign="top" align="left">II.</td><td align="left"><a href="#art03">BIOLOGY.—Development of the Embryo.—A note of some interesting +biological researches.—By Prof. <span class="smcap">Preyer</span>, of Berlin.</a></td><td>11365</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art04">The "Hatchery" of the Sun Fish.—A curious incident in the +life history of the common sunfish.—1 illustration.</a></td><td>11363</td> +</tr> + +<tr><td valign="top" align="left">III.</td><td align="left"><a href="#art05">CHEMISTRY.—On Allotropic Forms of Silver.—By M. <span class="smcap">Carey +Lea.</span>—A continuation of this paper, containing one of the most +important researches in the history of silver, with statement of +interesting results attained.</a></td><td>11361</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art06">On the Occurrence of Paraffine in Crude Petroleum.—A valuable +contribution to the history of paraffine, with reference to petroleum +and ozokerite.</a></td><td>11361</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art07">Turpentine and its Products.—By <span class="smcap">Edward Davies.</span>—A resume +of the work done by chemists in the turpentine products.—The +different compounds produced therefrom.</a></td><td>11361</td> +</tr> + +<tr><td valign="top" align="left">IV.</td><td align="left"><a href="#art08">ELECTRICITY.—Electric Lighting at the Paris Exhibition.—The +Oerlikon works.—A very exhaustive exhibition of electric apparatus +described and illustrated.—12 illustrations.</a></td><td>11356</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art09">Magnetism in its Relation to Induced Electromotive Force and +Current.—By <span class="smcap">Elihu Thomson.</span>—A most impressive paper, bringing +the obscure laws of magnetic induction within the understanding +of all without the application of mathematics.—12 illustrations.</a></td><td>11354</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art10">The Ader Flourish of Trumpets.—One of the curiosities in +telephony from the Paris exhibition, by which sounds are transmitted +to a large audience.—4 illustrations.</a></td><td>11358</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art11">The Electric Motor Tests on the New York Elevated Railroad.—Abstracts +of tests which were recently made of the Daft motor +on the elevated railroad of this city.</a></td><td>11353</td> +</tr> + +<tr><td valign="top" align="left">V.</td><td align="left"><a href="#art12">ETHNOLOGY.—Ancient Lake Dwellings.—Interesting abstract of +what is known about lake dwellings, the history of their construction, +and the "finds" made on the sites by archæologists.</a></td><td>11363</td> +</tr> + +<tr><td valign="top" align="left">VI.</td><td align="left"><a href="#art13">FORESTRY.—Succession of Forest Growths.—A valuable paper +on forestry, treating of the evils done by man and a plea for the +necessity of intelligent treatment of our woods.</a></td><td>11362</td> +</tr> + +<tr><td valign="top" align="left">VII.</td><td align="left"><a href="#art14">HYGIENE AND MEDICINE.—Acetic Acid as a Disinfectant.—Use +of acetic acid in septic medical cases as a substitute for carbolic +acid and bichloride of mercury.</a></td><td>11365</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art15">Counter-Irritation in Whooping Cough.—By <span class="smcap">G.F. Inglott</span>, +M.D.—Application of irritants to the skin for curing the paroxysms +of whooping cough.</a></td><td>11365</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art16">On the Health Value to Man of the So-called Divinely Beneficent +Gift, Tobacco.—By J.M.W. <span class="smcap">Kitchen</span>, M.D.—The evils to +man and to the soil.—A formidable series of accusations well +expressed.</a></td><td>11365</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art17">Water as a Therapeutical Agent.—By F.C. <span class="smcap">Robinson</span>, M.D.—An +interesting resume of different applications of water in therapeutics.—Suggestions +of use for all households.</a></td><td>11364</td> +</tr> + +<tr><td valign="top" align="left">VIII.</td><td align="left"><a href="#art18">MILITARY ENGINEERING.—Gibraltar.—A history of this +important strategic position and of the different sieges the fortress +has undergone.</a></td><td>11352</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art19">Gibraltar and Neighborhood.—A consular report on the statistics +of the famous military station.</a></td><td>11352</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art20">The Defense of Gibraltar—Experimental Naval and Military +Operations.—Interesting series of operations recently carried out +under the shadow of the historic rock.—1 illustration.</a></td><td>11352</td> +</tr> + +<tr><td valign="top" align="left">IX.</td><td align="left"><a href="#art21">NAVAL ENGINEERING.—Clark's Gyroscopic Torpedoes.—A +recent torpedo, in which all the possible parts are made to rotate.—2 +illustrations.</a></td><td>11353</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art22">The First Steamboat on the Seine.—The Marquis de Jouffroy's +steamer of 1816.—1 illustration.</a></td><td>11353</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art23">The Franz Josef I., New War Ship.—Details of the dimensions +of the new Austrian ship.—Her armament, speed, armor, etc.</a></td><td>11353</td> +</tr> + +<tr><td valign="top" align="left">X.</td><td align="left"><a href="#art24">PHOTOGRAPHY.—Orthochromatic Photography.—By <span class="smcap">Oscar O. +Litzkow.</span>—The last developments in this interesting branch of +photographic art, with formulæ.</a></td><td>11360</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art25">Platinotype Printing.—A description of the most advanced +method of conducting the platinum print process.</a></td><td>11360</td> +</tr> + +<tr><td valign="top" align="left">XI.</td><td align="left"><a href="#art26">PHYSICS.—Iridescent Crystals.—By <span class="smcap">Lord Rayleigh</span>.—An abstract +of a lecture by the distinguished physicist, detailing some interesting +experiments applicable to the colored reflection observed +in crystals of chloride of potash.—1 illustration.</a></td><td>11366</td> +</tr> + +<tr> +<td></td> +<td align="left"><a href="#art27">Transmission of Pressure in Fluids.—By <span class="smcap">Albert B. Porter</span>.—An +apparatus for illustrating the laws of transmission of pressure +in fluids, suitable for lecture purposes.—1 illustration.</a></td><td>11362</td> +</tr> + +<tr><td valign="top" align="left">XII.</td><td align="left"><a href="#art28">TECHNOLOGY.—Notes on Dyewood Extracts and Similar Preparations.—By +<span class="smcap">Louis Siebold</span>.—The recent development in the +preparation of dyewood extracts, with notes of their adulterations.</a></td><td>11359</td> +</tr> + +</table> +<hr /> + +<div class="figcenter"><a name="Page_11351"></a> +<a href="./images/1.jpg"> +<img src="./images/1_th.png" alt="THE DEFENSE OF GIBRALTAR—EXPERIMENTAL NAVAL AND MILITARY OPERATIONS." title="GIBRALTAR" /> +</a><br /> +<span class="caption">THE DEFENSE OF GIBRALTAR—EXPERIMENTAL NAVAL AND +MILITARY OPERATIONS.</span> +</div> + +<h2><a name="Page_11352" id="Page_11352"></a><a name="art20" id="art20"></a>THE DEFENSE OF GIBRALTAR: EXPERIMENTAL NAVAL AND MILITARY +OPERATIONS.</h2> + + + +<p>A novel and interesting series of operations was carried out at +Gibraltar a few weeks ago, with a view to test the promptitude with +which the garrison of the famous Rock could turn out to resist a +sudden attack by a powerful iron-clad fleet. The supposed enemy was +represented by the Channel Squadron, under the command of Vice-Admiral +Baird, and consisting of H.M.S. Northumberland (flag ship), the +Agincourt, Monarch, Iron Duke, and Curlew. The "general idea" of the +operations was that a hostile fleet was known to be cruising in the +vicinity, and that an attack on the Rock might be made. The squadron +left Gibraltar and proceeded to the westward, returning to the +eastward through the Straits under cover of the night.</p> + +<p>The Governor of Gibraltar, General the Hon. Sir Arthur Hardinge, +issued orders for the whole garrison to stand to their arms at dawn, +and subsequent days, until the attack should be made; but by his +express command no batteries were to be manned, or any troops moved +from their alarm posts, until the signal was given that an attack was +imminent. The alarm signal ordered was that of three guns fired in +rapid succession from the Upper Signal Station on the summit of the +Rock, to be followed, after a short pause, by two more shots. It was a +matter of complete uncertainty as to the direction from which the +attack would be made.</p> + +<p>Every detail was carefully carried out, as if the impending attack was +a real affair. The telegraphic communication between the various parts +of the Rock was supplemented by signalers; arrangements were made for +the ready supply of reserve ammunition for all arms; and the medical +authorities established dressing stations, at numerous points of the +Rock, to render "first aid" to those who might chance to be numbered +among the "wounded." Day broke with a "Levanter," and the heavy clouds +hanging about rendered any distant view a matter of difficulty. +However, before it had become actually daylight the alarm guns gave +notice that the enemy had been sighted. The troops turned out with +great promptitude, being all at their assigned stations in less than a +quarter of an hour, and were shortly ordered to various points +commanding the east side of the Rock. As day broke, the hostile ships +were to be discerned steaming in single line ahead, from the +northeast, along the back of the Rock, and about 5,000 yards from it. +The flag ship, followed by the Monarch and the Agincourt, proceeded +toward Europa Point, while the Iron Duke and the Curlew stood close in +to the eastern beach, so as to engage the northern defenses of the +fortress. The first shot was fired by the flag ship, shortly before +six o'clock in the morning, at the southern defenses. It was replied +to, in less than three minutes, by the Europa batteries, and very +shortly the engagement became general. The plan of tactics employed by +the squadron was that of steaming rapidly up and down, and +concentrating their fire in turn on the various shore batteries. Later +on, the whole squadron assembled off Europa Point, and fired +broadsides by electricity as they steamed past at speed. The spectacle +at this moment was a very fine one, the roar of the heavy guns of the +ships being supplemented by the sharp, rapid report of the +quick-firing guns, which were supposed to be sending a storm of small +shell among the defenders of the Rock. The incessant rattle of the +ships' machine guns was also heard in the intervals between the +thundering broadsides of heavy ordnance. All the ships were, of +course, cleared for action, with topmasts and yards sent down, and it +is needless to say they looked exceedingly workmanlike and formidable.</p> + +<p>The various batteries on the Rock replied with great vivacity, and the +general effect produced as gun after gun was brought to bear on the +ships, and the white smoke wreathed itself round the many crags and +precipices of the grim old Rock, was a sight long to be remembered. +The exercise afforded to both branches of the service was undoubtedly +most instructive. Our illustration is a sketch by Captain Willoughby +Verner from one of the batteries above the Europa Flats, at which +point the governor took up his position to watch the +operations.—<i>Illustrated London News.</i></p> + +<hr /> + + + + +<h2><a name="art19" id="art19"></a>GIBRALTAR AND NEIGHBORHOOD.</h2> + +<h3>REPORT BY CONSUL SPRAGUE.</h3> + + +<p>Notwithstanding that the political situation of Europe seems to be +less threatening among its leading powers, still the uncertainty +prevalent among those who are generally considered the arbiters of +public affairs has had its influence in contracting the limits of +speculative adventure, thereby circumscribing the general course of +trade throughout the Mediterranean.</p> + +<p>In renewing to the department my reports upon the navigation and +general commerce of Gibraltar, I beg to state that there has been a +tolerably fair current business prevailing in American produce during +the past quarter, consisting chiefly in flour, tobacco, and refined +petroleum in cases, imported direct from New York.</p> + +<p>The steady demand for American petroleum confirms the fact that +Russian petroleum so far receives but little attention in this market +from the regular traders and consumers, so long as supplies from the +United States can be regularly imported at reasonable prices. It, +however, remains an open question, in the event of lower prices ruling +in the Russian petroleum regions, whether American supplies may not +later on experience some greater competitive foreign interference.</p> + +<p>According to the statistical data, steam vessels of all nationalities +have continued to make Gibraltar their port of call, not only for +orders, but also for replenishing their stock of fuel and provisions, +and in larger numbers than ever before, the number in 1888 having +reached 5,712 steam vessels, measuring in all 5,969,563 tons, while in +1887 the number was only 5,187 steam vessels, with an aggregate +tonnage of 5,372,962. This increase cannot but result in considerable +benefit to the coal and maritime traffic, which now forms the most +important portion of the general commerce of Gibraltar, in spite of +the keen competition it experiences from other British and foreign +coaling ports.</p> + +<p>Freights have also advanced in favor of steamship interests, which, +with higher prices in England for coal, have also caused an advance in +the price of coal at this port, to the benefit of the coal merchants +and others interested in this important trade. At present the ruling +price for steam coal is 24<i>s.</i> per ton, deliverable from alongside of +coal hulks moored in the bay. As near as I have been able to +ascertain, the quantity of coal sold in this market during the past +year for supplying merchant steam vessels has amounted to about +508,000 tons, which is an increase of about 20,000 tons over the year +1887.</p> + +<p>Notwithstanding that plans have already been submitted to the British +government for the construction of a dry dock in Gibraltar, the matter +remains somewhat in suspense, since it meets with some opposition on +the part of the British government, which, in face of the European +fever for general arming, seems more inclined to utilize in another +form the expense which such a work would entail upon the imperial +government, by replacing the obsolete ordnance recently removed from +this fortress and substituting new defenses and guns of the most +approved patterns, a matter which has evidently been receiving, for +some time past, the special attention of the British military +authorities, not doubting that the recent visit to the fortress of the +Duke of Cambridge has had some connection with it. In fact, it is +reported that the duke has already expressed the opinion that this +fortress requires a larger number of artillerymen than are quartered +here at present to man its batteries, and it would seem that this +recommendation is likely to be carried out.</p> + +<p>It is yet somewhat too early to venture an opinion regarding the +growing crops of cereals in this Spanish neighborhood, but the +agricultural and manufacturing interests in Spain have suffered so +much in the past years that the general feeling in Spain continues to +tend toward establishing increased restrictions against foreign +competition in her home markets. There is every probability that the +provinces of Malaga and Granada may shortly be granted the privilege +of cultivating the tobacco plant under government supervision, as an +essay. If properly managed, it may form an important and lucrative +business for those interested in land and agricultural pursuits.</p> + +<p>After many consecutive years of heavy outlays, difficulties, and +constant disappointments, a new English company has recently succeeded +in commencing the construction of a railway from the neighboring +Spanish town of Algeciras to join, via Ronda, the railway station of +Bobadilla, on the railroad line toward Malaga. It is presumed that +when this railroad will be in running order it will greatly benefit +this community, especially if the Spanish government should decide to +establish custom houses at Algeciras and the Spanish lines outside the +gates of this fortress, similar to those existing on the frontiers of +France and Portugal.</p> + +<p>That some idea may be formed of the constant important daily +intercourse which exists between this fortress and Spain, I may state +that late police statistics show that 1,887,617 passes were issued to +visitors entering this fortress on daily permits during the year 1888, +1,608,004 entering by the land route and 279,613 by sea. I must, +however, observe that the larger portion of these visitors consists of +laborers, coal heavers, market people, and others engaged in general +traffic.</p> + +<p>A new industry in cork has lately sprung up, in which leading Spanish +and native commercial firms in Gibraltar are directly interested to a +considerable extent. Extensive warehouses for the storing of cork wood +and machinery for the manufacture of bottle corks have recently been +established at the Spanish lines, about a mile distant from this +fortress, in Spanish territory, where large quantities of cork have +already been stored. The cork is obtained and collected from the +valuable trees, which are owned by the representatives of some of the +oldest nobility of Spain, who have sold the products of their +extensive woods to private individuals for periods reaching as far on +as ten years, for which concession large cash advances have already +been made. The woods commence at a distance of about twelve miles from +Gibraltar, and are of considerable extent.</p> + +<p>The railway now in course of construction passes through these woods, +which may ere long offer quite picturesque scenery for travelers, +especially when the cork trees are bearing acorns, which form the +principal food for the fattening of large herds of swine during +certain seasons of the year, in this way, also, contributing to the +value of this tree, which, like the other kinds of oak trees, is of +long and tardy growth. The tree from which the cork is obtained is +somewhat abundant in the mountainous districts of Andalusia. It grows +to a height of about 30 feet, and resembles the <i>Quercus ilex</i>, or +evergreen oak, and attains to a great age. After arriving at a certain +state of maturity it periodically sheds its bark, but this bark is +found to be of better quality when artificially removed from the tree, +which may be effected without injury to the tree itself. After the +tree has attained twenty-five years it may be barked, and the +operation is afterward repeated once in every seven years. The quality +of the cork seems to improve with the increasing age of the tree, +which is said to live over one hundred and fifty years. The bark is +taken off during July and August.</p> + +<p>Cork dust is also obtained from this cork wood, and is much used in +the packing of grapes, which fruit is largely shipped from the eastern +coast of Spain, especially from Almeria, during the vintage seasons, +for the American and British markets.—<i>Reports of U.S. Consuls.</i></p> + +<hr /> + + + + +<h2><a name="art18" id="art18"></a>GIBRALTAR.</h2> + + +<p>The point or rock known as Gibraltar is a promontory two and one-half +miles long and from a quarter to three-quarters of a mile wide. It +rises abruptly from the sandy shore to a height at its highest point +of 1,408 ft. It is composed of gray limestone, honeycombed with caves +and subterranean passages, some of which contain most beautiful +stalactites in the form of massive pillars.</p> + +<p>Gibraltar is emphatically a fortress, and in some respects its +fortifications are unique. On the eastern side the rock needs no +defense beyond its own precipitous cliffs, and in all other directions +it has been rendered practically impregnable. Besides a sea wall +extending at intervals round the western base of the rock, and +strengthened by curtains and bastions and three formidable forts, +there are batteries in all available positions from the sea wall up to +the summit, 1,350 feet above the sea, and a remarkable series of +galleries has been hewn out of the solid face of the rock toward the +north and northwest. These galleries have an aggregate length of +between two and three miles, and their breadth is sufficient to let a +carriage pass. Portholes are cut at intervals of twelve yards, so +contrived that the gunners are safe from the shot of any possible +assailants. At the end of one of the galleries hollowed out in a +prominent part of the cliff is St. George's Hall, 50 feet long by 85 +feet wide, in which the governor was accustomed to give fetes. +Alterations, extensions, and improvements are continually taking place +in the defensive system, and new guns of the most formidable sort are +gradually displacing or supplementing the old fashioned ordnance.</p> + +<p>The whole population of Gibraltar, whether civil or military, is +subjected to certain stringent rules. For even a day's sojourn the +alien must obtain a pass from the town major, and if he wish to remain +longer, a consul or householder must become security for his good +behavior. Licenses of residence are granted only for short +periods—ten, fifteen, or twenty days—but they can be renewed if +occasion require. Military officers may introduce a stranger for +thirty days. A special permit is necessary if the visitor wishes to +sketch.</p> + +<p>Though the town of Gibraltar may be said to date from the fourteenth +century, it has preserved very little architectural evidence of its +antiquity. Rebuilt on an enlarged and improved plan after its almost +complete destruction during the great siege, it is still, on the +whole, a mean-looking town, with narrow streets and lanes and an +incongruous mixture of houses after the English and the Spanish types. +As a proprietor may at any moment be called upon to give up his house +and ground at the demand of the military authorities, he is naturally +deterred from spending his money on substantial or sumptuous +erections. The area of the town is about one hundred acres.</p> + +<p>Gibraltar was known to the Greek and Roman geographers as Calpe or +Alybe, the two names being probably corruptions of the same local +(perhaps Phenician) word. The eminence on the African coast near +Ceuta, which bears the modern English name of Apes' Hill, was then +designated Abyla; and Calpe and Abyla, at least according to an +ancient and widely current interpretation, formed the renowned pillars +of Hercules (Herculis columnæ), which for centuries were the limits of +enterprise to the seafaring peoples of the Mediterranean world.</p> + +<p>The strategic importance of the rock appears to have been first +discovered by the Moors, who, when they crossed over from Africa in +the eighth century, selected it as the site of a fortress. From their +leader, Tarik Ibn Zeyad, it was called Gebel Tarik or Tarik's Hill; +and, though the name had a competitor in Gebel af Futah, or Hill of +the Entrance, it gradually gained acceptance, and still remains +sufficiently recognizable in the corrupted form of the present day. +The first siege of the rock was in 1309, when it was taken by Alonzo +Perez de Guzman for Ferdinand IV. of Spain, who, in order to attract +inhabitants to the spot, offered an asylum to swindlers, thieves, and +murderers, and promised to levy no taxes on the import or export of +goods. The attack of Ismail Ben Ferez, in 1315 (second siege), was +frustrated; but in 1333 Vasco Paez de Meira, having allowed the +fortifications and garrison to decay, was obliged to capitulate to +Mahomet IV. (third siege). Alphonso's attempts to recover possession +(fourth siege) were futile, though pertinacious and heroic, and he was +obliged to content himself with a tribute for the rock from Abdul +Melek of Granada; but after his successful attack on Algeciras in 1344 +he was encouraged to try his fortune again at Gibraltar. In 1349 he +invested the rock, but the siege (fifth siege) was brought to an +untimely close by his death from the plague in February, 1350. The +next or sixth siege resulted simply in the transference of the coveted +position from the hands of the King of Morocco to those of Yussef III. +of Granada; and the seventh, undertaken by the Spanish Count of +Niebla, Enrico de Guzman, proved fatal to the besieger and his forces. +In 1462, however, success attended the efforts of Alphonso de Arcos +(eighth siege), and in August the rock passed once more under +Christian sway. The Duke of Medina Sidonia, a powerful grandee who had +assisted in its capture, was anxious to get possession of the +fortress, and though Henry IV. at first managed to maintain the claims +of the crown, the duke ultimately made good his ambition by force of +arms (ninth siege), and in 1469 the king was constrained to declare +his son and his heirs perpetual governors of Gibraltar. In 1479 +Ferdinand and Isabella made the second duke Marquis of Gibraltar, and +in 1492 the third duke, Don Juan, was reluctantly allowed to retain +the fortress. At length, in 1501, Garcilaso de la Vega was ordered to +take possession of the place in the king's name, and it was formally +incorporated with the domains of the crown. After Ferdinand and +Isabella were both dead the duke, Don Juan, tried in 1506 to recover +possession, and added a tenth to the list of sieges. Thirty-four years +afterward the garrison had to defend itself against a much more +formidable attack (eleventh siege)—the pirates of Algiers having +determined to recover the rock for Mahomet and themselves. The +conflict was severe, but resulted in the repulse of the besiegers. +After this the Spaniards made great efforts to strengthen the place, +and they succeeded so well that throughout Europe Gibraltar was +regarded as impregnable.</p> + +<p>In the course of the war of the Spanish succession, however, it was +taken by a combined English and Dutch fleet under Sir George Rooke, +assisted by a body of troops under Prince George of Hesse-Darmstadt. +The captors had ostensibly fought in the interests of Charles Archduke +of Austria (afterward Charles III.), but, though his sovereignty over +the rock was proclaimed on July 24, 1704, Sir George Rooke on his own +responsibility caused the English flag to be hoisted, and took +possession in name of Queen Anne. It is hardly to the honor of England +that it was both unprincipled enough to sanction and ratify the +occupation and ungrateful enough to leave unrewarded the general to +whose unscrupulous patriotism the acquisition was due. The Spaniards +keenly felt the injustice done to them, and the inhabitants of the +town of Gibraltar in great numbers abandoned their homes rather than +recognize the authority of the invaders. In October, 1704, the rock +was invested by sea and land; but the Spanish ships were dispersed by +Sir John Leake, and the Marquis of Villadarias fared so ill with his +forces that he was replaced by Marshal Tesse, <a name="Page_11353" id="Page_11353"></a>who was at length +compelled to raise the siege in April, 1705. During the next twenty +years there were endless negotiations for the peaceful surrender of +the fortress, and in 1726 the Spaniards again appealed to arms. But +the Conde de la Torres, who had the chief command, succeeded no better +than his predecessors, and the defense of the garrison under General +Clayton and the Earl of Portmore was so effectual that the armistice +of June 23 practically put a close to the siege, though two years +elapsed before the general pacification ensued. The most memorable +siege of Gibraltar, indeed one of the most memorable of all sieges, +was that which it sustained from the combined land and sea forces of +France and Spain during the years 1779-1783. The grand attack on the +place was made on the 13th September, 1782, and all the resources of +power and science were exhausted by the assailants in the fruitless +attempt. On the side of the sea they brought to bear against the +fortress forty-six sail of the line and a countless fleet of gun and +mortar boats. But their chief hope lay in the floating batteries +planned by D'Arcon, an eminent French engineer, and built at the cost +of half a million sterling. They were so constructed as to be +impenetrable by the red hot shot which it was foreseen the garrison +would employ; and such hopes were entertained of their efficiency that +they were styled invincible. The Count D'Artois (afterward Charles X.) +hastened from Paris to witness the capture of the place. He arrived in +time to see the total destruction of the floating batteries and a +considerable portion of the combined fleet by the English fire. +Despite this disaster, however, the siege continued till brought to a +close by the general pacification, February 2, 1783. The history of +the four eventful years' siege is fully detailed in the work of +Drinkwater, who himself took part in the defense, and in the life of +its gallant defender Sir George Augustus Eliott, afterward Lord +Heathfield, whose military skill and moral courage place him among the +best soldiers and noblest men whom Europe produced during the 18th +century.</p> + +<p>Since 1783 the history of Gibraltar has been comparatively uneventful. +In the beginning of 1801 there were rumors of a Spanish and French +attack, but the Spanish ships were defeated off Algeciras in June by +Admiral Saumarez. Improvements in the fortifications, maintenance of +military discipline, and legislation in regard to trade and smuggling +are the principal matters of recent interest.</p> + +<hr /> + + + + +<h2><a name="art23" id="art23"></a>THE FRANZ JOSEF I., NEW WAR SHIP.</h2> + + +<p>Another addition was made to the Austrian navy by the launching on May +18 of the ram cruiser Franz Josef I. from the yards of S. Rocco in the +Stabilimento Tecnico Triestino. Her dimensions are: Length (over all), +103.7 meters; length (between perpendiculars), 97.9 meters; greatest +breadth (outside), 14.8 meters; draught (bow), 5.28 meters; draught +(stern), 6.05 meters; displacement on the construction water line, +4,000 tons. The armament consists of two 24-centimeter and six +15-centimeter Krupp breech loaders of 35 caliber length, two +7-centimeter Uchatius guns as an armament for the boats and for +landing purposes, eleven Hotchkiss quick-firing guns, and several +torpedo-launching ports; indicated horse power with natural draught +6,400, speed 17.5 knots; with forced draught 9,800, speed 19 knots.</p> + +<p>The ship is built of steel, and constructed according to the "double +bottom" system along the engine, boiler, and ammunition rooms. The +vaulted armor deck, extending 1.25 meters below the water line and +protecting the most vital parts of the ship, is 0.057 meter thick. +There are more than 100 water tight compartments below and above the +deck. A protecting belt of "cellulose" is provided for the engines and +boilers, extending from the armor deck downward.</p> + +<p>The two main guns, placed on Krupp's hydraulic carriages, occupy +positions in front and rear, and are protected by stands 0.09 meter +thick and 1.60 meters high. They fire <i>en barbette</i> with a lateral +range each of 260 degrees at bow and stern—<i>i.e.</i>, 130 degrees on +either of the broadsides. The weight of the barrel of the gun is 25 +tons, that of the steel shell 215 kilogrammes (about 430 lb.), that of +the brown powder charge 100 kilogrammes; initial velocity of +projectile, 610 meters; penetration, 0.524 meter iron; longest range, +17 kilometers (about 10½ English miles); range at 15 deg. elevation, +10 kilometers. The six 15-centimeter guns are placed in a kind of +machicouli arrangement in two tiers on each of the broadsides, so that +always four guns can fire in the direction of the keel to the front +and rear. The weight of the barrel of the gun is each six tons, that +of the steel shells 51 kilogrammes, that of the charge 22 kilogrammes; +initial velocity, 610 meters.</p> + +<p>The 11 quick-firing guns are partly placed along the broadsides, +partly in the masts, of which there are two. The triple expansion +engines, having each a bronze screw of 4.42 meters diameter, with +three blades and a rise of 6.3 meters, make with natural draught 105 +revolutions, and with forced draught 120. The pumping apparatus are +able to lift in one hour 400 tons of water. The front boiler room +contains a special cylindrical boiler for the working of the +electrical apparatus, for hydraulic pumps of the artillery service, +for anchor windlasses, ventilators, fire engines, etc. The whole +engines weigh 890 tons. The bunkers have a capacity for 660 tons of +coal, which allows for a run of 4,500 sea miles.</p> + +<hr /> + + + + +<h2><a name="art21" id="art21"></a>CLARK'S GYROSCOPIC TORPEDOES.</h2> + + +<p>Figs. 1 and 2 represent, upon a scale of about 1/10, two types of +torpedoes, the greatest number possible of the parts of which are made +revolvable, so as to render the torpedoes as dirigible as the gyrating +motion permits of.</p> + +<p>Fig. 1 represents an electric torpedo actuated by accumulators, A A, +keyed upon the shaft, and revolving along with the gearings. At the +beginning of the running, the accumulators are not all coupled, but +under the action of a clockwork movement which is set in motion at the +moment of starting, metallic brushes descend one after another upon +the collectors, B, and set in action new batteries for keeping +constant or, if need be, accelerating the speed at the end of the +travel.</p> + +<div class="figcenter"> +<img src="./images/3a.png" width="600" height="101" alt="Fig. 1." title="" /><br /> +<span class="caption">Fig. 1.</span> +</div> + +<div class="figcenter"> +<img src="./images/3b.png" width="600" height="104" alt="Fig. 2. CLARK'S GYROSCOPIC TORPEDOES." title="" /><br /> +<span class="caption">Fig. 2.<br />CLARK'S GYROSCOPIC TORPEDOES.</span> +</div> + +<p>Fig. 2 represents an air torpedo proposed by the same inventor. The +air reservoir, C, revolves along with the gearings under the action +of the pneumatic machine, D. The central shaft is hollow, so as to +serve as a conduit. The admission of air into the slide valve of the +machine is regulated by a clockwork which actuates a slide in an +aperture whose form and dimensions are so calculated that the speed +remains as constant as possible toward the end of the travel.</p> + +<p>The trajectory of the two torpedoes is regulated by a cylindrical +bellows, F, which gives entrance to the sea water. The springs shown +in the figure balance the hydraulic pressure. The tension of these +springs is regulated by the rod, H, according to the indications of +the scale of depths, I.</p> + +<p>When the torpedo reaches too great a depth, the action of the springs +can no longer balance the increase of the hydraulic pressure, and the +accumulation of the charge in the rear causes the front to rise toward +the surface. When the torpedo reaches the surface, a contrary action +is produced.—<i>Revue Industrielle.</i></p> + +<hr /> + + + + +<h2><a name="art22" id="art22"></a>THE FIRST STEAMBOAT ON THE SEINE.</h2> + + +<div class="figcenter"> +<a href="./images/3c.png"> +<img src="./images/3c_th.png" alt="FIRST STEAMBOAT BUILT ON THE SEINE." title="" /> +</a><br /> +<span class="caption">FIRST STEAMBOAT BUILT ON THE SEINE.</span> +</div> + +<p>The accompanying engraving represents the remarkable steamboat that +the unfortunate Marquis de Jouffroy constructed at Paris in 1816, +after organizing a company for the carriage of passengers on the +Seine. De Jouffroy, as well known, made the first experiment in steam +navigation at Lyons in 1783, but the inventor's genius was not +recognized, and he met with nothing but deception and hostility. With +the obstinacy of men of conviction, he did not cease to prosecute his +task. He assuredly had an inkling of the future in store for the +invention that he was offering to humanity.</p> + +<p>The paddle wheel boat that he constructed at Paris in 1816 did not +succeed any better than its predecessors; it was remarkable +nevertheless in appearance and structure.</p> + +<p>The engine was forward, as shown in the engraving, which is copied +from a composition of Dubucourt's.</p> + +<p>The company organized by the marquis was ruined, and, as well known, +the unfortunate inventor himself died in poverty in 1832, at the age +of eighty-one years.—<i>La Nature.</i></p> + +<hr /> + + + + +<h2><a name="art11" id="art11"></a>THE ELECTRIC MOTOR TESTS ON THE NEW YORK ELEVATED RAILROAD.</h2> + + +<p>The American Institute of Electrical Engineers at its last meeting of +the season, held June 25, again considered the subject of electrical +traction, the paper presented by Mr. Leo Daft being based upon some +recent electrical work on the elevated railroads and its bearing on +the rapid transit problem. The <i>Railroad Gazette</i> gives the following +abstract:</p> + +<div class="note"> +<p> + He introduced the subject with a tribute to the efficiency of + the elevated railroad system as it is now operated by steam, + with special reference to that section of it known as the Ninth + Avenue line, upon which his experiments with the electric motor + have been conducted, over which passengers are now conveyed a + distance of five miles in 26 minutes for five cents, which he + considered the best and cheapest municipal rapid transit in the + world, and which is operated with a higher degree of safety than + any other railroad in the world making an equal number of stops + per 100 miles. On a recent holiday, April 30 last, 835,720 + passengers were carried upon the entire system without + noticeable detention or accident. The rapidly increasing traffic + makes the demand for better facilities a pressing one, and as + the average half million now carried daily will soon become a + million, it appears doubtful if any method can be devised of + providing for the growth by the use of steam motors on the + present structures, which are now taxed to their utmost. To the + mind of the mechanical engineer, having in view the ordinary + coefficients of tractive ability, there is no remedy for this. + The speaker stated that these coefficients were not entirely + trustworthy. He reiterated his previously expressed opinion, + based on frequent experiments, that there is a decided increase + in traction gained by the passage of the electric current from + the wheels to the rails, giving the details of one test where a + motor with a load making a total of 600 lb. climbed a gradient + of 2,900 ft. per mile, starting from a state of rest. He stated + that some of those people who had ridiculed his statements had + finally admitted that they were true.</p> + +<p> The motor Ben Franklin, which had been used in making these + tests on the elevated roads, weighed 10 tons, and performed + service nearly equal to the steam motors weighing 18 tons. The + object of these tests was the determination of coal economy. + Tests with a Prony brake showed that the motor developed 128 + H.P. The piece of track on which the experiments were conducted + embraced 2,200 ft. of level track and 1-8/10 miles of gradients, + varying from 11-3/10 to 98-7/10 ft. per mile, while at Thirtieth + street the station is at the foot of the steepest grade, thus + testing to the utmost the tractive capacity of the motor. The + experiments were begun in October, 1888, and carried on between + the hours of 9 P.M. and 4 A.M., beginning with one or two cars, + the load being increased nightly until it was finally made up of + eight coaches of 12 tons each, which were hauled up the 98 ft. + grade at a speed of 7½ miles per hour, the entire distance being + covered at the rate of 14-6/10 miles per hour. The maximum speed + obtained on level with that train was 16.36 miles per hour. + Seventy trips were subsequently made with a 70 ton train + operated between the steam trains under 3 minutes headway, but + the work was considered too critical on account of the absence + of suitable brakes. A number of experiments made about this time + showed that the mean speed with a three-car train running + express on the up-town track was about 24 miles per hour, + although the ability of the motor on a level with a similar + train was nearly 28 miles per hour. This, however, was not the + maximum speed, as the level track was not long enough to permit + of its attaining the highest rate. It was the opinion of the + speaker, however, that the speed attained could not be exceeded + with prudence on the elevated structure.</p> + +<p> The measurements of speed were made by dividing the track into + 19 sections of 500 ft., each section being provided with a + circuit-closing plate connected with a chronograph which was + carefully tested. The indicator cards were taken at the central + station by Mr. Idell and his assistants, and the dynamometer + used was of the liquid type made by Mr. Shaw, of Philadelphia. + The diagrams prepared from the data obtained were then explained + by the speaker, who stated that there was not a marked + difference between the 10 ton motor and the 18 ton locomotive in + the initial effort on the level, as will be seen by comparing a + run observed by a railroad officer on March 9 with a steam motor + and a load of about 57½ tons. The steam motor required 1 min. + and 29 sec. to make the distance from 14th to 23d streets, while + the electric motor with a train of 70 tons made the same trip in + 1 min. and 50 sec.; the absence of <a name="Page_11354" id="Page_11354"></a>power brakes compelled the + current to be taken off at 19th street, while it was probable + that the throttle of the steam locomotive was not closed until + it reached 23d street, this being the usual practice. The data + obtained in these experiments shows that 29,940 h.p. is required + to operate the Ninth avenue railroad for the 16 hours' service, + or an average of 1,871 h.p. per hour, or 2,181 h.p., adding + station friction. The varying requirements of the traffic during + the day shows that the service could be advantageously divided + up between four stationary engines of 800 h.p. each, there being + but five hours of the day when all of them would be required. + The fuel consumption per day, allowing 22 lb. of coal per h.p. + per hour at $2.25 per ton, would make a total of $92.25 per diem + for fuel, the coal being a mixture deliverable at the dock for + about $1.80 per ton. The weight of coal used for the present + locomotives is about the same, viz., 40 tons per day, but + practice has shown it to be most economical to use coal of the + best quality, costing $5 per ton, making the cost of fuel about + double that required for the electric system. Without entering + into other economies which the speaker claimed were in favor of + electricity, and ignoring the plan suggested by Sir William + Siemens of braking the train by converting the motor into a + dynamo and thus utilizing the energy of momentum, he believed + that the economy in fuel alone was sufficient to prove that the + application of power by electricity was preferable to direct + steam propulsion for the elevated railroad service.</p> +</div> + +<hr /> + + + + +<h2><a name="art09" id="art09"></a>MAGNETISM IN ITS RELATION TO INDUCED ELECTROMOTIVE FORCE AND +CURRENT.<a name="FNanchor_1" id="FNanchor_1"></a><a href="#Footnote_1"><sup>1</sup></a></h2> + +<h3>By <span class="smcap">Elihu Thomson</span>.</h3> + +<p>There is perhaps no subject which at the present time can have a +greater interest to the physicist, the electrician, and the electrical +engineer than the one which heads this paper. The advances which have +been made in the study from its purely theoretical or scientific side, +and the great technical progress in the utilization of the known facts +and principles concerning magnetic inductions, can but deepen and +strengthen that interest.</p> + +<p>On the side of pure theory we find the eager collection of +experimental data to be submitted to the scrutiny of the ablest and +brightest minds, to be examined and reasoned upon with the hope of +finding some clew to satisfying explanations, and on the side of +practice we find the search for new facts and relations no less +diligent, though often stimulated by practical problems presented for +solution. Indeed, the urgency for results is often the greater on the +practical side, for theory can wait, practice cannot, at least in the +United States.</p> + +<p>We must look for continued triumphs in both directions, and the most +welcome of all will be the framing of a theory or explanation which +will enable us to interpret magnetic and electric phenomena. The +recent beautiful experiments of Hertz on magnetic waves have opened a +fertile region for investigation.</p> + +<p>It would seem that the study of magnetism and electricity will give us +the ability to investigate the ether of space, which medium has been +theorized upon at great length, with the result of leaving it very +much where it was before, a mysterious necessity.</p> + +<p>Faraday says, speaking of magnetism:</p> + +<div class="note"> +<p> "Such an action may be a function of the ether, for it is not at + all unlikely that if there be an ether it should have other uses + than simply the conveyance of radiations." 3,075. Vol. III., + Exp. Res.</p> + +<p> "It may be a vibration of the hypothetical ether, or a state of + tension of that ether equivalent to either a dynamic or a static + condition," etc. 3,263. Vol. III., Exp. Res.</p> +</div> + +<p>Faraday again says, speaking of the magnetic power of a vacuum:</p> + +<div class="note"> + "What that surrounding magnetic medium deprived of all material + substance may be I cannot tell, perhaps the ether." 3,277. Vol. + III., Exp. Res. +</div> + +<p>Modern views would seem to point that through a study of magnetic +phenomena we may take a feeble hold upon the universal ether. +Magnetism is an action or condition of that medium, and it may be that +electrical actions are the expression of molecular disturbances +brought about by ether strains or interferences. The close relations +which are shown to exist between magnetism and light tend to +strengthen such views. Indeed, it would not be too much to expect that +if the mechanics of the ether are ever worked out, we should find the +relation between sensible heat and electric currents to be as close as +that of light to magnetism, perhaps find ultimately the forms of +matter, the elements and compounds to be the more complex +manifestations of the universal medium—aggregations in stable +equilibrium. It is a difficult conception, I confess, and a most +shadowy and imperfect one, yet facts and inferences which favor such +views are not wanting.</p> + +<p>Our science of electricity seems almost to be in the same condition +that chemistry was before the work of Lavoisier had shed its light on +chemical theory. Our store of facts is daily increasing, and +apparently disconnected phenomena are being brought into harmonious +relation. Perhaps the edifice of complete theory will not be more than +begun in our time, perhaps the building process will be a very gradual +one, but I cannot refrain from the conviction that the intelligence of +man will, if it has time, continue its advance until such a structure +exists.</p> + +<p>I have been led to make these general allusions to electrical theory +in order to emphasize the fact that in the present paper no unraveling +of the mystery is to be attempted, but rather the presentation of some +few considerations upon a subject of absorbing interest.</p> + +<p>The conception of Faraday in regard to the existence of lines of +magnetic force representing directions of magnetic strain or tension +in a medium has not only lost nothing of its usefulness up to the +present time, but has continually been of great service in the +understanding of magnetic phenomena. We need spend no time in showing, +as Faraday and others have done, that these lines are always closed +circuits, polarized so that the direction of the lines cannot be +reversed without reversal of the actions. Nor need we take time to +show that in any medium the lines are mutually repellent laterally if +of the same direction of polarization. Opposing this tendency to +separation or lateral diffusion of magnetic force is the strong +apparent tendency of the lines to shorten themselves in any medium. +These actions are distributed by the presentation of a better medium, +as iron instead of space or air. Lines of force will move into the +better medium, having apparently the constant tendency to diminish the +resistance in their paths.</p> + +<p>The peculiar and mysterious nature of media, such as iron, is to +permit an extraordinary crowding of lines on account of slight +resistance to their passage through it. We need not, in addition, do +more than refer to the other well-known facts of an electric current +developing magnetic lines encircling the conductor, as being the +general type, which includes all forms of magnetic field or +electro-magnets, sustained by currents, and the fact of a development +when magnetic lines or circuits and material masses are in relative +movement of electromotive forces transversely to the direction of the +lines of magnetism, and also transversely to the direction of relative +movement, as in the case of electric conductors traversing or cutting +through a field, or of a field traversing or being moved across a +conductor. We must not forget that even insulators, as well as +conductors, cutting lines of force, have the electromotive force +developed in them. The action simply develops potential difference, +and this generates the current where a circuit exists. While we are in +the habit of saying that a conductor moved across a field of lines, or +<i>vice versa</i>, generates electric current, I think the statement +incomplete. The movement only sets up a potential difference, and the +power expended in effecting the movement generates C × E. The current +is energy less the potential, or the energy expended gives the two +effects of potential or pressure and current or rate of movement. +Consequently an insulator, or an open-circuited conductor, traversing +a field, consumes no energy, potential difference only being produced. +Nevertheless, as will be shown, the magnetic circuits or lines +themselves may furnish the energy for their own movement across a +conductor, and so develop current as well as potential.</p> + +<p>This occurs in the effort of lines to shorten their paths, to lessen +their density, to pass to better media. Indeed, a close examination +will show that wherever power is expended in developing current in a +circuit, cutting lines of force, the energy expended is first employed +in stretching the lines, which thus receive the energy required to +permit them, in shortening, to cut the conductor and set up currents +in the electric circuit in accordance with the potential difference +developed in that circuit and its resistance.</p> + +<p>I think we may also say, though I do not remember to have seen the +statement so put, that whenever electric potential is set up +inductively, as in self-induction, mutual induction, induction from +one circuit to another, and induction from magnets or magnetic field, +it is set up by the movement of lines of force laterally across the +body, mass or conductor in which the potential is developed, and that +whenever current is set up in a wire or an existing current prolonged, +or an existing current checked by induction, self-induction, or +induction from magnets, the action is a transfer of energy, +represented by strained lines of force shortening or lessening their +resistance, or lengthening and increasing the resistance in their +paths. The magnetic field is like an elastic spring—it can in one +condition represent stored energy—it can be strained and will store +energy—it can be made to relieve its strain and impart energy.</p> + +<div class="figright" style="width: 297px"> +<img src="./images/4.png" width="297" height="300" alt="Fig. 1." title="" /> +<span class="caption">Fig. 1.</span> +</div> + +<p>Let us examine some known phenomena in this light. Take the case of a +simple wire, conveying current, say, in a line away from observer, +Fig. 1. There exists a free field of circular magnetism (so called), +shading off away from the wire, and which is represented by concentric +circles of increased diameter. The superior intensity or strength of +the lines near the wire may also be represented by their thickness. +This is often shown also by crowding the lines near the wire, though I +am disposed to regard Fig. 1 as more nearly expressing the condition, +unless we are to regard the lines as simply indicating a sort of +atmosphere of magnetic effect whose density becomes less as we proceed +outward from the wire, in which case either form of symbol suffices. +The direction of polarization of the lines may be indicated by an +arrow head pointing in a direction of right-handed rotation in the +path of the lines. This is the typical figure or expression for all +forms of simple magnetic circuit—the form of the lines, their length, +position, density, will depend on the shape of the conductor or +conductors (when more than one) and the materials surrounding or in +proximity to the wire or wires.</p> + +<p>If the current traversing the conductor is constant, the magnetic +field around it is stable and static, unless other influences come in +to modify it. The cutting off of the current is followed by +instability of the field whereby it can and must produce dynamic +effects. I say <i>must</i> because the field represents stored energy, and +in disappearing <i>must</i> give out that energy. To throw light on this +part of the subject is one of the objects of the present paper. +Cutting off the current supply in the case assumed leaves the +developed magnetic lines or strains unsupported. They at once shorten +their paths or circuits, collapsing upon the conductor as it were, and +continuing this action, cut the section of the conductor, and +apparently disappear in magnetic closed circuits of infinitesimal +diameter but of great strength of polarization. It appears to me that +we must either be prepared to give up the idea of lines of force or +take the position that the magnetic circuits precipitate themselves in +shortening their circuits and disappearing upon and cut the conductor. +It was Hughes who put forward the idea that an iron bar in losing its +apparent magnetism really short-circuits the lines in itself as +innumerable strongly magnetized closed circuits among the molecules. +In becoming magnetic once more these short circuits are opened or +extended into the air by some source of energy applied to strain the +lines, such as a current in a conductor around the bar.</p> + +<p>May not this idea be extended, then, to include the magnetic medium, +the ether itself? Does it contain intensely polarized closed circuits +of magnetism which are ready to be stretched or extended under certain +conditions by the application of energy, which energy is returned by +the collapse of the extended circuits? This is doubtless but a crude +expression of the real condition of things, for the lines are only +symbols for a condition of strain in a medium which cannot be +represented in thought, as we know nothing of its real nature. There +is one point in this connection which I must emphasize. The strained +lines, Fig. 1, are indications of stored energy in the ether, and the +lines <i>cannot</i> disappear without giving out that energy. Ordinarily, +it makes its appearance as the extra current, and adds itself so as to +prolong the current which extended the lines when an attempt is made +to cut off such current. Were it conceivable that the current could be +cut off and the wire put on open circuit while the lines still +remained open or strained, the energy must still escape when the field +disappears. It would then produce such a high potential as to be able +to discharge from the ends of the conductor, and if the conductor were +of some section, part of the energy would be expended in setting up +local currents in it. The field could not disappear without an outlet +for the energy it represents. But we cannot cut off a current in a +wire so as to leave the wire on open circuit with the lines of the +magnetic circuit remaining around it without iron or steel or the like +in the magnetic circuit. We can approach that condition, however, by +breaking the circuit very quickly with a condenser of limited capacity +around the break. This is done in the Ruhmkorff coil primary; the +condenser forms a sort of blind alley for the extra current on its +beginning to flow out of the primary coil. But the condenser charges +and backs up and stops the discharge from the primary, even giving a +reverse current. The lines of magnetic force collapse, however, and +have their effect in the enormous potential set up in the secondary +coil.</p> + +<p>Take away the secondary coil so as to stop that outlet, the energy +expends itself on the iron core and the primary coil. Take away the +iron core, and the energy of magnetization of the air or ether core +expends itself on the wire of the primary and, possibly, also on the +dielectric of the condenser to some extent. The extra current becomes +in this instance an oscillatory discharge of very high period back and +forth through the primary coil from the condenser, until the energy is +lost in the heat of C<sup>2</sup> × R. This conversion is doubtless rendered +all the more rapid by uneven distribution of current and eddy current +set up in the wire of the coil.</p> + +<p>The considerations just given concern the loss of field or the +shortening and apparent disappearance of the magnetic lines or +circuits, as giving rise to the self-induction or increased potential +on breaking. Where the energizing current is slowly cut off or +diminished the energy is gradually transferred to the wire in +producing elevation of potential during the decrease; and the collapse +and cutting of the wire by the collapsing circuits or lines is then +only more gradual.</p> + +<p>Let the current be returned to the wire after disappearance of +magnetism, and the lines again seem to emanate from the wire and at +the same time cut it and produce a counter potential in it, which is +the index of the abstraction of energy from the circuit, and its +storing up in the form of elastically strained lines of magnetism +around the conductor. The effect is that of self-induction on making +or upon increase of current, the measure of the amount being the +energy stored in the magnetic circuits which have been extended or +opened up by the current. The greater the current and the shorter the +path for the lines developed around the axis of the conductor, the +greater the energy stored up. Hence, a circular section conductor has +the highest self-induction, a tube of same section less as its +diameter increases, a flat strip has less as its width increases and +thickness diminishes, a divided conductor much less than a single +conductor of same shape and section. Separating the strands of a +divided conductor increases the length of magnetic paths around it, +and so diminishes the self-induction. A striking instance of this +latter fact was developed in conveying very heavy alternating currents +of a very low potential a distance of about three feet by copper +conductors, the current being used in electric welding operations.</p> + +<p>The conductors were built up of flat thin strips of copper for +flexibility. When the strips were allowed to lie closely together, the +short conductor showed an enormous self-induction, which cut down the +effective potential at its ends near the work. By spreading apart the +strips so as to lengthen a line around the conductor, the +self-induction could be easily made less than 35 per cent. of what it +had been before. The interweaving of the outgoing and return conductor +strands as one compound conductor gets rid almost entirely of the +self-inductive effects, because neither conductor has any free space +in which to develop strong magnetic forces, but is opposed in effect +everywhere by the opposite current in its neighbor.</p> + +<p>Where a number of conductors are parallel, and have the same direction +of current, as in a coil or in a strand, it is evident that statically +the conductor may be considered as replaceable by a single conductor +with the same external dimensions and same total current in the area +occupied, the magnetic forces or lines surrounding them being of same +intensity. But with changing current strength the distribution of +current in the conductor has also a powerful effect on the energy +absorbed or given out in accordance with the magnetism produced. Hence +the self-induction of a strand, coil or conductor of the same section +varies with the rapidity of current changes, owing to the conduction +being uneven.</p> + +<p>The uneven distribution of current, or its tendency to flow on the +outer parts of a conductor when the rate of variation or alternation +is made great, is in itself a consequence of the fact that less energy +is transferred into magnetism in this case than when the current flows +uniformly over the section, or is concentrated at the center. In other +words, when a uniform current traverses a conductor of the same +section, the circular magnetism, or surrounding magnetic lines, are to +be <a name="Page_11355" id="Page_11355"></a>found not only outside the conductor, but also beneath its +exterior. Since in forming these lines on passage of current the +middle of section would be surrounded by more lines than any other +part of the conductor, the current tends to keep out of that part and +move nearer the exterior in greater amount. Hence, in rapidly +alternating currents the conductor section is practically lessened, +being restricted largely to the outer metal of the conductor. If the +round conductor, Fig. 2, were made of iron, the magnetism interior to +it and set up by a current in it would be very much greater, the +section of the conductor being filled with magnetic circuits or lines +around the center. The total magnetism, external and internal, would +be much greater in this case for a given current flow, and the energy +absorbed and given out in formation and loss of field or the +self-induction would be much increased. This could, however, be +greatly diminished by slitting the conductor radially or making it of +a number of separate wires out of lateral magnetic contact one with +the other, Fig. 3. In these cases the resistance of the interior +magnetic circuits would be increased, as there would be several breaks +in the continuity around the center of the conductor. The total +magnetism which could be set up by a current would be lessened, and +the self-induction, therefore, lessened.</p> + +<div class="figcenter"> +<img src="./images/5a.png" alt="Fig. 2." title="" /><br /> +<span class="caption">Fig. 2.</span> +</div> + +<div class="figcenter"> +<img src="./images/5b.png" alt="Fig. 3." title="" /><br /> +<span class="caption">Fig. 3.</span> +</div> + +<p>The moment we begin the bringing of iron into proximity with an +electric conductor conveying current, we provide a better medium for +the flow or development of magnetic lines or circuits. In other words, +the lines may then be longer, yet equally intense, or more lines may +be crowded into a section of this metal than in air or space. Figs. +4<i>a</i>, 4<i>b</i>, 4<i>c</i> show the effect brought about by bringing iron of +different forms near to the conductor.</p> + +<div class="figcenter"> +<img src="./images/5c.png" alt="Fig. 4a, 4b, 4c" title="" /><br /> +<span class="caption">Figs. 4.</span> +</div> + + +<p>It shows, in other words, the development of the ordinary +electro-magnet of the horseshoe form, and the concentration of the +lines in the better medium. The lines also tend to shorten and +diminish the resistance to their passage, so that attraction of the +iron to the conductor takes place, and if there is more than one piece +of iron, they tend to string themselves around the conductor in +magnetic contact with one another.</p> + +<p>When copper bars of 1 inch diameter are traversed by currents of +40,000 to 60,000 amperes, as in welding them, the magnetic forces just +referred to become so enormous that very heavy masses of iron brought +up to the bar are firmly held, even though the current be of an +alternating character, changing direction many times a second.</p> + +<div class="figleft" style="width: 173px;"> +<img src="./images/5d-5.png" width="173" height="194" alt="Fig. 5" title="" /> +<span class="caption">Fig. 5.</span> +</div> + + +<p>When a conductor is surrounded by a cast iron ring, as in Fig. 5, the +current in such conductor has an excellent magnetic medium surrounding +it. A large amount of energy is then abstracted on the first impulse +of current, which goes to develop strong and dense magnetic lines +through the iron ring and across the gap in it. On taking off the +current the energy is returned as extra current, and its force is many +times what would be found with air alone surrounding the conductor. We +have then greatly increased the self-induction, the storing of energy +and opposition to current flow at the beginning, the giving back of +energy and assistance to the current flow on attempting to remove or +stop the current. Let us now complete the ring, by making it of iron, +endless, Fig. 6, with the conductor in the middle.</p> + +<div class="figright" style="width: 170px;"> +<img src="./images/5d-6.png" width="173" height="171" alt="Fig. 6" title="" /> +<span class="caption">Fig. 6.</span> +</div> +<p>We now find that on passing current through the conductor it meets +with a very strong opposing effect or counter potential. The evolution +of magnetic lines, or the opening out of magnetic circuits, goes on at +a very rapid rate. Each line or magnetic circuit evolved, and cutting +the conductor, flies at once outward, and locates itself in the iron +ring. This ring can carry innumerable lines, and they do not crowd one +another. It permits the lines even to lengthen in reaching it, and +yet, on account of its low resistance to their passage, the +lengthening is equivalent to their having shortened in other media. We +will suppose the current not sufficient to exhaust this peculiar +capacity for lines which the iron has. Equilibrium is reached, the +conductor has opened up innumerable closed circuits, and caused them +to exist in the ring still closed; but in iron, not space or ether +merely. The current passing has continued its action and storage of +energy until to emit another line in view of the resistance now found +in the crowded iron ring is impossible.</p> + +<p>Now let us cut off the current. We are surprised to find a very weak +extra current, a practical absence of self-induction on breaking, or, +at least, a giving out of energy in nowise comparable to that on +making. Let us put on the current as it was before. Another curious +result. But little self-induction now on making energy not absorbed.</p> + +<p>Now cut off the current again. Same effect as before. Now let us put +on the current reversed in direction. At once we find a very strong +counter potential or opposing self-induction developed.</p> + +<p>The ring had been polarized, or retained its magnetic energy, and we +are now taking out one set of lines and putting in reversely polarized +lines of force. This done, we break the reversed current without much +effect of self-induction. The ring remains polarized and inert until +an opposite flow of current be sent through. Iron is then a different +medium from the ether.</p> + +<p>The ring once magnetized must, in losing its magnetism, permit a +closure of the lines by shortening. This involves their passage from +the iron across the space in the center of the ring, notwithstanding +its great resistance to the lines of force. As passage from iron to +air is equivalent to lengthening of the lines, it is readily seen that +such lengthening may oppose more effect than a slight shortening due +to leaving iron, for air or space may give in provoking a closure and +disappearance of the lines. Looked at from another standpoint, the +lines on the iron may actually require a small amount of initial +energy to dislodge them therefrom, so that after being dislodged they +may collapse and yield whatever energy they represent.</p> + +<p>I must reserve for the future further consideration of the iron ring, +but in thinking upon this matter I am led to think that the production +of a magnetic line in an iron ring around a conductor may represent a +sort of wave of energy, an absorption of energy on the evolution of +the line from the conductor, and a slight giving out of energy on the +line reaching that position of proximity to the iron ring, that its +passage thereto may be said to be a shortening process or a lessening +of its resistance.</p> + +<p>The magnetism in air, gases, and non-magnetic bodies, being assumed to +be that of the ether, this medium shows no such effects as those we +get with the ring. It does not become permanently polarized, as does +even soft iron under the condition of a closed ring. The iron +possesses coercive force, or magnetic rigidity, and a steel ring would +show more of it. The molecules of the iron or steel take a set. If we +were to cut the soft iron ring, or separate it in any way, this +introduction of resistance of air for ether in the magnetic circuit +would cause the lines to collapse and set up a current in the +conductor. The energy of the ring would have been restored to the +latter. The curious thing is that physically the polarized ring does +not present any different appearance or ordinary properties different +from those of a plain ring, and will not deflect a compass needle. Its +condition is discoverable, however, by the test of self-induction to +currents of different direction. As a practical consideration, we may +mention in this connection that a self-inductive coil for currents of +one direction must be constructed differently from one to be used with +alternating currents. The former must have in its magnetic circuit a +section of air or the like, or be an imperfectly closed circuit, as it +were. The latter should have as perfectly closed a magnetic circuit as +can be made. We see here also the futility of constructing a Ruhmkorff +core coil on the closed iron magnetic circuit plan, because the +currents in the primary are interrupted, not reversed.</p> + +<p>The considerations just put forward in relation to the closed iron +ring, and its passive character under the condition of becoming +polarized, are more important than at first appears. It has been found +that the secondary current wave of a closed iron circuit induction +coil or transformer, whose primary circuit receives alternating +current, is lagged from its theoretical position of 90 degrees behind +the primary wave an additional 90 degrees, so that the phases of the +two currents are directly opposed; or the secondary current working +lamps only in its circuit is one half a wave length behind a primary, +instead of a quarter wave length, as might have been expected.</p> + +<p>But when it is understood that the iron core polarized in one +direction by the primary impulse does not begin to lose its magnetism +when that impulse simply weakens, but waits until an actual reversal +of current has taken place, it will be seen that the secondary +current, which can only be produced when magnetic lines are leaving +the core and cutting the secondary coil, or when the lines are being +evolved and passing into the core from the primary coil, will have a +beginning at the moment the primary reverses, will continue during the +flow of that impulse, and will end at substantially the same time with +the primary impulse, provided the work of the secondary current is not +expended in overcoming self-induction, which would introduce a further +lag. Moreover, the direction of the secondary current will be opposite +to that of the primary, because the magnetic circuits which are opened +up by the primary current in magnetizing the core, or which are closed +or collapsed by it in demagnetizing the core, will always cut the +secondary coil in the direction proper for this result. Transformers +of the straight core type with very soft iron in the cores and not too +high rates of alternation should approximate more nearly the +theoretical relation of primary and secondary waves, because the +magnetic changes in the core are capable of taking place almost +simultaneously with the changes of strength of the primary current. +This fact also has other important practical and theoretical bearings.</p> + +<div class="figright" style="width: 353px"> +<img src="./images/5e.png" alt="Fig. 7." title="" /> +<span class="caption">Fig. 7.</span> +</div> + +<p>Let us assume a plain iron core, Fig. 7, magnetized as indicated, so +that its poles, N, S, complete their magnetic circuits by what is +called free field or lines in space around it. Let a coil of wire be +wound thereon as indicated. Now assume that the magnetism is to be +lost or cease, either suddenly or slowly. An electric potential will +be set up in the coil, and if it has a circuit, work or energy will be +produced or given out in that circuit, and in any other inductively +related to it. Hence the magnetic field represents work or potential +energy. But to develop potential in the wire the lines must cut the +wire. This they can do by collapsing or closing on themselves. The bar +seems, therefore, to lose its magnetism by gaining it all, and in +doing so all the external lines of force moving inward cut the wire. +The magnetic circuits shorten and short-circuit themselves in the bar, +perhaps as innumerable molecular magnetic circuits interior to the +iron medium. To remagnetize the bar we may pass an electric current +through the coil. The small closed circuits are again distended, the +free field appears, and the lines moving outward cut across the wire +coil opposite to the former direction and produce a counter potential +in the wire, and consequent absorption of the energy represented in +the free field produced. As before studied, the magnetism cannot +disappear without giving out the energy it represents, even though the +wire coil be on open circuit, and therefore unable to discharge that +energy. The coil open-circuited is static, not dynamic. In such +assumed case the lines in closing cut the core and heat it. Let us, +however, laminate the core or subdivide it as far as possible, and we +appear to have cut off this escape for the energy. This is not really +so, however. We have simply increased the possible rate of speed of +closure, or movement of the lines, and so have increased for the +divided core the intensity of the actions of magnetic friction and +local currents in the core, the latter still receiving the energy of +the magnetic circuit. This reasoning is based on the possibility in +this case of cutting off the current in the magnetizing coil and +retaining the magnetic field. This is of itself probably impossible +with soft iron. That the core receives the energy when the coil cannot +is shown in the well known fact that in some dynamos with armatures of +bobbins on iron cores, the running of the armature coils on open +circuit gives rise to dangerous heating of the cores, and that under +normal work the heating is less. In the former case the core +accumulates the energy represented in the magnetic changes. In the +latter the external circuit of the machine and its wire coils take the +larger part of the energy which is expended in doing the work in the +circuit. In this case, also, the current in the coils causes a +retardation of the speed of change and extent of change of magnetism +in the iron cores, which keeps down the intensity of the magnetic +reaction. In fact, this retardation or lag and reduction of range of +magnetic change may in some machines be made so great by closing the +circuit of the armature coils themselves or short-circuiting them that +the total heat developed in the cores is much less than under normal +load.</p> + + +<p>I wish now, in closing, to refer briefly to phenomena of moving lines +of force, and to the effects of speed of movement. In order to +generate a given potential in a length of conductor we have choice of +certain conditions. We can vary the strength of field and we can vary +the velocity. We can use a strong field and slow movement of +conductor, or we can use a weak field and rapid movement of the +conductor. But we find also that where the conductor has large section +it is liable to heat from eddy currents caused by one part of its +section being in a stronger field than another at the same time. One +part cuts the lines where they are dense and the other where they are +not dense, with the result of difference of potential and local +currents which waste energy in heat. We cannot make the conductor move +in a field of uniform density, because it must pass into and out of +the field. The conditions just stated are present in dynamos for heavy +current work, where the speed of cutting of lines is low and the +armature conductor large in section.</p> + +<p>But we find that in a transformer secondary we can use very large +section of conductor, even (as in welding machines) 12 to 15 square +inches solid copper, without meeting appreciable difficulty from eddy +currents in it. The magnetic lines certainly cut the heavy conductor +and generate the heavy current and potential needed. What difference, +if any, exists? In the transformer the currents are generated by +magnetic field of very low density, in which the lines are moving +across the conductor with extreme rapidity. The velocity of emanation +of lines around the primary coil is probably near that of light, and +each line passes across the section secondary conductor in a +practically inappreciable time. There is no cause then for differences +of potential at different parts of the section heavy secondary. Then +to avoid eddy currents in large conductors and generate useful +currents in them, we may cause the conductor to be either moved into +and out of a low density field with very great speed, or better, we +must cause the lines of a very low or diffused field to traverse or +cut across the conductor with very high velocity.</p> + +<div class="figleft" style="width: 300px"> +<img src="./images/6a.png" width="300" height="222" alt="Fig. 8." title="" /> +<span class="caption">Fig. 8.</span> +</div> + +<p>It is a known fact that, in dynamos with large section armature +conductors, there are less eddy currents produced in the conductors +when they are provided with iron cores or wound upon iron cores than +when the conductors are made into flat bobbins moved in front of field +poles. Projections existing on the armature between which the +conductors are placed have a like effect, and enable us to employ +heavy bars or bundles of wire without much difficulty from local +currents. The reason is simple. In the armatures with coils without +iron in them, or without projections extending between the turns, the +conductor moves into and out of a very dense field at comparatively +low velocity, so that any differences of potential developed <a name="Page_11356" id="Page_11356"></a>in the +parts of the section of conductor have full effect and abundant time +to act in setting up harmful local currents. In the cases in which +iron projects through the coil or conductor, the real action is that +the lines of the magnetic circuits move at high speeds across the +conductor, and the conductor is at all times in a field of very low +density. Figs. 8 and 9 will make this plain. In Fig. 8 we have shown a +smooth armature surface, having a heavy conductor laid thereon, and +which is at <i>a</i> just entering a dense field at the edge of the pole, +N, and at <i>b</i> leaving such field. It will be seen that when in such +position the conductor, if wide, is subjected to varying field +strength, and moves at a low speed for the generation of the working +potential as it passes through the field, thus giving rise to eddy +currents in the conductor.</p> + +<div class="figright" style="width: 300px"> +<img src="./images/6b.png" width="300" height="217" alt="Fig. 9." title="" /> +<span class="caption">Fig. 9.</span> +</div> + +<p>In Fig. 9 the conductors are set down between projections, in which +case both armature and field poles are laminated or subdivided. As +each projection leaves the edge of field pole, N, the lines which it +had concentrated on and through it snap backward at an enormous speed, +and cross the gap to the next succeeding projection on the armature, +cutting the whole section of the heavy armature conductor at +practically the same instant. This brisk transfer of lines goes on +from each projection to the succeeding one in front of the field pole, +leaving a very low density of field at any time between the +projections. The best results would be obtained when the armature +conductor does not project beyond or quite fill the depth of groove +between the projections. Of course there are other remedies for the +eddy current difficulty, notably the stranding and twisting of the +conductor on the armatures so as to average the position of the parts +of the compound conductor.</p> + + +<div class="figleft" style="width: 300px"> +<img src="./images/6c.png" width="300" height="267" alt="Fig. 10." title="" /> +<span class="caption">Fig. 10.</span> +</div> + +<p>Perhaps the most extreme case of what may be called dilution of field +by projections and by closed magnetic circuits in transformers would +be that of a block of iron, B, Fig. 10, moved between poles, N and S, +and having a hole through it, into and through which a conductor is +carried. The path through the iron is so good that we can scarcely +consider that any lines cross the hole from N to S; yet as B moves +forward there is a continual snapping transfer of lines from the right +forward side of the hole to the left or backward side, cutting the +conductor as they fly across, and developing an electromotive force in +it. I have described this action more in detail because we have in it +whatever distinction in the manner of cutting the lines of the field +is to be found between wire on smooth armatures and on projection +armatures and modifications thereof; and also between flat, open coils +passing through a field and bobbins with cores of iron. The +considerations advanced also bring out the relation which exists +between closed iron circuit transformers and closed iron circuit +(projection) dynamos, as we may call them.</p> + + + +<p>I had intended at the outset of this paper to deal to some extent with +the propagation of lines of magnetism undergoing retardation in +reference to alternating current motor devices, transformers with +limited secondary current, or constant average current, an alternating +motor working with what I may term a translation lag, etc.; but it was +soon found that these matters must remain over for a continuation of +this paper at some future time. My endeavor has been in the present +paper to deal with the lines of force theory as though it were a +symbol of the reality, but I confess that it is done with many +misgivings that I may have carried it too far. Yet, if we are to use +the idea at all it has seemed but right to apply it wherever it may +throw any light on the subject or assist in our understanding of +phenomena.</p> + +<p><a name="Footnote_1" id="Footnote_1"></a><a href="#FNanchor_1">[1]</a></p><div class="note"><p>A paper read before the American Institute of Electrical +Engineers, New York, May 22, 1889.</p></div> + +<hr /> + + + + +<h2><a name="art08" id="art08"></a>ELECTRIC LIGHTING AT THE PARIS EXHIBITION—THE OERLIKON +WORKS.</h2> + + +<p>Immediately on entering the Machinery Hall by the <i>galerie</i> leading +from the central dome, and occupying a prominent position at the +commencement of the Swiss section, is a very important plant of +dynamos, motors, and steam engines, put down by the Oerlikon Works, of +Zurich. During the time the machinery is kept running in the hall, +power is supplied electrically to drive the whole of the main shafting +in the Swiss section and part of that in the Belgian section, +amounting in all to some 200 ft., a large number of machines of +various industries deriving their power from these lines of shafting, +while during the evening a portion of the upper and lower galleries +adjoining this section is lit by some twenty-five arc lamps run from +this exhibit. Steam is supplied from the Roser boilers in the motive +power court. The whole of the generating plant is illustrated in one +view, and a separate view is given of the motor employed to drive the +main shafting, this latter view showing the details of connection to +the same. On the extreme right hand side of the first view is a direct +coupled engine and dynamo of 20 horse power, a separate cut of which +is given in Fig. 3. The engine is of the vertical single cylinder +type, standing 5 ft. high, and fitted, as are the other two engines +exhibited, with centrifugal governor gear on the fly wheel, acting +directly on the throw of the cutoff valve eccentric. The two +standards, supporting the cylinder and forming the guide bars, +together with the entire field magnets and pole pieces of the dynamo, +and the bed plate common to both, are cast in one piece.</p> + +<div class="figcenter" style="width: 381px"> +<a href="./images/6d.png"> +<img src="./images/6d_th.png" width="381" height="450" alt="FIG. 3 ENGINE AND DYNAMO FOR STEAMSHIPS." title="" /> +</a> +<span class="caption">FIG. 3 ENGINE AND DYNAMO FOR STEAMSHIPS.</span> +</div> + +<p>The machine is specially designed for ship lighting, and with the view +of preventing any magnetic effect upon the ship's compass, the field +is arranged so that the armature, pole pieces, and coils are entirely +inclosed by iron. Any tendency to leakage of magnetic lines will +therefore be within the machine, the iron acting as a shield. This +build of field—shown in Fig. 3<span class="smcap">a</span>—is also advantageous as a +mechanical shield to the parts of the machine most likely to suffer +from rough handling in transport, and it will be seen that the field +coils are easily slipped on before the armature is mounted in its +bearings.</p> + +<div class="figcenter" style="width: 500px"> +<img src="./images/6e.png" width="500" height="324" alt="FIG. 3A" title="" /> +<span class="caption">FIG. 3<sup>A</sup></span> +</div> + +<p>The winding is compound, and in such a direction that the two opposite +horizontal poles have the same polarity; it follows from this that +there will be two consequent poles in the iron, these being opposite +in name to the horizontal poles and at right angles to them, viz., +above and below the armature. Opposite sections of the commutator are +connected together internally as in most four-pole machines, so that +only two brushes are necessary, at 90 deg. apart.</p> + +<p>The section of iron in the field is 60 square inches and rectangular +in form, and the whole machine measures 4 ft. 3 in. in length, and 2 +ft. in height, without including the height of the bed plate. The +armature is 17 in. in length and the same in diameter, measured over +the winding, and develops at the machine terminals 70 volts and 200 +amperes at 480 revolutions. The moving parts of the engine are well +balanced, and run remarkably well and without noise at this high rate +of speed.</p> + +<p>This dynamo serves to develop power to run a motor in an adjoining +inclosure, containing some fine specimens of lathes and machine tools +constructed by the Oerlikon Works. These are driven by the motor +through the medium of a countershaft, and the power and speed are +controlled from the switch board seen at the left of the exhibit, and +in Fig. 11. The resistance, R<sub>1</sub>, serves to vary the intensity of the +shunt field of the dynamo, the volts being indicated by the voltmeter +V<sub>1</sub>, and a resistance separate from the switch board is inserted in +the main circuit of the two machines. The ammeter, A<sub>2</sub>, is directly +connected to the dynamo, and therefore indicates the current, whatever +circuit this machine is running.</p> + +<div class="figcenter" style="width: 600px"><a name="Page_11357" id="Page_11357"></a> +<a href="./images/7.png"> +<img src="./images/7_th.png" width="600" height="423" alt="Figs. 5-9, 11 plus THE PARIS EXHIBITION—STAND OF THE +OERLIKON WORKS." title="" /> +</a><br /> +<span class="caption">Figs. 5, 6, 7, 8, 9, 11 and<br /> +THE PARIS EXHIBITION—STAND OF THE OERLIKON WORKS.</span> +</div> + +<p>A larger combined engine and dynamo, seen in the center of the stand, +serves to run the lighting of the galleries. The engine is a 60 horse +power compound, running at 350 revolutions, and fitted with a governor +on the fly wheel, like that described above.</p> + +<p>The dynamo is a two-pole machine, the upper pole and <a name="Page_11358" id="Page_11358"></a>yoke being cast +in one, and the lower pole, yoke, and combined bed plate forming a +separate casting. The two vertical cores, over which the field bobbins +are slipped, are of wrought iron, and are turned with a shoulder at +either end, the yokes being recessed to fit them exactly. The cores +are then bolted to the yokes vertically from the top and horizontally +below. The field of this machine is shunt-wound, and in order to +maintain the potential constant a hand-regulated resistance—R<sub>2</sub> on +the switch board—is added in circuit with the shunt field. The +voltmeter, V<sub>2</sub>, immediately above this resistance, serves to +indicate the difference of potential at the machine terminals. Both +voltmeters are fitted with keys, so that they are only put in circuit +when the readings are taken.</p> + +<p>The main terminals of this machine are fitted on substantial +insulating bases, fixed one at each end of the top yoke. These connect +to the external circuit by a heavy cable—the machine being capable of +developing 500 amperes—and to the shunt circuit, and regulating +resistance by small wires; while the two connections to the brushes +are by four covered wires in parallel on each side. This mode of +connection is more flexible than a short length of heavy cable, and +looks well, the wires being held neatly together by vulcanized fiber +bridges. The dynamo is a low tension machine, the field being +regulated to give 65 volts when running the lamp circuits.</p> + +<div class="figcenter" style="width: 389px;"> +<img src="./images/8a.png" width="389" height="450" alt="Fig. 10." title="" /> +<span class="caption">Fig. 10.</span> +</div> + +<p>The illustration, Fig. 10, represents the automatic +re-regulator—C.E.L. Brown's patent. Motion is imparted to the cores +of two electro-magnets at the ends by the pulleys, W W<sub>1</sub>. The cores +have a projection opposite to the spindle, <i>a b</i>, which latter is +screw-threaded. By a relay one or other electro-magnet is put in +action, and the rotating core, which is magnetized, causes rotation of +the spindle by attraction, resulting in the movement of the contact +along the resistance stops. The relay is acted upon directly by the +potential of the dynamo, and the variable resistance is included in +the shunt field of the machine, so that changes in the potential, +resulting from changes in load or speed, are compensated for.</p> + +<p>The arrangements of the lamp circuits and the lamp itself may now be +described. The lamps are all run in parallel circuit, but are divided +into groups of five, each group being controlled by a separate switch +on the board—Figs. 11 and 11<span class="smcap">a</span>. These switches are not in +direct communication with the dynamo, but make that connection through +a large central switch, S<sub>2</sub>, which therefore carries the whole +current. The returns from each group are brought to the connections +seen between the two resistances, where the circuits may be +disconnected if desired, and the main current then passes through the +ammeter, A<sub>3</sub>, to the other terminal of the machine. One of the +smaller switches at the top, Fig. 11<span class="smcap">a</span>, is directly connected +with one terminal of the 20 horse power dynamo before mentioned, and +the other side of the switch to the motor in the machine tool exhibit. +Also one of the switches in connection with the central switch, S<sub>2</sub>, +is connected to the same motor, and therefore the latter may be run by +either machine, or, in fact, any combination of machines, lamps, and +motor be made as required.</p> + +<div class="figcenter" style="width: 402px"> +<img src="./images/8b.png" width="402" height="450" alt="FIG. 11A" title="" /> +<span class="caption">Fig. 11<span class="smcap">a</span></span> +</div> + +<p>The form of switch made by the Oerlikon Works is illustrated in Fig. +7. Two thick semicircular bands of copper are screwed at one end to +opposite sides of a square block which is turned round by the switch +handle. The block has a projection at each corner, and two strong, +flat, stationary springs are attached to the framework of the switch +and press on opposite sides of the block. The ends of the springs +engage in the projections and prevent the switch being turned round +the wrong way, while the pressure of the springs on opposite sides +forces the copper bands to take up a position exactly in line with the +terminal contacts when the switch is closed, or at right angles to +them when it is opened.</p> + +<div class="figleft" style="width: 239px"> +<img src="./images/6f.png" width="239" height="400" alt="FIGS 4A" title="" /> +<span class="caption">Fig. 4A</span> +</div> + + +<p>Further, each lamp has its own separate adjustable resistance, fuse, +and switch. These are of special construction, combined in one, and +are illustrated in Figs. 4 and 4<span class="smcap">a</span>; the other figures, +4<span class="smcap">b</span> and 4<span class="smcap">c</span>, showing some of the details of the same. +The wires, W W, lead from and to one lamp. The current enters at one +wire, passes through the fuse, <i>f</i>—Figs. 4<span class="smcap">c</span> and +4<span class="smcap">a</span>—down the center of the cylinder to a divided contact, +into which a switch arm can be shot. When this is so, a connection is +made to the upright brass rod, T, which serves to grip the band, R, +passing round the body of the cylinder. The current then passes +through all the turns of wire above the band, and out at the other +terminal. The resistance can be varied by raising or lowering the +band. Fig. 4<span class="smcap">b</span> shows the manner of tightening the band against +the wires on the cylinder. The upright rod, T, is seen in section, and +is fixed in one position to the frame of the apparatus. Abutting +against this, and working in the block to which the two ends of the +band are screwed, is a thumb screw, S, by turning which the band may +be loosened for adjusting, and tightened when the right position is +found. The cylinder is covered with asbestos sheet, and the wire, +which is of nickel, and measures altogether from 3 to 4 ohms, is wound +helically round this. The switch arm, to which the handle is attached +below, does not itself make and break the circuit, but carries a +spring, as shown, which, when the arm is at the end of its movement, +pulls over the contact lever with a rapid action, shooting the same +between the divided contact piece, and making a perfect contact. The +switchboard forms one side of a closed wooden case or cupboard, with +sufficient room for a man to enter and adjust the resistances or +switches for each lamp. These are screwed to the inside of the case in +rows, to the number of twenty-five. The greatest care has been taken +in the fixing of the connections to the inside of this case, and no +leading wires of different potential are allowed to cross each other.</p> + +<div class="figright" style="width: 325px"> +<img src="./images/6g.png" width="325" height="400" alt="FIGS 4, 4B, 4C" title="" /> +<span class="caption">Figs. 4, 4B and 4C</span> +</div> + +<p>The Oerlikon lamp, which is designed to work with constant potential, +is shown partly in section in Fig. 8. There is only one solenoid, A, +through which all the current passes, and whose action is to strike +the arc and maintain the current constant. The soft iron core, C, is +suspended from the inside of the tube, T, in which it has an up and +down movement checked by an air piston in the tube. An end elevation +of the brake wheels and solenoid is given in Fig. 9, where it will be +seen that the spindle carrying these wheels also carries between them +a pinion engaging with the rack rod, R. The top carbon attached to the +rack rod falls by its own weight, and is therefore in contact with the +lower carbon before the lamp is switched in circuit. When this is done +the core is instantly magnetized, and attracted to the soft iron brake +wheels, which it holds firmly. The air cushion in the tube prevents +the core being drawn up until it has fairly gripped the sides of the +wheels. The subsequent raising of the core therefore turns the wheels, +raises the rack rod, and strikes the arc. The feed is operated by the +weakening of the magnetic field of the coil, which causes the core to +lose its grip of the wheels, and allows the top carbon to descend. The +catch, L, Fig. 8, has a lateral play, and serves to engage in the +teeth of the rack rod, so as to prevent its falling when being +trimmed. Each carbon when in position is held against two rectangular +guide bars by the pressure of a wire spring—see figure. In this way +the carbon is pressed against two parallel knife edges, and is +therefore always in true alignment. The action of the lamp is very +simple, the working parts are few and solidly constructed, and the +regulation, as exhibited by the lamps running in the galleries, is +exceptionally steady.</p> + +<p>The transmission of power plant consists of two 250 horse power +dynamos—C.E.L. Brown's patent—the generator being driven by a +vertical compound condensing engine of the same power, running at 180 +revolutions. The dynamo generator is a four-pole 600 volt direct +current machine, series wound, and may be distinguished in the +engraving next to the switch board; while the motor receiver +connected to it, and erected in another portion of the Swiss section, +is of exactly the same size and type. The field, which is hexagonal in +shape, is cast in two pieces, bolted together horizontally, the +cross-sectional area of iron being 170 square inches. The armature is +cylindrical, and built up of flat rings stamped out of soft sheet +iron, eight notches in the same being provided to fit over the arms of +the spider keyed to the shaft. The spider is in halves, which are +bolted together longitudinally after the rings are in position. It is +Gramme wound, and measures over the winding 7 in. radial depth, 37 in. +outside diameter, and 22 in. in length. The current is collected by +four brushes. The fitting and mechanical build of the dynamos leaves +nothing to be desired. All the working parts of the dynamos and +engines are turned up to gauge and template, so as to be +interchangeable. As an instance of this, the armature of the generator +was built in the works, while the field magnets were being erected in +the exhibition, and, on arrival, fitted in position perfectly, and ran +at once without trouble.</p> + +<p>The energy taken off on the motor shaft is close on 200 horse power, +but varies according to the machines at work; the speed of the motor +does not, however, vary more than 3 per cent., and the brushes need no +adjustment. About 6 ft. of shafting is coupled on in line with the +motor shaft, and an extra plummer block fixed at the end. This +shafting carries at its extremity an additional 2 ft. pulley, the +power being delivered by belting from these pulleys to two large +pulleys on the main shaft.</p> + +<p>The machines run by this transmission consist of the looms of Rieter & +Co., of Winterthur; the large flour mill and lift of A. Millot & Co.; +the flour milling machinery of Frederick Wegmann & Co., of Zurich; the +brick and tile making machines of the Rorschach foundries; and the +looms of Messrs. Houget & Teston, of Verviers, in the Belgian section. +A 15 horse power two-pole Oerlikon dynamo is also run by a belt from +the main shaft, and generates power to drive a motor of similar type +in the Swiss section of the upper gallery. This runs a length of +countershafting supplying power to three silk-weaving machines +constructed by Benninger Frères; six weaving machines from the Ruti +works, near Zurich; and one knitting machine exhibited by Edward +Dubied & Co., of Couvet.</p> + +<p>The dynamo and motor are connected to the main cable by switches of +the type shown in Fig. 5. These are specially designed to destroy the +extra current on breaking circuit by the formation of an arc which +gradually increases the resistance till the break occurs, rendering it +less sudden. One wire passes through the handle and makes contact with +the springs, and the other is attached to the clamp in which the +carbon rod is held. The current is made to enter at the carbon rod, so +that the arcs formed cause consumption of the carbon. A magnetic +cut-out—Fig. 6—is also provided to each machine; this consists of an +electro-magnet, through which the main current passes, provided with +side pole pieces. A flat soft iron plate armature is hinged so as to +come up against the pole pieces when attracted. When the current is +not sufficiently strong to cause the plate to be attracted, a hole in +the center of the latter engages over a small projection in the top of +a weighted arm hinged in the center of the board, and keeps it +upright. If now the current exceeds the limits of safety to the +machine, due to a too heavy load being thrown on, the armature is +attracted and releases the vertical arm, which falls over and enters +with considerable force between the two spring contacts below. These +contacts are connected to the field terminals, which are, therefore, +short-circuited, and prevent the dynamo generating any current. A +retractile spring can be adjusted to cause cut-off at any required +current. These details are indicated in our illustrations mounted on +their respective switch boards.</p> + +<p>Since the erection of plant by these works at Solothurn for +transmitting 50 horse power five miles distant, which attracted so +much interest some time ago, several important works have been carried +out. Among these we may mention a 280 horse power transmission at 1½ +kilom. distance to a cotton mill at Derendingen in Switzerland, a 250 +horse power transmission at ½ kilom. distance, carried out for Gaetano +Rossi at Piovene in Italy, and a 300 horse transmission at 6 kilom. +distance installed for Giovanni Rossi, in which the power is given off +at two different stations.—<i>The Engineer.</i></p> + +<hr /> + + + + +<h2><a name="art10" id="art10"></a>THE ADER FLOURISH OF TRUMPETS.</h2> + + +<p>Although telephonic novelties are not numerous at the Universal +Exposition, telephony—that quite young branch of electric science—is +daily the object of curious <a name="Page_11359" id="Page_11359"></a>and interesting experiments which we must +make known to our readers, a large number of whom were not yet born to +scientific life when the experiments were made for the first time at +Paris in 1881; and it is proper to congratulate the Société Générale +des Téléphones on having repeated them in 1889 to the great +satisfaction of the rising generation.</p> + + +<p>We allude to the Ader system of telephonic transmissions of sounds in +such a way that they can be heard by an audience.</p> + +<p>The essential parts of this mode of transmission consist of two +distinct systems—transmitters and receivers.</p> + +<div class="figcenter" style="width: 600px"> +<img src="./images/8c_th.png" width="600" height="331" alt="Fig. 1.—THE ADER FLOURISH OF TRUMPETS" title="" /> +<span class="caption">Fig. 1.—THE ADER FLOURISH OF TRUMPETS</span> +</div> + +<div class="figleft" style="width: 337px;"> +<img src="./images/9a_th.png" width="337" height="450" alt="Fig. 2.—DETAILS OF THE TRANSMITTER." title="" /> +<span class="caption">Fig. 2.—DETAILS OF THE TRANSMITTER.</span> +</div> + +<p>The transmitters are four in number, and are actuated by the same +number of musicians, each humming into them his part of the quartet +(Fig. 1). This transmitter, represented apart in elevation and section +in Fig. 2, is identical with the one used in the curious experiment +with the singing condenser. At A is a mouthpiece before which the +musician hums his part as upon a reed pipe. He causes the plate, B, to +vibrate in unison with the sound that he emits, and this produces +periodical interruptions of varying rapidity between the disk, B, and +the point, C. The button, D, serves to regulate the distance in such a +way that the breakings of the circuit shall be very complete and +produce sounds in the receivers as pure as allowed by this special +mode of transmission, in which all the harmonics are systematically +suppressed in order to re-enforce the fundamental.</p> + +<div class="figcenter" style="width: 600px;"> +<a href="./images/9b.png"> +<img src="./images/9b_th.png" width="600" height="330" alt="Fig. 3.—THE ADER FLOURISH OF TRUMPETS" title="" /> +</a> +<span class="caption">Fig. 3.—THE ADER FLOURISH OF TRUMPETS</span> +</div> + +<p>This transmitter interrupter is interposed in the circuit of a battery +of accumulators, with the five receivers that it actuates, in such a +way that the four transmitters and five receivers form in reality four +groups of distinct autonomous transmission, the accordance of which is +absolutely dependent upon that of the artists who make them vibrate.</p> + +<div class="figright" style="width: 307px;"> +<a href="./images/9c.png"> +<img src="./images/9c_th.png" width="307" height="400" alt="Fig. 4.—DETAILS OF THE RECEIVER." title="" /> +</a> +<span class="caption">Fig. 4.—DETAILS OF THE RECEIVER.</span> +</div> + +<p>The five receivers are arranged over the front door of the telephone +pavilion, near the Eiffel tower (Fig. 3). Each consists of a horseshoe +magnet provided, between its branches, with two small iron cores +having a space of a few millimeters between them (Fig. 4). Each of +these soft iron cores carries a copper wire bobbin, N, the number of +spirals of which is properly calculated for the effect to be produced. +Opposite the vacant space left by the two cores, there is a small +piece, <i>t</i>, of rectangular form, and also of soft iron, fixed to a +vibrating strip of firwood, L, of about 4 inches section. The +periodical breaking of the circuit produced by the transmitter causes +a variation in the magnetization of the iron cores of the five +receivers and makes the firwood strips vibrate energetically. These +vibrations are received and poured forth as it were in front of the +telephone pavilion, by large brass trumpets arranged in front of each +receiver, as shown in Fig. 3.</p> + +<p>It would be difficult for us to pass any judgment whatever upon the +musical and artistic value of these transmissions of trumpet music to +a distance; we prefer to confess our incompetency in the matter. But +it is none the less certain that these experiments are having the same +success that they had at their inception in 1881 at the Universal +Exposition of Electricity, and they allow us to foresee that there is +a time coming in which it will be possible to transmit speech to a +distance with the same intensity that the present trumpet flourishes +have. Although all the tentatives hitherto made in this direction have +not given very brilliant results, we must not despair of attaining the +end some day or other. Less than fifteen years ago the telephone did +not exist; now it covers the world with its lines.—<i>La Nature.</i></p> + +<div class="figcenter" style="width: 600px"> +<hr /> +</div> + + + + +<h2><a name="art28" id="art28"></a>NOTES ON DYEWOOD EXTRACTS AND SIMILAR PREPARATIONS.</h2> + +<h3>By <span class="smcap">Louis Siebold</span>, F.I.C., F.C.S.</h3> + + +<p>During the last ten years there has been an enormous increase in the +production of these preparations, and the time will come when their +application in dyeing and calico printing will become so general as to +completely supersede the employment of the raw materials. The +manufacture of these extracts, to be thoroughly successful, requires +to be so conducted as to secure the perfect exhaustion of the dyewoods +without the slightest destruction or deterioration of the coloring +matters contained in them; and though nothing like perfection has been +reached in the attainment of these objects, it is certain that the +processes of extraction and evaporation now employed by the best +makers are a very great improvement on the older methods. Indeed, +there is no difficulty nowadays in procuring dyewood extracts of high +excellence if the consumer is willing to pay a price for them +corresponding to their quality, and knows how to avail himself of the +aid of chemical skill to control his purchases. Unfortunately, +however, there is so much hankering after cheap articles, and so +little care is taken to ascertain their real quality, that every scope +is afforded to the malpractices of the adulterer. There are many dye +and print works in which large quantities of these extracts are used +without being subjected to trustworthy tests. Moreover, much of the +testing is done by fallacious methods and often by biased hands. So +fallacious, indeed, are some of these tests, that grossly adulterated +extracts are often declared superior to the purer ones, the cause of +this being the application of an insufficient proportion of mordant in +the dyeing or printing trials, and the consequent waste of the excess +of coloring matter in the case of the purer preparation.</p> + +<p>Professional analytical chemists have hitherto given but little +attention to these preparations, and the employment of experienced +chemists in works is as yet far from general. The testing of dyewood +extracts in such a manner as to throw full light on their purity, the +quality of raw material from which they are prepared, their exact +commercial value their suitability for special purposes, and the +proportion and nature of any adulterants they may contain, is of +course a difficult and tedious task, and must be left to the expert +who is in possession of authentic specimens prepared by himself of all +the different extracts made from every variety and quality of raw +materials, and who combines a thorough knowledge of experimental +dyeing and printing with a large experience in the chemical +investigation of these preparations. But when the object of the +testing is merely careful comparison of the sample in question with an +original sample or previous deliveries, the case is much simplified, +and comes within the scope of the general chemist or the laboratory +attached to works. A few years ago I recommended carefully conducted +dyeing trials on woolen cloth mordanted with bichromate of potash as +the best and simplest mode adapted to such cases, and my subsequent +experience enables me to confirm that observation to the fullest +extent. Most of these extracts contain the coloring matter in two +states, the developed and the undeveloped, and an oxidizing mordant +such as bichromate of potash causes the latter as well as the former +to enter completely into combination with a metallic base; whereas +many of the other mordants, such as alumina or tin compounds, merely +take up the developed portion of the coloring matter together with +such small and variable proportions of the undeveloped as might +undergo oxidation during the process of dyeing. I would therefore +suggest dyeing trials with alumina, tin, iron, etc., only as +subsidiary tests indicating the suitability of an extract for certain +special purposes, while recommending the trial with bichromate of +potash as the one giving the best information respecting the actual +strength of the extract in relation to the raw material from which it +was obtained, and as giving a fair idea of the money value of the +sample. Cotton dyeing does not, as a general rule, afford a good means +of assaying extracts, as it is generally done under conditions which +do not admit of complete exhaustion of the dye bath, but it might +often with advantage be resorted to as an additional trial throwing +further light on the degree of oxidation or development of the +coloring matter. Printing trials are apt to give fallacious results +unless the proportion of mordant is carefully adjusted to the amount +of coloring matter present, and several trials with different +proportions would be necessary to prevent erroneous conclusions. For +the trials with bichromate of potash on wool I would recommend pieces +of cloth weighing about 150 grains, and the most suitable proportion +of bichromate of potash is 3 per cent. of the weight of the cloth. The +requisite number of pieces (equal to the number of samples to be +tested) should be thoroughly scoured and then heated in the bichromate +solution at or near the boiling point for not less than 1½ hours, +after which they should be well washed and then dyed separately in the +solutions of equal weights of the extracts at the same temperature and +for the same length of time; 15 grains of extract is a suitable +quantity for a first trial under these conditions. These trials can +then be repeated with different relative proportions of extract in +order to ascertain what weight of a sample would give the same depth +of color as 15 grains of the standard example. Many precautions are +required both in the mordanting and dyeing processes in order to +obtain trustworthy results; and though the trials with bichromate of +potash give the most reliable information of any single test, they +should be supplemented by the subsidiary tests already alluded to, and +also by a chemical examination, in order to obtain a knowledge, not +merely of the wood strength, but also of the general nature of the +extract. An adulteration with molasses or glucose can be best +determined by fermentation in comparison with a pure sample. Mineral +adulterants may, of course, be detected by an estimation and analysis +of the ash, after making due allowances for variations due to +differences in different kinds of the same dyewoods. The estimation of +the individual coloring matters in these extracts by means of a +chemical analysis is under all circumstances a task requiring much +experience, especially as the coloring principles are associated in +different qualities of each class of dyewood with different +proportions of other constituents which often give much trouble to the +unpracticed experimenter. Extracts made from logwood roots are now +largely manufactured and often substituted or mixed with the extracts +of real logwood, and have in some instances been palmed of as logwood +extracts of high quality. The correct determination of such +admixtures, like the fixing of anything like the exact commercial +value of dyewood extracts, requires nothing less than a complete +chemical investigation coupled with numerous dyeing trials in +comparison with standard preparations, and should be left to an +expert.</p> + +<p>The presence in dyewood extracts of coloring matters in various stages +of development has hitherto militated against their use in place of +the raw materials by many dyers and printers who are still employing +inherited and antiquated processes in which the whole of the coloring +matter is not rendered available. It is often asserted by these that +even the best of extracts fail to give anything like the results +attained by the use of well-prepared woods, and that, indeed, their +application proves a complete failure. Such failure, however, is +simply due to the want of chemical knowledge on the part of the dyers, +for there is no real difficulty in making any good and pure extract +serve all the purposes for which the woods were used. It is to be +hoped that in this branch of industry, as well as in many others, the +employment of chemists will become more general than at present, and +not be restricted, as is often the case, to young men without +experience and without the trained intellect so essential to success +in chemical investigations. High class chemical skill is of course +available to the manufacturer, but the man of science who brings +matured knowledge and valuable brain work into the business required +social as well as pecuniary recognition, and the sooner and more +fuller this fact is appreciated the better it will be for the +maintenance and progress of our industries.</p> + +<p>With regard to the astringent extracts, such as sumac, myrabolam, +divi, valonia, quebracho, oak, etc., it is the aim of the +manufacturer, whenever such extracts are intended for the purposes of +dyeing and printing, to obtain the tannin in a form in which it is +<a name="Page_11360" id="Page_11360"></a>best calculated to fix itself upon the fiber. The case is somewhat +different when the same extracts are required for tanning. For this +purpose it is necessary that the extract shall have considerable +permeating power, and that the tannin contained in it shall readily +yield leather of the desired texture, color, and permanency. Extracts +specially suited for this purpose are by no means always the most +suitable for the dyer, and <i>vice versa</i>.</p> + +<p>A brief description of the processes by which the astringent extracts +may be tested with particular reference to their fitness for definite +purposes concluded the paper.</p> + +<p>With regard to the question as to whether experimental dyeing with +bichromate of potash should be employed as a test even in works where +all the dyeing was done with other mordants, he was decidedly of +opinion that it should always be resorted to as one of the tests, +inasmuch as it was the only simple and expeditious method giving a +fair idea of the actual wood strength and money value of the extract. +The test should, in such cases, be supplemented by dyeing trials with +the mordants used at the works, and, if necessary, also by a chemical +analysis. Printing trials were not necessarily bad tests, since +oxidizing was usually added in these where it was necessary, and any +undeveloped coloring matter would thus be oxidized during the steaming +process: but, as he had stated before, it was essentially necessary in +such cases to have a fair idea of the amount of actual coloring matter +in the extract and to adjust the proportion of mordant accordingly. +Such trials should therefore be preceded by carefully conducted dyeing +trials with bichromate of potash. Mr. Thomson had raised the question +whether it would not be well for the manufacturer to prepare these +extracts in such a manner that they would contain all the coloring +matter in one condition only, in order to insure greater uniformity in +their quality and mode of application. This would, no doubt, be a +desirable step to take if the owners of dye and print works were more +in the habit of availing themselves of the service of competent +chemists experienced in this branch, for then they would be able to +make any extract do its full work irrespective of the state of +development of the coloring matter. Such, however, was not the case, +and it was a very common thing for the consumer of dyewood extracts to +require the manufacturer to prepare them specially for him so as to +suit his own dyeing recipes, or in other words to give exactly the +same shades, weight for weight, by his own method of dyeing as the +article he was in the habit of using. The manufacturer was thus often +compelled to make many different qualities of the same extract to suit +different customers. For the same reason adulterated articles were +often preferred to the pure ones. There was, perhaps, no branch of +industry in which chemical skill of a high order could be applied with +greater advantage than in dyeing, and nowhere was this fact less +recognized. Some of the processes of dyeing were exceedingly wasteful +and stood in much need of improvement. He (Mr. Siebold) knew a large +works in which a ton of logwood extract was used daily for black +dyeing only, and he might safely assert that of this enormous quantity +only a very small proportion would be fixed on the fiber, while by far +the greater proportion was utterly wasted. Such a waste could only be +prevented by a searching investigation of its causes by trained skill. +Mr. Thomson had further alluded to the color obtained with logwood or +logwood extract and wool mordanted with bichromate of potash, and +seemed to be under the impression that the color thus obtained was not +black, but blue. This was undoubtedly the case in dyeing trials +performed as tests, as these were conducted purposely with a very +small proportion of coloring matter in order to admit of a better +comparison of the resulting depth of shades. But with larger +proportions of logwood the color obtained was a fine bluish-black, and +with the addition of a small proportion of fustic or quercitron bark +to the logwood a jet black was readily produced. With regard to Mr. +Watson Smith's observation as to fractional dyeing, he (Mr. Siebold) +did not regard this method as a suitable trial for ascertaining the +strength of an extract, but he admitted it was occasionally very +valuable for detecting an admixture of extracts of other dyewoods, +such as quercitron bark extract in logwood extract. It was also a good +method of ascertaining the speed of dyeing and hence the relative +proportion of fully developed coloring matter of an extract.—<i>Jour. +Soc. Chem. Industry.</i></p> + +<hr /> + + + + +<h2><a name="art24" id="art24"></a>ORTHOCHROMATIC PHOTOGRAPHY.<a name="FNanchor_2" id="FNanchor_2"></a><a href="#Footnote_2"><sup>1</sup></a></h2> + +<h3>By <span class="smcap">Oscar O. Litzkow</span>.</h3> + + +<p>What I want to show is the manner in which the process has been +tested. My employer, Mr. Bierstadt, has given me permission to show +you some samples, and also his chart containing the spectrum colors: +violet, indigo blue, green, yellow, orange, red, and black. This chart +has been photographed in the orthochromatic and also in the ordinary +way.</p> + +<p>There are many ways of producing an orthochromatic effect; one is the +use of a glass tank placed behind or in front of the lens, in which a +coloring matter from either a vegetable or mineral product is placed; +this tank or cell is, however, only for use in the studio, as for +outdoor photography we have a colored glass screen, so as not to be +bothered with carrying colored solution.</p> + +<p>The tank is constructed as follows: Procure two pieces of best white +plate glass, about 6 inches square; between these place a piece of +rubber of the same size square, and about 3/8 of an inch thick. In the +center of this rubber cut out a circle about 4 inches diameter, and +from one of the corners to the center of the circle cut out a narrow +strip ¼ inch wide; this serves as the mouth of the tank. The two +pieces of glass and the rubber are cemented together with rubber +cement; then, to hold it firmly together, two brass flanges are used +as a clamp, with four screws at an equal distance apart; a thin sheet +of rubber is on the glass side of the flanges to prevent direct +contact with the glass, the center remaining clear for the rays of +light to pass through solution and glass.</p> + +<p>One of the best orthochromatic effects made through this tank is with +a three-grains-to-the-ounce solution of bichromatic of ammonia or +bichromate of potassium. In this method there is no preparation used +on the plate. A common rapid dry plate is exposed through this +solution; the exposure, however, is about twenty times longer than it +would be if you removed the tank with the yellow solution, or, in +other words, if a dry-plate is exposed one minute without the yellow +solution it would have to be exposed twenty minutes through a +three-grain solution of bichromate of potassium or ammonia. It +produces wonderful results on an oil painting or any highly colored +object.</p> + +<p>Another method, and the one best adapted for landscapes, is to bathe +the plate in erythrosine and then expose it through a yellow glass +screen.</p> + +<p>As an illustration, suppose we have before us a beautiful landscape. +In the foreground beautiful foliage, in the center a lake, in the +distance hills, with a bluish haze appearing pleasing to the eye, also +a nice sky with light clouds. Now make a plain negative, and see what +has become of your clouds, hills, and the distance—not visible! Some +photographers have been led to think that by underexposing they retain +the distance, but they sacrifice the foreground; besides, it does not +produce an orthochromatic effect.</p> + +<p>But it is a good idea to expose longer on the foreground than you do +on the distance. This can be done by raising the cap of the lens +skyward and gradually shut off, giving the foreground more exposure.</p> + +<p>Plates are prepared for orthochromatic work as follows: Take any +ordinary rapid dry plate, place it in a bath containing</p> + + +<div class='center'> +<table border="0" cellpadding="2" cellspacing="0" summary=""> +<tr><td align='left'></td></tr> +<tr><td align='left'>Distilled water</td><td align='right'>200 c.c.</td></tr> +<tr><td align='left'>Strong liquid ammonia</td><td align='right'>2 c.c.</td></tr> +<tr><td align='left'></td></tr> +</table></div> + +<p>Rock it for two minutes, work as dark as you possibly can. Now take it +out, and place it in the second bath for one and one-fourth minutes +and keep it rocking. Have on hand for use a stock solution of</p> + + + +<div class='center'> +<table border="0" cellpadding="2" cellspacing="0" summary=""> +<tr><td align='left'>Distilled water</td><td align='right'>1,000 parts.</td></tr> +<tr><td align='left'>Erythrosine "Y" brand</td><td align='right'>1 part.</td></tr> +</table></div> + +<p>Prepare second bath as follows:</p> + +<div class='center'> +<table border="0" cellpadding="2" cellspacing="0" summary=""> +<tr><td align='left'>Erythrosine stock solution</td><td align='right'>25 c.c.</td></tr> +<tr><td align='left'>Distilled water</td><td align='right'>175 c.c.</td></tr> +<tr><td align='left'>Strong water ammonia</td><td align='right'>4 c.c.</td></tr> +</table></div> + +<p>After removing the plate, dip it again face down to rinse off any +particles of scum, etc., that may get in the bath accidentally. This +bath may be used for one dozen 8 by 10, when it should be thrown away +and fresh bath used.</p> + +<p>After the plates come out of the last bath, they should be stood on +clean blotting paper to absorb the excess of solution. I would also +advise to use clean fingers. Pyro. or hypo. on the fingers is a +drawback to success.</p> + +<p>After plates have been drained, place them in a cleaned rack in an +absolutely light-tight closet, with air holes so constructed as to +admit air but no light; the plates will dry in from eight to twelve +hours. They are best prepared in the evening, and, if the closet is +good, will be dry in the morning.</p> + +<p>After the plates are dry they may be packed face to face with nothing +between them, in a double-cover paper box, and put in a dark closet +free from sulphureted hydrogen gas, until ready for use. I have kept +plates for three months in this way, and they were in good condition. +Great care should be used in developing these plates, as they are +sensitive to the red; get used to developing in a dark part of the +dark room; occasionally you may look at the process of development in +a little stronger light.</p> + +<p>The exposure through the yellow screen with an erythrosine plate is +about the same as if you had no orthochromatic plate—a plain plate +instead—provided you are not using too dark a yellow on your screen. +This can only be determined by experience. I will give to a common +plate about four seconds, an orthochromatic plate under the same +conditions five seconds.</p> + +<p>The yellow glass screen is prepared as follows: Take a piece of best +plate glass—common cannot be used—clean it nicely; take another +large plate glass, or anything that is level and true, level it with a +small spirit-level. Now take the cleaned piece of glass and coat it +with</p> + +<div class='center'> +<table border="0" cellpadding="2" cellspacing="0" summary=""> +<tr><th align="center" colspan="3">AURENTIA COLLODION.</th></tr> +<tr><td align='left'>Ether</td><td align='right'>5</td><td align='left'>oz.</td></tr> +<tr><td align='left'>Alcohol</td><td align='right'>5</td><td align='left'>oz.</td></tr> +<tr><td align='left'>Cotton</td><td align='right'>60</td><td align='left'>grs.</td></tr> +</table></div> + +<p>The aurentia to be added to suit your judgment; it takes a very small +quantity to make an intense yellowish-red collodion. Pour it on the +center of the glass, flow it to the edges, and before it sets place it +on the level glass and allow it to set; when set put it in a rack to +dry.</p> + +<p>Should it dry in ridges, the collodion may be too thick, and it must +be thinned down with equal parts of alcohol and ether. A single piece +of plate glass, about one-eighth inch thick, coated with aurentia +collodion, is all that is required with an erythrosine plate. Or, +after a piece has been successfully coated, another piece of the same +plate glass, and the same size, may be cemented together with balsam, +having the coated aurentia side between the two glasses; the edges may +then be bound with paper.</p> + +<p>In using different colored solutions, collodion, etc., I have found +that one will change the focus and the other not. With some screens +you must focus with them in their positions; take away the screen, and +the picture appears out of focus. I cannot fully explain why it is, +and for this reason will not make the attempt; experience alone can +teach it.</p> + +<p>Another thing that has been tried lately is to do away with the yellow +screen by substituting a yellow coating direct on the plate. No doubt +the focus on an object that requires absolute sharpness is somewhat +affected by the use of a glass. We have been successful, on a small +scale, to coat the plate with the following yellow solution:</p> + +<p>Place in a tray enough of a saturated solution of tropæolin in wood +alcohol to cover the plate; allow it to remain ten seconds. It is +necessary that the plate should be bathed previously in erythrosine +and dried. Before applying the tropæolin, which, being in alcohol, +dries in a few minutes, have some blotting paper on hand, as the +solution gathers in a pool and leaves bad marks on the end of the +plate.</p> + +<p>The plate can be developed in the usual way. Try it and see the +results.—<i>Reported in the Beacon.</i></p> + +<p><a name="Footnote_2" id="Footnote_2"></a><a href="#FNanchor_2">[1]</a></p> +<div class="note"><p>Read before the Photographic Association of Brooklyn.</p></div> + +<hr /> + + + + +<h2><a name="art25" id="art25"></a>PLATINOTYPE PRINTING.<a name="FNanchor_3" id="FNanchor_3"></a><a href="#Footnote_3"><sup>1</sup></a></h2> + + +<p>Platinotype, which may be considered to be the most artistic of +photographic printing processes, may be separated into its three +modifications—the hot bath and cold bath, in which a faintly visible +image is developed, and the Pizzighelli printing-out paper. The hot +bath process, again, may be divided into the black and white and sepia +papers. I intend to give you a rough outline of the preparation of the +paper and working of these modifications, concluding by demonstrating +the hot bath method, and handing around prints by it.</p> + +<p>Platinotype may almost be styled an iron printing process, for, while +no trace of iron or its salts is found in the finished print, certain +salts of iron are mixed with the platinum salt, which is platinum +combined with two atoms of chlorine (PtCl<sub>2</sub>), as a means for readily +reducing it; this, however, cannot be effected without the presence of +neutral oxalate of potash, hence the use of the oxalate bath. There is +no platinum in the paper for the cold bath process, it being coated +with ferric oxalate mixed with a very small quantity of chloride of +mercury—somewhere about one grain to an ounce of ferric oxalate +solution. When dry it is ready for exposure, which is about three +times less than with silver printing.</p> + +<p>It is absolutely necessary to store all papers for platinum printing +in an air-tight tin containing chloride of calcium, which must be +dried by heating from time to time. For the cold bath, however, it is +important to have moisture present during printing, or it may be after +printing and before development. If the paper is left in a dampish +room for fifteen minutes, it should be sufficient. Prints made by +exposing damp paper, or damping dry paper just before development, +must be developed within one hour if the maximum of vigor is desired; +by delaying the development some hours, the prints in the meantime +being stored in a drawer so that they may retain their moisture, an +increase of half tone and warmth of color will be obtained. If it +should be necessary to delay development for a day or two, the prints +must be dried before a fire soon after being removed from the frames, +and then stored in a calcium tube until wanted for development.</p> + +<p>While printing, the lemon color of the paper receives a grayish +colored image, which, although faint, can, with practice, be judged as +easily as silver printing.</p> + +<p>The developer consists of oxalate of potash and potassic +chloro-platinite—about thirty grains of the platinum salt to half an +ounce of oxalate forming about six ounces of solution; a great many +variations, however, may be made in the proportions of platinum salt +and oxalate, and different effects secured. Development is effected by +sliding the print face downward on to the developer, which must be +rocked after the development of each print to avoid scum marks. To +clear the prints they are washed in three or four baths of a weak +solution of hydrochloric acid after leaving the developer, to remove +all traces of the iron salts, and finally washed for a quarter of an +hour in three changes of water; they are then finished, and may be +dried between clean blotting paper.</p> + +<p>Pizzighelli's process differs from the above in being one that prints +fully out in the frame without development; the paper contains the +platinum and iron salts as well as the developer, and so prints and +develops at the same time. Although excellent prints can be produced +with it, for general work the results of the paper, as at present +made, will not compare with the hot and cold bath processes. It is, +however, excellent for printing from very dense negatives, and +occasional negatives that seem extremely suitable for it. The paper +should be breathed on before printing, as if it is quite dry the +printing will be very slow and irregular. The best conditions for the +preparation of the paper have scarcely been decided upon yet, and it +is not quite fair to judge the process. The prints are cleared in the +acid baths and washed for about a quarter of an hour.</p> + +<p>The sepia and black hot bath processes are much alike in the general +treatment. There are, however, some special precautions to be observed +with the sepia paper, the chief being to protect it from any but the +faintest rays of light; the prints, unlike the black ones, may be +affected by light when in the acid bath. A special solution must be +added to the developer to keep the lights pure. Over-exposure cannot +be corrected by using a cooler bath, as is the case with the black +prints, and the paper does not remain good so long.</p> + +<p>The paper for the black prints by the hot bath process is washed with +a mixture of potassic platinous chloride and ferric oxalate, the +proportion being about sixty grains of the platinum salt to one ounce +of the iron solution. It will not keep good longer than twenty minutes +or so, and must be applied to the paper directly after mixing. The +ferric oxalate in the paper is reduced by the action of light to +ferrous oxalate, which forms the faint visible image; this, when the +paper is floated on the oxalate of potash bath, is capable of reducing +the platinum salt in contact with it into metallic platinum; but the +ferric salt, which remains unaltered, has no action on the platinum +salt, leaving these parts, which represent the high lights of the +print, untouched. The ferric oxalate is removed by the acid baths +which follow the development. A good temperature for development is +150° Fahr., and when using this so much detail should not be apparent +as when printing for the cold bath process, in which all the detail +desired should be very faintly visible. There are, however, many +methods of exposing the paper and developing it, and no fixed rule can +be made, but the development must in every case be suited to the +exposure or the result will be a failure. For instance, the paper may +be printed until all detail is visible, but a very much cooler +development must be used, say 80° or 90°; on the other hand, a +slightly short exposure may be given, and a temperature of 180° to +200° used. 150° should be taken as the normal temperature, and kept to +until some experience has been gained, as employing all temperatures +will lead to confusion, and nothing will be learned. Some negatives +require a special treatment, and both printing and development must be +altered, while for a very dense negative the paper may be left out in +a dampish room for some time. It will then print with less contrast +and more half tone. A thin negative is better printed by the cold bath +process, but negatives <a name="Page_11361" id="Page_11361"></a>should be good and brilliant for platinotype +printing. Any one taking up platinotype and getting only weak prints +would do well to look to his negatives instead of blaming the paper, +as the high lights should be fairly dense, and the deep shadows nearly +clear glass.</p> + +<p>Time for complete development should always be allowed; with a hot +bath fifteen seconds will be sufficient, but if a cooler development +is used, or the prints are solarized in the shadows, more time should +be allowed. When the deep shadows are solarized, or appear lighter +than surrounding parts, a hot and prolonged development is required to +obtain sufficient blackness, as they have a tendency to look like +brown paper. I have found breathing on solarized shadows useful, as in +the presence of slight moisture they begin to print out and become +dark before development, getting black almost directly the print is +floated on the oxalate. Three or four acid baths of about ten minutes +each are used, and the prints are washed as before. The process +throughout takes much less time than silver printing, and can be kept +on all the winter, when it is nearly impossible to print in silver. +Prints can be developed in weak daylight or gaslight, and prolonged +washing is dispensed with.—<i>N.P. Fox, reported in Br. Jour. of +Photo.</i></p> + + +<p><a name="Footnote_3" id="Footnote_3"></a><a href="#FNanchor_3">[1]</a></p><div class="note"> +<p>A communication to the North London Photographic Society.</p></div> + +<hr /> + +<div class="center">[Continued from <span class="smcap">Supplement</span>, No. 706, page 11283.]</div> + + + + +<h2><a name="art05" id="art05"></a>ON ALLOTROPIC FORMS OF SILVER.</h2> + +<h3>By <span class="smcap">M. Carey Lea.</span></h3> + + +<p>In the first part of this paper were described certain forms of +silver; among them a lilac blue substance, very soluble in water, with +a deep red color. After undergoing purification, it was shown to be +nearly pure silver. During the purification by washing it seemed to +change somewhat, and, consequently, some uncertainty existed as to +whether or not the purified substance was essentially the same as the +first product; it seemed possible that the extreme solubility of the +product in its first condition might be due to a combination in some +way with citric acid, the acid separating during the washing. Many +attempts were made to get a decisive indication, and two series of +analyses, one a long one, to determine the ratio between the silver +and the citric acid present, without obtaining a wholly satisfactory +result, inasmuch as even these determinations of mere ratio involved a +certain degree of previous purification which might have caused a +separation.</p> + +<p>This question has since been settled in an extremely simple way, and +the fact established that the soluble blue substance contains not a +trace of combined citric acid.</p> + +<p>The precipitated lilac blue substance (obtained by reducing silver +citrate by ferrous citrate) was thrown on a filter and cleared of +mother water as far as possible with a filter pump. Pure water was +then poured on in successive portions until more than half the +substance was dissolved. The residue, evidently quite unchanged, was, +of course, tolerably free from mother water. It was found that by +evaporating it to dryness over a water bath, most of the silver +separated out as bright white normal silver; by adding water and +evaporating a second time, the separation was complete, and water +added dissolved no silver. <i>The solution thus obtained was neutral.</i> +It must have been acid had any citric acid been combined originally +with the silver. This experiment, repeated with every precaution, +seems conclusive. The ferrous solution, used for reducing the silver +citrate, had been brought to exact neutrality with sodium hydroxide. +After the reduction had been effected, the mother water over the lilac +blue precipitate was neutral or faintly acid.</p> + +<p>A corroborating indication is the following: The portions of the lilac +blue substance which were dissolved on the filter (see above) were +received into a dilute solution of magnesium sulphate, which throws +down insoluble allotropic silver of the form I have called B (see +previous paper). This form has already been shown to be nearly pure +silver. The magnesia solution, neutral before use, was also neutral +after it had effected the precipitation, indicating that no citric +acid had been set free in the precipitation of the silver.</p> + +<p>It seems, therefore, clear that the lilac blue substance contains no +combined citric acid. Had the solubility of the silver been due to +combination with either acid or alkali, the liquid from which it was +separated by digestion at or below 100° C. must have been acid or +alkaline; it could not have been neutral.</p> + +<p>We have, therefore, this alternative: In the lilac blue substance we +have either pure silver in a soluble form or else a compound of +silver, with a perfectly neutral substance generated from citric acid +in the reaction which leads to the formation of the lilac blue +substance. If this last should prove the true explanation, then we +have to do with a combination of silver of a quite different nature +from any silver compounds hitherto known. A neutral substance +generated from citric acid must have one or more atoms of hydrogen +replaced by silver. This possibility recalls the recent observations +of Ballo, who, by acting with a ferrous salt on tartaric acid, +obtained a neutral colloid substance having the constitution of +arabin, C<sub>6</sub>H<sub>10</sub>O<sub>6</sub>.</p> + +<p>To appreciate the difficulty of arriving at a correct conclusion, it +must be remembered that the silver precipitate is obtained saturated +with strong solutions of ferric and ferrous citrate, sodium citrate, +sulphate, etc. These cannot be removed by washing with pure water, in +which the substance itself is very soluble, but must be got rid of by +washing with saline solutions, under the influence of which the +substance itself slowly but continually changes. Next, the saline +solution used for washing must be removed by alcohol. During this +treatment, the substance, at first very soluble, gradually loses its +solubility, and, when ready for analysis, has become wholly insoluble. +It is impossible at present to say whether it may not have undergone +other change; this is a matter as to which I hope to speak more +positively later. It is to be remarked, however, that these allotropic +forms of silver acquire and lose solubility from very slight causes, +as an instance of which may be mentioned the ease with which the +insoluble form B recovers its solubility under the influence of sodium +sulphate and borate, and other salts, as described in the previous +part of this paper.</p> + +<p>The two insoluble forms of allotropic silver which I have described as +B and C—B, bluish green; C, rich golden color—show the following +curious reaction. A film of B, spread on glass and heated in a water +stove to 100° C. for a few minutes becomes superficially bright +yellow. A similar film of the gold colored substance, C, treated in +the same way, acquires a blue bloom. In both cases it is the surface +only that changes.</p> + +<p><i>Sensitiveness to Light.</i>—All these forms of silver are acted upon by +light. A and B acquire a brownish tinge by some hours' exposure to +sunlight. With C the case is quite different, the color changes from +that of red gold to that of pure yellow gold. The experiment is an +interesting one. The exposed portion retains its full metallic +brilliancy, giving an additional proof that the color depends upon +molecular arrangement, and this with the allotropic forms of silver is +subject to change from almost any influence.</p> + +<p><i>Stability.</i>—These substances vary greatly in stability under +influences difficult to appreciate. I have two specimens of the gold +yellow substance, C, both made in December, 1886, with the same +proportions, under the same conditions. One has passed to dazzling +white, normal silver, without falling to powder, or undergoing +disaggregation of any sort; the fragments have retained their shape, +simply changing to a pure frosted white, remaining apparently as solid +as before; the other is unchanged, and still shows its deep yellow +color and golden luster. Another specimen made within a few months and +supposed to be permanent has changed to brown. Complete exclusion of +air and light is certainly favorable to permanence.</p> + +<p><i>Physical Condition.</i>—The brittleness of the substances B and C, the +facility with which they can be reduced to the finest powder, makes a +striking point of difference between allotropic and normal silver. It +is probable that normal silver, precipitated in fine powder and set +aside moist to dry gradually, may cohere into brittle lumps, but these +would be mere aggregations of discontinuous material. With allotropic +silver the case is very different, the particles dry in optical +contact with each other, the surfaces are brilliant, and the material +evidently continuous. That this should be brittle indicates a totally +different state of molecular constitution from that of normal silver.</p> + +<p><i>Specific Gravities.</i>—The allotropic forms of silver show a lower +specific gravity than that of normal silver.</p> + +<p>In determining the specific gravities it was found essential to keep +the sp. gr. bottle after placing the material in it for some hours +under the bell of an air pump. Films of air attach themselves +obstinately to the surfaces, and escape but slowly even in vacuo.</p> + +<p>Taken with this precaution, the blue substance, B, gave specific +gravity 9.58, and the yellow substance, C, specific gravity 8.51. The +specific gravity of normal silver, after melting, was found by G. Rose +to be 10.5. That of finely divided silver obtained by precipitation is +stated to be 10.62.<a name="FNanchor_4" id="FNanchor_4"></a><a href="#Footnote_4"><sup>1</sup></a></p> + +<p>I believe these determinations to be exact for the specimens employed. +But the condition of aggregation may not improbably vary somewhat in +different specimens. It seems, however, clear that these forms of +silver have a lower specific gravity than the normal, and this is what +would be expected.</p> + +<p>Chestnut Hill, Philadelphia, May, 1889.—<i>Amer. Jour. of Science.</i></p> + + +<p><a name="Footnote_4" id="Footnote_4"></a><a href="#FNanchor_4">[1]</a></p> +<div class="note"><p>Watts' Dict., orig. ed., v. 277.</p></div> + +<hr /> + + + + +<h2><a name="art07" id="art07"></a>TURPENTINE AND ITS PRODUCTS.<a name="FNanchor_5" id="FNanchor_5"></a><a href="#Footnote_5"><sup>1</sup></a></h2> + + +<h3>By <span class="smcap">Edward Davies</span>, F.C.S., F.I.C.</h3> + + +<p>In treating this subject it is necessary to limit it within +comparatively narrow bounds, for bodies of the turpentine class are +exceedingly numerous and not well understood. In this definite class +turpentine means the exudation from various trees of the natural order +Coniferæ, consisting of a hydrocarbon, C<sub>10</sub>H<sub>16</sub>, and a resin. The +constitution of the hydrocarbons in turpentine from different sources, +though identical chemically, varies physically, the boiling point +ranging from 156° C. to 163° C., the density from 0.855 to 0.880, and +the action on polarized light from -40.3 to +21.5. They are very +unstable bodies in their molecular constitution, heat, sulphuric acid, +and other reagents modifying their properties. The resins are also +very variable bodies formed probably by oxidation of the hydrocarbons, +and as this oxidation is more or less complete, mixtures are formed +very difficult to separate and study.</p> + +<p>Turpentine as met with in commerce is mainly derived from <i>Pinus +maritima</i>, yielding French turpentine, and <i>Pinus australis</i>, +furnishing most of the American turpentine. The latter is obtained +from North and South Carolina, Georgia and Alabama. In Hanbury and +Fluckiger's Pharmacographia there is a full description of the manner +in which the trees are wounded to obtain the turpentine. Besides these +there are Venice turpentine from the larch, <i>Pinus Larix</i>, Strassburg +turpentine from <i>Abies pectinata</i>, and Canada balsam from <i>Pinus +balsamea</i>.</p> + +<p>The crude American turpentine is a viscid liquid of about the +consistence of honey, but varying to a soft solid, known as gum, thus, +according to the amount of exposure which it has undergone, it +contains about 10 to 25 per cent. of "spirits," to which the name of +turpentine is commonly given, the rest being resin, or as it is +usually called, rosin.</p> + +<p>In Liverpool almost all the spirits of turpentine comes from America, +so that it is almost impossible to get a sample of French.</p> + +<p>The terpene from American turpentine is called austraterebenthene. It +possesses dextro-rotatory polarization of +21.5. Its density is 0.864. +Boiling point 156° C.</p> + +<p>In taking the boiling point of a commercial sample of spirits it is +necessary to wait until the thermometer becomes steady. Not more than +5 per cent. should pass over before this takes place, and then there +is not more than two or three degrees of rise until almost all is +distilled over.</p> + +<p>The liquids of lower boiling point do not appear to have been much +studied. In French spirits they seem to be of the same composition as +the main product, but with more action on polarized light.</p> + +<p>French spirits of turpentine is mainly composed of terebenthene. The +boiling point and sp. gr. are the same as those of the austraterebenthene, +but the polarization is left handed and amounts to +-40.5.</p> + +<p>Isomeric modifications. Heated to 300° C. in a sealed tube for two +hours, it becomes an isomeric compound, boiling at 175° C., while the +density is lowered, being only 0.8586 at 0° C. The rotatory power is +only -9°. It oxidizes much more rapidly. It is called isoterebenthene +and has a smell of essential oil of lemons.</p> + +<p>By the action of a small quantity of sulphuric acid, among other +products terebene is formed. It has the same boiling point and sp. gr. +as terebenthene, but is without action on polarized light. +Austraterebenthene forms similar if not identical bodies.</p> + +<p>Polymers. One part of boron fluoride BF<sub>3</sub> instantly converts 160 +parts of terebenthene into polymers boiling above 300° C., and +optically inactive. H<sub>2</sub>SO<sub>4</sub> does the same on heating and forms +diterebene C<sub>20</sub>H<sub>32</sub>.</p> + +<p>Terchloride of antimony does the same, and also produces tetraterebene +C<sub>40</sub>H<sub>64</sub>, a solid brittle compound formed by the union of four +molecules of C<sub>10</sub>H<sub>16</sub>. It does not boil below 350° C. and +decomposes on heating.</p> + +<p>Compound with H<sub>2</sub>O. Terpin C<sub>10</sub>H<sub>18</sub>2HO is formed when 1 volume +of spirits of turpentine is mixed with 6 of nitric acid and 1 of +alcohol, and exposed to air for some weeks. Crystals are formed which +are pressed, decolorized by animal charcoal, and recrystallized from +boiling water.</p> + +<p>Compounds with HCl. When a slow current of HCl is passed through +cooled spirits of turpentine, two isomeric compounds are formed, one +solid, and one liquid. The lower the temperature is kept, the more of +the solid body is produced. To obtain the solid body pure it is +pressed and recrystallized from ether or alcohol. It is volatile and +has the odor of camphor. It is called artificial camphor, and has the +composition C<sub>10</sub>H<sub>16</sub>HCl. There is also a compound with 2HCl.</p> + +<p>Oxidation products. By passing air into spirits of turpentine oxygen +is absorbed. It was thought at one time that ozone was produced, but +Kingzett's view is that camphoric peroxide is formed C<sub>10</sub>H<sub>14</sub>O<sub>4</sub>, +and that in presence of water it decomposes into camphoric acid and +H<sub>2</sub>O<sub>2</sub>. This liquid constitutes the disinfectant known as +"sanitas," which possesses the advantages of a pleasant smell and +non-poisonous properties. C<sub>10</sub>H<sub>18</sub>O<sub>2</sub> may be obtained by +exposing spirits of turpentine in a flask full of oxygen with a little +water.</p> + +<p>Camphor C<sub>16</sub>H<sub>16</sub>O has been made in small quantity by oxidizing +spirits of turpentine. Terebenthene belongs to the benzene or aromatic +series, which can be shown from its connection with cymene. Cymene is +methylpropyl-benzene, and can be made from terpenes by removing two +atoms of H. It has not yet been converted again into terpene, but the +connection is sufficiently proved. The presence of CH<sub>3</sub> in terpenes +is shown by their yielding chloroform when distilled with bleaching +powder and water. The resin is imperfectly known. It was supposed to +consist of picric and sylvic acids. It is also stated to contain +abietic anhydride C<sub>44</sub>H<sub>62</sub>O<sub>4</sub>, but it is difficult to understand +how a compound containing C<sub>44</sub> can be produced from C<sub>10</sub>H<sub>16</sub>. +The most probable view is that it is the anhydride of sylvic acid, +which is probably C<sub>20</sub>H<sub>30</sub>O<sub>2</sub>.</p> + +<p>The dark colored resin which is obtained when the turpentine is +distilled without water can be converted into a transparent slightly +yellow body by distillation with superheated steam. A small portion is +decomposed, but the greater part distills unchanged. It is used in +making soap which will lather with sea water.</p> + +<p>When distilled alone, various hydrocarbons, resin oil and resin pitch, +are obtained.</p> + +<p>I find that commercial spirits of turpentine varies in sp. gr. from +0.865 to 0.869 at 15° C. The higher sp. gr. appears to be connected +with the presence of resinous bodies, the result of oxidation. The +boiling point is very uniform, ranging from 155° C. to 157° C. at 760 +mm. Taking these two points together, it is hardly possible to +adulterate spirits of turpentine without detection. I give the figures +for a few imitations or adulterations:</p> + + +<div class='center'> +<table border="0" cellpadding="4" cellspacing="0" summary=""> +<tr><td align='left'></td><td align='right'>Sp. gr.</td><td align='right'>B.P.</td></tr> +<tr><td align='left'>No. 1</td><td align='right'>0.821</td><td align='right'>137° C.</td></tr> +<tr><td align='left'>No. 2</td><td align='right'>0.884</td><td align='right'>165° C.</td></tr> +<tr><td align='left'>No. 3</td><td align='right'>0.815</td><td align='right'>150° C.</td></tr> +<tr><td align='left'>No. 4</td><td align='right'>0.895</td><td align='right'>156° C.</td></tr> +</table></div> + +<p>There is a considerable difference in the flashing point, no doubt due +to the longer or shorter exposure of the crude turpentine, by which +more or less of the volatile portion escapes.</p> + +<p><a name="Footnote_5" id="Footnote_5"></a><a href="#FNanchor_5">[1]</a></p> +<div class="note"><p>Read at a meeting of the Liverpool Chemists' Association.</p></div> + +<hr /> + + + + +<h2><a name="art06" id="art06"></a>ON THE OCCURRENCE OF PARAFFINE IN CRUDE PETROLEUM.<a name="FNanchor_6" id="FNanchor_6"></a><a href="#Footnote_6"><sup>1</sup></a></h2> + + + +<p>It is well known that the paraffine obtained by the distillation of +petroleum residues is crystalline, while that obtained directly (as in +the filtration of residuum) is amorphous. Ozokerite or ceresine +differs but slightly from paraffine, the principal distinction being +want of crystalline structure in it as found. Other characteristics, +such as the melting point, specific gravity, etc., vary in both, and +so are not of importance in a comparison. Hence it has been asked, Is +the paraffine occurring in petroleum and ozokerite identical with that +which is produced by their distillation? As crystalline paraffine +could be obtained from ozokerite by distillation alone, many persons +have supposed that it was engendered in the process. Recently, +however, crystalline paraffine has been obtained from ozokerite by +dissolving the latter in warm amyl alcohol; on cooling the greater +part separates out in crystals having the luster of mother-of-pearl. +By repetition of this process, a substance is obtained that is +scarcely to be distinguished from the paraffine obtained by +distillation. Apparently there exists then in ozokerite, together with +paraffine, other substances not capable of crystallization which keep +the paraffine from crystallizing. These colloids appear to be +separated by amyl alcohol in virtue of their greater solubility in +that menstruum. It is also reasonable to suppose that they undergo +change or decomposition by distillation.</p> + +<p>So as petroleum residues are amorphous, and the crystalline paraffine +is first produced by distillation, it has been argued that the +paraffine present in crude petroleum is approximately the same thing +as ozokerite.</p> + +<p>This, however, is not sufficient to establish the pyrogenic origin of +all crystallized paraffine, as crystals can be obtained from the +amorphous residues by distillation at normal or reduced pressure or in +a current of <a name="Page_11362" id="Page_11362"></a>steam. To explain these facts two assumptions are +possible. Either the chemical and physical properties of all or some +of the solid constituents are changed by the distillation, and the +paraffine is changed from the amorphous into the crystalline variety, +or the change produced by the distillation takes place in the medium +(<i>i.e.</i>, the mother liquid) in which the paraffine exists. The change +effected in ozokerite and in petroleum residues when crystalline +paraffine is obtained by distillation is to be regarded as a +purification, and can be effected partially by treatment with amyl +alcohol. In the same way, by repeated treatment of petroleum residuum +with amyl alcohol, a substance of melting point 59° C. can be +obtained, which cannot be distinguished from ordinary paraffine.</p> + +<p>The treatment with amyl alcohol has therefore accomplished the same +results as was obtained by distillation, and the action is probably +the same, <i>i.e.</i>, a partial separation of colloid substance. These +facts point to the conclusion that crystallizable paraffine exists +ready formed in both petroleum and in ozokerite, but in both cases +other colloidal substances prevent its crystallization. By +distillation, these colloids appear to be destroyed or changed so as +to allow the paraffine to crystallize.</p> + +<p>It is a generally known fact that liquids always appear among the +products of the distillation of paraffine, no matter in what way the +distillation be conducted. This shows that some paraffine is +decomposed in the operation.</p> + +<p>The name <i>proto-paraffine</i> has been given to ozokerite and to the +paraffine of petroleum in contradistinction to <i>pyro-paraffine</i>, the +name that has been applied to the paraffine obtained by distillation +from any source.</p> + +<p>According to Reichenbach, paraffine may crystallize in three forms: +needles, angular grains, and leaflets having the luster of +mother-of-pearl. Hofstadter, in an article on the identity of +paraffine from different sources, confirmed this statement, and added +further that at first needles, then the angular forms, and then the +leaflets are formed. Fritsche found, by means of the microscope, in +the ethereal solution of ozokerite, very fine and thin crystal +leaflets concentrically grouped, and in the alcoholic solution fine +irregular leaflets. Zaloziecki has recently developed these +microscopic investigations to a much greater extent. According to this +observer, the principal part of paraffine, as seen under the +microscope, consists of shining stratified leaflets with a darker +edge. The most characteristic and well developed crystals are formed +by dissolving paraffine in a mixture of ethyl and amyl alcohols and +chilling. The crystals are rhombic or hexagonal tablets or leaves, and +are quite regularly formed. They are unequally developed in different +varieties of paraffine. The best developed are those obtained from +ceresine. Their relative size and appearance give an indication as to +the purity of the paraffine, and, as they are always present, they are +to be counted among the characteristic tests for paraffine. +Reichenbach observed that mere traces of empyreumatic oil prevented +their formation.</p> + +<p>The old method of determining the amount of paraffine in petroleum was +to carry out the refining process on a small scale; that is, to +distill the residue from the kerosene oils to coking, chill out the +paraffine, press it thoroughly between filter paper, and weigh the +residue. The sources of error in this procedure are manifold; the +principal one is the solubility of paraffine in oils, which depends +upon the character of both the paraffine and the oil, and also upon +the temperature. The next greatest source of error is variation in the +process of distillation and the difference between working on the +small scale and on the large scale.</p> + +<p>In most cases, where a paraffine determination is to be carried out, +one has to deal with a mixture of paraffine with liquid oils. Now, +paraffine is not a substance defined by characteristic physical +properties which distinguish it from the liquid portions of petroleum. +It consists of a mixture of homologous hydrocarbons, which form a +solid under ordinary conditions. The hydrocarbons of this mixture show +a gradation in their properties, and gradually approximate to those +which are liquid at ordinary temperatures. It is a well known fact +that a separation of these homologues is entirely impossible by +distillation. It has also been ascertained that the liquid +constituents of petroleum do not always possess boiling points that +are lower than those of the solid constituents. This shows that we +have to deal not merely with hydrocarbons of one, but of several +series.</p> + +<p>When determinations of the amount of paraffine are to be made, then it +becomes necessary to specify with exactness what is to be called +paraffine. The most definite property that can be made use of for this +purpose is the melting point. For several reasons it is convenient to +include under this name hydrocarbons of melting point as low as +35°-40° C.</p> + +<p>The method proposed by Zaloziecki for the determination of paraffine +is the following: The most volatile portions of the petroleum are +separated by distillation, until the thermometer shows 200° C. These +portions are separated, as they exert great solvent action upon +paraffine. At the same time he finds that no pyro-paraffine is formed +under this temperature. A weighed portion of the residue is taken and +mixed with ten parts by weight of amyl alcohol and ten parts of +seventy-five per cent. ethyl alcohol: the mixture is then chilled for +twelve hours to 0° C. It is then filtered cold, washed first with a +mixture of amyl and ethyl alcohols, and then with ethyl alcohol alone. +The paraffine is transferred to a small porcelain evaporating dish and +dried at 110° C. It is then heated with concentrated sulphuric acid to +150°-160° C. for fifteen to thirty minutes with constant stirring. The +acid is then neutralized and the paraffine extracted by petroleum +ether. On evaporation of the solvent, the paraffine is dried at 100° +C. and weighed. Zaloziecki found, according to this method, in three +samples of Galician petroleums, 4.6, 5.8 and 6.5 per cent., +respectively, of proto-paraffine. The method was carried out as above +with four samples of American petroleums, Colorado oil from Florence, +Col.; Warren County oil from Wing Well, Warren, Pa.; Washington oil +from Washington County, Pa.; Middle District oil from Butler County, +Pa., all furnished by Professor Sadtler.</p> + +<p>They were very different in physical properties and in appearance, the +Colorado oil being a much heavier oil than the others and the +Washington oil being an amber oil, while the other two were of the +ordinary dark green color and consistence. The losses on distillation +to 200° C. were very different, being about one-tenth in the case of +the Colorado oil and nearly one-half in the case of the others. The +percentages of partially refined proto-paraffine in the four reduced +oils (all below 200° C. off) were as follows: for the Colorado oil, +23.9 per cent.; for the Warren oil, 26.5 per cent.; for the Washington +oil, 26.6 per cent.; and for the Middle District oil, 28.2 per cent.</p> + +<p>The question now arises, What value has this determination of the +proto-paraffine which may exist in an oil? As before said, a portion +of the paraffine is always decomposed in distillation at temperatures +sufficiently high to drive over the paraffine oils, so the yield of +pyro-paraffine is always less than the proto-paraffine shown to be +present originally. Zaloziecki found this in the case of the several +Galician oils he examined. Corresponding to the 4.6, 5.8 and 6.5 per +cent. of proto-paraffine in the several oils he obtained 2.18, 2.65 +and 2.35 per cent., respectively, of pyro-paraffine.</p> + +<p>For the present, however, the extraction of proto-paraffine on a large +scale by means of such solvents as amyl and ethyl alcohols is out of +the question on account of their cost. A distillation, under reduced +pressure and with superheated steam, would, however, prevent much of +the decomposition of the original proto-paraffine and increase the +yield of pyro-paraffine.</p> + +<p>This study of Zaloziecki's method and the examination of American oils +was suggested by Professor Sadtler and carried out in his laboratory.</p> + +<p><a name="Footnote_6" id="Footnote_6"></a><a href="#FNanchor_6">[1]</a></p> +<div class="note"><p>An abstract of thesis by E.A. Partridge, class of '89, +Univ. of Pa. Read before the Chemical Section of the Franklin +Institute by Prof. S.P. Sadtler.</p></div> + +<hr /> + + + + +<h2><a name="art27" id="art27"></a>TRANSMISSION OF PRESSURE IN FLUIDS.</h2> + +<h3>By <span class="smcap">Albert B. Porter.</span></h3> + + +<p>The young student of physics occasionally has difficulty in grasping +the laws of pressure in fluids. His every day experience has taught +him that a push against a solid body causes it to push in the same +direction, and he often receives with some doubt the statement that +pressure applied to a fluid is transmitted equally in every direction. +The experiments ordinarily shown in illustration of this principle +prove that pressure is transmitted in all directions, but do not prove +the equality of transmission, and in spite of all the text books may +tell him, the student is apt to cling to the idea that a downward +pressure applied to a liquid is more apt to burst the bottom than the +side of the containing vessel.</p> + + +<div class="figcenter"> +<img src="./images/12.png" alt="Figs. 1. and 2." title="" /><br /> +<span class="caption">Figs. 1. and 2.</span> +</div> + +<p>The little piece of apparatus shown in Fig. 1 was designed to furnish +a clear demonstration of the principle under consideration. It is +essentially an arrangement by which a downward pressure is applied to +a confined mass of air or water, and the resultant pressures measured +in the three directions, down, up, and sideways. By means of a broken +rat tail file kept wet with turpentine three holes are bored through a +bottle, one through the bottom, one through the side, and one through +the shoulder, as near the neck as may be convenient. The operation is +quick and easy, the only precaution to be observed being to work very +slowly and use but a slight pressure when the glass is nearly +perforated. The holes may be enlarged to any size required by careful +filing with the wet file. From each of the holes a rubber tube leads +to one of the glass manometer tubes at the right in the figure, the +joints being made air tight by slipping into each rubber tube a piece +of glass tubing about half an inch long in order to swell it to the +size of the hole it is to fit. The ends of these glass tubes must be +well rounded by partial fusion in a gas flame, that there may be no +sharp edges to cut the rubber. The bottle rests in a depression in the +turned wood base, the lower rubber tube passing out through a hole in +the wood. Fig. 2 shows the shape of the manometer tubes. They are made +of quarter inch glass tubing bent to shape in a flame and left open at +both ends. They are mounted on a scale board which has several +equidistant horizontal lines running across it. The two bent wires +which support the scale board fit loosely in holes in it and in the +base. This method of mounting is very handy, since it permits the +scale board to be swung to right or left as may be convenient, or +turned round so as to show the fittings on its back, without moving +the bottle. The three manometers are filled to the same level with +mercury, the quantity being adjusted by means of a pipette. A +perforated rubber stopper, fitted with a glass tube on which is +slipped a rubber syringe bulb, completes the apparatus.</p> + +<p>When the bulb is pinched between the fingers, the mercury is forced up +to the same height in each of the manometers, thus proving that the +pressure is exerted equally in the three directions, up, down, and +sideways. With the bottle filled with water the same effect follows, +the law being the same for liquids and gases. When using water in the +apparatus it is essential that the rubber tubes, as well as the +bottle, be filled, and when used in the class room it is better to +show the experiment with water first, it being easier and quicker to +empty the bottle and tubes than to fill them.</p> + +<hr /> + + + + +<h2><a name="art02" id="art02"></a>PEAR DUCHESSE D'ANGOULEME.</h2> + + +<p>Although well known to fruit growers and generally represented in all +parts of Britain, this noble French pear has not become a universal +favorite. If the quality of the fruit, independently of its fine, +handsome appearance, was bad, or even indifferent, it might be +exterminated from our lists, but this we know is not the case, as any +one who has tasted good samples grown in France, the Channel Islands, +and upon favorable soils in this country will bear out the statement +that the flavor is superb. Some fruits, we know, are quite incapable +of being good, as they have no quality in them; but here we have one +of the hardiest of trees, capable of giving us quantity as well as +quality, provided we cultivate properly. Pears, no doubt, are +capricious, like our seasons, but given a good average year, soils and +stocks which suit them, a light, warm, airy aspect, and good culture, +a great number of varieties formerly only good enough for stewing are +now elevated, and most deservedly so, to the dessert table. But, +assuming that some sorts known to be good do not reach their highest +standard of excellence every year, they are infinitely superior to +many of the old stewers, as they carry their own sugar, a quality +which fits them for consumption by the most delicate invalids. Indeed, +so prominently have choice dessert pears, and apples too for that +matter, come to the front for cooking purposes, that a new demand is +now established, and although Duchesse d'Angoulême, always juicy and +sweet, from bad situations does not always come up to the fine quality +met within Covent Garden in November, it is worthy of our skill, as we +know it has all the good points of a first rate pear when properly +ripened.</p> + +<p>The original tree of this pear was observed by M. Anne Pierre +Andusson, a nurseryman at Angers, growing in a farm garden near +Champigne, in Anjou, and having procured grafts of it, he sold the +trees, in 1812, under the name of Poire des Eparannais. In 1820, he +sent a basket of the fruit to the Duchesse d'Angoulême, with a request +to be permitted to name the pear in honor of her. The request was +granted, and the pear has since borne its present name.</p> + +<p>That such a fine pear, which does so well in France, would soon find +its way to England there exists little doubt, as we find that within a +few years it became established and well known throughout the United +Kingdom. All the earliest trees would be worked upon the pear or free +stock, and as root pruning until recently was but little practiced, we +may reasonably suppose that the majority of them are deeply anchored +in clay, marl, and other subsoils calculated to force a crude, gross +growth from which high flavored fruit could not be expected. These +defects under modern culture upon the quince and double grafting are +giving way, as we find, on reference to the report of the committee of +the pear conference, held at Chiswick in 1885, that twenty counties in +England, also Scotland, Ireland, and Wales, contributed no less than +121 dishes to the tables, and thirty-eight growers voted in favor of +the Duchesse being recognized as one of our standard dessert +varieties. This step looks like progress, as it is a record of facts +which cannot be gainsaid, and it now remains to be seen whether the +English grower, whose indomitable will has brought him to the front in +the subjugation of other fruits, will be successful with the fine +Duchesse d'Angoulême. Although this remarkable pear cannot easily be +mistaken, for the benefit of those who do not know it, the following +description may not be out of place. Fruit large, often very large, 3½ +inches wide and 3 inches to 4 inches high, roundish obovate, uneven, +and bossed in its outline. Skin greenish yellow, changing to pale dull +yellow, covered with veins and freckles of pale brown russet, and when +grown against a south wall it acquires a brown cheek. Eye open, with +erect dry segments, set in a deep irregular basin. Stalk 1 inch long, +inserted in a deep irregular cavity. Flesh white, buttery, and +melting, with a rich flavor when well ripened; otherwise rather coarse +grained and gritty.</p> + +<p>As to culture, experienced fruitists say the tree grows vigorously and +well. It bears abundantly, and succeeds either on the pear or quince +stock, forming handsome pyramids, but is better on the quince. Here, +then, we have the key to the secret of success: The cordon on the +quince; roots near the surface; loam, sound, sandy, and good; and good +feeding. Aspect, a good wall facing south or west—the latter, +perhaps, the best. Those who have not already done so, should try +trees on the quince as pyramids and bushes, as this, like some other +capricious pears, although the fruit be smaller, may put in better +flavor than is met with in fruit from hot walls.—<i>The Garden.</i></p> + +<hr /> + + + + +<h2><a name="art13" id="art13"></a>SUCCESSION OF FOREST GROWTHS.</h2> + + +<p>The following is from an address delivered by Mr. Robert Douglas +before the Association of American Nurserymen at the meeting in +Chicago recently.</p> + +<p>It is the prevailing and almost universal belief that when native +forests are destroyed they will be replaced by other kinds, for the +simple reason that the soil has been impoverished of the constituents +required for the growth of that particular tree or trees. This I +believe to be one of the fallacies handed down from past ages, taken +for granted, and never questioned. Nowhere does the English oak grow +better than where it grew when William the Conqueror found it at the +time he invaded Britain. Where do you find white pines growing better +than in parts of New England where this tree has grown from time +immemorial? Where can you find young redwoods growing more thriftily +than among their giant ancestors, nearly or quite as old as the +Christian era?</p> + +<p>The question why the original growth is not reproduced can best be +answered by some illustrations. When a pine forest is burned over, +both trees and seeds are destroyed, and as the burned trees cannot +sprout from the stump like oaks and many other trees, the land is left +in a condition well suited for the germination of tree seeds, but +there are no seeds to germinate. It is an open field for pioneers to +enter, and the seeds <a name="Page_11363" id="Page_11363"></a>which arrive there first have the right of +possession. The aspen poplar (<i>Populus tremuloides</i>) has the advantage +over all other trees. It is a native of all our northern forests, from +the Atlantic to the Pacific. Even fires cannot eradicate it, as it +grows in moist as well as dry places, and sprouts from any part of the +root. It is a short-lived tree, consequently it seeds when quite young +and seeds abundantly; the seeds are light, almost infinitesimal, and +are carried on wings of down. Its seeds ripen in spring, and are +carried to great distances at the very time when the ground is in the +best condition for them. Even on the dry mountain sides in Colorado, +the snows are just melting and the ground is moist where they fall.</p> + +<p>To grow this tree from seed would require the greatest skill of the +nurseryman, but the burnt land is its paradise. Wherever you see it on +high, dry land you may rest assured that a fire has been there. On +land slides you will not find its seeds germinating, although they +have been deposited there as abundantly as on the burned land.</p> + +<p>Next to the aspen and poplars comes the canoe birch, and further north +the yellow birch, and such other trees as have provision for +scattering their seeds. I have seen acorns and nuts germinating in +clusters on burned lands in a few instances. They had evidently been +buried there by animals and had escaped the fires. I have seen the red +cherry (<i>Prunus Pennsylvanica</i>) coming up in great quantities where +they might never have germinated had not the fires destroyed the +debris which covered the seed too deeply.</p> + +<p>A careful examination around the margin of a burned forest will show +the trees of surrounding kinds working in again. Thus by the time the +short-lived aspens (and they are very short-lived on high land) have +made a covering on the burned land, the surrounding kinds will be +found re-established in the new forest, the seeds of the conifers, +carried in by the winds, the berries by the birds, the nuts and acorns +by the squirrels, the mixture varying more or less from the kinds +which grew there before the fire.</p> + +<p>It is wonderful how far the seeds of berries are carried by birds. The +waxwings and cedar birds carry seeds of our tartarean honeysuckles, +purple barberries and many other kinds four miles distant, where we +see them spring up on the lake shore, where these birds fly in flocks +to feed on the juniper berries. It seems to be the same everywhere. I +found European mountain ash trees last summer in a forest in New +Hampshire; the seed must have been carried over two miles as the crow +flies.</p> + +<p>While this alternation is going on in the East, and may have been +going on for thousands of years, the Rocky Mountain district is not so +fortunate. When a forest is burned down in that dry region, it is +doubtful if coniferous trees will ever grow again, except in some +localities specially favored. I have seen localities where short-lived +trees were dying out and no others taking their places. Such spots +will hereafter take their places above the timber line, which seems to +me to be a line governed by circumstances more than by altitude or +quality of soil.</p> + +<p>There are a few exceptions where pines will succeed pines in a +burned-down forest. <i>Pinus Murrayana</i> grows up near the timber line in +the Rocky Mountains. This tree has persistent cones which adhere to +the trees for many years. I have counted the cones of sixteen years on +one of these trees, and examined burned forests of this species, where +many of the cones had apparently been bedded in the earth as the trees +fell. The heat had opened the cones and the seedlings were growing up +in myriads; but not a conifer of any other kind could be seen as far +as the fire had reached.</p> + +<p>In the Michigan Peninsula, northern Wisconsin and Minnesota, <i>P. +Banksiana</i>, a comparatively worthless tree, is replacing the valuable +red pine (<i>P. resinosa</i>), and in the Sierras <i>P. Murrayana</i> and <i>P. +tuberculata</i> are replacing the more valuable species by the same +process.</p> + +<p>In this case, also, the worthless trees are the shortest lived. So we +see that nature is doing all that she can to remedy the evil. Man only +is reckless, and especially the American man. The Mexican will cut +large limbs off his trees for fuel, but will spare the tree. Even the +poor Indian, when at the starvation point, stripping the bark from the +yellow pine (<i>P. ponderosa</i>), for the mucilaginous matter being formed +into sap wood, will never take a strip wider than one third the +circumference of the tree, so that its growth may not be injured.</p> + +<p>We often read that oaks are springing up in destroyed forests where +oaks had never grown before. The writers are no doubt sincere, but +they are careless. The only pine forests where oaks are not intermixed +are either in land so sandy that oaks cannot be made to grow on them +at all, or so far north that they are beyond their northern limit. In +the Green Mountains and in the New England forests, in the pine +forests in Pennsylvania, in the Adirondacks, in Wisconsin and +Michigan—except in sand—I have found oaks mixed with the pines and +spruces. In northwestern Minnesota and in northern Dakota the oaks are +near their northern limit, but even there the burr oak drags on a bare +existence among the pines and spruces. In the Black Hills, in Dakota, +poor, forlorn, scrubby burr oaks are scattered through the hills among +the yellow pines. In Colorado we find them as shrubs among the pines +and Douglas spruces. In New Mexico we find them scattered among the +piñons. In Arizona they grow like hazel bushes among the yellow pines. +On the Sierra Nevada the oak region crosses the pine region, and +scattering oaks reach far up into the mountains. Yet oaks will not +flourish between the one hundredth meridian and the eastern base of +the Sierras, owing to the aridity of the climate. I recently found +oaks scattered among the redwoods on both sides of the Coast Range +Mountains.</p> + +<p>Darwin has truly said, "The oaks are driving the pines to the sands." +Wherever the oak is established—and we have seen that it is already +established whereever it can endure the soil and climate—there it +will remain and keep on advancing. The oak produces comparatively few +seeds. Where it produces a hundred, the ash and maple will yield a +thousand, the elm ten thousand, and many other trees a hundred +thousand. The acorn has no provision for protection and transportation +like many tree seeds. Many kinds are furnished with wings to float +them on the water and carry them in the air. Nearly every tree seed, +except the acorn, has a case to protect it while growing, either +opening and casting the seeds off to a distance when ripe or falling +with them to protect them till they begin to germinate. Even the +equally large seeds of other kinds are protected in some way. The +hickory nut has a hard shell, which shell itself is protected by a +strong covering until ripe. The black walnut has both a hard shell and +a fleshy covering. The acorn is the only seed I can think of which is +left by nature to take care of itself. It matures without protection, +falls heavily and helplessly to the ground, to be eaten and trodden on +by animals, yet the few which escape and those which are trodden under +are well able to compete in the race for life. While the elm and maple +seeds are drying up on the surface, the hickories and the walnuts +waiting to be cracked, the acorn is at work with its coat off. It +drives its tap root into the earth in spite of grass, and brush, and +litter. No matter if it is shaded by forest trees so that the sun +cannot penetrate, it will manage to make a short stem and a few leaves +the first season, enough to keep life in the root, which will drill in +deeper and deeper. When age or accident removes the tree which has +overshadowed it, then it will assert itself. Fires may run over the +land, destroying almost everything else, the oak will be killed to the +ground, but it will throw up a new shoot the next spring, the root +will keep enlarging, and when the opportunity arrives it will make a +vigorous growth, in proportion to the strength of the root, and throw +out strong side roots, and after that care no more for its tap root, +which has been its only support, than the frog cares for the tail of +the tadpole after it has got on its own legs.</p> + +<p>There is no mystery about the succession of forest growths, nothing in +nature is more plain and simple. We cannot but admire her wisdom, +economy, and justness, compensating in another direction for any +disadvantage a species may have to labor under. Every kind of tree has +an interesting history in itself. Seeds with a hard shell, or with a +pulpy or resinous covering which retards their germination, are often +saved from becoming extinct by these means.</p> + +<p>The red cedar (<i>Juniperus Virginiana</i>) reaches from Florida to and +beyond Cape Cod; it is among the hills of Tennessee, through the +Middle States and New England. It is scattered through the Western +States and Territories, at long distances apart, creeping up the +Platte River, in Nebraska. (I found only three in the Black Hills, in +Dakota, in an extended search for the different trees which grow +there. Found only one in a long ramble in the hills at Las Vegas, New +Mexico.) Yet this tree has crept across the continent, and is found +here and there in a northwesterly direction between the Platte and the +Pacific Coast. It is owing to the resinous coating which protects its +seeds that this tree is found to-day scattered over that immense +region.</p> + +<hr /> + +<div class="center">[<span class="smcap">NATURE.</span>]</div> + + + + +<h2><a name="art04" id="art04"></a>THE "HATCHERY" OF THE SUN-FISH.</h2> + + +<p>I have thought that an example of the intelligence (instinct?) of a +class of fish which has come under my observation during my excursions +into the Adirondack region of New York State might possibly be of +interest to your readers, especially as I am not aware that any one +except myself has noticed it, or, at least, has given it publicity.</p> + +<p>The female sun-fish (called, I believe, in England, the roach or +bream) makes a "hatchery" for her eggs in this wise. Selecting a spot +near the banks of the numerous lakes in which this region abounds, and +where the water is about 4 inches deep, and still, she builds, with +her tail and snout, a circular embankment 3 inches in height and 2 +thick. The circle, which is as perfect a one as could be formed with +mathematical instruments, is usually a foot and a half in diameter; +and at one side of this circular wall an opening is left by the fish +of just sufficient width to admit her body, thus:</p> + + +<div class="figcenter"> +<img src="./images/13.png" alt="Sunfish hatchery." title="" /> +</div> + + +<p>The mother sun-fish, having now built or provided her "hatchery," +deposits her spawn within the circular inclosure, and mounts guard at +the entrance until the fry are hatched out and are sufficiently large +to take charge of themselves. As the embankment, moreover, is built up +to the surface of the water, no enemy can very easily obtain an +entrance within the inclosure from the top; while there being only one +entrance, the fish is able, with comparative ease, to keep out all +intruders.</p> + +<p>I have, as I say, noticed this beautiful instinct of the sun-fish for +the perpetuity of her species more particularly in the lakes of this +region; but doubtless the same habit is common to these fish in other +waters.</p> + +<p class="signature">William L. Stone.</p> + +<p>Jersey City Heights, N.J.</p> + +<hr /> + + + + +<h2><a name="art12" id="art12"></a>ANCIENT LAKE DWELLINGS.</h2> + + +<p>Among the many traces which man has left of his existence in long past +ages on the face of the earth, says a correspondent of the <i>Scotsman</i>, +none are more interesting and instructive than the lake dwellings of +Switzerland and other countries, which have been discovered within the +last fifty years or so. Although these relics of the past are far more +modern than those which we referred to in a late article on "Primeval +Man," and are probably included within the range of Egyptian and +other chronologies, yet they stretch far beyond the historic period, +so far as Europe is concerned, and throw a flood of light on the +habits of our ancestors, or at any rate predecessors, in these +regions. We are tolerably well acquainted with the history of the Jews +when David worked his way up from the shepherd's staff to the royal +scepter, or when Joshua drove out the Canaanites and took possession +of their land, but of what was going on in Europe in these times we +have hitherto had no knowledge whatever. These lake dwellings, +however, were in all probability inhabited by human beings somewhere +about the time when the events we have referred to took place, and may +have been inhabited before the earlier of them.</p> + +<p>The first hint we had of the existence of these remarkable dwellings +was obtained in 1829, when an excavation was being made on the shore +of a Swiss lake. Some wooden piles, apparently very old, and other +antiquities were found by the workmen. Not much attention, however, +was paid to this discovery till 1854, when a Mr. Aeppli drew attention +to some remains of human handiwork found near his house, in part of +the bed of a lake which had been left dry during a season of great +drought. The workmen employed in recovering some land from the lake +found the heads of a great many wooden piles protruding through the +mud, and also a number of stags' horns, and implements of various +descriptions. Stimulated by this discovery, search was made in various +lakes, and the result was truly astonishing. In every direction +remains of the habitations of prehistoric man were discovered, and +relics were found in such abundance that the history of this unknown +past could be traced through long ages, and the habits of the people +ascertained with a very considerable amount of probability. The +details are so numerous that it would be impossible in the space at +our disposal to go into them all.</p> + +<p>Of course, during the long time that has elapsed since these +structures were erected, their remains have been reduced to mere +ruins, and it is only by comparing one with another that we are able +to picture to ourselves what they were originally like and what sort +of life was led by the men who inhabited them. The oldest of these +dwellings belong to the stone age, when man had not acquired any +knowledge of the use of metal; when all his instruments were merely +sharpened stones, fixed in wooden handles, or pieces of bone, horn, or +other natural material. They are therefore somewhat roughly finished, +but at the same time exhibit considerable ingenuity and skill. The +method of construction seems to have been somewhat as follows: A +suitable situation, not far from the shore, where the water was not +very deep, having been fixed upon, these prehistoric builders drove +into the muddy bottom of the lake a number of piles or long stakes, +arranged generally pretty close together, and in some sort of regular +order. These piles were formed generally from stems of trees, with the +bark on, but occasionally from split wood. The ends were sharpened to +a point by the aid of fire or by cutting with stone axes. On a +sufficient number being driven in, and their upper ends brought to a +level above the surface of the water, platform beams were laid across, +fastened by wooden pegs, or in some cases fixed into notches cut in +the heads of the vertical piles. The platform was generally very +roughly made, just a series of unbarked stems placed side by side and +covered with layers of earth or clay, with numerous openings through +which refuse of all kinds fell into the water beneath. In many cases +connection with the shore was made by means of a narrow bridge or +gangway, constructed in the same manner. On this rude platform huts +were erected by driving small piles or stakes which projected above +the floor, and to these were fastened boards standing edgeways like +the skirting of our ordinary rooms, and marking out the size of each +building. The walls of the huts were formed of small branches of twigs +interwoven and plastered over with clay. The roof was made of straw or +reeds like a thatched cottage. In size these huts were probably +eighteen to twenty feet long, eight or ten feet broad, and about six +feet high. They may have been divided into rooms, but there is no +evidence of this. Each was provided with a hearth formed of three or +four slabs of stone. The number of huts in each settlement must have +been considerable, in fact, they must have formed villages of no mean +extent, for as many as forty, fifty, or even a hundred thousand piles +have been found spread over a large extent of ground, forming the +foundation of one such settlement. It is probable, however, that these +were not so numerous when first erected, but were gradually added to +as the population increased. This fact, along with many others, shows +that these dwellings were inhabited for long periods of time, during +which the population pursued their ordinary life in comparative peace +and quietness in their island homes.</p> + +<p>Such is, in brief, a general account of these remarkable structures. +Of course there were several variations in the methods of fixing these +piles, one of which may be mentioned as showing the ingenuity of the +builders. Where the piles did not get a firm hold of the lake bottom, +they carried out in boats or rafts loads of stones, which they threw +down between the piles, thus firmly fixing them, just as modern +engineers sometimes do for a similar purpose. As to the habits of the +people who dwelt in these lake dwellings, we get a considerable amount +of information from the various implements, refuse, etc., which fell +through the imperfectly closed platforms into the lake, and which have +been preserved in the mud at the bottom. They were fishers, hunters, +shepherds, and agriculturists. Skeletons of fish are found in large +abundance, and in some settlements even the fishing nets, and hooks +made of boar's tusks, have been discovered. Then again there is an +abundance of remains of the hunter's feast; bones of the stag, wild +boar, bear, wolf, otter, squirrel, and many other wild animals are +found in rich profusion, and often these are split and the marrow +extracted. These ancient men, however, did not entirely rely on such +precarious provision for their wants, but were so far advanced in +civilization that they kept cattle and domestic animals of various +kinds. They possessed dogs in great numbers, as well as cows, sheep, +goats, and pigs, and in winter time had these housed on their +settlements, as among the remains found are litters of straw, etc., +which had evidently served as bedding for these animals. This, of +course, necessitated the gathering of grass or other material for +their food. They also cultivated wheat, barley, flax, and a number of +other <a name="Page_11364" id="Page_11364"></a>vegetable products. Their methods of cultivation were no doubt +very rude, consisting of a mere scratching of the ground with crooked +branches of trees or with simple instruments made of stags' horn; but, +nevertheless, they succeeded in getting very good results. Among the +relics which they have left are found stones for crushing corn, the +grain which they used, and even the very cakes or bread which they +made. There are also fruits, such as the apple, pear, nut, etc.; so +that the bill of fare of prehistoric man was by no means contemptible. +He had fish, game, beef, mutton, pork, bread, and fruit, besides a +plentiful supply of water from the lake at his door. He was acquainted +with the potter's art, and manufactured earthen vessels of various +kinds. He seems to have produced two kinds—a coarser and a finer; the +former made from clay mixed with a quantity of grains of stone, and +the latter of washed loam. These he ornamented in an elementary +fashion with certain lines and marks. Some of the vessels he used have +been found with a burnt crust of the porridge which he had been making +adhering. As to his clothes, these were probably formed in great part +from the skins of wild or domestic animals, but he also used fabrics +made from flax, which he had learned to weave, as remains of cloth, +twine, rope, etc., are not infrequently found in his dwellings.</p> + +<p>One prominent feature in the history of these lake dwellers is their +gradual advance in the arts of civilization. While the main features +of their settlements remain very much the same during the whole period +of their residence, there is a gradual improvement in the details; the +settlements become larger, and the implements, etc., better finished. +And this is especially observable in the change of material which the +dweller uses. In the earlier stages of his existence stone is the +predominant feature, all his knives, saws, chisels, axes, etc., are +made from this substance; but as time rolls on, one or two implements +are found made of bronze, which is a mixture of tin and copper, and +requires for its production a certain amount of knowledge and +mechanical skill. Gradually the number of bronze implements increases +until eventually stone is superseded altogether, and improved forms of +weapons of war make their appearance, and his work has a more finished +look, arising from his improved implements. Whether the manufacture of +bronze was an original discovery of his own, or whether it was an +importation from some more advanced race, is not certainly known; but +as he undoubtedly had intercourse with the East, it is probable that +the first bronze was imported, and that afterward he discovered the +way to manufacture it himself. However this may be, it seems evident +that the introduction of this material greatly aided his development. +As stone gave place to bronze, so in the course of time this latter +gave place to iron, probably introduced in the same manner some +considerable time before the dawn of history; and this metal held its +place until these habitations were finally abandoned.</p> + +<p>With regard to the religion of these lake dwellers, if they had any, +nothing is known. From some curious objects formed somewhat like the +crescent of the moon, which are found in considerable numbers, it has +been supposed that they worshiped that body; but there seems to be +really no evidence for this supposition, and these objects may only +have been ornaments, or perhaps charms, fixed above the doors of their +huts something after the manner of the horse shoe nailed over the door +in modern times to keep away evil spirits. So far as can be inferred +from the remains that have been examined, the same race seems to have +inhabited these dwellings from their commencement to their end. There +is no appearance of invasion from without; all seems continuous. +Probably his race came in early time from the East, and were a +pastoral people, with flocks, herds, and domestic animals, and built +their peculiar habitations to protect themselves from human enemies. +Certainly the arrangements were well fitted for the purpose in those +days, when the club and the spear were almost the only weapons of +offense. Dr. Keller, who has investigated this subject with great +care, is of the opinion that these lake dwellers were a branch of the +great Celtic race.</p> + +<hr /> + +<div class="center">[New England Farmer.]</div> + + + + +<h2><a name="art01" id="art01"></a>HOW TO RAISE TURKEYS.</h2> + + +<p>The best feed for young turkeys and ducks is yelks of hard-boiled +eggs, and after they are several days old the white may be added. +Continue this for two or three weeks, occasionally chopping onions +fine and sometimes sprinkling the boiled eggs with black pepper; then +give rice, a teacupful with enough milk to just cover it, and boil +slowly until the milk is evaporated. Put in enough more to cover the +rice again, so that when boiled down the second time it will be soft +if pressed between the fingers. Milk must not be used too freely, as +it will get too soft and the grains will adhere together. Stir +frequently when boiling. Do not use water with the rice, as it forms a +paste and the chicks cannot swallow it. In cold, damp weather, a half +teaspoonful of Cayenne pepper in a pint of flour, with lard enough to +make it stick together, will protect them from diarrhea. This amount +of food is sufficient for two meals for seventy-five chicks. Give all +food in shallow tin pans. Water and boiled milk, with a little lime +water in each occasionally, is the best drink until the chicks are two +or three months old, when loppered and buttermilk may take the place +of the boiled milk. Turkeys like best to roost on trees, and in their +place artificial roots may be made by planting long forked locust +poles and laying others across the forks.—<i>American Agriculturist.</i></p> + +<h3>HOW TO RAISE TURKEYS.</h3> + +<p>Keep the turkey hens tame by feeding them close to the house. Have two +or three barrels in sheltered corners containing plenty of straw or +leaves for them to lay in. Gather the eggs every evening, as turkey +eggs are very easily chilled. Keep the eggs in a woolen cloth on end +and turn them every three days. Set the first seven eggs under a +chicken hen, as they get too old before the turkey hen will go to +sitting. Make a board pen ten or twelve feet square and twelve or +fourteen inches high. Put a coop in it and put your hen and turkeys in +it. Feed the hen with corn and the turkeys soaked wheat bread (corn +meal will kill them), until they are a week old (I feed five or six +times a day). Then feed wheat until they are big enough to eat corn. +Give plenty of fresh water in a shallow vessel. Keep the mother in +the pen until they are large enough to fly over the top of the boards. +Let them out awhile about the middle of the day. Shut them in at +night. A turkey hen does not like to be shut up, but have a good big +coop for her and she will go in. Don't let the little turkeys get +their backs wet until they are feathered. The turkey hen will sit down +when night comes just where she happens to be, but if you drive her +home a few times she will come herself after that. Always feed them +when they come home, no matter if they are full of "hoppers." Have +your No. 2 pen in the orchard under an apple tree where it is shady. +Have the turkey hen's pen close to the chicken hen's pen, so that when +the chicken hen weans her turkeys, they will soon learn to go with the +turkey hen. Give them a dose of black pepper in their feed every cold +rain. And never, no never, get excited and in a hurry while working +with turkeys if you don't want them to get wild and fly all over the +plantation. Three or four weeks before selling, feed all the corn they +will eat.</p> + + +<h3>FOOD HINTS.</h3> + +<p>Restrain your desire to count your young turkeys, and let them alone +for twenty-four hours after they get into this world. Remove them to a +clean, airy, roomy coop, and give them boiled eggs, stale wheat bread +crumbs just moistened with milk or water, "Dutch" cheese, or a mixture +of all these.</p> + +<p>For the first two weeks feed entirely with the eggs, bread, curds, +cooked rice and cooked oatmeal. About the third week commence feeding +cooked cornmeal; and from that on they may have any cooked food that +would be suitable for chickens of the same age. Season all food +slightly with salt and pepper, and twice a week add a level +tablespoonful of bone meal to a pint of feed. Never feed any sour food +or sloppy food of any kind, except sour milk, and never feed any +uncooked food of any kind until after they have thrown out the red on +their heads. Feed often, five or six times a day, until after they are +three months old; then, if insects are numerous, you may gradually +reduce the number of meals per day to three or even two.</p> + +<p>After they are three months old they may be given wheat, cracked corn, +etc., but not whole corn until they are five months old. Keep the +coops dry and clean, and the turkeys out of the dew and rain until +they are fully feathered, and have thrown out the red. Dampness and +filth will kill young turkeys as surely as a dose of poison. For the +first few days confine the poults to the limits of the coop and safety +run; then, if all appear strong and well, give the mother hen and her +brood liberty on pleasant days after the dew is off.</p> + +<p>If they get caught out in a shower, get them to shelter as soon as +possible; and if they are chilled take them to the house and +thoroughly dry and warm them. See that the little turkeys come home +every night. The turkey mother must, for the first few nights, be +hunted up and driven home. After they are three months old, turkeys +are quite hardy, and may be allowed range at all times. If turkeys +that are well cared for, and have always seemed all right, show signs +of drooping when about six weeks or two months old, give Douglas +mixture in the drink or food, and add a little cooked meat to the food +once a day.—<i>The Practical Farmer.</i></p> + + +<h3>ABOUT SITTING.</h3> + +<p>For an ordinary place, select from a good breed (I prefer the bronze) +a large gobbler and two or three hens. As soon as the warm weather +comes, place about the barn in sheltered places two or three barrels +on their sides, and in them make nice nests. In these the hens will +lay. Gather the eggs every day, keeping them in a cool place. When a +box contains 23 eggs mark it No. 1 and begin to fill a second box, and +when it contains 23 eggs mark it No. 2 and so continue. It is well to +leave turkey hens on the nest two or three days, for they often lay +one or two eggs after they begin to show signs of sitting.</p> + +<p>When you have decided to sit a hen, give her a good nest and 15 eggs +and at the same time give a common hen eight eggs. These, when +hatched, are all to be given to the turkey hen. Never try to raise +turkeys with a domestic fowl. If you have no place free of grass, you +can start turkeys with difficulty. Feeding is of the greatest +importance. For the first week I have found wheat bread moistened in +water the most satisfactory. If you can feed them by sunrise for the +first three or four weeks, you need lose hardly a bird. Each evening +try and call them nearer and nearer home, so that you will not be +troubled with their wandering to the neighbors'. As early as possible +train them to roost high, so as to be out of danger at night. Bird +dogs are often very destructive to turkeys, at times destroying a +whole flock in a single night. Fatten with corn. The turkey crop ought +to be one of the most profitable on our farms.</p> + +<p class="signature">Dr. G.G. Groff.</p> +<p>Pennsylvania.</p> + + +<h3>GRAHAM.</h3> + +<p>Turkeys want care, especially for the first two or three weeks. I feed +graham and wheat bread, made by scalding the flour, making a very +stiff dough, and baking in a hot oven; soak over night in cold water. +I also give them plenty of young onions, cutting them up with +scissors. Be careful not to let young turkeys out in the morning while +the grass is wet. After the birds are two weeks old I feed wheat, but +no corn until they are about a month old. I like hen mothers best, for +turkey mothers are rangers, and do not take kindly to being kept in a +coop. The bread will keep a week if made right, but do not soak more +than will be wanted in a day, as it soon sours. I feed scraps from the +table, such as potatoes and bits of meat cut very fine, but not much +of the latter to young birds. I rarely lose a bird.—<i>Mrs. E. Reith, +in Homestead.</i></p> + + +<h3>CARE AND GENERAL MANAGEMENT.</h3> + +<p>In turkey raising the one who is the most careful and attentive to the +small things is the most successful. The first laying of eggs should +be set under a chicken hen. The turkey hen will, after a few days' +confinement, lay another batch of eggs. A good-sized hen will cover +and care for ten eggs; a turkey hen, seventeen. Make a large, roomy +nest of soft, fine hay—straw is too brittle and slippery. If there is +danger of lice in the nest-box, sprinkle with water in which carbolic +acid has been mixed in the proportion of eight drops to a half gallon +of water. Don't wet the eggs with this. After the eggs have been sat +on one week, sprinkle with warm water every other day, until the last +week; then every day, until they hatch. Have the water clear, and use +a flower or fine rose sprinkler. Let the water be of the same +temperature as the eggs, which can be ascertained by slipping a +thermometer under the hen for a few minutes. This softens the shells, +and as a little turkey is very weak, it is helped out easily, and is +stronger than if working long to get out.</p> + +<p>Let the little turkeys get well dried and strong enough to climb +around the edges of their nest before taking them off. Have a pen, say +six feet square, built for them, and made tight at the sides clear +down to the ground, to keep them from getting out and being chilled. +Put sand and fine gravel over the ground, and cover enough of it to +afford shelter at night and when it rains. They may be kept in this +pen the first four or five days, then let out after dew is off, and +shut up before night.</p> + +<p>For the first few days' feed, nothing is better than clabber cheese or +curd made by scalding clabbered milk until the curd separates and is +cooked, then skimmed out and fed. Mix a little black pepper with this +every other day. Meal must not be fed raw for several weeks, and then +should be mixed with sour milk instead of water. Bake the meal into +bread by mixing it, unsifted, with sour milk, and adding a little soda +and pepper. Spinach, lettuce, onion tops and any other tender greens, +chopped fine, are excellent food. From the time a turkey is hatched +until it is ready for market it should have plenty of milk. Give them +clear water to drink, for milk is a food. See that the very young ones +have milk and water in quite shallow dishes, for they are in danger of +getting wet if the dish is deep.</p> + + +<h3>GATHER THE LITTLE TURKEYS IN</h3> + +<p>at the first signs of rain, and they will soon learn to run and fly to +their coop at the first drops. Always shut them up at night, for they +are early risers and will be out long before the dew is dried off. +Don't pen them too near the house. Feed them at or near the same place +all the time and they will learn to go there when hungry. Give them a +good feed at night and they will remember to come home for it. If the +morning is dry, feed lightly and let them hunt the rest in the orchard +and fields. Keep the grass and weeds mowed around their pen and +feeding places. Mix slaked lime in the dust for them to take their +dust bath in, and sprinkle the carbolic acid and water over and around +their roosting pen. Keep pails and kettles covered, for they will get +drowned if they have half a chance, as they begin to fly so young. Of +course a turkey hen will take her young off, and care for them after a +fashion, but the safest way to make them tame is to raise them where +they may be cared for. Even if the turkey hen hatches her last batch +of eggs, it is a good plan to have a hen ready to take the little +turkeys and slip them away at night. If she still stays on her nest +give her 20 or 25 hen's eggs, and if she hatches them let her run with +the chickens. They are not so tender or so easily led astray as +turkeys are, nor as valuable.—<i>Mrs. Jas. R. Hinds, in Orange Judd +Farmer.</i></p> + +<hr /> + + + + +<h2><a name="art17" id="art17"></a>WATER AS A THERAPEUTICAL AGENT.</h2> + +<h3>By <span class="smcap">F.C. Robinson</span>, M.D.</h3> + + +<p>My experience in the use of water in almost every disease occurring in +this climate has long since satisfied me that it is less objectionable +and produces quicker and better results than any other treatment, and +can be used when all other medication is contra-indicated. Drinking +water should be pure, uncontaminated by animal or vegetable +impurities, and given <i>ad libitum</i>, unless, in rare instances, it +should cause vomiting or interfere with the capability of digesting +food. If children are comatose or delirious, as they frequently are in +typhoid fever, give water to them regularly, or force it upon them, if +they refuse to take it, as I was obliged to do with a child of six +years just recovering from that fever.</p> + +<p>It is my custom to allow cold drinks of water in all cases of measles +whenever patients desire it, and I am satisfied that it aids the early +appearance of the rash, and certainly is cooling and grateful to the +patient. Hot drinks or vile and nauseous teas are unnecessary in this +disease, and should be discarded as useless, odious, and disgusting. +If congestion of the lungs or any intercurrent inflammation occurs, or +the rash is much delayed, a hot water bath or the old reliable corn +sweat will break up the complication with amazing rapidity, and if the +head is kept cool, will not generally be unacceptable to the patient.</p> + +<p>Hot baths reduce temperature by causing free perspiration afterward, +and cold packs reduce it by cooling the surface sufficiently long to +reduce the heat of the blood, and, if used judiciously, seldom fail of +success. I have reduced the temperature four degrees in two hours by +wrapping around a child a sheet wet with tepid water, and no other +covering. Cold packs are sometimes objectionable, because of their +depressing effects, and should only be used to reduce high temperature +and when there is no congestion or inflammation of any of the vital +organs of the body.</p> + +<p>Cold water poured in a small stream from a pitcher upon the head for +five or ten minutes will often relieve headache, and is a benefit in +all inflammatory brain diseases, if, at the same time, you can put the +feet into hot water containing mustard or pepper.</p> + +<p>Large enemas of warm water will care for spasmodic colic, and I have, +in one instance, relieved strangulated hernia by the same method, and +at another time the same result was accomplished by a large injection +of warm linseed oil. I have often applied a cloth wet with cold water +upon the throats of children suffering with spasmodic croup, with +satisfactory results.</p> + +<p>I have seen infants suffering with diarrhea or summer complaint, +sleepless, worrying, fretting, or crying from thirst, begging for +water, and the mother or nurse afraid to give it more than a +teaspoonful or two at a time, saying that it vomited everything it +drank as soon as taken. I have often, when visiting such cases, called +for a glass of cold water, and, to the surprise of the mother, would +allow it to take all it could drink, which usually would be retained, +and the child would soon be wrapped in a refreshing sleep. Without +medicine, a proper regulation of the child's diet would soon restore +it to health again.</p> + +<p><a name="Page_11365" id="Page_11365"></a>The spasms of children, from whatever causes, or the eclampsia from +uræmic poisoning, are often readily controlled when immersed in hot +water or given a hot vapor bath or corn sweat. If the convulsions of +children are accompanied by a high temperature, put them into water of +100° and then gradually cool it down to 68° or 70°, and then keep them +in a room of the same temperature, with little covering. If the +temperature rises, repeat the treatment as frequently as necessary, +and I think you will not be disappointed in the results.</p> + +<p>Scarlet fever and diphtheria, two of the most dreaded and formidable +diseases of children, are largely shorn of their terrors when, in +addition to an early and thorough medicinal treatment, the little +patients are bathed in as warm water as the surface will allow +frequently, or for thirty minutes wrapped in a warm, wet blanket, +followed by warm, dry coverings, to maintain the perspiration that +such treatment usually produces. It has proved to me a valuable aid in +eliminating from the blood the specific poison which causes these +diseases, and I can safely recommend it to your notice and trial.</p> + +<p>There is no disease more favorably influenced by this treatment than +pneumonia, and in mild cases one daily warm bath or sweat, without +medicine, will be sufficient to arrest this disease, and it is among +the first things I usually order. If I find a child or infant with a +temperature of 103° to 105°, short, dry, and painful cough, +dyspnœa, rapid pulse, great thirst, or vomiting, with dry +crepitation in any part of the lung tissue, I order it rolled up in a +blanket or sheet coming out of hot water, and in thirty minutes change +it to warm, dry blankets, and soon the little fretful, worrying +sufferer would rest in a quiet, peaceful sleep.—<i>Peoria Med. Mo.</i></p> + +<hr /> + + + + +<h2><a name="art16" id="art16"></a>ON THE HEALTH VALUE TO MAN OF THE SO-CALLED DIVINELY BENEFICENT +GIFT, TOBACCO.</h2> + +<h3>By <span class="smcap">J.M.W. Kitchen</span>, M.D., New York.</h3> + + +<p>With perhaps the exception of heredity, the question of stimulants and +narcotics in their relation to the physical welfare of the race is +second to none in importance. With trifling exceptions, the whole +world is addicted to their use. The universality of such use has led +many to consider them a necessity to man, and that they are God's +gifts to him, and, if rightly used, are of physical benefit. It may +not be a perversion of judgment to consider that their widespread +popular use is greatly due to the efforts of the race to gain +anæsthesia for, and distraction from, those pains and punishments that +are the inevitable sequence of departure from hygienic and social law +on the part of the individual, his ancestry, and society in general.</p> + +<p>The taste for these things is acquired, not natural, though the +acquisition may be through hereditary influence. An idea is held by a +majority of even fairly intelligent individuals that there is a +justifiable, harmless, and even beneficial use of these substances by +the general public, though acknowledging that beyond a certain +indefinite line this use becomes an abuse.</p> + +<p>I believe that there may occasionally be cases in which the physical +benefits derived from their use outweigh the injury they inflict, but +I think this use is very much less than is generally supposed, and if +we can judge from the preponderance of evil effected by such use, +these substances ought to be considered as the materialized curses of +God rather than as beneficent gifts. The prevalent idea as to the +beneficent nature of these substances I consider to be a delusion that +can only be explained upon the hypothesis that there is a widespread +lack of appreciation of the fact that, though they may have an +immediate pleasant and agreeable effect upon the body, their injurious +effects are cumulative, and are usually ultimate, and so distant as to +be difficult of direct connection with their cause to ordinary +observation. The more moderate the use of these substances, the more +remotely is the effect removed from the cause and more difficult of +detection. That the ordinary habitual, so-called moderate use of +stimulants and narcotics, such as tea, coffee, tobacco, and alcohol, +is, in the vast majority of cases, really an abuse, is a proposition +that I think should be admitted by all who have given the subject an +unbiased study.</p> + +<p>The idea that the user of tobacco and other injurious substances will +be cognizant of the injury inflicted by habitual use in moderate or +even excessive amounts is an undoubted fallacy. The daily, weekly, or +monthly injurious effect may be entirely unobservable to even trained +physicians, and yet the ultimate cumulative effect may be fatal. I can +instance numerous cases of physicians directly fatally injured by the +use of alcohol, who have never had the slightest cognizance of the +fact; and I can also instance cases of grave disease from the use of +tobacco where the patients never have believed that tobacco has been +the cause of their troubles, even after a unanimous opinion to that +effect has been expressed by a number of competent medical advisers. +The habitual consumption of opium, in doses of any amount, is +generally admitted by most people to be physically injurious outside +of its strict medicinal application. Moderate indulgence in alcohol as +a beverage is beginning to acquire a very widespread evil reputation. +But how about tobacco? Tea and coffee we can confidently leave to the +consideration of a somewhat remote posterity of a considerably +advanced intelligence and elevated hygienic ideals.</p> + +<p>The relation of tobacco to the physical welfare of man can only be +fairly estimated by viewing the subject in its broadest aspect; by +considering its effects upon the race as a whole rather than in +individual cases; by taking into consideration economical and other +social conditions that at first sight might be considered as having +little relevancy to the medical side of the subject. But there can be +no just consideration of the matter otherwise. The direct deleterious +effects of the immoderate use of tobacco are readily observable; but +the great bulk of the evil physical effects due to the moderate use of +this plant are of an intermediate nature and not directly noticeable; +nevertheless, they are real, and worthy of medical attention. The +plainly marked results following the use of tobacco in relatively +large amounts seem to be due to quick and extreme interference with +nutrition, and a diminution of function of all kinds, which may be +represented by anything from a slight decrease of appetite and +digestive ability up to a complete loss of function of almost any +important organ. Tobacco has stimulating as well narcotic properties, +but as ordinarily used its stimulating effect appears to be slight as +compared with its narcotic influence. In this respect it differs from +alcohol, the use of which, owing to the usual method of introduction +in large amounts through the stomach, produces directly, by +stimulation, readily noticeable structural changes. But with tobacco +the direct evil results are mostly of a functional character, and are +more generally diffused, owing to the usual slow manner of +introduction into the body. These two properties have an effect upon +the body in moderate use as well as in immoderate use, the effect +being simply in proportion to the quantity used, though the effects of +moderate use may not be measurable by ordinary means. It is easy to +see the effects of large amounts of tobacco in the stunted growth of +adolescents; in functional cardiac disorders; in intellectual +sluggishness, loss of memory, and color blindness; in loss of +appetite, and other neuroses of motion, and marked blunting of various +functions of sensation, and in degeneracy of descendants; but that +lesser evils are produced must be proved mostly by inference, +circumstantial collateral evidence, and analogy.</p> + +<p>The greater evils that are the outcome of a moderate use of tobacco +are probably due to prolonged slight interference with nutrition, and +consequent general decrease of vitality, which renders the individual +more susceptible through indirect influence to the invasion of +disease, and which lessens the capacity for productive effort.</p> + +<p>It is of course difficult, and perhaps even impossible, to accurately +estimate the value of tobacco to the race; but let us glance at the +pros and cons, and then each one can roughly estimate for himself. +Tobacco may be used medicinally, but it is a dangerous and uncertain +remedy, and it probably has not one medicinal use that cannot be more +suitably met by other remedies. One can readily imagine easier +digestion as the result of the sedative influence of the after-dinner +cigar upon a disquieted nervous system, especially if the coincident +irritation of alcohol and coffee have need of correction; but it can +also be imagined that in most of such cases the remedy has been the +cause of and will further increase the disordered condition, and that +nutrition of deficiently nourished nerve tissue is rationally +indicated rather than partial narcotization. There then remains, so +far as I can see, the solace of moderate anæsthesia and, occasionally, +of occupation for idlers, as the only items that can be placed to the +credit of tobacco. There certainly are individual cases where such +usage may be more provocative of physical benefit than evil, but, +before judging for the race as a whole, compute the other side of the +question.</p> + +<p>Tobacco injures the general health of the public through the economic +loss caused by its consumption. The people of our country spend +annually over seven hundred millions of dollars for tobacco—twenty +per cent. more than is spent for bread. This sum represents only a +minor part of the cost of the tobacco habit to the country. The crop +is immensely exhaustive to the soil. Its culture has blighted whole +sections of fertile territory. In the time consumed by the producer +and the trader in its production, manufacture, and sale, and by the +consumer in its use, and by the general interference with vital +activity and consequent decreased productive capacity, there is +represented an almost unimaginable sum of money. Certainly the people +at large are not so well fed both as to quantity and quality, or so +thoroughly clothed, or so hygienically housed that they can afford +this gigantic economic waste.</p> + +<p>There can be little doubt that if the people had sufficient +intelligence and moral strength to taboo tobacco, this comparatively +senseless outgo would be largely devoted to supplying these and other +necessities of an exalted health status.</p> + +<p>Tobacco injures health through its moral effects. The tobacco habit is +certainly a dirty and frequently a disgusting habit, and encourages +other dirty practices. Its use tends to make men cowardly, irritable +in temper, and low in spirits. It blunts ideas of purity and courtesy, +leading to invasion of the rights of others. It is presumed that few +medical men would visit a delicate, sensitive patient after saturation +with the "fragrant" effluvia of onions, but thousands whose systems +are saturated with nicotine and who reek with nauseating odor do not +hesitate to inflict their presence on sick or well. The time will come +when the tobacco user will not be allowed to poison the atmosphere +that is the common property of the public—will not be allowed to +force the inhalation of nicotine upon the general public, to say +nothing of being allowed to poison the infants and women in his own +family. What would be said of a man who introduced poison in any +degree into the food or drink of his child? Is the poisoning of the +household atmosphere by the ignorant, thoughtless, or selfish smoker +morally more defensible? Tobacco injures health through hereditary +influence. The tobacco user begets, more certainly than the non-user, +puny children with disordered nervous conditions. Luckily for our +race, the women, who have the most important prenatal influence in +guarding its physical well-being, are practically non-users of the +plant. The general health status of the race is improving, not because +the use of tobacco or the indulgence in other questionable practices +is harmless, but because, among other things, of the great advance in +general intelligence and knowledge of hygienic law.</p> + +<p>A person, or the public in general, may practice an injurious habit, +and yet more than counteract its influence by opposing beneficial +practices.</p> + +<p>Horace Greeley said, "Show me a drunkard who does not use tobacco, and +I will show you a white blackbird." In this country, where dietetic +drinking habits are not common in the family, the weakening of moral +fiber by indulgence in tobacco is usually the introduction into the +round of vicious indulgences, and thus directly or indirectly affects +health. Smoking induces dryness of the mucous membrane of the mouth +and consequent thirst. The partially paralyzed nerve terminals want +something more stimulating than water to afford relief. Furthermore, +blunted appetite induces deficient nutrition, and consequently there +is a call for some "pick-me-up;" hence we find that the use of tobacco +tends to the habitual use of alcoholic beverages, and there are very +few habitual users of alcohol who escape without structural injuries +to the body as well as perversion of its functions. Decrease of vital +activity in all the tissues of the body marks the use of tobacco. The +tendency is toward functional paralysis, though occasional signs of +stimulative irritation are to be noticed, especially in the +respiratory passages. The interference with intellectual activity is +marked. It is said that during a period of fifty years no tobacco user +stood at the head of his class in Harvard. The accumulated testimony +of investigating observers is conclusive that, other things being +equal, users of tobacco, in schools of all grades, never do so well in +their studies as non-users.</p> + +<p>One head of a public school said he could always tell when a boy +commenced to use tobacco by the record of his recitations. Professor +Oliver, of the Annapolis Academy, said he could indicate the boy who +used tobacco by his absolute inability to draw a clean, straight line. +The deleterious effects of tobacco have become so clearly apparent +that we find its sale to minors is prohibited in France, Germany, and +various sections of this country. It is somewhat a question if, at the +present time, the race is not doing itself more injury by its use of +tobacco than it is with alcohol, because of its more universal use, +particularly by youth, and because of the respectability of the habit, +which comes of its use by a certain intelligent part of the race, +including teachers of morals and physics, and even temperance +reformers. There is a widespread sentiment in existence that it is not +a respectable thing to be even partly paralyzed by alcohol, but how +few there are who consider narcosis as in any way connected with the +use of tobacco. Its effect is more diffused and masked, and is not so +acutely serious in individual cases, but through its interference with +vital activity, tobacco is probably more generally injurious to the +race than alcohol.</p> + +<p>The editorial fiat of "too long" prevents a full exposition of the +subject, but, in closing, let me say I hear millions of tobacco users +ask, "Why, then, was this plant given to man, if its general effects +are so decidedly evil?" The question presupposes design in creation. +Without subscribing to this theory, or pretending to have solved the +mystery of the presence of evil in the world, the answer may be +suggested that the overcoming of many seductive evils becomes to man a +means of his progressive higher development. Of one thing I am +convinced, that the physical development and welfare of man is +interfered with in strict sequence to his consumption of substances +that are unnecessary for his nutrition—stimulants and narcotics +inclusive.—<i>Medical Record.</i></p> + +<hr /> + + + + +<h2><a name="art14" id="art14"></a>ACETIC ACID AS A DISINFECTANT.</h2> + + +<p>Dr. F. Engelmann, in <i>Cent. f. Gyn.</i>, claims that acetic acid +possesses equally as good antiseptic properties as carbolic acid; in +fact, that it is to be preferred, as it is completely harmless, even +if used in concentrated solutions, and that it is a valuable +hæmostatic, an advantageous addition particularly in obstetrics. +Another important property is its ease of transition into the tissues, +which, according to Engelmann's experiments, is by far greater than +that of all the other antiseptics. Of bichloride it is well known that +it forms an insoluble combination with albumen, and can therefore act +only on the surface, while acetic acid extends into the deeper tissues +with ease.</p> + +<p>Acetic acid also affects the metal of the instruments, but not as +severely as the bichloride; the forceps, for instance, may be placed +for a quarter of an hour in an irrigator filled with a three per cent. +solution of acetic acid without being injured.</p> + +<p>A pleasant effect of acetic acid is that it softens and lubricates the +skin. The author generally used a three per cent. solution; at times +he has made use of a five per cent. solution, which would easily cause +a painful burning at sore places, so that he only used the latter +strength in septic cases, as the three per cent. solution proved to be +a satisfactory antiseptic for general purposes.</p> + +<hr /> + + + + +<h2><a name="art15" id="art15"></a>COUNTER-IRRITATION IN WHOOPING COUGH.</h2> + +<h3>By <span class="smcap">G.F. Inglott</span>, M.D.</h3> + + +<p>To combat this often distressing disease I have tried the +administration of several medicines, namely, bromide of potassium, +asafœtida, valerian, morphine, belladonna, etc., and I have very +closely watched their effects, but none of them proved of much use. +Having observed, however, that during the late cholera epidemic some +of the patients admitted into the hospital under my medical charge +slept well, had their anxiety improved, and some of them ultimately +recovered, after the application of a strong counter-irritation of the +pneumogastric nerves in the neck, namely, between the mastoid process +and the angle of the lower jaw, I tried the same treatment on whooping +patients, and I have no hesitation in stating that the result was very +satisfactory. I may quote one single case of the many I have had under +treatment.</p> + +<p>A boy, aged twelve years, of weak constitution, was suffering from +frequent and intense attacks of whooping cough. At a time the fits +were so vehement that blood came out of his eyes and mouth. The case +was a severe one, and I thought it would very likely end fatally. I +prescribed several medicines, and even subcutaneous injections of +morphine, but without any avail. I then tried for the first time the +counter-irritation on both sides of the neck, and this means acted +like magic. In four or five days the patient recovered, and was able +to go to school. Since that time I have been applying the same +treatment, either on the right side only or on both, with the greatest +benefit.—<i>Br. Med. Jour.</i></p> + +<hr /> + + + + +<h2><a name="art03" id="art03"></a>DEVELOPMENT OF THE EMBRYO.</h2> + + +<p>At a recent meeting of the Physical Society, Berlin, Prof. Preyer +spoke on reflexes in the embryo. His researches extended over many +classes of animals. As representing mammals, guinea pigs were chiefly +used; and for reptiles, snakes; while in addition the embryos of +fishes, frogs, mollusks, and other lower animals were also employed. +But of all animals birds are most suitable for embryological +observations, inasmuch as with due precautions the development of one +and the same individual can be followed for a considerable time. +Birds' eggs can be incubated in a warm chamber, and by removing a +portion of the shell and replacing it by an unbroken piece from +another egg, it becomes possible <a name="Page_11366" id="Page_11366"></a>to follow the daily development of +the chick and to experiment upon it. As early as the ninetieth hour of +incubation, spontaneous "impulsive" movements may be observed, taking +place apparently without any external stimulus as a cause, and at a +time when no muscles or nerves have as yet been developed. After the +occurrence of these spontaneous movements, and at the earliest on the +fifth day of incubation, movements are observed to result from the +application of mechanical, chemical, and electrical stimuli. In order +to observe these the eggs must be allowed to cool down until all +spontaneous movements have ceased. From the tenth to the thirteenth +day more complicated and reflex actions occur on the application of +stimuli, as, for instance, movements of the eyelids, beak, and limbs; +and if the stimuli are strong, reflex respiratory movements. These +reflexes make their appearance before any ganglia have become +differentiated. Prof. Preyer considered himself justified in +concluding from this that ganglia are not essential for the liberation +of reflex actions. He intends, on some future occasion, to give a more +detailed account of these experiments, and of the conclusions which +may be drawn from them. In the discussion which ensued the conclusions +of the speaker were contested from many sides.</p> + +<hr /> + + + + +<h2><a name="art26" id="art26"></a>IRIDESCENT CRYSTALS.<a name="FNanchor_7" id="FNanchor_7"></a><a href="#Footnote_7"><sup>1</sup></a></h2> + + +<h3>By <span class="smcap">Lord Rayleigh.</span></h3> + + +<p>The principal subject of the lecture is the peculiar colored +reflection observed in certain specimens of chlorate of potash. +Reflection implies a high degree of discontinuity. In some cases, as +in decomposed glass, and probably in opals, the discontinuity is due +to the interposition of layers of air; but, as was proved by Stokes, +in the case of chlorate crystals the discontinuity is that known as +twinning. The seat of the color is a very thin layer in the interior +of the crystal and parallel to its faces.</p> + +<p>The following laws were discovered by Stokes:</p> + +<div class="note"> +<p> (1) If one of the crystalline plates be turned round in its own + plane, without alteration of the angle of incidence, the + peculiar reflection vanishes twice in a revolution, viz., when + the plane of incidence coincides with the plane of symmetry of + the crystal. [Shown.]</p> + +<p> (2) As the angle of incidence is increased, the reflected light + becomes brighter and rises in refrangibility. [Shown.]</p> + +<p> (3) The colors are not due to absorption, the transmitted light + being strictly complementary to the reflected.</p> + +<p> (4) The colored light is not polarized. It is produced + indifferently, whether the incident light be common light or + light polarized in any plane, and is seen whether the reflected + light be viewed directly or through a Nicol's prism turned in + any way. [Shown.]</p> + +<p> (5) The spectrum of the reflected light is frequently found to + consist almost entirely of a comparatively narrow band. When the + angle of incidence is increased, the band moves in the direction + of increasing refrangibility, and at the same time increases + rapidly in width. In many cases the reflection appears to be + almost total.</p> +</div> + +<div class="figcenter"> +<span class="caption"><span class="smcap">Fig.</span> 1 <span class="smcap">general scheme</span></span><br /> +<img src="./images/16.png" alt="Figs 1 and 2." title="" /><br /> +<span class="caption"><span class="smcap">Fig.</span> 2. <span class="smcap">Detail of Lazy-tongs</span></span> +</div> + +<p>In order to project these phenomena a crystal is prepared by cementing +a smooth face to a strip of glass whose sides are not quite parallel. +The white reflection from the anterior face of the glass can then be +separated from the real subject of the experiment.</p> + +<p>A very remarkable feature in the reflected light remains to be +noticed. If the angle of incidence be small, and if the incident light +be polarized in or perpendicularly to the plane of incidence, the +reflected light is polarized in the <i>opposite</i> manner. [Shown.]</p> + +<p>Similar phenomena, except that the reflection is white, are exhibited +by crystals prepared in a manner described by Madan. If the crystal be +heated beyond a certain point the peculiar reflection disappears, but +returns upon cooling. [Shown.]</p> + +<p>In all these cases there can be little doubt that the reflection takes +place at twin surfaces, the theory of such reflection (<i>Phil. Mag.</i>, +Sept., 1888) reproducing with remarkable exactness most of the +features above described. In order to explain the vigor and purity of +the color reflected in certain crystals, it is necessary to suppose +that there are a considerable number of twin surfaces disposed at +approximate equal intervals. At each angle of incidence there would be +a particular wave length for which the phases of the several +reflections are in agreement. The selection of light of a particular +wave length would thus take place upon the same principle as in +diffraction spectra, and might reach a high degree of perfection.</p> + +<p>In illustration of this explanation an acoustical analogue is +exhibited. The successive twin planes are imitated by parallel and +equidistant disks of muslin (Figs. 1 and 2) stretched upon brass rings +and mounted (with the aid of three lazy-tongs arrangements) so that +there is but one degree of freedom to move, and that of such a +character as to vary the interval between the disks without disturbing +their equidistance and parallelism.</p> + +<p>The source of sound is a bird call, giving a pure tone of high pitch +(inaudible), and the percipient is a high-pressure flame issuing from +a burner so oriented that the direct waves are without influence upon +the flame (see <i>Nature</i>, xxxviii., 208; Proc. Roy. Inst., January, +1888). But the waves reflected from the muslin arrive in the effective +direction, and if of sufficient intensity induce flaring. The +experiment consists in showing that the action depends upon the +distance between the disks. If the distance be such that the waves +reflected from the several disks co-operate,<a name="FNanchor_8" id="FNanchor_8"></a><a href="#Footnote_8"><sup>2</sup></a> the flame flares, but +for intermediate adjustments recovers its equilibrium. For full +success it is necessary that the reflective power of a single disk be +neither too great nor too small. A somewhat open fabric appears +suitable.</p> + +<p>It was shown by Brewster that certain natural specimens of Iceland +spar are traversed by thin twin strata. A convergent beam, reflected +at a nearly grazing incidence from the twin planes, depicts upon the +screen an arc of light, which is interrupted by a dark spot +corresponding to the plane of symmetry. [Shown.] A similar experiment +may be made with small rhombs in which twin layers have been developed +by mechanical force after the manner of Reusch.</p> + +<p>The light reflected from fiery opals has been shown by Crookes to +possess in many cases a high degree of purity, rivaling in this +respect the reflection from chlorate of potash.</p> + +<p>The explanation is to be sought in a periodic stratified structure. +But the other features differ widely in the two cases. There is here +no semicircular evanescence, as the specimen is rotated in azimuth. On +the contrary, the colored light transmitted perpendicularly through a +thin plate of opal undergoes no change when the gem is turned round in +its own plane. This appears to prove that the alternate states are not +related to one another as twin crystals. More probably the alternate +strata are of air, as in decomposed glass. The brilliancy of opals is +said to be readily affected by atmospheric conditions.</p> + +<p><a name="Footnote_7" id="Footnote_7"></a><a href="#FNanchor_7">[1]</a></p> +<div class="note"><p>Abstract of the Friday evening lecture delivered by Lord +Rayleigh, F.R.S., at the Royal Institution, on April 12, 1889.</p></div> + +<p><a name="Footnote_8" id="Footnote_8"></a><a href="#FNanchor_8">[2]</a></p> +<div class="note"><p>If the reflection were perpendicular, the interval +between successive disks would be equal to the half wave-length, or to +some multiple of this.</p></div> + +<hr /> + + +<h2>A New Catalogue of Valuable Papers</h2> + +<p>Contained in <span class="smcap">Scientific American Supplement</span> during the past +ten years, sent <i>free of charge</i> to any address. MUNN & CO., 361 +Broadway, New York.</p> + +<hr /> + + +<h3>THE SCIENTIFIC AMERICAN</h3> + +<h2>Architects and Builders Edition.</h2> + +<p class="center">$2.50 a Year. 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Gutenberg EBook of Scientific American Supplement, No. 711, +August 17, 1889, 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. 711, August 17, 1889 + +Author: Various + +Release Date: October 31, 2005 [EBook #16972] + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** + + + + +Produced by Juliet Sutherland and the Online Distributed +Proofreading Team at www.pgdp.net + + + + + +[Illustration] + + + + +SCIENTIFIC AMERICAN SUPPLEMENT NO. 711 + + + + +NEW YORK, AUGUST 17, 1889 + +Scientific American Supplement. Vol. XXVIII., No. 711. + +Scientific American established 1845 + +Scientific American Supplement, $5 a year. + +Scientific American and Supplement, $7 a year. + + * * * * * + + + + +TABLE OF CONTENTS. + + +I. AGRICULTURE.--How to Raise Turkeys.--A collection of hints + and suggestions on the raising of the delicate fowls, so + often the cause of trouble to farmers. 11364 + + Pear Duchesse D'Angouleme.--The history of the famous pear + tree, with hints as to its culture and general treatment. 11362 + + +II. BIOLOGY.--Development of the Embryo.--A note of some + interesting biological researches.--By Prof. PREYER, + of Berlin. 11365 + + The "Hatchery" of the Sun Fish.--A curious incident in the + life history of the common sunfish.--1 illustration. 11363 + +III. CHEMISTRY.--On Allotropic Forms of Silver.--By M. CAREY + LEA.--A continuation of this paper, containing one of the + most important researches in the history of silver, with + statement of interesting results attained. 11361 + + On the Occurrence of Paraffine in Crude Petroleum.--A + valuable contribution to the history of paraffine, with + reference to petroleum and ozokerite. 11361 + + Turpentine and its Products.--By EDWARD DAVIES.--A resume + of the work done by chemists in the turpentine products. + --The different compounds produced therefrom. 11361 + +IV. ELECTRICITY.--Electric Lighting at the Paris Exhibition. + --The Oerlikon works.--A very exhaustive exhibition of + electric apparatus described and illustrated.--12 + illustrations. 11356 + + Magnetism in its Relation to Induced Electromotive Force + and Current.--By ELIHU THOMSON.--A most impressive paper, + bringing the obscure laws of magnetic induction within the + understanding of all without the application of + mathematics.--12 illustrations. 11354 + + The Ader Flourish of Trumpets.--One of the curiosities in + telephony from the Paris exhibition, by which sounds are + transmitted to a large audience.--4 illustrations. 11358 + + The Electric Motor Tests on the New York Elevated + Railroad.--Abstracts of tests which were recently made of + the Daft motor on the elevated railroad of this city. 11353 + +V. ETHNOLOGY.--Ancient Lake Dwellings.--Interesting abstract + of what is known about lake dwellings, the history of + their construction, and the "finds" made on the sites by + archaeologists. 11363 + +VI. FORESTRY.--Succession of Forest Growths.--A valuable paper + on forestry, treating of the evils done by man and a plea + for the necessity of intelligent treatment of our woods. 11362 + +VII. HYGIENE AND MEDICINE.--Acetic Acid as a Disinfectant.--Use + of acetic acid in septic medical cases as a substitute + for carbolic acid and bichloride of mercury. 11365 + + Counter-Irritation in Whooping Cough.--By G.F. INGLOTT, + M.D.--Application of irritants to the skin for curing the + paroxysms of whooping cough. 11365 + + On the Health Value to Man of the So-called Divinely + Beneficent Gift, Tobacco.--By J.M.W. KITCHEN, M.D.--The + evils to man and to the soil.--A formidable series of + accusations well expressed. 11365 + + Water as a Therapeutical Agent.--By F.C. ROBINSON, + M.D.--An interesting resume of different applications of + water in therapeutics.--Suggestions of use for all + households. 11364 + +VIII. MILITARY ENGINEERING.--Gibraltar.--A history of this + important strategic position and of the different sieges + the fortress has undergone. 11352 + + Gibraltar and Neighborhood.--A consular report on the + statistics of the famous military station. 11352 + + The Defense of Gibraltar--Experimental Naval and Military + Operations.--Interesting series of operations recently + carried out under the shadow of the historic rock.--1 + illustration. 11352 + +IX. NAVAL ENGINEERING.--Clark's Gyroscopic Torpedoes.--A + recent torpedo, in which all the possible parts are made + to rotate.--2 illustrations. 11353 + + The First Steamboat on the Seine.--The Marquis de + Jouffroy's steamer of 1816.--1 illustration. 11353 + + The Franz Josef I., New War Ship.--Details of the + dimensions of the new Austrian ship.--Her armament, + speed, armor, etc. 11353 + +X. PHOTOGRAPHY.--Orthochromatic Photography.--By OSCAR O. + LITZKOW.--The last developments in this interesting + branch of photographic art, with formulae. 11360 + + Platinotype Printing.--A description of the most advanced + method of conducting the platinum print process. 11360 + +XI. PHYSICS.--Iridescent Crystals.--By LORD RAYLEIGH.--An + abstract of a lecture by the distinguished physicist, + detailing some interesting experiments applicable to the + colored reflection observed in crystals of chloride of + potash.--1 illustration. 11366 + + Transmission of Pressure in Fluids.--By ALBERT B. + PORTER.--An apparatus for illustrating the laws of + transmission of pressure in fluids, suitable for lecture + purposes.--1 illustration. 11362 + + XII. TECHNOLOGY.--Notes on Dyewood Extracts and Similar + Preparations.--By LOUIS SIEBOLD.--The recent development + in the preparation of dyewood extracts, with notes of + their adulterations. 11359 + + * * * * * + + + + +THE DEFENSE OF GIBRALTAR: EXPERIMENTAL NAVAL AND MILITARY +OPERATIONS. + + +[Illustration: THE DEFENSE OF GIBRALTAR--EXPERIMENTAL NAVAL AND +MILITARY OPERATIONS.] + +A novel and interesting series of operations was carried out at +Gibraltar a few weeks ago, with a view to test the promptitude with +which the garrison of the famous Rock could turn out to resist a +sudden attack by a powerful iron-clad fleet. The supposed enemy was +represented by the Channel Squadron, under the command of Vice-Admiral +Baird, and consisting of H.M.S. Northumberland (flag ship), the +Agincourt, Monarch, Iron Duke, and Curlew. The "general idea" of the +operations was that a hostile fleet was known to be cruising in the +vicinity, and that an attack on the Rock might be made. The squadron +left Gibraltar and proceeded to the westward, returning to the +eastward through the Straits under cover of the night. + +The Governor of Gibraltar, General the Hon. Sir Arthur Hardinge, +issued orders for the whole garrison to stand to their arms at dawn, +and subsequent days, until the attack should be made; but by his +express command no batteries were to be manned, or any troops moved +from their alarm posts, until the signal was given that an attack was +imminent. The alarm signal ordered was that of three guns fired in +rapid succession from the Upper Signal Station on the summit of the +Rock, to be followed, after a short pause, by two more shots. It was a +matter of complete uncertainty as to the direction from which the +attack would be made. + +Every detail was carefully carried out, as if the impending attack was +a real affair. The telegraphic communication between the various parts +of the Rock was supplemented by signalers; arrangements were made for +the ready supply of reserve ammunition for all arms; and the medical +authorities established dressing stations, at numerous points of the +Rock, to render "first aid" to those who might chance to be numbered +among the "wounded." Day broke with a "Levanter," and the heavy clouds +hanging about rendered any distant view a matter of difficulty. +However, before it had become actually daylight the alarm guns gave +notice that the enemy had been sighted. The troops turned out with +great promptitude, being all at their assigned stations in less than a +quarter of an hour, and were shortly ordered to various points +commanding the east side of the Rock. As day broke, the hostile ships +were to be discerned steaming in single line ahead, from the northeast, +along the back of the Rock, and about 5,000 yards from it. The flag +ship, followed by the Monarch and the Agincourt, proceeded toward +Europa Point, while the Iron Duke and the Curlew stood close in to the +eastern beach, so as to engage the northern defenses of the fortress. +The first shot was fired by the flag ship, shortly before six o'clock +in the morning, at the southern defenses. It was replied to, in less +than three minutes, by the Europa batteries, and very shortly the +engagement became general. The plan of tactics employed by the +squadron was that of steaming rapidly up and down, and concentrating +their fire in turn on the various shore batteries. Later on, the whole +squadron assembled off Europa Point, and fired broadsides by +electricity as they steamed past at speed. The spectacle at this +moment was a very fine one, the roar of the heavy guns of the ships +being supplemented by the sharp, rapid report of the quick-firing +guns, which were supposed to be sending a storm of small shell among +the defenders of the Rock. The incessant rattle of the ships' machine +guns was also heard in the intervals between the thundering broadsides +of heavy ordnance. All the ships were, of course, cleared for action, +with topmasts and yards sent down, and it is needless to say they +looked exceedingly workmanlike and formidable. + +The various batteries on the Rock replied with great vivacity, and the +general effect produced as gun after gun was brought to bear on the +ships, and the white smoke wreathed itself round the many crags and +precipices of the grim old Rock, was a sight long to be remembered. +The exercise afforded to both branches of the service was undoubtedly +most instructive. Our illustration is a sketch by Captain Willoughby +Verner from one of the batteries above the Europa Flats, at which +point the governor took up his position to watch the operations. +--_Illustrated London News._ + + * * * * * + + + + +GIBRALTAR AND NEIGHBORHOOD. + +REPORT BY CONSUL SPRAGUE. + + +Notwithstanding that the political situation of Europe seems to be +less threatening among its leading powers, still the uncertainty +prevalent among those who are generally considered the arbiters of +public affairs has had its influence in contracting the limits of +speculative adventure, thereby circumscribing the general course of +trade throughout the Mediterranean. + +In renewing to the department my reports upon the navigation and +general commerce of Gibraltar, I beg to state that there has been a +tolerably fair current business prevailing in American produce during +the past quarter, consisting chiefly in flour, tobacco, and refined +petroleum in cases, imported direct from New York. + +The steady demand for American petroleum confirms the fact that +Russian petroleum so far receives but little attention in this market +from the regular traders and consumers, so long as supplies from the +United States can be regularly imported at reasonable prices. It, +however, remains an open question, in the event of lower prices ruling +in the Russian petroleum regions, whether American supplies may not +later on experience some greater competitive foreign interference. + +According to the statistical data, steam vessels of all nationalities +have continued to make Gibraltar their port of call, not only for +orders, but also for replenishing their stock of fuel and provisions, +and in larger numbers than ever before, the number in 1888 having +reached 5,712 steam vessels, measuring in all 5,969,563 tons, while in +1887 the number was only 5,187 steam vessels, with an aggregate +tonnage of 5,372,962. This increase cannot but result in considerable +benefit to the coal and maritime traffic, which now forms the most +important portion of the general commerce of Gibraltar, in spite of +the keen competition it experiences from other British and foreign +coaling ports. + +Freights have also advanced in favor of steamship interests, which, +with higher prices in England for coal, have also caused an advance in +the price of coal at this port, to the benefit of the coal merchants +and others interested in this important trade. At present the ruling +price for steam coal is 24s. per ton, deliverable from alongside of +coal hulks moored in the bay. As near as I have been able to +ascertain, the quantity of coal sold in this market during the past +year for supplying merchant steam vessels has amounted to about +508,000 tons, which is an increase of about 20,000 tons over the year +1887. + +Notwithstanding that plans have already been submitted to the British +government for the construction of a dry dock in Gibraltar, the matter +remains somewhat in suspense, since it meets with some opposition on +the part of the British government, which, in face of the European +fever for general arming, seems more inclined to utilize in another +form the expense which such a work would entail upon the imperial +government, by replacing the obsolete ordnance recently removed from +this fortress and substituting new defenses and guns of the most +approved patterns, a matter which has evidently been receiving, for +some time past, the special attention of the British military +authorities, not doubting that the recent visit to the fortress of the +Duke of Cambridge has had some connection with it. In fact, it is +reported that the duke has already expressed the opinion that this +fortress requires a larger number of artillerymen than are quartered +here at present to man its batteries, and it would seem that this +recommendation is likely to be carried out. + +It is yet somewhat too early to venture an opinion regarding the +growing crops of cereals in this Spanish neighborhood, but the +agricultural and manufacturing interests in Spain have suffered so +much in the past years that the general feeling in Spain continues to +tend toward establishing increased restrictions against foreign +competition in her home markets. There is every probability that the +provinces of Malaga and Granada may shortly be granted the privilege +of cultivating the tobacco plant under government supervision, as an +essay. If properly managed, it may form an important and lucrative +business for those interested in land and agricultural pursuits. + +After many consecutive years of heavy outlays, difficulties, and +constant disappointments, a new English company has recently succeeded +in commencing the construction of a railway from the neighboring +Spanish town of Algeciras to join, via Ronda, the railway station of +Bobadilla, on the railroad line toward Malaga. It is presumed that +when this railroad will be in running order it will greatly benefit +this community, especially if the Spanish government should decide to +establish custom houses at Algeciras and the Spanish lines outside the +gates of this fortress, similar to those existing on the frontiers of +France and Portugal. + +That some idea may be formed of the constant important daily +intercourse which exists between this fortress and Spain, I may state +that late police statistics show that 1,887,617 passes were issued to +visitors entering this fortress on daily permits during the year 1888, +1,608,004 entering by the land route and 279,613 by sea. I must, +however, observe that the larger portion of these visitors consists of +laborers, coal heavers, market people, and others engaged in general +traffic. + +A new industry in cork has lately sprung up, in which leading Spanish +and native commercial firms in Gibraltar are directly interested to a +considerable extent. Extensive warehouses for the storing of cork wood +and machinery for the manufacture of bottle corks have recently been +established at the Spanish lines, about a mile distant from this +fortress, in Spanish territory, where large quantities of cork have +already been stored. The cork is obtained and collected from the +valuable trees, which are owned by the representatives of some of the +oldest nobility of Spain, who have sold the products of their +extensive woods to private individuals for periods reaching as far on +as ten years, for which concession large cash advances have already +been made. The woods commence at a distance of about twelve miles from +Gibraltar, and are of considerable extent. + +The railway now in course of construction passes through these woods, +which may ere long offer quite picturesque scenery for travelers, +especially when the cork trees are bearing acorns, which form the +principal food for the fattening of large herds of swine during +certain seasons of the year, in this way, also, contributing to the +value of this tree, which, like the other kinds of oak trees, is of +long and tardy growth. The tree from which the cork is obtained is +somewhat abundant in the mountainous districts of Andalusia. It grows +to a height of about 30 feet, and resembles the _Quercus ilex_, or +evergreen oak, and attains to a great age. After arriving at a certain +state of maturity it periodically sheds its bark, but this bark is +found to be of better quality when artificially removed from the tree, +which may be effected without injury to the tree itself. After the +tree has attained twenty-five years it may be barked, and the +operation is afterward repeated once in every seven years. The quality +of the cork seems to improve with the increasing age of the tree, +which is said to live over one hundred and fifty years. The bark is +taken off during July and August. + +Cork dust is also obtained from this cork wood, and is much used in +the packing of grapes, which fruit is largely shipped from the eastern +coast of Spain, especially from Almeria, during the vintage seasons, +for the American and British markets.--_Reports of U.S. Consuls._ + + * * * * * + + + + +GIBRALTAR. + + +The point or rock known as Gibraltar is a promontory two and one-half +miles long and from a quarter to three-quarters of a mile wide. It +rises abruptly from the sandy shore to a height at its highest point +of 1,408 ft. It is composed of gray limestone, honeycombed with caves +and subterranean passages, some of which contain most beautiful +stalactites in the form of massive pillars. + +Gibraltar is emphatically a fortress, and in some respects its +fortifications are unique. On the eastern side the rock needs no +defense beyond its own precipitous cliffs, and in all other directions +it has been rendered practically impregnable. Besides a sea wall +extending at intervals round the western base of the rock, and +strengthened by curtains and bastions and three formidable forts, +there are batteries in all available positions from the sea wall up to +the summit, 1,350 feet above the sea, and a remarkable series of +galleries has been hewn out of the solid face of the rock toward the +north and northwest. These galleries have an aggregate length of +between two and three miles, and their breadth is sufficient to let a +carriage pass. Portholes are cut at intervals of twelve yards, so +contrived that the gunners are safe from the shot of any possible +assailants. At the end of one of the galleries hollowed out in a +prominent part of the cliff is St. George's Hall, 50 feet long by 85 +feet wide, in which the governor was accustomed to give fetes. +Alterations, extensions, and improvements are continually taking place +in the defensive system, and new guns of the most formidable sort are +gradually displacing or supplementing the old fashioned ordnance. + +The whole population of Gibraltar, whether civil or military, is +subjected to certain stringent rules. For even a day's sojourn the +alien must obtain a pass from the town major, and if he wish to remain +longer, a consul or householder must become security for his good +behavior. Licenses of residence are granted only for short +periods--ten, fifteen, or twenty days--but they can be renewed if +occasion require. Military officers may introduce a stranger for +thirty days. A special permit is necessary if the visitor wishes to +sketch. + +Though the town of Gibraltar may be said to date from the fourteenth +century, it has preserved very little architectural evidence of its +antiquity. Rebuilt on an enlarged and improved plan after its almost +complete destruction during the great siege, it is still, on the +whole, a mean-looking town, with narrow streets and lanes and an +incongruous mixture of houses after the English and the Spanish types. +As a proprietor may at any moment be called upon to give up his house +and ground at the demand of the military authorities, he is naturally +deterred from spending his money on substantial or sumptuous +erections. The area of the town is about one hundred acres. + +Gibraltar was known to the Greek and Roman geographers as Calpe or +Alybe, the two names being probably corruptions of the same local +(perhaps Phenician) word. The eminence on the African coast near +Ceuta, which bears the modern English name of Apes' Hill, was then +designated Abyla; and Calpe and Abyla, at least according to an +ancient and widely current interpretation, formed the renowned pillars +of Hercules (Herculis columnae), which for centuries were the limits of +enterprise to the seafaring peoples of the Mediterranean world. + +The strategic importance of the rock appears to have been first +discovered by the Moors, who, when they crossed over from Africa in +the eighth century, selected it as the site of a fortress. From their +leader, Tarik Ibn Zeyad, it was called Gebel Tarik or Tarik's Hill; +and, though the name had a competitor in Gebel af Futah, or Hill of +the Entrance, it gradually gained acceptance, and still remains +sufficiently recognizable in the corrupted form of the present day. +The first siege of the rock was in 1309, when it was taken by Alonzo +Perez de Guzman for Ferdinand IV. of Spain, who, in order to attract +inhabitants to the spot, offered an asylum to swindlers, thieves, and +murderers, and promised to levy no taxes on the import or export of +goods. The attack of Ismail Ben Ferez, in 1315 (second siege), was +frustrated; but in 1333 Vasco Paez de Meira, having allowed the +fortifications and garrison to decay, was obliged to capitulate to +Mahomet IV. (third siege). Alphonso's attempts to recover possession +(fourth siege) were futile, though pertinacious and heroic, and he was +obliged to content himself with a tribute for the rock from Abdul +Melek of Granada; but after his successful attack on Algeciras in 1344 +he was encouraged to try his fortune again at Gibraltar. In 1349 he +invested the rock, but the siege (fifth siege) was brought to an +untimely close by his death from the plague in February, 1350. The +next or sixth siege resulted simply in the transference of the coveted +position from the hands of the King of Morocco to those of Yussef III. +of Granada; and the seventh, undertaken by the Spanish Count of +Niebla, Enrico de Guzman, proved fatal to the besieger and his forces. +In 1462, however, success attended the efforts of Alphonso de Arcos +(eighth siege), and in August the rock passed once more under +Christian sway. The Duke of Medina Sidonia, a powerful grandee who had +assisted in its capture, was anxious to get possession of the +fortress, and though Henry IV. at first managed to maintain the claims +of the crown, the duke ultimately made good his ambition by force of +arms (ninth siege), and in 1469 the king was constrained to declare +his son and his heirs perpetual governors of Gibraltar. In 1479 +Ferdinand and Isabella made the second duke Marquis of Gibraltar, and +in 1492 the third duke, Don Juan, was reluctantly allowed to retain +the fortress. At length, in 1501, Garcilaso de la Vega was ordered to +take possession of the place in the king's name, and it was formally +incorporated with the domains of the crown. After Ferdinand and +Isabella were both dead the duke, Don Juan, tried in 1506 to recover +possession, and added a tenth to the list of sieges. Thirty-four years +afterward the garrison had to defend itself against a much more +formidable attack (eleventh siege)--the pirates of Algiers having +determined to recover the rock for Mahomet and themselves. The +conflict was severe, but resulted in the repulse of the besiegers. +After this the Spaniards made great efforts to strengthen the place, +and they succeeded so well that throughout Europe Gibraltar was +regarded as impregnable. + +In the course of the war of the Spanish succession, however, it was +taken by a combined English and Dutch fleet under Sir George Rooke, +assisted by a body of troops under Prince George of Hesse-Darmstadt. +The captors had ostensibly fought in the interests of Charles Archduke +of Austria (afterward Charles III.), but, though his sovereignty over +the rock was proclaimed on July 24, 1704, Sir George Rooke on his own +responsibility caused the English flag to be hoisted, and took +possession in name of Queen Anne. It is hardly to the honor of England +that it was both unprincipled enough to sanction and ratify the +occupation and ungrateful enough to leave unrewarded the general to +whose unscrupulous patriotism the acquisition was due. The Spaniards +keenly felt the injustice done to them, and the inhabitants of the +town of Gibraltar in great numbers abandoned their homes rather than +recognize the authority of the invaders. In October, 1704, the rock +was invested by sea and land; but the Spanish ships were dispersed by +Sir John Leake, and the Marquis of Villadarias fared so ill with his +forces that he was replaced by Marshal Tesse, who was at length +compelled to raise the siege in April, 1705. During the next twenty +years there were endless negotiations for the peaceful surrender of +the fortress, and in 1726 the Spaniards again appealed to arms. But +the Conde de la Torres, who had the chief command, succeeded no better +than his predecessors, and the defense of the garrison under General +Clayton and the Earl of Portmore was so effectual that the armistice +of June 23 practically put a close to the siege, though two years +elapsed before the general pacification ensued. The most memorable +siege of Gibraltar, indeed one of the most memorable of all sieges, +was that which it sustained from the combined land and sea forces of +France and Spain during the years 1779-1783. The grand attack on the +place was made on the 13th September, 1782, and all the resources of +power and science were exhausted by the assailants in the fruitless +attempt. On the side of the sea they brought to bear against the +fortress forty-six sail of the line and a countless fleet of gun and +mortar boats. But their chief hope lay in the floating batteries +planned by D'Arcon, an eminent French engineer, and built at the cost +of half a million sterling. They were so constructed as to be +impenetrable by the red hot shot which it was foreseen the garrison +would employ; and such hopes were entertained of their efficiency that +they were styled invincible. The Count D'Artois (afterward Charles X.) +hastened from Paris to witness the capture of the place. He arrived in +time to see the total destruction of the floating batteries and a +considerable portion of the combined fleet by the English fire. +Despite this disaster, however, the siege continued till brought to a +close by the general pacification, February 2, 1783. The history of +the four eventful years' siege is fully detailed in the work of +Drinkwater, who himself took part in the defense, and in the life of +its gallant defender Sir George Augustus Eliott, afterward Lord +Heathfield, whose military skill and moral courage place him among the +best soldiers and noblest men whom Europe produced during the 18th +century. + +Since 1783 the history of Gibraltar has been comparatively uneventful. +In the beginning of 1801 there were rumors of a Spanish and French +attack, but the Spanish ships were defeated off Algeciras in June by +Admiral Saumarez. Improvements in the fortifications, maintenance of +military discipline, and legislation in regard to trade and smuggling +are the principal matters of recent interest. + + * * * * * + + + + +THE FRANZ JOSEF I., NEW WAR SHIP. + + +Another addition was made to the Austrian navy by the launching on May +18 of the ram cruiser Franz Josef I. from the yards of S. Rocco in the +Stabilimento Tecnico Triestino. Her dimensions are: Length (over all), +103.7 meters; length (between perpendiculars), 97.9 meters; greatest +breadth (outside), 14.8 meters; draught (bow), 5.28 meters; draught +(stern), 6.05 meters; displacement on the construction water line, +4,000 tons. The armament consists of two 24-centimeter and six +15-centimeter Krupp breech loaders of 35 caliber length, two +7-centimeter Uchatius guns as an armament for the boats and for +landing purposes, eleven Hotchkiss quick-firing guns, and several +torpedo-launching ports; indicated horse power with natural draught +6,400, speed 17.5 knots; with forced draught 9,800, speed 19 knots. + +The ship is built of steel, and constructed according to the "double +bottom" system along the engine, boiler, and ammunition rooms. The +vaulted armor deck, extending 1.25 meters below the water line and +protecting the most vital parts of the ship, is 0.057 meter thick. +There are more than 100 water tight compartments below and above the +deck. A protecting belt of "cellulose" is provided for the engines and +boilers, extending from the armor deck downward. + +The two main guns, placed on Krupp's hydraulic carriages, occupy +positions in front and rear, and are protected by stands 0.09 meter +thick and 1.60 meters high. They fire _en barbette_ with a lateral +range each of 260 degrees at bow and stern--i.e., 130 degrees on +either of the broadsides. The weight of the barrel of the gun is 25 +tons, that of the steel shell 215 kilogrammes (about 430 lb.), that of +the brown powder charge 100 kilogrammes; initial velocity of +projectile, 610 meters; penetration, 0.524 meter iron; longest range, +17 kilometers (about 101/2 English miles); range at 15 deg. elevation, +10 kilometers. The six 15-centimeter guns are placed in a kind of +machicouli arrangement in two tiers on each of the broadsides, so that +always four guns can fire in the direction of the keel to the front +and rear. The weight of the barrel of the gun is each six tons, that +of the steel shells 51 kilogrammes, that of the charge 22 kilogrammes; +initial velocity, 610 meters. + +The 11 quick-firing guns are partly placed along the broadsides, +partly in the masts, of which there are two. The triple expansion +engines, having each a bronze screw of 4.42 meters diameter, with +three blades and a rise of 6.3 meters, make with natural draught 105 +revolutions, and with forced draught 120. The pumping apparatus are +able to lift in one hour 400 tons of water. The front boiler room +contains a special cylindrical boiler for the working of the +electrical apparatus, for hydraulic pumps of the artillery service, +for anchor windlasses, ventilators, fire engines, etc. The whole +engines weigh 890 tons. The bunkers have a capacity for 660 tons of +coal, which allows for a run of 4,500 sea miles. + + * * * * * + + + + +CLARK'S GYROSCOPIC TORPEDOES. + + +Figs. 1 and 2 represent, upon a scale of about 1/10, two types of +torpedoes, the greatest number possible of the parts of which are made +revolvable, so as to render the torpedoes as dirigible as the gyrating +motion permits of. + +Fig. 1 represents an electric torpedo actuated by accumulators, A A, +keyed upon the shaft, and revolving along with the gearings. At the +beginning of the running, the accumulators are not all coupled, but +under the action of a clockwork movement which is set in motion at the +moment of starting, metallic brushes descend one after another upon +the collectors, B, and set in action new batteries for keeping +constant or, if need be, accelerating the speed at the end of the +travel. + +[Illustration: Fig. 1.] + +[Illustration: Fig. 2. CLARK'S GYROSCOPIC TORPEDOES.] + +Fig. 2 represents an air torpedo proposed by the same inventor. The +air reservoir, C, revolves along with the gearings under the action +of the pneumatic machine, D. The central shaft is hollow, so as to +serve as a conduit. The admission of air into the slide valve of the +machine is regulated by a clockwork which actuates a slide in an +aperture whose form and dimensions are so calculated that the speed +remains as constant as possible toward the end of the travel. + +The trajectory of the two torpedoes is regulated by a cylindrical +bellows, F, which gives entrance to the sea water. The springs shown +in the figure balance the hydraulic pressure. The tension of these +springs is regulated by the rod, H, according to the indications of +the scale of depths, I. + +When the torpedo reaches too great a depth, the action of the springs +can no longer balance the increase of the hydraulic pressure, and the +accumulation of the charge in the rear causes the front to rise toward +the surface. When the torpedo reaches the surface, a contrary action +is produced.--_Revue Industrielle._ + + * * * * * + + + + +THE FIRST STEAMBOAT ON THE SEINE. + + +[Illustration: FIRST STEAMBOAT BUILT ON THE SEINE.] + +The accompanying engraving represents the remarkable steamboat that +the unfortunate Marquis de Jouffroy constructed at Paris in 1816, +after organizing a company for the carriage of passengers on the +Seine. De Jouffroy, as well known, made the first experiment in steam +navigation at Lyons in 1783, but the inventor's genius was not +recognized, and he met with nothing but deception and hostility. With +the obstinacy of men of conviction, he did not cease to prosecute his +task. He assuredly had an inkling of the future in store for the +invention that he was offering to humanity. + +The paddle wheel boat that he constructed at Paris in 1816 did not +succeed any better than its predecessors; it was remarkable +nevertheless in appearance and structure. + +The engine was forward, as shown in the engraving, which is copied +from a composition of Dubucourt's. + +The company organized by the marquis was ruined, and, as well known, +the unfortunate inventor himself died in poverty in 1832, at the age +of eighty-one years.--_La Nature._ + + * * * * * + + + + +THE ELECTRIC MOTOR TESTS ON THE NEW YORK ELEVATED RAILROAD. + + +The American Institute of Electrical Engineers at its last meeting of +the season, held June 25, again considered the subject of electrical +traction, the paper presented by Mr. Leo Daft being based upon some +recent electrical work on the elevated railroads and its bearing on +the rapid transit problem. The _Railroad Gazette_ gives the following +abstract: + + He introduced the subject with a tribute to the efficiency of + the elevated railroad system as it is now operated by steam, + with special reference to that section of it known as the Ninth + Avenue line, upon which his experiments with the electric motor + have been conducted, over which passengers are now conveyed a + distance of five miles in 26 minutes for five cents, which he + considered the best and cheapest municipal rapid transit in the + world, and which is operated with a higher degree of safety than + any other railroad in the world making an equal number of stops + per 100 miles. On a recent holiday, April 30 last, 835,720 + passengers were carried upon the entire system without + noticeable detention or accident. The rapidly increasing traffic + makes the demand for better facilities a pressing one, and as + the average half million now carried daily will soon become a + million, it appears doubtful if any method can be devised of + providing for the growth by the use of steam motors on the + present structures, which are now taxed to their utmost. To the + mind of the mechanical engineer, having in view the ordinary + coefficients of tractive ability, there is no remedy for this. + The speaker stated that these coefficients were not entirely + trustworthy. He reiterated his previously expressed opinion, + based on frequent experiments, that there is a decided increase + in traction gained by the passage of the electric current from + the wheels to the rails, giving the details of one test where a + motor with a load making a total of 600 lb. climbed a gradient + of 2,900 ft. per mile, starting from a state of rest. He stated + that some of those people who had ridiculed his statements had + finally admitted that they were true. + + The motor Ben Franklin, which had been used in making these + tests on the elevated roads, weighed 10 tons, and performed + service nearly equal to the steam motors weighing 18 tons. The + object of these tests was the determination of coal economy. + Tests with a Prony brake showed that the motor developed 128 + H.P. The piece of track on which the experiments were conducted + embraced 2,200 ft. of level track and 1-8/10 miles of gradients, + varying from 11-3/10 to 98-7/10 ft. per mile, while at Thirtieth + street the station is at the foot of the steepest grade, thus + testing to the utmost the tractive capacity of the motor. The + experiments were begun in October, 1888, and carried on between + the hours of 9 P.M. and 4 A.M., beginning with one or two cars, + the load being increased nightly until it was finally made up of + eight coaches of 12 tons each, which were hauled up the 98 ft. + grade at a speed of 71/2 miles per hour, the entire distance being + covered at the rate of 14-6/10 miles per hour. The maximum speed + obtained on level with that train was 16.36 miles per hour. + Seventy trips were subsequently made with a 70 ton train + operated between the steam trains under 3 minutes headway, but + the work was considered too critical on account of the absence + of suitable brakes. A number of experiments made about this time + showed that the mean speed with a three-car train running + express on the up-town track was about 24 miles per hour, + although the ability of the motor on a level with a similar + train was nearly 28 miles per hour. This, however, was not the + maximum speed, as the level track was not long enough to permit + of its attaining the highest rate. It was the opinion of the + speaker, however, that the speed attained could not be exceeded + with prudence on the elevated structure. + + The measurements of speed were made by dividing the track into + 19 sections of 500 ft., each section being provided with a + circuit-closing plate connected with a chronograph which was + carefully tested. The indicator cards were taken at the central + station by Mr. Idell and his assistants, and the dynamometer + used was of the liquid type made by Mr. Shaw, of Philadelphia. + The diagrams prepared from the data obtained were then explained + by the speaker, who stated that there was not a marked + difference between the 10 ton motor and the 18 ton locomotive in + the initial effort on the level, as will be seen by comparing a + run observed by a railroad officer on March 9 with a steam motor + and a load of about 571/2 tons. The steam motor required 1 min. + and 29 sec. to make the distance from 14th to 23d streets, while + the electric motor with a train of 70 tons made the same trip in + 1 min. and 50 sec.; the absence of power brakes compelled the + current to be taken off at 19th street, while it was probable + that the throttle of the steam locomotive was not closed until + it reached 23d street, this being the usual practice. The data + obtained in these experiments shows that 29,940 h.p. is required + to operate the Ninth avenue railroad for the 16 hours' service, + or an average of 1,871 h.p. per hour, or 2,181 h.p., adding + station friction. The varying requirements of the traffic during + the day shows that the service could be advantageously divided + up between four stationary engines of 800 h.p. each, there being + but five hours of the day when all of them would be required. + The fuel consumption per day, allowing 22 lb. of coal per h.p. + per hour at $2.25 per ton, would make a total of $92.25 per diem + for fuel, the coal being a mixture deliverable at the dock for + about $1.80 per ton. The weight of coal used for the present + locomotives is about the same, viz., 40 tons per day, but + practice has shown it to be most economical to use coal of the + best quality, costing $5 per ton, making the cost of fuel about + double that required for the electric system. Without entering + into other economies which the speaker claimed were in favor of + electricity, and ignoring the plan suggested by Sir William + Siemens of braking the train by converting the motor into a + dynamo and thus utilizing the energy of momentum, he believed + that the economy in fuel alone was sufficient to prove that the + application of power by electricity was preferable to direct + steam propulsion for the elevated railroad service. + + * * * * * + + + + +MAGNETISM IN ITS RELATION TO INDUCED ELECTROMOTIVE FORCE AND +CURRENT.[1] + + [Footnote 1: A paper read before the American Institute of + Electrical Engineers, New York, May 22, 1889.] + +By ELIHU THOMSON. + + +There is perhaps no subject which at the present time can have a +greater interest to the physicist, the electrician, and the electrical +engineer than the one which heads this paper. The advances which have +been made in the study from its purely theoretical or scientific side, +and the great technical progress in the utilization of the known facts +and principles concerning magnetic inductions, can but deepen and +strengthen that interest. + +On the side of pure theory we find the eager collection of +experimental data to be submitted to the scrutiny of the ablest and +brightest minds, to be examined and reasoned upon with the hope of +finding some clew to satisfying explanations, and on the side of +practice we find the search for new facts and relations no less +diligent, though often stimulated by practical problems presented for +solution. Indeed, the urgency for results is often the greater on the +practical side, for theory can wait, practice cannot, at least in the +United States. + +We must look for continued triumphs in both directions, and the most +welcome of all will be the framing of a theory or explanation which +will enable us to interpret magnetic and electric phenomena. The +recent beautiful experiments of Hertz on magnetic waves have opened a +fertile region for investigation. + +It would seem that the study of magnetism and electricity will give us +the ability to investigate the ether of space, which medium has been +theorized upon at great length, with the result of leaving it very +much where it was before, a mysterious necessity. + +Faraday says, speaking of magnetism: + + "Such an action may be a function of the ether, for it is not at + all unlikely that if there be an ether it should have other uses + than simply the conveyance of radiations." 3,075. Vol. III., + Exp. Res. + + "It may be a vibration of the hypothetical ether, or a state of + tension of that ether equivalent to either a dynamic or a static + condition," etc. 3,263. Vol. III., Exp. Res. + +Faraday again says, speaking of the magnetic power of a vacuum: + + "What that surrounding magnetic medium deprived of all material + substance may be I cannot tell, perhaps the ether." 3,277. Vol. + III., Exp. Res. + +Modern views would seem to point that through a study of magnetic +phenomena we may take a feeble hold upon the universal ether. +Magnetism is an action or condition of that medium, and it may be that +electrical actions are the expression of molecular disturbances +brought about by ether strains or interferences. The close relations +which are shown to exist between magnetism and light tend to +strengthen such views. Indeed, it would not be too much to expect that +if the mechanics of the ether are ever worked out, we should find the +relation between sensible heat and electric currents to be as close as +that of light to magnetism, perhaps find ultimately the forms of +matter, the elements and compounds to be the more complex +manifestations of the universal medium--aggregations in stable +equilibrium. It is a difficult conception, I confess, and a most +shadowy and imperfect one, yet facts and inferences which favor such +views are not wanting. + +Our science of electricity seems almost to be in the same condition +that chemistry was before the work of Lavoisier had shed its light on +chemical theory. Our store of facts is daily increasing, and +apparently disconnected phenomena are being brought into harmonious +relation. Perhaps the edifice of complete theory will not be more than +begun in our time, perhaps the building process will be a very gradual +one, but I cannot refrain from the conviction that the intelligence of +man will, if it has time, continue its advance until such a structure +exists. + +I have been led to make these general allusions to electrical theory +in order to emphasize the fact that in the present paper no unraveling +of the mystery is to be attempted, but rather the presentation of some +few considerations upon a subject of absorbing interest. + +The conception of Faraday in regard to the existence of lines of +magnetic force representing directions of magnetic strain or tension +in a medium has not only lost nothing of its usefulness up to the +present time, but has continually been of great service in the +understanding of magnetic phenomena. We need spend no time in showing, +as Faraday and others have done, that these lines are always closed +circuits, polarized so that the direction of the lines cannot be +reversed without reversal of the actions. Nor need we take time to +show that in any medium the lines are mutually repellent laterally if +of the same direction of polarization. Opposing this tendency to +separation or lateral diffusion of magnetic force is the strong +apparent tendency of the lines to shorten themselves in any medium. +These actions are distributed by the presentation of a better medium, +as iron instead of space or air. Lines of force will move into the +better medium, having apparently the constant tendency to diminish the +resistance in their paths. + +The peculiar and mysterious nature of media, such as iron, is to +permit an extraordinary crowding of lines on account of slight +resistance to their passage through it. We need not, in addition, do +more than refer to the other well-known facts of an electric current +developing magnetic lines encircling the conductor, as being the +general type, which includes all forms of magnetic field or +electro-magnets, sustained by currents, and the fact of a development +when magnetic lines or circuits and material masses are in relative +movement of electromotive forces transversely to the direction of the +lines of magnetism, and also transversely to the direction of relative +movement, as in the case of electric conductors traversing or cutting +through a field, or of a field traversing or being moved across a +conductor. We must not forget that even insulators, as well as +conductors, cutting lines of force, have the electromotive force +developed in them. The action simply develops potential difference, +and this generates the current where a circuit exists. While we are in +the habit of saying that a conductor moved across a field of lines, or +_vice versa_, generates electric current, I think the statement +incomplete. The movement only sets up a potential difference, and the +power expended in effecting the movement generates C x E. The current +is energy less the potential, or the energy expended gives the two +effects of potential or pressure and current or rate of movement. +Consequently an insulator, or an open-circuited conductor, traversing +a field, consumes no energy, potential difference only being produced. +Nevertheless, as will be shown, the magnetic circuits or lines +themselves may furnish the energy for their own movement across a +conductor, and so develop current as well as potential. + +This occurs in the effort of lines to shorten their paths, to lessen +their density, to pass to better media. Indeed, a close examination +will show that wherever power is expended in developing current in a +circuit, cutting lines of force, the energy expended is first employed +in stretching the lines, which thus receive the energy required to +permit them, in shortening, to cut the conductor and set up currents +in the electric circuit in accordance with the potential difference +developed in that circuit and its resistance. + +I think we may also say, though I do not remember to have seen the +statement so put, that whenever electric potential is set up +inductively, as in self-induction, mutual induction, induction from +one circuit to another, and induction from magnets or magnetic field, +it is set up by the movement of lines of force laterally across the +body, mass or conductor in which the potential is developed, and that +whenever current is set up in a wire or an existing current prolonged, +or an existing current checked by induction, self-induction, or +induction from magnets, the action is a transfer of energy, +represented by strained lines of force shortening or lessening their +resistance, or lengthening and increasing the resistance in their +paths. The magnetic field is like an elastic spring--it can in one +condition represent stored energy--it can be strained and will store +energy--it can be made to relieve its strain and impart energy. + +[Illustration: Fig. 1.] + +Let us examine some known phenomena in this light. Take the case of a +simple wire, conveying current, say, in a line away from observer, +Fig. 1. There exists a free field of circular magnetism (so called), +shading off away from the wire, and which is represented by concentric +circles of increased diameter. The superior intensity or strength of +the lines near the wire may also be represented by their thickness. +This is often shown also by crowding the lines near the wire, though I +am disposed to regard Fig. 1 as more nearly expressing the condition, +unless we are to regard the lines as simply indicating a sort of +atmosphere of magnetic effect whose density becomes less as we proceed +outward from the wire, in which case either form of symbol suffices. +The direction of polarization of the lines may be indicated by an +arrow head pointing in a direction of right-handed rotation in the +path of the lines. This is the typical figure or expression for all +forms of simple magnetic circuit--the form of the lines, their length, +position, density, will depend on the shape of the conductor or +conductors (when more than one) and the materials surrounding or in +proximity to the wire or wires. + +If the current traversing the conductor is constant, the magnetic +field around it is stable and static, unless other influences come in +to modify it. The cutting off of the current is followed by +instability of the field whereby it can and must produce dynamic +effects. I say _must_ because the field represents stored energy, and +in disappearing _must_ give out that energy. To throw light on this +part of the subject is one of the objects of the present paper. +Cutting off the current supply in the case assumed leaves the +developed magnetic lines or strains unsupported. They at once shorten +their paths or circuits, collapsing upon the conductor as it were, and +continuing this action, cut the section of the conductor, and +apparently disappear in magnetic closed circuits of infinitesimal +diameter but of great strength of polarization. It appears to me that +we must either be prepared to give up the idea of lines of force or +take the position that the magnetic circuits precipitate themselves in +shortening their circuits and disappearing upon and cut the conductor. +It was Hughes who put forward the idea that an iron bar in losing its +apparent magnetism really short-circuits the lines in itself as +innumerable strongly magnetized closed circuits among the molecules. +In becoming magnetic once more these short circuits are opened or +extended into the air by some source of energy applied to strain the +lines, such as a current in a conductor around the bar. + +May not this idea be extended, then, to include the magnetic medium, +the ether itself? Does it contain intensely polarized closed circuits +of magnetism which are ready to be stretched or extended under certain +conditions by the application of energy, which energy is returned by +the collapse of the extended circuits? This is doubtless but a crude +expression of the real condition of things, for the lines are only +symbols for a condition of strain in a medium which cannot be +represented in thought, as we know nothing of its real nature. There +is one point in this connection which I must emphasize. The strained +lines, Fig. 1, are indications of stored energy in the ether, and the +lines _cannot_ disappear without giving out that energy. Ordinarily, +it makes its appearance as the extra current, and adds itself so as to +prolong the current which extended the lines when an attempt is made +to cut off such current. Were it conceivable that the current could be +cut off and the wire put on open circuit while the lines still +remained open or strained, the energy must still escape when the field +disappears. It would then produce such a high potential as to be able +to discharge from the ends of the conductor, and if the conductor were +of some section, part of the energy would be expended in setting up +local currents in it. The field could not disappear without an outlet +for the energy it represents. But we cannot cut off a current in a +wire so as to leave the wire on open circuit with the lines of the +magnetic circuit remaining around it without iron or steel or the like +in the magnetic circuit. We can approach that condition, however, by +breaking the circuit very quickly with a condenser of limited capacity +around the break. This is done in the Ruhmkorff coil primary; the +condenser forms a sort of blind alley for the extra current on its +beginning to flow out of the primary coil. But the condenser charges +and backs up and stops the discharge from the primary, even giving a +reverse current. The lines of magnetic force collapse, however, and +have their effect in the enormous potential set up in the secondary +coil. + +Take away the secondary coil so as to stop that outlet, the energy +expends itself on the iron core and the primary coil. Take away the +iron core, and the energy of magnetization of the air or ether core +expends itself on the wire of the primary and, possibly, also on the +dielectric of the condenser to some extent. The extra current becomes +in this instance an oscillatory discharge of very high period back and +forth through the primary coil from the condenser, until the energy is +lost in the heat of C2 x R. This conversion is doubtless rendered +all the more rapid by uneven distribution of current and eddy current +set up in the wire of the coil. + +The considerations just given concern the loss of field or the +shortening and apparent disappearance of the magnetic lines or +circuits, as giving rise to the self-induction or increased potential +on breaking. Where the energizing current is slowly cut off or +diminished the energy is gradually transferred to the wire in +producing elevation of potential during the decrease; and the collapse +and cutting of the wire by the collapsing circuits or lines is then +only more gradual. + +Let the current be returned to the wire after disappearance of +magnetism, and the lines again seem to emanate from the wire and at +the same time cut it and produce a counter potential in it, which is +the index of the abstraction of energy from the circuit, and its +storing up in the form of elastically strained lines of magnetism +around the conductor. The effect is that of self-induction on making +or upon increase of current, the measure of the amount being the +energy stored in the magnetic circuits which have been extended or +opened up by the current. The greater the current and the shorter the +path for the lines developed around the axis of the conductor, the +greater the energy stored up. Hence, a circular section conductor has +the highest self-induction, a tube of same section less as its +diameter increases, a flat strip has less as its width increases and +thickness diminishes, a divided conductor much less than a single +conductor of same shape and section. Separating the strands of a +divided conductor increases the length of magnetic paths around it, +and so diminishes the self-induction. A striking instance of this +latter fact was developed in conveying very heavy alternating currents +of a very low potential a distance of about three feet by copper +conductors, the current being used in electric welding operations. + +The conductors were built up of flat thin strips of copper for +flexibility. When the strips were allowed to lie closely together, the +short conductor showed an enormous self-induction, which cut down the +effective potential at its ends near the work. By spreading apart the +strips so as to lengthen a line around the conductor, the +self-induction could be easily made less than 35 per cent. of what it +had been before. The interweaving of the outgoing and return conductor +strands as one compound conductor gets rid almost entirely of the +self-inductive effects, because neither conductor has any free space +in which to develop strong magnetic forces, but is opposed in effect +everywhere by the opposite current in its neighbor. + +Where a number of conductors are parallel, and have the same direction +of current, as in a coil or in a strand, it is evident that statically +the conductor may be considered as replaceable by a single conductor +with the same external dimensions and same total current in the area +occupied, the magnetic forces or lines surrounding them being of same +intensity. But with changing current strength the distribution of +current in the conductor has also a powerful effect on the energy +absorbed or given out in accordance with the magnetism produced. Hence +the self-induction of a strand, coil or conductor of the same section +varies with the rapidity of current changes, owing to the conduction +being uneven. + +The uneven distribution of current, or its tendency to flow on the +outer parts of a conductor when the rate of variation or alternation +is made great, is in itself a consequence of the fact that less energy +is transferred into magnetism in this case than when the current flows +uniformly over the section, or is concentrated at the center. In other +words, when a uniform current traverses a conductor of the same +section, the circular magnetism, or surrounding magnetic lines, are to +be found not only outside the conductor, but also beneath its +exterior. Since in forming these lines on passage of current the +middle of section would be surrounded by more lines than any other +part of the conductor, the current tends to keep out of that part and +move nearer the exterior in greater amount. Hence, in rapidly +alternating currents the conductor section is practically lessened, +being restricted largely to the outer metal of the conductor. If the +round conductor, Fig. 2, were made of iron, the magnetism interior to +it and set up by a current in it would be very much greater, the +section of the conductor being filled with magnetic circuits or lines +around the center. The total magnetism, external and internal, would +be much greater in this case for a given current flow, and the energy +absorbed and given out in formation and loss of field or the +self-induction would be much increased. This could, however, be +greatly diminished by slitting the conductor radially or making it of +a number of separate wires out of lateral magnetic contact one with +the other, Fig. 3. In these cases the resistance of the interior +magnetic circuits would be increased, as there would be several breaks +in the continuity around the center of the conductor. The total +magnetism which could be set up by a current would be lessened, and +the self-induction, therefore, lessened. + +[Illustration: Fig. 2.] + +[Illustration: Fig. 3.] + +The moment we begin the bringing of iron into proximity with an +electric conductor conveying current, we provide a better medium for +the flow or development of magnetic lines or circuits. In other words, +the lines may then be longer, yet equally intense, or more lines may +be crowded into a section of this metal than in air or space. Figs. +4a, 4b, 4c show the effect brought about by bringing iron of +different forms near to the conductor. + +[Illustration: Fig. 4a.] + +[Illustration: Fig. 4b.] + +[Illustration: Fig. 4c.] + +It shows, in other words, the development of the ordinary +electro-magnet of the horseshoe form, and the concentration of the +lines in the better medium. The lines also tend to shorten and +diminish the resistance to their passage, so that attraction of the +iron to the conductor takes place, and if there is more than one piece +of iron, they tend to string themselves around the conductor in +magnetic contact with one another. + +When copper bars of 1 inch diameter are traversed by currents of +40,000 to 60,000 amperes, as in welding them, the magnetic forces just +referred to become so enormous that very heavy masses of iron brought +up to the bar are firmly held, even though the current be of an +alternating character, changing direction many times a second. + +[Illustration: Fig. 5] + +[Illustration: Fig. 6] + +When a conductor is surrounded by a cast iron ring, as in Fig. 5, the +current in such conductor has an excellent magnetic medium surrounding +it. A large amount of energy is then abstracted on the first impulse +of current, which goes to develop strong and dense magnetic lines +through the iron ring and across the gap in it. On taking off the +current the energy is returned as extra current, and its force is many +times what would be found with air alone surrounding the conductor. We +have then greatly increased the self-induction, the storing of energy +and opposition to current flow at the beginning, the giving back of +energy and assistance to the current flow on attempting to remove or +stop the current. Let us now complete the ring, by making it of iron, +endless, Fig. 6, with the conductor in the middle. + +We now find that on passing current through the conductor it meets +with a very strong opposing effect or counter potential. The evolution +of magnetic lines, or the opening out of magnetic circuits, goes on at +a very rapid rate. Each line or magnetic circuit evolved, and cutting +the conductor, flies at once outward, and locates itself in the iron +ring. This ring can carry innumerable lines, and they do not crowd one +another. It permits the lines even to lengthen in reaching it, and +yet, on account of its low resistance to their passage, the +lengthening is equivalent to their having shortened in other media. We +will suppose the current not sufficient to exhaust this peculiar +capacity for lines which the iron has. Equilibrium is reached, the +conductor has opened up innumerable closed circuits, and caused them +to exist in the ring still closed; but in iron, not space or ether +merely. The current passing has continued its action and storage of +energy until to emit another line in view of the resistance now found +in the crowded iron ring is impossible. + +Now let us cut off the current. We are surprised to find a very weak +extra current, a practical absence of self-induction on breaking, or, +at least, a giving out of energy in nowise comparable to that on +making. Let us put on the current as it was before. Another curious +result. But little self-induction now on making energy not absorbed. + +Now cut off the current again. Same effect as before. Now let us put +on the current reversed in direction. At once we find a very strong +counter potential or opposing self-induction developed. + +The ring had been polarized, or retained its magnetic energy, and we +are now taking out one set of lines and putting in reversely polarized +lines of force. This done, we break the reversed current without much +effect of self-induction. The ring remains polarized and inert until +an opposite flow of current be sent through. Iron is then a different +medium from the ether. + +The ring once magnetized must, in losing its magnetism, permit a +closure of the lines by shortening. This involves their passage from +the iron across the space in the center of the ring, notwithstanding +its great resistance to the lines of force. As passage from iron to +air is equivalent to lengthening of the lines, it is readily seen that +such lengthening may oppose more effect than a slight shortening due +to leaving iron, for air or space may give in provoking a closure and +disappearance of the lines. Looked at from another standpoint, the +lines on the iron may actually require a small amount of initial +energy to dislodge them therefrom, so that after being dislodged they +may collapse and yield whatever energy they represent. + +I must reserve for the future further consideration of the iron ring, +but in thinking upon this matter I am led to think that the production +of a magnetic line in an iron ring around a conductor may represent a +sort of wave of energy, an absorption of energy on the evolution of +the line from the conductor, and a slight giving out of energy on the +line reaching that position of proximity to the iron ring, that its +passage thereto may be said to be a shortening process or a lessening +of its resistance. + +The magnetism in air, gases, and non-magnetic bodies, being assumed to +be that of the ether, this medium shows no such effects as those we +get with the ring. It does not become permanently polarized, as does +even soft iron under the condition of a closed ring. The iron +possesses coercive force, or magnetic rigidity, and a steel ring would +show more of it. The molecules of the iron or steel take a set. If we +were to cut the soft iron ring, or separate it in any way, this +introduction of resistance of air for ether in the magnetic circuit +would cause the lines to collapse and set up a current in the +conductor. The energy of the ring would have been restored to the +latter. The curious thing is that physically the polarized ring does +not present any different appearance or ordinary properties different +from those of a plain ring, and will not deflect a compass needle. Its +condition is discoverable, however, by the test of self-induction to +currents of different direction. As a practical consideration, we may +mention in this connection that a self-inductive coil for currents of +one direction must be constructed differently from one to be used with +alternating currents. The former must have in its magnetic circuit a +section of air or the like, or be an imperfectly closed circuit, as it +were. The latter should have as perfectly closed a magnetic circuit as +can be made. We see here also the futility of constructing a Ruhmkorff +core coil on the closed iron magnetic circuit plan, because the +currents in the primary are interrupted, not reversed. + +The considerations just put forward in relation to the closed iron +ring, and its passive character under the condition of becoming +polarized, are more important than at first appears. It has been found +that the secondary current wave of a closed iron circuit induction +coil or transformer, whose primary circuit receives alternating +current, is lagged from its theoretical position of 90 degrees behind +the primary wave an additional 90 degrees, so that the phases of the +two currents are directly opposed; or the secondary current working +lamps only in its circuit is one half a wave length behind a primary, +instead of a quarter wave length, as might have been expected. + +But when it is understood that the iron core polarized in one +direction by the primary impulse does not begin to lose its magnetism +when that impulse simply weakens, but waits until an actual reversal +of current has taken place, it will be seen that the secondary +current, which can only be produced when magnetic lines are leaving +the core and cutting the secondary coil, or when the lines are being +evolved and passing into the core from the primary coil, will have a +beginning at the moment the primary reverses, will continue during the +flow of that impulse, and will end at substantially the same time with +the primary impulse, provided the work of the secondary current is not +expended in overcoming self-induction, which would introduce a further +lag. Moreover, the direction of the secondary current will be opposite +to that of the primary, because the magnetic circuits which are opened +up by the primary current in magnetizing the core, or which are closed +or collapsed by it in demagnetizing the core, will always cut the +secondary coil in the direction proper for this result. Transformers +of the straight core type with very soft iron in the cores and not too +high rates of alternation should approximate more nearly the +theoretical relation of primary and secondary waves, because the +magnetic changes in the core are capable of taking place almost +simultaneously with the changes of strength of the primary current. +This fact also has other important practical and theoretical bearings. + +Let us assume a plain iron core, Fig. 7, magnetized as indicated, so +that its poles, N, S, complete their magnetic circuits by what is +called free field or lines in space around it. Let a coil of wire be +wound thereon as indicated. Now assume that the magnetism is to be +lost or cease, either suddenly or slowly. An electric potential will +be set up in the coil, and if it has a circuit, work or energy will be +produced or given out in that circuit, and in any other inductively +related to it. Hence the magnetic field represents work or potential +energy. But to develop potential in the wire the lines must cut the +wire. This they can do by collapsing or closing on themselves. The bar +seems, therefore, to lose its magnetism by gaining it all, and in +doing so all the external lines of force moving inward cut the wire. +The magnetic circuits shorten and short-circuit themselves in the bar, +perhaps as innumerable molecular magnetic circuits interior to the +iron medium. To remagnetize the bar we may pass an electric current +through the coil. The small closed circuits are again distended, the +free field appears, and the lines moving outward cut across the wire +coil opposite to the former direction and produce a counter potential +in the wire, and consequent absorption of the energy represented in +the free field produced. As before studied, the magnetism cannot +disappear without giving out the energy it represents, even though the +wire coil be on open circuit, and therefore unable to discharge that +energy. The coil open-circuited is static, not dynamic. In such +assumed case the lines in closing cut the core and heat it. Let us, +however, laminate the core or subdivide it as far as possible, and we +appear to have cut off this escape for the energy. This is not really +so, however. We have simply increased the possible rate of speed of +closure, or movement of the lines, and so have increased for the +divided core the intensity of the actions of magnetic friction and +local currents in the core, the latter still receiving the energy of +the magnetic circuit. This reasoning is based on the possibility in +this case of cutting off the current in the magnetizing coil and +retaining the magnetic field. This is of itself probably impossible +with soft iron. That the core receives the energy when the coil cannot +is shown in the well known fact that in some dynamos with armatures of +bobbins on iron cores, the running of the armature coils on open +circuit gives rise to dangerous heating of the cores, and that under +normal work the heating is less. In the former case the core +accumulates the energy represented in the magnetic changes. In the +latter the external circuit of the machine and its wire coils take the +larger part of the energy which is expended in doing the work in the +circuit. In this case, also, the current in the coils causes a +retardation of the speed of change and extent of change of magnetism +in the iron cores, which keeps down the intensity of the magnetic +reaction. In fact, this retardation or lag and reduction of range of +magnetic change may in some machines be made so great by closing the +circuit of the armature coils themselves or short-circuiting them that +the total heat developed in the cores is much less than under normal +load. + +[Illustration: Fig. 7.] + +I wish now, in closing, to refer briefly to phenomena of moving lines +of force, and to the effects of speed of movement. In order to +generate a given potential in a length of conductor we have choice of +certain conditions. We can vary the strength of field and we can vary +the velocity. We can use a strong field and slow movement of +conductor, or we can use a weak field and rapid movement of the +conductor. But we find also that where the conductor has large section +it is liable to heat from eddy currents caused by one part of its +section being in a stronger field than another at the same time. One +part cuts the lines where they are dense and the other where they are +not dense, with the result of difference of potential and local +currents which waste energy in heat. We cannot make the conductor move +in a field of uniform density, because it must pass into and out of +the field. The conditions just stated are present in dynamos for heavy +current work, where the speed of cutting of lines is low and the +armature conductor large in section. + +But we find that in a transformer secondary we can use very large +section of conductor, even (as in welding machines) 12 to 15 square +inches solid copper, without meeting appreciable difficulty from eddy +currents in it. The magnetic lines certainly cut the heavy conductor +and generate the heavy current and potential needed. What difference, +if any, exists? In the transformer the currents are generated by +magnetic field of very low density, in which the lines are moving +across the conductor with extreme rapidity. The velocity of emanation +of lines around the primary coil is probably near that of light, and +each line passes across the section secondary conductor in a +practically inappreciable time. There is no cause then for differences +of potential at different parts of the section heavy secondary. Then +to avoid eddy currents in large conductors and generate useful +currents in them, we may cause the conductor to be either moved into +and out of a low density field with very great speed, or better, we +must cause the lines of a very low or diffused field to traverse or +cut across the conductor with very high velocity. + +It is a known fact that, in dynamos with large section armature +conductors, there are less eddy currents produced in the conductors +when they are provided with iron cores or wound upon iron cores than +when the conductors are made into flat bobbins moved in front of field +poles. Projections existing on the armature between which the +conductors are placed have a like effect, and enable us to employ +heavy bars or bundles of wire without much difficulty from local +currents. The reason is simple. In the armatures with coils without +iron in them, or without projections extending between the turns, the +conductor moves into and out of a very dense field at comparatively +low velocity, so that any differences of potential developed in the +parts of the section of conductor have full effect and abundant time +to act in setting up harmful local currents. In the cases in which +iron projects through the coil or conductor, the real action is that +the lines of the magnetic circuits move at high speeds across the +conductor, and the conductor is at all times in a field of very low +density. Figs. 8 and 9 will make this plain. In Fig. 8 we have shown a +smooth armature surface, having a heavy conductor laid thereon, and +which is at a just entering a dense field at the edge of the pole, +N, and at b leaving such field. It will be seen that when in such +position the conductor, if wide, is subjected to varying field +strength, and moves at a low speed for the generation of the working +potential as it passes through the field, thus giving rise to eddy +currents in the conductor. + +[Illustration: Fig. 8.] + +In Fig. 9 the conductors are set down between projections, in which +case both armature and field poles are laminated or subdivided. As +each projection leaves the edge of field pole, N, the lines which it +had concentrated on and through it snap backward at an enormous speed, +and cross the gap to the next succeeding projection on the armature, +cutting the whole section of the heavy armature conductor at +practically the same instant. This brisk transfer of lines goes on +from each projection to the succeeding one in front of the field pole, +leaving a very low density of field at any time between the +projections. The best results would be obtained when the armature +conductor does not project beyond or quite fill the depth of groove +between the projections. Of course there are other remedies for the +eddy current difficulty, notably the stranding and twisting of the +conductor on the armatures so as to average the position of the parts +of the compound conductor. + +[Illustration: Fig. 9.] + +Perhaps the most extreme case of what may be called dilution of field +by projections and by closed magnetic circuits in transformers would +be that of a block of iron, B, Fig. 10, moved between poles, N and S, +and having a hole through it, into and through which a conductor is +carried. The path through the iron is so good that we can scarcely +consider that any lines cross the hole from N to S; yet as B moves +forward there is a continual snapping transfer of lines from the right +forward side of the hole to the left or backward side, cutting the +conductor as they fly across, and developing an electromotive force in +it. I have described this action more in detail because we have in it +whatever distinction in the manner of cutting the lines of the field +is to be found between wire on smooth armatures and on projection +armatures and modifications thereof; and also between flat, open coils +passing through a field and bobbins with cores of iron. The +considerations advanced also bring out the relation which exists +between closed iron circuit transformers and closed iron circuit +(projection) dynamos, as we may call them. + +[Illustration: Fig. 10.] + +I had intended at the outset of this paper to deal to some extent with +the propagation of lines of magnetism undergoing retardation in +reference to alternating current motor devices, transformers with +limited secondary current, or constant average current, an alternating +motor working with what I may term a translation lag, etc.; but it was +soon found that these matters must remain over for a continuation of +this paper at some future time. My endeavor has been in the present +paper to deal with the lines of force theory as though it were a +symbol of the reality, but I confess that it is done with many +misgivings that I may have carried it too far. Yet, if we are to use +the idea at all it has seemed but right to apply it wherever it may +throw any light on the subject or assist in our understanding of +phenomena. + + * * * * * + + + + +ELECTRIC LIGHTING AT THE PARIS EXHIBITION--THE OERLIKON +WORKS. + + +Immediately on entering the Machinery Hall by the _galerie_ leading +from the central dome, and occupying a prominent position at the +commencement of the Swiss section, is a very important plant of +dynamos, motors, and steam engines, put down by the Oerlikon Works, of +Zurich. During the time the machinery is kept running in the hall, +power is supplied electrically to drive the whole of the main shafting +in the Swiss section and part of that in the Belgian section, +amounting in all to some 200 ft., a large number of machines of +various industries deriving their power from these lines of shafting, +while during the evening a portion of the upper and lower galleries +adjoining this section is lit by some twenty-five arc lamps run from +this exhibit. Steam is supplied from the Roser boilers in the motive +power court. The whole of the generating plant is illustrated in one +view, and a separate view is given of the motor employed to drive the +main shafting, this latter view showing the details of connection to +the same. On the extreme right hand side of the first view is a direct +coupled engine and dynamo of 20 horse power, a separate cut of which +is given in Fig. 3. The engine is of the vertical single cylinder +type, standing 5 ft. high, and fitted, as are the other two engines +exhibited, with centrifugal governor gear on the fly wheel, acting +directly on the throw of the cutoff valve eccentric. The two +standards, supporting the cylinder and forming the guide bars, +together with the entire field magnets and pole pieces of the dynamo, +and the bed plate common to both, are cast in one piece. + +[Illustration: FIG. 3 ENGINE AND DYNAMO FOR STEAMSHIPS.] + +The machine is specially designed for ship lighting, and with the view +of preventing any magnetic effect upon the ship's compass, the field +is arranged so that the armature, pole pieces, and coils are entirely +inclosed by iron. Any tendency to leakage of magnetic lines will +therefore be within the machine, the iron acting as a shield. This +build of field--shown in Fig. 3A--is also advantageous as a mechanical +shield to the parts of the machine most likely to suffer from rough +handling in transport, and it will be seen that the field coils are +easily slipped on before the armature is mounted in its bearings. + +[Illustration: FIG. 3A] + +The winding is compound, and in such a direction that the two opposite +horizontal poles have the same polarity; it follows from this that +there will be two consequent poles in the iron, these being opposite +in name to the horizontal poles and at right angles to them, viz., +above and below the armature. Opposite sections of the commutator are +connected together internally as in most four-pole machines, so that +only two brushes are necessary, at 90 deg. apart. + +The section of iron in the field is 60 square inches and rectangular +in form, and the whole machine measures 4 ft. 3 in. in length, and 2 +ft. in height, without including the height of the bed plate. The +armature is 17 in. in length and the same in diameter, measured over +the winding, and develops at the machine terminals 70 volts and 200 +amperes at 480 revolutions. The moving parts of the engine are well +balanced, and run remarkably well and without noise at this high rate +of speed. + +This dynamo serves to develop power to run a motor in an adjoining +inclosure, containing some fine specimens of lathes and machine tools +constructed by the Oerlikon Works. These are driven by the motor +through the medium of a countershaft, and the power and speed are +controlled from the switch board seen at the left of the exhibit, and +in Fig. 11. The resistance, R1, serves to vary the intensity of the +shunt field of the dynamo, the volts being indicated by the voltmeter +V1, and a resistance separate from the switch board is inserted in +the main circuit of the two machines. The ammeter, A2, is directly +connected to the dynamo, and therefore indicates the current, whatever +circuit this machine is running. + +[Illustration: Figs. 5-9, 11 plus THE PARIS EXHIBITION--STAND OF THE +OERLIKON WORKS.] + +A larger combined engine and dynamo, seen in the center of the stand, +serves to run the lighting of the galleries. The engine is a 60 horse +power compound, running at 350 revolutions, and fitted with a governor +on the fly wheel, like that described above. + +The dynamo is a two-pole machine, the upper pole and yoke being cast +in one, and the lower pole, yoke, and combined bed plate forming a +separate casting. The two vertical cores, over which the field bobbins +are slipped, are of wrought iron, and are turned with a shoulder at +either end, the yokes being recessed to fit them exactly. The cores +are then bolted to the yokes vertically from the top and horizontally +below. The field of this machine is shunt-wound, and in order to +maintain the potential constant a hand-regulated resistance--R2 on +the switch board--is added in circuit with the shunt field. The +voltmeter, V2, immediately above this resistance, serves to +indicate the difference of potential at the machine terminals. Both +voltmeters are fitted with keys, so that they are only put in circuit +when the readings are taken. + +The main terminals of this machine are fitted on substantial +insulating bases, fixed one at each end of the top yoke. These connect +to the external circuit by a heavy cable--the machine being capable of +developing 500 amperes--and to the shunt circuit, and regulating +resistance by small wires; while the two connections to the brushes +are by four covered wires in parallel on each side. This mode of +connection is more flexible than a short length of heavy cable, and +looks well, the wires being held neatly together by vulcanized fiber +bridges. The dynamo is a low tension machine, the field being +regulated to give 65 volts when running the lamp circuits. + +[Illustration: Fig. 10.] + +The illustration, Fig. 10, represents the automatic +re-regulator--C.E.L. Brown's patent. Motion is imparted to the cores +of two electro-magnets at the ends by the pulleys, W W1. The cores +have a projection opposite to the spindle, ab, which latter is +screw-threaded. By a relay one or other electro-magnet is put in +action, and the rotating core, which is magnetized, causes rotation of +the spindle by attraction, resulting in the movement of the contact +along the resistance stops. The relay is acted upon directly by the +potential of the dynamo, and the variable resistance is included in +the shunt field of the machine, so that changes in the potential, +resulting from changes in load or speed, are compensated for. + +The arrangements of the lamp circuits and the lamp itself may now be +described. The lamps are all run in parallel circuit, but are divided +into groups of five, each group being controlled by a separate switch +on the board--Figs. 11 and 11A. These switches are not in +direct communication with the dynamo, but make that connection through +a large central switch, S2, which therefore carries the whole +current. The returns from each group are brought to the connections +seen between the two resistances, where the circuits may be +disconnected if desired, and the main current then passes through the +ammeter, A3, to the other terminal of the machine. One of the smaller +switches at the top, Fig. 11A, is directly connected with one terminal +of the 20 horse power dynamo before mentioned, and the other side of +the switch to the motor in the machine tool exhibit. Also one of the +switches in connection with the central switch, S2, is connected to +the same motor, and therefore the latter may be run by either machine, +or, in fact, any combination of machines, lamps, and motor be made as +required. + +The form of switch made by the Oerlikon Works is illustrated in Fig. +7. Two thick semicircular bands of copper are screwed at one end to +opposite sides of a square block which is turned round by the switch +handle. The block has a projection at each corner, and two strong, +flat, stationary springs are attached to the framework of the switch +and press on opposite sides of the block. The ends of the springs +engage in the projections and prevent the switch being turned round +the wrong way, while the pressure of the springs on opposite sides +forces the copper bands to take up a position exactly in line with the +terminal contacts when the switch is closed, or at right angles to +them when it is opened. + +[Illustration: FIG. 4A] + +[Illustration: FIGS. 4, 4B and 4C] + +Further, each lamp has its own separate adjustable resistance, fuse, +and switch. These are of special construction, combined in one, and +are illustrated in Figs. 4 and 4A; the other figures, 4B and 4C, +showing some of the details of the same. The wires, W W, lead from and +to one lamp. The current enters at one wire, passes through the fuse, +f--Figs. 4C and 4A--down the center of the cylinder to a divided +contact, into which a switch arm can be shot. When this is so, a +connection is made to the upright brass rod, T, which serves to grip +the band, R, passing round the body of the cylinder. The current then +passes through all the turns of wire above the band, and out at the +other terminal. The resistance can be varied by raising or lowering +the band. Fig. 4B shows the manner of tightening the band against the +wires on the cylinder. The upright rod, T, is seen in section, and is +fixed in one position to the frame of the apparatus. Abutting against +this, and working in the block to which the two ends of the band are +screwed, is a thumb screw, S, by turning which the band may be +loosened for adjusting, and tightened when the right position is +found. The cylinder is covered with asbestos sheet, and the wire, +which is of nickel, and measures altogether from 3 to 4 ohms, is wound +helically round this. The switch arm, to which the handle is attached +below, does not itself make and break the circuit, but carries a +spring, as shown, which, when the arm is at the end of its movement, +pulls over the contact lever with a rapid action, shooting the same +between the divided contact piece, and making a perfect contact. The +switchboard forms one side of a closed wooden case or cupboard, with +sufficient room for a man to enter and adjust the resistances or +switches for each lamp. These are screwed to the inside of the case in +rows, to the number of twenty-five. The greatest care has been taken +in the fixing of the connections to the inside of this case, and no +leading wires of different potential are allowed to cross each other. + +[Illustration: FIG. 11A] + +The Oerlikon lamp, which is designed to work with constant potential, +is shown partly in section in Fig. 8. There is only one solenoid, A, +through which all the current passes, and whose action is to strike +the arc and maintain the current constant. The soft iron core, C, is +suspended from the inside of the tube, T, in which it has an up and +down movement checked by an air piston in the tube. An end elevation +of the brake wheels and solenoid is given in Fig. 9, where it will be +seen that the spindle carrying these wheels also carries between them +a pinion engaging with the rack rod, R. The top carbon attached to the +rack rod falls by its own weight, and is therefore in contact with the +lower carbon before the lamp is switched in circuit. When this is done +the core is instantly magnetized, and attracted to the soft iron brake +wheels, which it holds firmly. The air cushion in the tube prevents +the core being drawn up until it has fairly gripped the sides of the +wheels. The subsequent raising of the core therefore turns the wheels, +raises the rack rod, and strikes the arc. The feed is operated by the +weakening of the magnetic field of the coil, which causes the core to +lose its grip of the wheels, and allows the top carbon to descend. The +catch, L, Fig. 8, has a lateral play, and serves to engage in the +teeth of the rack rod, so as to prevent its falling when being +trimmed. Each carbon when in position is held against two rectangular +guide bars by the pressure of a wire spring--see figure. In this way +the carbon is pressed against two parallel knife edges, and is +therefore always in true alignment. The action of the lamp is very +simple, the working parts are few and solidly constructed, and the +regulation, as exhibited by the lamps running in the galleries, is +exceptionally steady. + +The transmission of power plant consists of two 250 horse power +dynamos--C.E.L. Brown's patent--the generator being driven by a +vertical compound condensing engine of the same power, running at 180 +revolutions. The dynamo generator is a four-pole 600 volt direct +current machine, series wound, and may be distinguished in the +engraving next to the switch board; while the motor receiver +connected to it, and erected in another portion of the Swiss section, +is of exactly the same size and type. The field, which is hexagonal in +shape, is cast in two pieces, bolted together horizontally, the +cross-sectional area of iron being 170 square inches. The armature is +cylindrical, and built up of flat rings stamped out of soft sheet +iron, eight notches in the same being provided to fit over the arms of +the spider keyed to the shaft. The spider is in halves, which are +bolted together longitudinally after the rings are in position. It is +Gramme wound, and measures over the winding 7 in. radial depth, 37 in. +outside diameter, and 22 in. in length. The current is collected by +four brushes. The fitting and mechanical build of the dynamos leaves +nothing to be desired. All the working parts of the dynamos and +engines are turned up to gauge and template, so as to be +interchangeable. As an instance of this, the armature of the generator +was built in the works, while the field magnets were being erected in +the exhibition, and, on arrival, fitted in position perfectly, and ran +at once without trouble. + +The energy taken off on the motor shaft is close on 200 horse power, +but varies according to the machines at work; the speed of the motor +does not, however, vary more than 3 per cent., and the brushes need no +adjustment. About 6 ft. of shafting is coupled on in line with the +motor shaft, and an extra plummer block fixed at the end. This +shafting carries at its extremity an additional 2 ft. pulley, the +power being delivered by belting from these pulleys to two large +pulleys on the main shaft. + +The machines run by this transmission consist of the looms of Rieter & +Co., of Winterthur; the large flour mill and lift of A. Millot & Co.; +the flour milling machinery of Frederick Wegmann & Co., of Zurich; the +brick and tile making machines of the Rorschach foundries; and the +looms of Messrs. Houget & Teston, of Verviers, in the Belgian section. +A 15 horse power two-pole Oerlikon dynamo is also run by a belt from +the main shaft, and generates power to drive a motor of similar type +in the Swiss section of the upper gallery. This runs a length of +countershafting supplying power to three silk-weaving machines +constructed by Benninger Freres; six weaving machines from the Ruti +works, near Zurich; and one knitting machine exhibited by Edward +Dubied & Co., of Couvet. + +The dynamo and motor are connected to the main cable by switches of +the type shown in Fig. 5. These are specially designed to destroy the +extra current on breaking circuit by the formation of an arc which +gradually increases the resistance till the break occurs, rendering it +less sudden. One wire passes through the handle and makes contact with +the springs, and the other is attached to the clamp in which the +carbon rod is held. The current is made to enter at the carbon rod, so +that the arcs formed cause consumption of the carbon. A magnetic +cut-out--Fig. 6--is also provided to each machine; this consists of an +electro-magnet, through which the main current passes, provided with +side pole pieces. A flat soft iron plate armature is hinged so as to +come up against the pole pieces when attracted. When the current is +not sufficiently strong to cause the plate to be attracted, a hole in +the center of the latter engages over a small projection in the top of +a weighted arm hinged in the center of the board, and keeps it +upright. If now the current exceeds the limits of safety to the +machine, due to a too heavy load being thrown on, the armature is +attracted and releases the vertical arm, which falls over and enters +with considerable force between the two spring contacts below. These +contacts are connected to the field terminals, which are, therefore, +short-circuited, and prevent the dynamo generating any current. A +retractile spring can be adjusted to cause cut-off at any required +current. These details are indicated in our illustrations mounted on +their respective switch boards. + +Since the erection of plant by these works at Solothurn for +transmitting 50 horse power five miles distant, which attracted so +much interest some time ago, several important works have been carried +out. Among these we may mention a 280 horse power transmission at 11/2 +kilom. distance to a cotton mill at Derendingen in Switzerland, a 250 +horse power transmission at 1/2 kilom. distance, carried out for Gaetano +Rossi at Piovene in Italy, and a 300 horse transmission at 6 kilom. +distance installed for Giovanni Rossi, in which the power is given off +at two different stations.--_The Engineer._ + + * * * * * + + + + +THE ADER FLOURISH OF TRUMPETS. + + +Although telephonic novelties are not numerous at the Universal +Exposition, telephony--that quite young branch of electric science--is +daily the object of curious and interesting experiments which we must +make known to our readers, a large number of whom were not yet born to +scientific life when the experiments were made for the first time at +Paris in 1881; and it is proper to congratulate the Societe Generale +des Telephones on having repeated them in 1889 to the great +satisfaction of the rising generation. + +We allude to the Ader system of telephonic transmissions of sounds in +such a way that they can be heard by an audience. + +The essential parts of this mode of transmission consist of two +distinct systems--transmitters and receivers. + +[Illustration: FIG. 1.--THE ADER FLOURISH OF TRUMPETS] + +The transmitters are four in number, and are actuated by the same +number of musicians, each humming into them his part of the quartet +(Fig. 1). This transmitter, represented apart in elevation and section +in Fig. 2, is identical with the one used in the curious experiment +with the singing condenser. At A is a mouthpiece before which the +musician hums his part as upon a reed pipe. He causes the plate, B, to +vibrate in unison with the sound that he emits, and this produces +periodical interruptions of varying rapidity between the disk, B, and +the point, C. The button, D, serves to regulate the distance in such a +way that the breakings of the circuit shall be very complete and +produce sounds in the receivers as pure as allowed by this special +mode of transmission, in which all the harmonics are systematically +suppressed in order to re-enforce the fundamental. + +[Illustration: FIG. 2.--DETAILS OF THE TRANSMITTER.] + +This transmitter interrupter is interposed in the circuit of a battery +of accumulators, with the five receivers that it actuates, in such a +way that the four transmitters and five receivers form in reality four +groups of distinct autonomous transmission, the accordance of which is +absolutely dependent upon that of the artists who make them vibrate. + +The five receivers are arranged over the front door of the telephone +pavilion, near the Eiffel tower (Fig. 3). Each consists of a horseshoe +magnet provided, between its branches, with two small iron cores +having a space of a few millimeters between them (Fig. 4). Each of +these soft iron cores carries a copper wire bobbin, N, the number of +spirals of which is properly calculated for the effect to be produced. +Opposite the vacant space left by the two cores, there is a small +piece, t, of rectangular form, and also of soft iron, fixed to a +vibrating strip of firwood, L, of about 4 inches section. The +periodical breaking of the circuit produced by the transmitter causes +a variation in the magnetization of the iron cores of the five +receivers and makes the firwood strips vibrate energetically. These +vibrations are received and poured forth as it were in front of the +telephone pavilion, by large brass trumpets arranged in front of each +receiver, as shown in Fig. 3. + +[Illustration: FIG. 3.--THE ADER FLOURISH OF TRUMPETS] + +It would be difficult for us to pass any judgment whatever upon the +musical and artistic value of these transmissions of trumpet music to +a distance; we prefer to confess our incompetency in the matter. But +it is none the less certain that these experiments are having the same +success that they had at their inception in 1881 at the Universal +Exposition of Electricity, and they allow us to foresee that there is +a time coming in which it will be possible to transmit speech to a +distance with the same intensity that the present trumpet flourishes +have. Although all the tentatives hitherto made in this direction have +not given very brilliant results, we must not despair of attaining the +end some day or other. Less than fifteen years ago the telephone did +not exist; now it covers the world with its lines.--_La Nature._ + +[Illustration: Fig. 4.--DETAILS OF THE RECEIVER.] + + * * * * * + + + + +NOTES ON DYEWOOD EXTRACTS AND SIMILAR PREPARATIONS. + +By LOUIS SIEBOLD, F.I.C., F.C.S. + + +During the last ten years there has been an enormous increase in the +production of these preparations, and the time will come when their +application in dyeing and calico printing will become so general as to +completely supersede the employment of the raw materials. The +manufacture of these extracts, to be thoroughly successful, requires +to be so conducted as to secure the perfect exhaustion of the dyewoods +without the slightest destruction or deterioration of the coloring +matters contained in them; and though nothing like perfection has been +reached in the attainment of these objects, it is certain that the +processes of extraction and evaporation now employed by the best +makers are a very great improvement on the older methods. Indeed, +there is no difficulty nowadays in procuring dyewood extracts of high +excellence if the consumer is willing to pay a price for them +corresponding to their quality, and knows how to avail himself of the +aid of chemical skill to control his purchases. Unfortunately, +however, there is so much hankering after cheap articles, and so +little care is taken to ascertain their real quality, that every scope +is afforded to the malpractices of the adulterer. There are many dye +and print works in which large quantities of these extracts are used +without being subjected to trustworthy tests. Moreover, much of the +testing is done by fallacious methods and often by biased hands. So +fallacious, indeed, are some of these tests, that grossly adulterated +extracts are often declared superior to the purer ones, the cause of +this being the application of an insufficient proportion of mordant in +the dyeing or printing trials, and the consequent waste of the excess +of coloring matter in the case of the purer preparation. + +Professional analytical chemists have hitherto given but little +attention to these preparations, and the employment of experienced +chemists in works is as yet far from general. The testing of dyewood +extracts in such a manner as to throw full light on their purity, the +quality of raw material from which they are prepared, their exact +commercial value their suitability for special purposes, and the +proportion and nature of any adulterants they may contain, is of +course a difficult and tedious task, and must be left to the expert +who is in possession of authentic specimens prepared by himself of all +the different extracts made from every variety and quality of raw +materials, and who combines a thorough knowledge of experimental +dyeing and printing with a large experience in the chemical +investigation of these preparations. But when the object of the +testing is merely careful comparison of the sample in question with an +original sample or previous deliveries, the case is much simplified, +and comes within the scope of the general chemist or the laboratory +attached to works. A few years ago I recommended carefully conducted +dyeing trials on woolen cloth mordanted with bichromate of potash as +the best and simplest mode adapted to such cases, and my subsequent +experience enables me to confirm that observation to the fullest +extent. Most of these extracts contain the coloring matter in two +states, the developed and the undeveloped, and an oxidizing mordant +such as bichromate of potash causes the latter as well as the former +to enter completely into combination with a metallic base; whereas +many of the other mordants, such as alumina or tin compounds, merely +take up the developed portion of the coloring matter together with +such small and variable proportions of the undeveloped as might +undergo oxidation during the process of dyeing. I would therefore +suggest dyeing trials with alumina, tin, iron, etc., only as +subsidiary tests indicating the suitability of an extract for certain +special purposes, while recommending the trial with bichromate of +potash as the one giving the best information respecting the actual +strength of the extract in relation to the raw material from which it +was obtained, and as giving a fair idea of the money value of the +sample. Cotton dyeing does not, as a general rule, afford a good means +of assaying extracts, as it is generally done under conditions which +do not admit of complete exhaustion of the dye bath, but it might +often with advantage be resorted to as an additional trial throwing +further light on the degree of oxidation or development of the +coloring matter. Printing trials are apt to give fallacious results +unless the proportion of mordant is carefully adjusted to the amount +of coloring matter present, and several trials with different +proportions would be necessary to prevent erroneous conclusions. For +the trials with bichromate of potash on wool I would recommend pieces +of cloth weighing about 150 grains, and the most suitable proportion +of bichromate of potash is 3 per cent. of the weight of the cloth. The +requisite number of pieces (equal to the number of samples to be +tested) should be thoroughly scoured and then heated in the bichromate +solution at or near the boiling point for not less than 11/2 hours, +after which they should be well washed and then dyed separately in the +solutions of equal weights of the extracts at the same temperature and +for the same length of time; 15 grains of extract is a suitable +quantity for a first trial under these conditions. These trials can +then be repeated with different relative proportions of extract in +order to ascertain what weight of a sample would give the same depth +of color as 15 grains of the standard example. Many precautions are +required both in the mordanting and dyeing processes in order to +obtain trustworthy results; and though the trials with bichromate of +potash give the most reliable information of any single test, they +should be supplemented by the subsidiary tests already alluded to, and +also by a chemical examination, in order to obtain a knowledge, not +merely of the wood strength, but also of the general nature of the +extract. An adulteration with molasses or glucose can be best +determined by fermentation in comparison with a pure sample. Mineral +adulterants may, of course, be detected by an estimation and analysis +of the ash, after making due allowances for variations due to +differences in different kinds of the same dyewoods. The estimation of +the individual coloring matters in these extracts by means of a +chemical analysis is under all circumstances a task requiring much +experience, especially as the coloring principles are associated in +different qualities of each class of dyewood with different +proportions of other constituents which often give much trouble to the +unpracticed experimenter. Extracts made from logwood roots are now +largely manufactured and often substituted or mixed with the extracts +of real logwood, and have in some instances been palmed of as logwood +extracts of high quality. The correct determination of such +admixtures, like the fixing of anything like the exact commercial +value of dyewood extracts, requires nothing less than a complete +chemical investigation coupled with numerous dyeing trials in +comparison with standard preparations, and should be left to an +expert. + +The presence in dyewood extracts of coloring matters in various stages +of development has hitherto militated against their use in place of +the raw materials by many dyers and printers who are still employing +inherited and antiquated processes in which the whole of the coloring +matter is not rendered available. It is often asserted by these that +even the best of extracts fail to give anything like the results +attained by the use of well-prepared woods, and that, indeed, their +application proves a complete failure. Such failure, however, is +simply due to the want of chemical knowledge on the part of the dyers, +for there is no real difficulty in making any good and pure extract +serve all the purposes for which the woods were used. It is to be +hoped that in this branch of industry, as well as in many others, the +employment of chemists will become more general than at present, and +not be restricted, as is often the case, to young men without +experience and without the trained intellect so essential to success +in chemical investigations. High class chemical skill is of course +available to the manufacturer, but the man of science who brings +matured knowledge and valuable brain work into the business required +social as well as pecuniary recognition, and the sooner and more +fuller this fact is appreciated the better it will be for the +maintenance and progress of our industries. + +With regard to the astringent extracts, such as sumac, myrabolam, +divi, valonia, quebracho, oak, etc., it is the aim of the +manufacturer, whenever such extracts are intended for the purposes of +dyeing and printing, to obtain the tannin in a form in which it is +best calculated to fix itself upon the fiber. The case is somewhat +different when the same extracts are required for tanning. For this +purpose it is necessary that the extract shall have considerable +permeating power, and that the tannin contained in it shall readily +yield leather of the desired texture, color, and permanency. Extracts +specially suited for this purpose are by no means always the most +suitable for the dyer, and _vice versa_. + +A brief description of the processes by which the astringent extracts +may be tested with particular reference to their fitness for definite +purposes concluded the paper. + +With regard to the question as to whether experimental dyeing with +bichromate of potash should be employed as a test even in works where +all the dyeing was done with other mordants, he was decidedly of +opinion that it should always be resorted to as one of the tests, +inasmuch as it was the only simple and expeditious method giving a +fair idea of the actual wood strength and money value of the extract. +The test should, in such cases, be supplemented by dyeing trials with +the mordants used at the works, and, if necessary, also by a chemical +analysis. Printing trials were not necessarily bad tests, since +oxidizing was usually added in these where it was necessary, and any +undeveloped coloring matter would thus be oxidized during the steaming +process: but, as he had stated before, it was essentially necessary in +such cases to have a fair idea of the amount of actual coloring matter +in the extract and to adjust the proportion of mordant accordingly. +Such trials should therefore be preceded by carefully conducted dyeing +trials with bichromate of potash. Mr. Thomson had raised the question +whether it would not be well for the manufacturer to prepare these +extracts in such a manner that they would contain all the coloring +matter in one condition only, in order to insure greater uniformity in +their quality and mode of application. This would, no doubt, be a +desirable step to take if the owners of dye and print works were more +in the habit of availing themselves of the service of competent +chemists experienced in this branch, for then they would be able to +make any extract do its full work irrespective of the state of +development of the coloring matter. Such, however, was not the case, +and it was a very common thing for the consumer of dyewood extracts to +require the manufacturer to prepare them specially for him so as to +suit his own dyeing recipes, or in other words to give exactly the +same shades, weight for weight, by his own method of dyeing as the +article he was in the habit of using. The manufacturer was thus often +compelled to make many different qualities of the same extract to suit +different customers. For the same reason adulterated articles were +often preferred to the pure ones. There was, perhaps, no branch of +industry in which chemical skill of a high order could be applied with +greater advantage than in dyeing, and nowhere was this fact less +recognized. Some of the processes of dyeing were exceedingly wasteful +and stood in much need of improvement. He (Mr. Siebold) knew a large +works in which a ton of logwood extract was used daily for black +dyeing only, and he might safely assert that of this enormous quantity +only a very small proportion would be fixed on the fiber, while by far +the greater proportion was utterly wasted. Such a waste could only be +prevented by a searching investigation of its causes by trained skill. +Mr. Thomson had further alluded to the color obtained with logwood or +logwood extract and wool mordanted with bichromate of potash, and +seemed to be under the impression that the color thus obtained was not +black, but blue. This was undoubtedly the case in dyeing trials +performed as tests, as these were conducted purposely with a very +small proportion of coloring matter in order to admit of a better +comparison of the resulting depth of shades. But with larger +proportions of logwood the color obtained was a fine bluish-black, and +with the addition of a small proportion of fustic or quercitron bark +to the logwood a jet black was readily produced. With regard to Mr. +Watson Smith's observation as to fractional dyeing, he (Mr. Siebold) +did not regard this method as a suitable trial for ascertaining the +strength of an extract, but he admitted it was occasionally very +valuable for detecting an admixture of extracts of other dyewoods, +such as quercitron bark extract in logwood extract. It was also a good +method of ascertaining the speed of dyeing and hence the relative +proportion of fully developed coloring matter of an extract.--_Jour. +Soc. Chem. Industry._ + + * * * * * + + + + +ORTHOCHROMATIC PHOTOGRAPHY.[1] + + [Footnote 1: Read before the Photographic Association of + Brooklyn.] + +By OSCAR O. LITZKOW. + + +What I want to show is the manner in which the process has been +tested. My employer, Mr. Bierstadt, has given me permission to show +you some samples, and also his chart containing the spectrum colors: +violet, indigo blue, green, yellow, orange, red, and black. This chart +has been photographed in the orthochromatic and also in the ordinary +way. + +There are many ways of producing an orthochromatic effect; one is the +use of a glass tank placed behind or in front of the lens, in which a +coloring matter from either a vegetable or mineral product is placed; +this tank or cell is, however, only for use in the studio, as for +outdoor photography we have a colored glass screen, so as not to be +bothered with carrying colored solution. + +The tank is constructed as follows: Procure two pieces of best white +plate glass, about 6 inches square; between these place a piece of +rubber of the same size square, and about 3/8 of an inch thick. In the +center of this rubber cut out a circle about 4 inches diameter, and +from one of the corners to the center of the circle cut out a narrow +strip 1/4 inch wide; this serves as the mouth of the tank. The two +pieces of glass and the rubber are cemented together with rubber +cement; then, to hold it firmly together, two brass flanges are used +as a clamp, with four screws at an equal distance apart; a thin sheet +of rubber is on the glass side of the flanges to prevent direct +contact with the glass, the center remaining clear for the rays of +light to pass through solution and glass. + +One of the best orthochromatic effects made through this tank is with +a three-grains-to-the-ounce solution of bichromatic of ammonia or +bichromate of potassium. In this method there is no preparation used +on the plate. A common rapid dry plate is exposed through this +solution; the exposure, however, is about twenty times longer than it +would be if you removed the tank with the yellow solution, or, in +other words, if a dry-plate is exposed one minute without the yellow +solution it would have to be exposed twenty minutes through a +three-grain solution of bichromate of potassium or ammonia. It +produces wonderful results on an oil painting or any highly colored +object. + +Another method, and the one best adapted for landscapes, is to bathe +the plate in erythrosine and then expose it through a yellow glass +screen. + +As an illustration, suppose we have before us a beautiful landscape. +In the foreground beautiful foliage, in the center a lake, in the +distance hills, with a bluish haze appearing pleasing to the eye, also +a nice sky with light clouds. Now make a plain negative, and see what +has become of your clouds, hills, and the distance--not visible! Some +photographers have been led to think that by underexposing they retain +the distance, but they sacrifice the foreground; besides, it does not +produce an orthochromatic effect. + +But it is a good idea to expose longer on the foreground than you do +on the distance. This can be done by raising the cap of the lens +skyward and gradually shut off, giving the foreground more exposure. + +Plates are prepared for orthochromatic work as follows: Take any +ordinary rapid dry plate, place it in a bath containing + + Distilled water 200 c.c. + Strong liquid ammonia 2 c.c. + +Rock it for two minutes, work as dark as you possibly can. Now take it +out, and place it in the second bath for one and one-fourth minutes +and keep it rocking. Have on hand for use a stock solution of + + Distilled water 1,000 parts. + Erythrosine "Y" brand 1 part. + +Prepare second bath as follows: + + Erythrosine stock solution 25 c.c. + Distilled water 175 c.c. + Strong water ammonia 4 c.c. + +After removing the plate, dip it again face down to rinse off any +particles of scum, etc., that may get in the bath accidentally. This +bath may be used for one dozen 8 by 10, when it should be thrown away +and fresh bath used. + +After the plates come out of the last bath, they should be stood on +clean blotting paper to absorb the excess of solution. I would also +advise to use clean fingers. Pyro. or hypo. on the fingers is a +drawback to success. + +After plates have been drained, place them in a cleaned rack in an +absolutely light-tight closet, with air holes so constructed as to +admit air but no light; the plates will dry in from eight to twelve +hours. They are best prepared in the evening, and, if the closet is +good, will be dry in the morning. + +After the plates are dry they may be packed face to face with nothing +between them, in a double-cover paper box, and put in a dark closet +free from sulphureted hydrogen gas, until ready for use. I have kept +plates for three months in this way, and they were in good condition. +Great care should be used in developing these plates, as they are +sensitive to the red; get used to developing in a dark part of the +dark room; occasionally you may look at the process of development in +a little stronger light. + +The exposure through the yellow screen with an erythrosine plate is +about the same as if you had no orthochromatic plate--a plain plate +instead--provided you are not using too dark a yellow on your screen. +This can only be determined by experience. I will give to a common +plate about four seconds, an orthochromatic plate under the same +conditions five seconds. + +The yellow glass screen is prepared as follows: Take a piece of best +plate glass--common cannot be used--clean it nicely; take another +large plate glass, or anything that is level and true, level it with a +small spirit-level. Now take the cleaned piece of glass and coat it +with + +AURENTIA COLLODION. + + Ether 5 oz. + Alcohol 5 oz. + Cotton 60 grs. + +The aurentia to be added to suit your judgment; it takes a very small +quantity to make an intense yellowish-red collodion. Pour it on the +center of the glass, flow it to the edges, and before it sets place it +on the level glass and allow it to set; when set put it in a rack to +dry. + +Should it dry in ridges, the collodion may be too thick, and it must +be thinned down with equal parts of alcohol and ether. A single piece +of plate glass, about one-eighth inch thick, coated with aurentia +collodion, is all that is required with an erythrosine plate. Or, +after a piece has been successfully coated, another piece of the same +plate glass, and the same size, may be cemented together with balsam, +having the coated aurentia side between the two glasses; the edges may +then be bound with paper. + +In using different colored solutions, collodion, etc., I have found +that one will change the focus and the other not. With some screens +you must focus with them in their positions; take away the screen, and +the picture appears out of focus. I cannot fully explain why it is, +and for this reason will not make the attempt; experience alone can +teach it. + +Another thing that has been tried lately is to do away with the yellow +screen by substituting a yellow coating direct on the plate. No doubt +the focus on an object that requires absolute sharpness is somewhat +affected by the use of a glass. We have been successful, on a small +scale, to coat the plate with the following yellow solution: + +Place in a tray enough of a saturated solution of tropaeolin in wood +alcohol to cover the plate; allow it to remain ten seconds. It is +necessary that the plate should be bathed previously in erythrosine +and dried. Before applying the tropaeolin, which, being in alcohol, +dries in a few minutes, have some blotting paper on hand, as the +solution gathers in a pool and leaves bad marks on the end of the +plate. + +The plate can be developed in the usual way. Try it and see the +results.--_Reported in the Beacon._ + + * * * * * + + + + +PLATINOTYPE PRINTING.[1] + + [Footnote 1: A communication to the North London Photographic + Society.] + + +Platinotype, which may be considered to be the most artistic of +photographic printing processes, may be separated into its three +modifications--the hot bath and cold bath, in which a faintly visible +image is developed, and the Pizzighelli printing-out paper. The hot +bath process, again, may be divided into the black and white and sepia +papers. I intend to give you a rough outline of the preparation of the +paper and working of these modifications, concluding by demonstrating +the hot bath method, and handing around prints by it. + +Platinotype may almost be styled an iron printing process, for, while +no trace of iron or its salts is found in the finished print, certain +salts of iron are mixed with the platinum salt, which is platinum +combined with two atoms of chlorine (PtCl2), as a means for readily +reducing it; this, however, cannot be effected without the presence of +neutral oxalate of potash, hence the use of the oxalate bath. There is +no platinum in the paper for the cold bath process, it being coated +with ferric oxalate mixed with a very small quantity of chloride of +mercury--somewhere about one grain to an ounce of ferric oxalate +solution. When dry it is ready for exposure, which is about three +times less than with silver printing. + +It is absolutely necessary to store all papers for platinum printing +in an air-tight tin containing chloride of calcium, which must be +dried by heating from time to time. For the cold bath, however, it is +important to have moisture present during printing, or it may be after +printing and before development. If the paper is left in a dampish +room for fifteen minutes, it should be sufficient. Prints made by +exposing damp paper, or damping dry paper just before development, +must be developed within one hour if the maximum of vigor is desired; +by delaying the development some hours, the prints in the meantime +being stored in a drawer so that they may retain their moisture, an +increase of half tone and warmth of color will be obtained. If it +should be necessary to delay development for a day or two, the prints +must be dried before a fire soon after being removed from the frames, +and then stored in a calcium tube until wanted for development. + +While printing, the lemon color of the paper receives a grayish +colored image, which, although faint, can, with practice, be judged as +easily as silver printing. + +The developer consists of oxalate of potash and potassic +chloro-platinite--about thirty grains of the platinum salt to half an +ounce of oxalate forming about six ounces of solution; a great many +variations, however, may be made in the proportions of platinum salt +and oxalate, and different effects secured. Development is effected by +sliding the print face downward on to the developer, which must be +rocked after the development of each print to avoid scum marks. To +clear the prints they are washed in three or four baths of a weak +solution of hydrochloric acid after leaving the developer, to remove +all traces of the iron salts, and finally washed for a quarter of an +hour in three changes of water; they are then finished, and may be +dried between clean blotting paper. + +Pizzighelli's process differs from the above in being one that prints +fully out in the frame without development; the paper contains the +platinum and iron salts as well as the developer, and so prints and +develops at the same time. Although excellent prints can be produced +with it, for general work the results of the paper, as at present +made, will not compare with the hot and cold bath processes. It is, +however, excellent for printing from very dense negatives, and +occasional negatives that seem extremely suitable for it. The paper +should be breathed on before printing, as if it is quite dry the +printing will be very slow and irregular. The best conditions for the +preparation of the paper have scarcely been decided upon yet, and it +is not quite fair to judge the process. The prints are cleared in the +acid baths and washed for about a quarter of an hour. + +The sepia and black hot bath processes are much alike in the general +treatment. There are, however, some special precautions to be observed +with the sepia paper, the chief being to protect it from any but the +faintest rays of light; the prints, unlike the black ones, may be +affected by light when in the acid bath. A special solution must be +added to the developer to keep the lights pure. Over-exposure cannot +be corrected by using a cooler bath, as is the case with the black +prints, and the paper does not remain good so long. + +The paper for the black prints by the hot bath process is washed with +a mixture of potassic platinous chloride and ferric oxalate, the +proportion being about sixty grains of the platinum salt to one ounce +of the iron solution. It will not keep good longer than twenty minutes +or so, and must be applied to the paper directly after mixing. The +ferric oxalate in the paper is reduced by the action of light to +ferrous oxalate, which forms the faint visible image; this, when the +paper is floated on the oxalate of potash bath, is capable of reducing +the platinum salt in contact with it into metallic platinum; but the +ferric salt, which remains unaltered, has no action on the platinum +salt, leaving these parts, which represent the high lights of the +print, untouched. The ferric oxalate is removed by the acid baths +which follow the development. A good temperature for development is +150 deg. Fahr., and when using this so much detail should not be apparent +as when printing for the cold bath process, in which all the detail +desired should be very faintly visible. There are, however, many +methods of exposing the paper and developing it, and no fixed rule can +be made, but the development must in every case be suited to the +exposure or the result will be a failure. For instance, the paper may +be printed until all detail is visible, but a very much cooler +development must be used, say 80 deg. or 90 deg.; on the other hand, a +slightly short exposure may be given, and a temperature of 180 deg. to +200 deg. used. 150 deg. should be taken as the normal temperature, and kept to +until some experience has been gained, as employing all temperatures +will lead to confusion, and nothing will be learned. Some negatives +require a special treatment, and both printing and development must be +altered, while for a very dense negative the paper may be left out in +a dampish room for some time. It will then print with less contrast +and more half tone. A thin negative is better printed by the cold bath +process, but negatives should be good and brilliant for platinotype +printing. Any one taking up platinotype and getting only weak prints +would do well to look to his negatives instead of blaming the paper, +as the high lights should be fairly dense, and the deep shadows nearly +clear glass. + +Time for complete development should always be allowed; with a hot +bath fifteen seconds will be sufficient, but if a cooler development +is used, or the prints are solarized in the shadows, more time should +be allowed. When the deep shadows are solarized, or appear lighter +than surrounding parts, a hot and prolonged development is required to +obtain sufficient blackness, as they have a tendency to look like +brown paper. I have found breathing on solarized shadows useful, as in +the presence of slight moisture they begin to print out and become +dark before development, getting black almost directly the print is +floated on the oxalate. Three or four acid baths of about ten minutes +each are used, and the prints are washed as before. The process +throughout takes much less time than silver printing, and can be kept +on all the winter, when it is nearly impossible to print in silver. +Prints can be developed in weak daylight or gaslight, and prolonged +washing is dispensed with.--_N.P. Fox, reported in Br. Jour. of +Photo._ + + * * * * * + +[Continued from Supplement, No. 706, page 11283.] + + + + +ON ALLOTROPIC FORMS OF SILVER. + +By M. CAREY LEA. + + +In the first part of this paper were described certain forms of +silver; among them a lilac blue substance, very soluble in water, with +a deep red color. After undergoing purification, it was shown to be +nearly pure silver. During the purification by washing it seemed to +change somewhat, and, consequently, some uncertainty existed as to +whether or not the purified substance was essentially the same as the +first product; it seemed possible that the extreme solubility of the +product in its first condition might be due to a combination in some +way with citric acid, the acid separating during the washing. Many +attempts were made to get a decisive indication, and two series of +analyses, one a long one, to determine the ratio between the silver +and the citric acid present, without obtaining a wholly satisfactory +result, inasmuch as even these determinations of mere ratio involved a +certain degree of previous purification which might have caused a +separation. + +This question has since been settled in an extremely simple way, and +the fact established that the soluble blue substance contains not a +trace of combined citric acid. + +The precipitated lilac blue substance (obtained by reducing silver +citrate by ferrous citrate) was thrown on a filter and cleared of +mother water as far as possible with a filter pump. Pure water was +then poured on in successive portions until more than half the +substance was dissolved. The residue, evidently quite unchanged, was, +of course, tolerably free from mother water. It was found that by +evaporating it to dryness over a water bath, most of the silver +separated out as bright white normal silver; by adding water and +evaporating a second time, the separation was complete, and water +added dissolved no silver. _The solution thus obtained was neutral._ +It must have been acid had any citric acid been combined originally +with the silver. This experiment, repeated with every precaution, +seems conclusive. The ferrous solution, used for reducing the silver +citrate, had been brought to exact neutrality with sodium hydroxide. +After the reduction had been effected, the mother water over the lilac +blue precipitate was neutral or faintly acid. + +A corroborating indication is the following: The portions of the lilac +blue substance which were dissolved on the filter (see above) were +received into a dilute solution of magnesium sulphate, which throws +down insoluble allotropic silver of the form I have called B (see +previous paper). This form has already been shown to be nearly pure +silver. The magnesia solution, neutral before use, was also neutral +after it had effected the precipitation, indicating that no citric +acid had been set free in the precipitation of the silver. + +It seems, therefore, clear that the lilac blue substance contains no +combined citric acid. Had the solubility of the silver been due to +combination with either acid or alkali, the liquid from which it was +separated by digestion at or below 100 deg. C. must have been acid or +alkaline; it could not have been neutral. + +We have, therefore, this alternative: In the lilac blue substance we +have either pure silver in a soluble form or else a compound of +silver, with a perfectly neutral substance generated from citric acid +in the reaction which leads to the formation of the lilac blue +substance. If this last should prove the true explanation, then we +have to do with a combination of silver of a quite different nature +from any silver compounds hitherto known. A neutral substance +generated from citric acid must have one or more atoms of hydrogen +replaced by silver. This possibility recalls the recent observations +of Ballo, who, by acting with a ferrous salt on tartaric acid, +obtained a neutral colloid substance having the constitution of +arabin, C6 H10 O6. + +To appreciate the difficulty of arriving at a correct conclusion, it +must be remembered that the silver precipitate is obtained saturated +with strong solutions of ferric and ferrous citrate, sodium citrate, +sulphate, etc. These cannot be removed by washing with pure water, in +which the substance itself is very soluble, but must be got rid of by +washing with saline solutions, under the influence of which the +substance itself slowly but continually changes. Next, the saline +solution used for washing must be removed by alcohol. During this +treatment, the substance, at first very soluble, gradually loses its +solubility, and, when ready for analysis, has become wholly insoluble. +It is impossible at present to say whether it may not have undergone +other change; this is a matter as to which I hope to speak more +positively later. It is to be remarked, however, that these allotropic +forms of silver acquire and lose solubility from very slight causes, +as an instance of which may be mentioned the ease with which the +insoluble form B recovers its solubility under the influence of sodium +sulphate and borate, and other salts, as described in the previous +part of this paper. + +The two insoluble forms of allotropic silver which I have described as +B and C--B, bluish green; C, rich golden color--show the following +curious reaction. A film of B, spread on glass and heated in a water +stove to 100 deg. C. for a few minutes becomes superficially bright +yellow. A similar film of the gold colored substance, C, treated in +the same way, acquires a blue bloom. In both cases it is the surface +only that changes. + +_Sensitiveness to Light._--All these forms of silver are acted upon by +light. A and B acquire a brownish tinge by some hours' exposure to +sunlight. With C the case is quite different, the color changes from +that of red gold to that of pure yellow gold. The experiment is an +interesting one. The exposed portion retains its full metallic +brilliancy, giving an additional proof that the color depends upon +molecular arrangement, and this with the allotropic forms of silver is +subject to change from almost any influence. + +_Stability._--These substances vary greatly in stability under +influences difficult to appreciate. I have two specimens of the gold +yellow substance, C, both made in December, 1886, with the same +proportions, under the same conditions. One has passed to dazzling +white, normal silver, without falling to powder, or undergoing +disaggregation of any sort; the fragments have retained their shape, +simply changing to a pure frosted white, remaining apparently as solid +as before; the other is unchanged, and still shows its deep yellow +color and golden luster. Another specimen made within a few months and +supposed to be permanent has changed to brown. Complete exclusion of +air and light is certainly favorable to permanence. + +_Physical Condition._--The brittleness of the substances B and C, the +facility with which they can be reduced to the finest powder, makes a +striking point of difference between allotropic and normal silver. It +is probable that normal silver, precipitated in fine powder and set +aside moist to dry gradually, may cohere into brittle lumps, but these +would be mere aggregations of discontinuous material. With allotropic +silver the case is very different, the particles dry in optical +contact with each other, the surfaces are brilliant, and the material +evidently continuous. That this should be brittle indicates a totally +different state of molecular constitution from that of normal silver. + +_Specific Gravities._--The allotropic forms of silver show a lower +specific gravity than that of normal silver. + +In determining the specific gravities it was found essential to keep +the sp. gr. bottle after placing the material in it for some hours +under the bell of an air pump. Films of air attach themselves +obstinately to the surfaces, and escape but slowly even in vacuo. + +Taken with this precaution, the blue substance, B, gave specific +gravity 9.58, and the yellow substance, C, specific gravity 8.51. The +specific gravity of normal silver, after melting, was found by G. Rose +to be 10.5. That of finely divided silver obtained by precipitation is +stated to be 10.62.[1] + + [Footnote 1: Watts' Dict., orig. ed., v. 277.] + +I believe these determinations to be exact for the specimens employed. +But the condition of aggregation may not improbably vary somewhat in +different specimens. It seems, however, clear that these forms of +silver have a lower specific gravity than the normal, and this is what +would be expected. + +Chestnut Hill, Philadelphia, May, 1889. + +--_Amer. Jour. of Science._ + + * * * * * + + + + +TURPENTINE AND ITS PRODUCTS.[1] + + [Footnote 1: Read at a meeting of the Liverpool Chemists' + Association.] + +By EDWARD DAVIES, F.C.S., F.I.C. + + +In treating this subject it is necessary to limit it within +comparatively narrow bounds, for bodies of the turpentine class are +exceedingly numerous and not well understood. In this definite class +turpentine means the exudation from various trees of the natural order +Coniferae, consisting of a hydrocarbon, C10 H16, and a resin. The +constitution of the hydrocarbons in turpentine from different sources, +though identical chemically, varies physically, the boiling point +ranging from 156 deg. C. to 163 deg. C., the density from 0.855 to 0.880, and +the action on polarized light from -40.3 to +21.5. They are very +unstable bodies in their molecular constitution, heat, sulphuric acid, +and other reagents modifying their properties. The resins are also +very variable bodies formed probably by oxidation of the hydrocarbons, +and as this oxidation is more or less complete, mixtures are formed +very difficult to separate and study. + +Turpentine as met with in commerce is mainly derived from _Pinus +maritima_, yielding French turpentine, and _Pinus australis_, +furnishing most of the American turpentine. The latter is obtained +from North and South Carolina, Georgia and Alabama. In Hanbury and +Fluckiger's Pharmacographia there is a full description of the manner +in which the trees are wounded to obtain the turpentine. Besides these +there are Venice turpentine from the larch, _Pinus Larix_, Strassburg +turpentine from _Abies pectinata_, and Canada balsam from _Pinus +balsamea_. + +The crude American turpentine is a viscid liquid of about the +consistence of honey, but varying to a soft solid, known as gum, thus, +according to the amount of exposure which it has undergone, it +contains about 10 to 25 per cent. of "spirits," to which the name of +turpentine is commonly given, the rest being resin, or as it is +usually called, rosin. + +In Liverpool almost all the spirits of turpentine comes from America, +so that it is almost impossible to get a sample of French. + +The terpene from American turpentine is called austraterebenthene. It +possesses dextro-rotatory polarization of +21.5. Its density is 0.864. +Boiling point 156 deg. C. + +In taking the boiling point of a commercial sample of spirits it is +necessary to wait until the thermometer becomes steady. Not more than +5 per cent. should pass over before this takes place, and then there +is not more than two or three degrees of rise until almost all is +distilled over. + +The liquids of lower boiling point do not appear to have been much +studied. In French spirits they seem to be of the same composition as +the main product, but with more action on polarized light. + +French spirits of turpentine is mainly composed of terebenthene. The +boiling point and sp. gr. are the same as those of the austraterebenthene, +but the polarization is left handed and amounts to -40.5. + +Isomeric modifications. Heated to 300 deg. C. in a sealed tube for two +hours, it becomes an isomeric compound, boiling at 175 deg. C., while the +density is lowered, being only 0.8586 at 0 deg. C. The rotatory power is +only -9 deg.. It oxidizes much more rapidly. It is called isoterebenthene +and has a smell of essential oil of lemons. + +By the action of a small quantity of sulphuric acid, among other +products terebene is formed. It has the same boiling point and sp. gr. +as terebenthene, but is without action on polarized light. +Austraterebenthene forms similar if not identical bodies. + +Polymers. One part of boron fluoride BF3 instantly converts 160 +parts of terebenthene into polymers boiling above 300 deg. C., and +optically inactive. H2 SO4 does the same on heating and forms +diterebene C20 H32. + +Terchloride of antimony does the same, and also produces tetraterebene +C40H64, a solid brittle compound formed by the union of four +molecules of C10 H16. It does not boil below 350 deg. C. and +decomposes on heating. + +Compound with H2O. Terpin C10 H18 2HO is formed when 1 volume +of spirits of turpentine is mixed with 6 of nitric acid and 1 of +alcohol, and exposed to air for some weeks. Crystals are formed which +are pressed, decolorized by animal charcoal, and recrystallized from +boiling water. + +Compounds with HCl. When a slow current of HCl is passed through +cooled spirits of turpentine, two isomeric compounds are formed, one +solid, and one liquid. The lower the temperature is kept, the more of +the solid body is produced. To obtain the solid body pure it is +pressed and recrystallized from ether or alcohol. It is volatile and +has the odor of camphor. It is called artificial camphor, and has the +composition C10 H16 HCl. There is also a compound with 2HCl. + +Oxidation products. By passing air into spirits of turpentine oxygen +is absorbed. It was thought at one time that ozone was produced, but +Kingzett's view is that camphoric peroxide is formed C10 H14 O4, +and that in presence of water it decomposes into camphoric acid and +H2 O2. This liquid constitutes the disinfectant known as +"sanitas," which possesses the advantages of a pleasant smell and +non-poisonous properties. C10 H18 O2 may be obtained by +exposing spirits of turpentine in a flask full of oxygen with a little +water. + +Camphor C16 H16 O has been made in small quantity by oxidizing spirits +of turpentine. Terebenthene belongs to the benzene or aromatic series, +which can be shown from its connection with cymene. Cymene is +methylpropyl-benzene, and can be made from terpenes by removing two +atoms of H. It has not yet been converted again into terpene, but the +connection is sufficiently proved. The presence of CH3 in terpenes is +shown by their yielding chloroform when distilled with bleaching +powder and water. The resin is imperfectly known. It was supposed to +consist of picric and sylvic acids. It is also stated to contain +abietic anhydride C44 H62 O4, but it is difficult to understand how a +compound containing C44 can be produced from C10 H16. The most +probable view is that it is the anhydride of sylvic acid, which is +probably C20 H30 O2. + +The dark colored resin which is obtained when the turpentine is +distilled without water can be converted into a transparent slightly +yellow body by distillation with superheated steam. A small portion is +decomposed, but the greater part distills unchanged. It is used in +making soap which will lather with sea water. + +When distilled alone, various hydrocarbons, resin oil and resin pitch, +are obtained. + +I find that commercial spirits of turpentine varies in sp. gr. from +0.865 to 0.869 at 15 deg. C. The higher sp. gr. appears to be connected +with the presence of resinous bodies, the result of oxidation. The +boiling point is very uniform, ranging from 155 deg. C. to 157 deg. C. at 760 +mm. Taking these two points together, it is hardly possible to +adulterate spirits of turpentine without detection. I give the figures +for a few imitations or adulterations: + + Sp. gr. B.P. + No. 1 0.821 137 deg. C. + No. 2 0.884 165 deg. C. + No. 3 0.815 150 deg. C. + No. 4 0.895 156 deg. C. + +There is a considerable difference in the flashing point, no doubt due +to the longer or shorter exposure of the crude turpentine, by which +more or less of the volatile portion escapes. + + * * * * * + + + + +ON THE OCCURRENCE OF PARAFFINE IN CRUDE PETROLEUM.[1] + + [Footnote 1: An abstract of thesis by E.A. Partridge, class of + '89, Univ. of Pa. Read before the Chemical Section of the + Franklin Institute by Prof. S.P. Sadtler.] + + +It is well known that the paraffine obtained by the distillation of +petroleum residues is crystalline, while that obtained directly (as in +the filtration of residuum) is amorphous. Ozokerite or ceresine +differs but slightly from paraffine, the principal distinction being +want of crystalline structure in it as found. Other characteristics, +such as the melting point, specific gravity, etc., vary in both, and +so are not of importance in a comparison. Hence it has been asked, Is +the paraffine occurring in petroleum and ozokerite identical with that +which is produced by their distillation? As crystalline paraffine +could be obtained from ozokerite by distillation alone, many persons +have supposed that it was engendered in the process. Recently, +however, crystalline paraffine has been obtained from ozokerite by +dissolving the latter in warm amyl alcohol; on cooling the greater +part separates out in crystals having the luster of mother-of-pearl. +By repetition of this process, a substance is obtained that is +scarcely to be distinguished from the paraffine obtained by +distillation. Apparently there exists then in ozokerite, together with +paraffine, other substances not capable of crystallization which keep +the paraffine from crystallizing. These colloids appear to be +separated by amyl alcohol in virtue of their greater solubility in +that menstruum. It is also reasonable to suppose that they undergo +change or decomposition by distillation. + +So as petroleum residues are amorphous, and the crystalline paraffine +is first produced by distillation, it has been argued that the +paraffine present in crude petroleum is approximately the same thing +as ozokerite. + +This, however, is not sufficient to establish the pyrogenic origin of +all crystallized paraffine, as crystals can be obtained from the +amorphous residues by distillation at normal or reduced pressure or in +a current of steam. To explain these facts two assumptions are +possible. Either the chemical and physical properties of all or some +of the solid constituents are changed by the distillation, and the +paraffine is changed from the amorphous into the crystalline variety, +or the change produced by the distillation takes place in the medium +(i.e., the mother liquid) in which the paraffine exists. The change +effected in ozokerite and in petroleum residues when crystalline +paraffine is obtained by distillation is to be regarded as a +purification, and can be effected partially by treatment with amyl +alcohol. In the same way, by repeated treatment of petroleum residuum +with amyl alcohol, a substance of melting point 59 deg. C. can be +obtained, which cannot be distinguished from ordinary paraffine. + +The treatment with amyl alcohol has therefore accomplished the same +results as was obtained by distillation, and the action is probably +the same, i.e., a partial separation of colloid substance. These +facts point to the conclusion that crystallizable paraffine exists +ready formed in both petroleum and in ozokerite, but in both cases +other colloidal substances prevent its crystallization. By +distillation, these colloids appear to be destroyed or changed so as +to allow the paraffine to crystallize. + +It is a generally known fact that liquids always appear among the +products of the distillation of paraffine, no matter in what way the +distillation be conducted. This shows that some paraffine is +decomposed in the operation. + +The name _proto-paraffine_ has been given to ozokerite and to the +paraffine of petroleum in contradistinction to _pyro-paraffine_, the +name that has been applied to the paraffine obtained by distillation +from any source. + +According to Reichenbach, paraffine may crystallize in three forms: +needles, angular grains, and leaflets having the luster of +mother-of-pearl. Hofstadter, in an article on the identity of +paraffine from different sources, confirmed this statement, and added +further that at first needles, then the angular forms, and then the +leaflets are formed. Fritsche found, by means of the microscope, in +the ethereal solution of ozokerite, very fine and thin crystal +leaflets concentrically grouped, and in the alcoholic solution fine +irregular leaflets. Zaloziecki has recently developed these +microscopic investigations to a much greater extent. According to this +observer, the principal part of paraffine, as seen under the +microscope, consists of shining stratified leaflets with a darker +edge. The most characteristic and well developed crystals are formed +by dissolving paraffine in a mixture of ethyl and amyl alcohols and +chilling. The crystals are rhombic or hexagonal tablets or leaves, and +are quite regularly formed. They are unequally developed in different +varieties of paraffine. The best developed are those obtained from +ceresine. Their relative size and appearance give an indication as to +the purity of the paraffine, and, as they are always present, they are +to be counted among the characteristic tests for paraffine. +Reichenbach observed that mere traces of empyreumatic oil prevented +their formation. + +The old method of determining the amount of paraffine in petroleum was +to carry out the refining process on a small scale; that is, to +distill the residue from the kerosene oils to coking, chill out the +paraffine, press it thoroughly between filter paper, and weigh the +residue. The sources of error in this procedure are manifold; the +principal one is the solubility of paraffine in oils, which depends +upon the character of both the paraffine and the oil, and also upon +the temperature. The next greatest source of error is variation in the +process of distillation and the difference between working on the +small scale and on the large scale. + +In most cases, where a paraffine determination is to be carried out, +one has to deal with a mixture of paraffine with liquid oils. Now, +paraffine is not a substance defined by characteristic physical +properties which distinguish it from the liquid portions of petroleum. +It consists of a mixture of homologous hydrocarbons, which form a +solid under ordinary conditions. The hydrocarbons of this mixture show +a gradation in their properties, and gradually approximate to those +which are liquid at ordinary temperatures. It is a well known fact +that a separation of these homologues is entirely impossible by +distillation. It has also been ascertained that the liquid +constituents of petroleum do not always possess boiling points that +are lower than those of the solid constituents. This shows that we +have to deal not merely with hydrocarbons of one, but of several +series. + +When determinations of the amount of paraffine are to be made, then it +becomes necessary to specify with exactness what is to be called +paraffine. The most definite property that can be made use of for this +purpose is the melting point. For several reasons it is convenient to +include under this name hydrocarbons of melting point as low as +35 deg.-40 deg. C. + +The method proposed by Zaloziecki for the determination of paraffine +is the following: The most volatile portions of the petroleum are +separated by distillation, until the thermometer shows 200 deg. C. These +portions are separated, as they exert great solvent action upon +paraffine. At the same time he finds that no pyro-paraffine is formed +under this temperature. A weighed portion of the residue is taken and +mixed with ten parts by weight of amyl alcohol and ten parts of +seventy-five per cent. ethyl alcohol: the mixture is then chilled for +twelve hours to 0 deg. C. It is then filtered cold, washed first with a +mixture of amyl and ethyl alcohols, and then with ethyl alcohol alone. +The paraffine is transferred to a small porcelain evaporating dish and +dried at 110 deg. C. It is then heated with concentrated sulphuric acid to +150 deg.-160 deg. C. for fifteen to thirty minutes with constant stirring. The +acid is then neutralized and the paraffine extracted by petroleum +ether. On evaporation of the solvent, the paraffine is dried at 100 deg. +C. and weighed. Zaloziecki found, according to this method, in three +samples of Galician petroleums, 4.6, 5.8 and 6.5 per cent., +respectively, of proto-paraffine. The method was carried out as above +with four samples of American petroleums, Colorado oil from Florence, +Col.; Warren County oil from Wing Well, Warren, Pa.; Washington oil +from Washington County, Pa.; Middle District oil from Butler County, +Pa., all furnished by Professor Sadtler. + +They were very different in physical properties and in appearance, the +Colorado oil being a much heavier oil than the others and the +Washington oil being an amber oil, while the other two were of the +ordinary dark green color and consistence. The losses on distillation +to 200 deg. C. were very different, being about one-tenth in the case of +the Colorado oil and nearly one-half in the case of the others. The +percentages of partially refined proto-paraffine in the four reduced +oils (all below 200 deg. C. off) were as follows: for the Colorado oil, +23.9 per cent.; for the Warren oil, 26.5 per cent.; for the Washington +oil, 26.6 per cent.; and for the Middle District oil, 28.2 per cent. + +The question now arises, What value has this determination of the +proto-paraffine which may exist in an oil? As before said, a portion +of the paraffine is always decomposed in distillation at temperatures +sufficiently high to drive over the paraffine oils, so the yield of +pyro-paraffine is always less than the proto-paraffine shown to be +present originally. Zaloziecki found this in the case of the several +Galician oils he examined. Corresponding to the 4.6, 5.8 and 6.5 per +cent. of proto-paraffine in the several oils he obtained 2.18, 2.65 +and 2.35 per cent., respectively, of pyro-paraffine. + +For the present, however, the extraction of proto-paraffine on a large +scale by means of such solvents as amyl and ethyl alcohols is out of +the question on account of their cost. A distillation, under reduced +pressure and with superheated steam, would, however, prevent much of +the decomposition of the original proto-paraffine and increase the +yield of pyro-paraffine. + +This study of Zaloziecki's method and the examination of American oils +was suggested by Professor Sadtler and carried out in his laboratory. + + * * * * * + + + + +TRANSMISSION OF PRESSURE IN FLUIDS. + +By ALBERT B. PORTER. + + +The young student of physics occasionally has difficulty in grasping +the laws of pressure in fluids. His every day experience has taught +him that a push against a solid body causes it to push in the same +direction, and he often receives with some doubt the statement that +pressure applied to a fluid is transmitted equally in every direction. +The experiments ordinarily shown in illustration of this principle +prove that pressure is transmitted in all directions, but do not prove +the equality of transmission, and in spite of all the text books may +tell him, the student is apt to cling to the idea that a downward +pressure applied to a liquid is more apt to burst the bottom than the +side of the containing vessel. + +[Illustration: Figs. 1. and 2.] + +The little piece of apparatus shown in Fig. 1 was designed to furnish +a clear demonstration of the principle under consideration. It is +essentially an arrangement by which a downward pressure is applied to +a confined mass of air or water, and the resultant pressures measured +in the three directions, down, up, and sideways. By means of a broken +rat tail file kept wet with turpentine three holes are bored through a +bottle, one through the bottom, one through the side, and one through +the shoulder, as near the neck as may be convenient. The operation is +quick and easy, the only precaution to be observed being to work very +slowly and use but a slight pressure when the glass is nearly +perforated. The holes may be enlarged to any size required by careful +filing with the wet file. From each of the holes a rubber tube leads +to one of the glass manometer tubes at the right in the figure, the +joints being made air tight by slipping into each rubber tube a piece +of glass tubing about half an inch long in order to swell it to the +size of the hole it is to fit. The ends of these glass tubes must be +well rounded by partial fusion in a gas flame, that there may be no +sharp edges to cut the rubber. The bottle rests in a depression in the +turned wood base, the lower rubber tube passing out through a hole in +the wood. Fig. 2 shows the shape of the manometer tubes. They are made +of quarter inch glass tubing bent to shape in a flame and left open at +both ends. They are mounted on a scale board which has several +equidistant horizontal lines running across it. The two bent wires +which support the scale board fit loosely in holes in it and in the +base. This method of mounting is very handy, since it permits the +scale board to be swung to right or left as may be convenient, or +turned round so as to show the fittings on its back, without moving +the bottle. The three manometers are filled to the same level with +mercury, the quantity being adjusted by means of a pipette. A +perforated rubber stopper, fitted with a glass tube on which is +slipped a rubber syringe bulb, completes the apparatus. + +When the bulb is pinched between the fingers, the mercury is forced up +to the same height in each of the manometers, thus proving that the +pressure is exerted equally in the three directions, up, down, and +sideways. With the bottle filled with water the same effect follows, +the law being the same for liquids and gases. When using water in the +apparatus it is essential that the rubber tubes, as well as the +bottle, be filled, and when used in the class room it is better to +show the experiment with water first, it being easier and quicker to +empty the bottle and tubes than to fill them. + + * * * * * + + + + +PEAR DUCHESSE D'ANGOULEME. + + +Although well known to fruit growers and generally represented in all +parts of Britain, this noble French pear has not become a universal +favorite. If the quality of the fruit, independently of its fine, +handsome appearance, was bad, or even indifferent, it might be +exterminated from our lists, but this we know is not the case, as any +one who has tasted good samples grown in France, the Channel Islands, +and upon favorable soils in this country will bear out the statement +that the flavor is superb. Some fruits, we know, are quite incapable +of being good, as they have no quality in them; but here we have one +of the hardiest of trees, capable of giving us quantity as well as +quality, provided we cultivate properly. Pears, no doubt, are +capricious, like our seasons, but given a good average year, soils and +stocks which suit them, a light, warm, airy aspect, and good culture, +a great number of varieties formerly only good enough for stewing are +now elevated, and most deservedly so, to the dessert table. But, +assuming that some sorts known to be good do not reach their highest +standard of excellence every year, they are infinitely superior to +many of the old stewers, as they carry their own sugar, a quality +which fits them for consumption by the most delicate invalids. Indeed, +so prominently have choice dessert pears, and apples too for that +matter, come to the front for cooking purposes, that a new demand is +now established, and although Duchesse d'Angouleme, always juicy and +sweet, from bad situations does not always come up to the fine quality +met within Covent Garden in November, it is worthy of our skill, as we +know it has all the good points of a first rate pear when properly +ripened. + +The original tree of this pear was observed by M. Anne Pierre +Andusson, a nurseryman at Angers, growing in a farm garden near +Champigne, in Anjou, and having procured grafts of it, he sold the +trees, in 1812, under the name of Poire des Eparannais. In 1820, he +sent a basket of the fruit to the Duchesse d'Angouleme, with a request +to be permitted to name the pear in honor of her. The request was +granted, and the pear has since borne its present name. + +That such a fine pear, which does so well in France, would soon find +its way to England there exists little doubt, as we find that within a +few years it became established and well known throughout the United +Kingdom. All the earliest trees would be worked upon the pear or free +stock, and as root pruning until recently was but little practiced, we +may reasonably suppose that the majority of them are deeply anchored +in clay, marl, and other subsoils calculated to force a crude, gross +growth from which high flavored fruit could not be expected. These +defects under modern culture upon the quince and double grafting are +giving way, as we find, on reference to the report of the committee of +the pear conference, held at Chiswick in 1885, that twenty counties in +England, also Scotland, Ireland, and Wales, contributed no less than +121 dishes to the tables, and thirty-eight growers voted in favor of +the Duchesse being recognized as one of our standard dessert +varieties. This step looks like progress, as it is a record of facts +which cannot be gainsaid, and it now remains to be seen whether the +English grower, whose indomitable will has brought him to the front in +the subjugation of other fruits, will be successful with the fine +Duchesse d'Angouleme. Although this remarkable pear cannot easily be +mistaken, for the benefit of those who do not know it, the following +description may not be out of place. Fruit large, often very large, 31/2 +inches wide and 3 inches to 4 inches high, roundish obovate, uneven, +and bossed in its outline. Skin greenish yellow, changing to pale dull +yellow, covered with veins and freckles of pale brown russet, and when +grown against a south wall it acquires a brown cheek. Eye open, with +erect dry segments, set in a deep irregular basin. Stalk 1 inch long, +inserted in a deep irregular cavity. Flesh white, buttery, and +melting, with a rich flavor when well ripened; otherwise rather coarse +grained and gritty. + +As to culture, experienced fruitists say the tree grows vigorously and +well. It bears abundantly, and succeeds either on the pear or quince +stock, forming handsome pyramids, but is better on the quince. Here, +then, we have the key to the secret of success: The cordon on the +quince; roots near the surface; loam, sound, sandy, and good; and good +feeding. Aspect, a good wall facing south or west--the latter, +perhaps, the best. Those who have not already done so, should try +trees on the quince as pyramids and bushes, as this, like some other +capricious pears, although the fruit be smaller, may put in better +flavor than is met with in fruit from hot walls.--_The Garden._ + + * * * * * + + + + +SUCCESSION OF FOREST GROWTHS. + + +The following is from an address delivered by Mr. Robert Douglas +before the Association of American Nurserymen at the meeting in +Chicago recently. + +It is the prevailing and almost universal belief that when native +forests are destroyed they will be replaced by other kinds, for the +simple reason that the soil has been impoverished of the constituents +required for the growth of that particular tree or trees. This I +believe to be one of the fallacies handed down from past ages, taken +for granted, and never questioned. Nowhere does the English oak grow +better than where it grew when William the Conqueror found it at the +time he invaded Britain. Where do you find white pines growing better +than in parts of New England where this tree has grown from time +immemorial? Where can you find young redwoods growing more thriftily +than among their giant ancestors, nearly or quite as old as the +Christian era? + +The question why the original growth is not reproduced can best be +answered by some illustrations. When a pine forest is burned over, +both trees and seeds are destroyed, and as the burned trees cannot +sprout from the stump like oaks and many other trees, the land is left +in a condition well suited for the germination of tree seeds, but +there are no seeds to germinate. It is an open field for pioneers to +enter, and the seeds which arrive there first have the right of +possession. The aspen poplar (_Populus tremuloides_) has the advantage +over all other trees. It is a native of all our northern forests, from +the Atlantic to the Pacific. Even fires cannot eradicate it, as it +grows in moist as well as dry places, and sprouts from any part of the +root. It is a short-lived tree, consequently it seeds when quite young +and seeds abundantly; the seeds are light, almost infinitesimal, and +are carried on wings of down. Its seeds ripen in spring, and are +carried to great distances at the very time when the ground is in the +best condition for them. Even on the dry mountain sides in Colorado, +the snows are just melting and the ground is moist where they fall. + +To grow this tree from seed would require the greatest skill of the +nurseryman, but the burnt land is its paradise. Wherever you see it on +high, dry land you may rest assured that a fire has been there. On +land slides you will not find its seeds germinating, although they +have been deposited there as abundantly as on the burned land. + +Next to the aspen and poplars comes the canoe birch, and further north +the yellow birch, and such other trees as have provision for +scattering their seeds. I have seen acorns and nuts germinating in +clusters on burned lands in a few instances. They had evidently been +buried there by animals and had escaped the fires. I have seen the red +cherry (_Prunus Pennsylvanica_) coming up in great quantities where +they might never have germinated had not the fires destroyed the +debris which covered the seed too deeply. + +A careful examination around the margin of a burned forest will show +the trees of surrounding kinds working in again. Thus by the time the +short-lived aspens (and they are very short-lived on high land) have +made a covering on the burned land, the surrounding kinds will be +found re-established in the new forest, the seeds of the conifers, +carried in by the winds, the berries by the birds, the nuts and acorns +by the squirrels, the mixture varying more or less from the kinds +which grew there before the fire. + +It is wonderful how far the seeds of berries are carried by birds. The +waxwings and cedar birds carry seeds of our tartarean honeysuckles, +purple barberries and many other kinds four miles distant, where we +see them spring up on the lake shore, where these birds fly in flocks +to feed on the juniper berries. It seems to be the same everywhere. I +found European mountain ash trees last summer in a forest in New +Hampshire; the seed must have been carried over two miles as the crow +flies. + +While this alternation is going on in the East, and may have been +going on for thousands of years, the Rocky Mountain district is not so +fortunate. When a forest is burned down in that dry region, it is +doubtful if coniferous trees will ever grow again, except in some +localities specially favored. I have seen localities where short-lived +trees were dying out and no others taking their places. Such spots +will hereafter take their places above the timber line, which seems to +me to be a line governed by circumstances more than by altitude or +quality of soil. + +There are a few exceptions where pines will succeed pines in a +burned-down forest. _Pinus Murrayana_ grows up near the timber line in +the Rocky Mountains. This tree has persistent cones which adhere to +the trees for many years. I have counted the cones of sixteen years on +one of these trees, and examined burned forests of this species, where +many of the cones had apparently been bedded in the earth as the trees +fell. The heat had opened the cones and the seedlings were growing up +in myriads; but not a conifer of any other kind could be seen as far +as the fire had reached. + +In the Michigan Peninsula, northern Wisconsin and Minnesota, _P. +Banksiana_, a comparatively worthless tree, is replacing the valuable +red pine (_P. resinosa_), and in the Sierras _P. Murrayana_ and _P. +tuberculata_ are replacing the more valuable species by the same +process. + +In this case, also, the worthless trees are the shortest lived. So we +see that nature is doing all that she can to remedy the evil. Man only +is reckless, and especially the American man. The Mexican will cut +large limbs off his trees for fuel, but will spare the tree. Even the +poor Indian, when at the starvation point, stripping the bark from the +yellow pine (_P. ponderosa_), for the mucilaginous matter being formed +into sap wood, will never take a strip wider than one third the +circumference of the tree, so that its growth may not be injured. + +We often read that oaks are springing up in destroyed forests where +oaks had never grown before. The writers are no doubt sincere, but +they are careless. The only pine forests where oaks are not intermixed +are either in land so sandy that oaks cannot be made to grow on them +at all, or so far north that they are beyond their northern limit. In +the Green Mountains and in the New England forests, in the pine +forests in Pennsylvania, in the Adirondacks, in Wisconsin and +Michigan--except in sand--I have found oaks mixed with the pines and +spruces. In northwestern Minnesota and in northern Dakota the oaks are +near their northern limit, but even there the burr oak drags on a bare +existence among the pines and spruces. In the Black Hills, in Dakota, +poor, forlorn, scrubby burr oaks are scattered through the hills among +the yellow pines. In Colorado we find them as shrubs among the pines +and Douglas spruces. In New Mexico we find them scattered among the +pinons. In Arizona they grow like hazel bushes among the yellow pines. +On the Sierra Nevada the oak region crosses the pine region, and +scattering oaks reach far up into the mountains. Yet oaks will not +flourish between the one hundredth meridian and the eastern base of +the Sierras, owing to the aridity of the climate. I recently found +oaks scattered among the redwoods on both sides of the Coast Range +Mountains. + +Darwin has truly said, "The oaks are driving the pines to the sands." +Wherever the oak is established--and we have seen that it is already +established whereever it can endure the soil and climate--there it +will remain and keep on advancing. The oak produces comparatively few +seeds. Where it produces a hundred, the ash and maple will yield a +thousand, the elm ten thousand, and many other trees a hundred +thousand. The acorn has no provision for protection and transportation +like many tree seeds. Many kinds are furnished with wings to float +them on the water and carry them in the air. Nearly every tree seed, +except the acorn, has a case to protect it while growing, either +opening and casting the seeds off to a distance when ripe or falling +with them to protect them till they begin to germinate. Even the +equally large seeds of other kinds are protected in some way. The +hickory nut has a hard shell, which shell itself is protected by a +strong covering until ripe. The black walnut has both a hard shell and +a fleshy covering. The acorn is the only seed I can think of which is +left by nature to take care of itself. It matures without protection, +falls heavily and helplessly to the ground, to be eaten and trodden on +by animals, yet the few which escape and those which are trodden under +are well able to compete in the race for life. While the elm and maple +seeds are drying up on the surface, the hickories and the walnuts +waiting to be cracked, the acorn is at work with its coat off. It +drives its tap root into the earth in spite of grass, and brush, and +litter. No matter if it is shaded by forest trees so that the sun +cannot penetrate, it will manage to make a short stem and a few leaves +the first season, enough to keep life in the root, which will drill in +deeper and deeper. When age or accident removes the tree which has +overshadowed it, then it will assert itself. Fires may run over the +land, destroying almost everything else, the oak will be killed to the +ground, but it will throw up a new shoot the next spring, the root +will keep enlarging, and when the opportunity arrives it will make a +vigorous growth, in proportion to the strength of the root, and throw +out strong side roots, and after that care no more for its tap root, +which has been its only support, than the frog cares for the tail of +the tadpole after it has got on its own legs. + +There is no mystery about the succession of forest growths, nothing in +nature is more plain and simple. We cannot but admire her wisdom, +economy, and justness, compensating in another direction for any +disadvantage a species may have to labor under. Every kind of tree has +an interesting history in itself. Seeds with a hard shell, or with a +pulpy or resinous covering which retards their germination, are often +saved from becoming extinct by these means. + +The red cedar (_Juniperus Virginiana_) reaches from Florida to and +beyond Cape Cod; it is among the hills of Tennessee, through the +Middle States and New England. It is scattered through the Western +States and Territories, at long distances apart, creeping up the +Platte River, in Nebraska. (I found only three in the Black Hills, in +Dakota, in an extended search for the different trees which grow +there. Found only one in a long ramble in the hills at Las Vegas, New +Mexico.) Yet this tree has crept across the continent, and is found +here and there in a northwesterly direction between the Platte and the +Pacific Coast. It is owing to the resinous coating which protects its +seeds that this tree is found to-day scattered over that immense +region. + + * * * * * + +[NATURE.] + + + + +THE "HATCHERY" OF THE SUN-FISH. + + +I have thought that an example of the intelligence (instinct?) of a +class of fish which has come under my observation during my excursions +into the Adirondack region of New York State might possibly be of +interest to your readers, especially as I am not aware that any one +except myself has noticed it, or, at least, has given it publicity. + +The female sun-fish (called, I believe, in England, the roach or +bream) makes a "hatchery" for her eggs in this wise. Selecting a spot +near the banks of the numerous lakes in which this region abounds, and +where the water is about 4 inches deep, and still, she builds, with +her tail and snout, a circular embankment 3 inches in height and 2 +thick. The circle, which is as perfect a one as could be formed with +mathematical instruments, is usually a foot and a half in diameter; +and at one side of this circular wall an opening is left by the fish +of just sufficient width to admit her body, thus: + +[Illustration] + +The mother sun-fish, having now built or provided her "hatchery," +deposits her spawn within the circular inclosure, and mounts guard at +the entrance until the fry are hatched out and are sufficiently large +to take charge of themselves. As the embankment, moreover, is built up +to the surface of the water, no enemy can very easily obtain an +entrance within the inclosure from the top; while there being only one +entrance, the fish is able, with comparative ease, to keep out all +intruders. + +I have, as I say, noticed this beautiful instinct of the sun-fish for +the perpetuity of her species more particularly in the lakes of this +region; but doubtless the same habit is common to these fish in other +waters. + +William L. Stone. + +Jersey City Heights, N.J. + + * * * * * + + + + +ANCIENT LAKE DWELLINGS. + + +Among the many traces which man has left of his existence in long past +ages on the face of the earth, says a correspondent of the _Scotsman_, +none are more interesting and instructive than the lake dwellings of +Switzerland and other countries, which have been discovered within the +last fifty years or so. Although these relics of the past are far more +modern than those which we referred to in a late article on "Primeval +Man," and are probably included within the range of Egyptian and +other chronologies, yet they stretch far beyond the historic period, +so far as Europe is concerned, and throw a flood of light on the +habits of our ancestors, or at any rate predecessors, in these +regions. We are tolerably well acquainted with the history of the Jews +when David worked his way up from the shepherd's staff to the royal +scepter, or when Joshua drove out the Canaanites and took possession +of their land, but of what was going on in Europe in these times we +have hitherto had no knowledge whatever. These lake dwellings, +however, were in all probability inhabited by human beings somewhere +about the time when the events we have referred to took place, and may +have been inhabited before the earlier of them. + +The first hint we had of the existence of these remarkable dwellings +was obtained in 1829, when an excavation was being made on the shore +of a Swiss lake. Some wooden piles, apparently very old, and other +antiquities were found by the workmen. Not much attention, however, +was paid to this discovery till 1854, when a Mr. Aeppli drew attention +to some remains of human handiwork found near his house, in part of +the bed of a lake which had been left dry during a season of great +drought. The workmen employed in recovering some land from the lake +found the heads of a great many wooden piles protruding through the +mud, and also a number of stags' horns, and implements of various +descriptions. Stimulated by this discovery, search was made in various +lakes, and the result was truly astonishing. In every direction +remains of the habitations of prehistoric man were discovered, and +relics were found in such abundance that the history of this unknown +past could be traced through long ages, and the habits of the people +ascertained with a very considerable amount of probability. The +details are so numerous that it would be impossible in the space at +our disposal to go into them all. + +Of course, during the long time that has elapsed since these +structures were erected, their remains have been reduced to mere +ruins, and it is only by comparing one with another that we are able +to picture to ourselves what they were originally like and what sort +of life was led by the men who inhabited them. The oldest of these +dwellings belong to the stone age, when man had not acquired any +knowledge of the use of metal; when all his instruments were merely +sharpened stones, fixed in wooden handles, or pieces of bone, horn, or +other natural material. They are therefore somewhat roughly finished, +but at the same time exhibit considerable ingenuity and skill. The +method of construction seems to have been somewhat as follows: A +suitable situation, not far from the shore, where the water was not +very deep, having been fixed upon, these prehistoric builders drove +into the muddy bottom of the lake a number of piles or long stakes, +arranged generally pretty close together, and in some sort of regular +order. These piles were formed generally from stems of trees, with the +bark on, but occasionally from split wood. The ends were sharpened to +a point by the aid of fire or by cutting with stone axes. On a +sufficient number being driven in, and their upper ends brought to a +level above the surface of the water, platform beams were laid across, +fastened by wooden pegs, or in some cases fixed into notches cut in +the heads of the vertical piles. The platform was generally very +roughly made, just a series of unbarked stems placed side by side and +covered with layers of earth or clay, with numerous openings through +which refuse of all kinds fell into the water beneath. In many cases +connection with the shore was made by means of a narrow bridge or +gangway, constructed in the same manner. On this rude platform huts +were erected by driving small piles or stakes which projected above +the floor, and to these were fastened boards standing edgeways like +the skirting of our ordinary rooms, and marking out the size of each +building. The walls of the huts were formed of small branches of twigs +interwoven and plastered over with clay. The roof was made of straw or +reeds like a thatched cottage. In size these huts were probably +eighteen to twenty feet long, eight or ten feet broad, and about six +feet high. They may have been divided into rooms, but there is no +evidence of this. Each was provided with a hearth formed of three or +four slabs of stone. The number of huts in each settlement must have +been considerable, in fact, they must have formed villages of no mean +extent, for as many as forty, fifty, or even a hundred thousand piles +have been found spread over a large extent of ground, forming the +foundation of one such settlement. It is probable, however, that these +were not so numerous when first erected, but were gradually added to +as the population increased. This fact, along with many others, shows +that these dwellings were inhabited for long periods of time, during +which the population pursued their ordinary life in comparative peace +and quietness in their island homes. + +Such is, in brief, a general account of these remarkable structures. +Of course there were several variations in the methods of fixing these +piles, one of which may be mentioned as showing the ingenuity of the +builders. Where the piles did not get a firm hold of the lake bottom, +they carried out in boats or rafts loads of stones, which they threw +down between the piles, thus firmly fixing them, just as modern +engineers sometimes do for a similar purpose. As to the habits of the +people who dwelt in these lake dwellings, we get a considerable amount +of information from the various implements, refuse, etc., which fell +through the imperfectly closed platforms into the lake, and which have +been preserved in the mud at the bottom. They were fishers, hunters, +shepherds, and agriculturists. Skeletons of fish are found in large +abundance, and in some settlements even the fishing nets, and hooks +made of boar's tusks, have been discovered. Then again there is an +abundance of remains of the hunter's feast; bones of the stag, wild +boar, bear, wolf, otter, squirrel, and many other wild animals are +found in rich profusion, and often these are split and the marrow +extracted. These ancient men, however, did not entirely rely on such +precarious provision for their wants, but were so far advanced in +civilization that they kept cattle and domestic animals of various +kinds. They possessed dogs in great numbers, as well as cows, sheep, +goats, and pigs, and in winter time had these housed on their +settlements, as among the remains found are litters of straw, etc., +which had evidently served as bedding for these animals. This, of +course, necessitated the gathering of grass or other material for +their food. They also cultivated wheat, barley, flax, and a number of +other vegetable products. Their methods of cultivation were no doubt +very rude, consisting of a mere scratching of the ground with crooked +branches of trees or with simple instruments made of stags' horn; but, +nevertheless, they succeeded in getting very good results. Among the +relics which they have left are found stones for crushing corn, the +grain which they used, and even the very cakes or bread which they +made. There are also fruits, such as the apple, pear, nut, etc.; so +that the bill of fare of prehistoric man was by no means contemptible. +He had fish, game, beef, mutton, pork, bread, and fruit, besides a +plentiful supply of water from the lake at his door. He was acquainted +with the potter's art, and manufactured earthen vessels of various +kinds. He seems to have produced two kinds--a coarser and a finer; the +former made from clay mixed with a quantity of grains of stone, and +the latter of washed loam. These he ornamented in an elementary +fashion with certain lines and marks. Some of the vessels he used have +been found with a burnt crust of the porridge which he had been making +adhering. As to his clothes, these were probably formed in great part +from the skins of wild or domestic animals, but he also used fabrics +made from flax, which he had learned to weave, as remains of cloth, +twine, rope, etc., are not infrequently found in his dwellings. + +One prominent feature in the history of these lake dwellers is their +gradual advance in the arts of civilization. While the main features +of their settlements remain very much the same during the whole period +of their residence, there is a gradual improvement in the details; the +settlements become larger, and the implements, etc., better finished. +And this is especially observable in the change of material which the +dweller uses. In the earlier stages of his existence stone is the +predominant feature, all his knives, saws, chisels, axes, etc., are +made from this substance; but as time rolls on, one or two implements +are found made of bronze, which is a mixture of tin and copper, and +requires for its production a certain amount of knowledge and +mechanical skill. Gradually the number of bronze implements increases +until eventually stone is superseded altogether, and improved forms of +weapons of war make their appearance, and his work has a more finished +look, arising from his improved implements. Whether the manufacture of +bronze was an original discovery of his own, or whether it was an +importation from some more advanced race, is not certainly known; but +as he undoubtedly had intercourse with the East, it is probable that +the first bronze was imported, and that afterward he discovered the +way to manufacture it himself. However this may be, it seems evident +that the introduction of this material greatly aided his development. +As stone gave place to bronze, so in the course of time this latter +gave place to iron, probably introduced in the same manner some +considerable time before the dawn of history; and this metal held its +place until these habitations were finally abandoned. + +With regard to the religion of these lake dwellers, if they had any, +nothing is known. From some curious objects formed somewhat like the +crescent of the moon, which are found in considerable numbers, it has +been supposed that they worshiped that body; but there seems to be +really no evidence for this supposition, and these objects may only +have been ornaments, or perhaps charms, fixed above the doors of their +huts something after the manner of the horse shoe nailed over the door +in modern times to keep away evil spirits. So far as can be inferred +from the remains that have been examined, the same race seems to have +inhabited these dwellings from their commencement to their end. There +is no appearance of invasion from without; all seems continuous. +Probably his race came in early time from the East, and were a +pastoral people, with flocks, herds, and domestic animals, and built +their peculiar habitations to protect themselves from human enemies. +Certainly the arrangements were well fitted for the purpose in those +days, when the club and the spear were almost the only weapons of +offense. Dr. Keller, who has investigated this subject with great +care, is of the opinion that these lake dwellers were a branch of the +great Celtic race. + + * * * * * + +[New England Farmer.] + + + + +HOW TO RAISE TURKEYS. + + +The best feed for young turkeys and ducks is yelks of hard-boiled +eggs, and after they are several days old the white may be added. +Continue this for two or three weeks, occasionally chopping onions +fine and sometimes sprinkling the boiled eggs with black pepper; then +give rice, a teacupful with enough milk to just cover it, and boil +slowly until the milk is evaporated. Put in enough more to cover the +rice again, so that when boiled down the second time it will be soft +if pressed between the fingers. Milk must not be used too freely, as +it will get too soft and the grains will adhere together. Stir +frequently when boiling. Do not use water with the rice, as it forms a +paste and the chicks cannot swallow it. In cold, damp weather, a half +teaspoonful of Cayenne pepper in a pint of flour, with lard enough to +make it stick together, will protect them from diarrhea. This amount +of food is sufficient for two meals for seventy-five chicks. Give all +food in shallow tin pans. Water and boiled milk, with a little lime +water in each occasionally, is the best drink until the chicks are two +or three months old, when loppered and buttermilk may take the place +of the boiled milk. Turkeys like best to roost on trees, and in their +place artificial roots may be made by planting long forked locust +poles and laying others across the forks.--_American Agriculturist._ + + +HOW TO RAISE TURKEYS. + +Keep the turkey hens tame by feeding them close to the house. Have two +or three barrels in sheltered corners containing plenty of straw or +leaves for them to lay in. Gather the eggs every evening, as turkey +eggs are very easily chilled. Keep the eggs in a woolen cloth on end +and turn them every three days. Set the first seven eggs under a +chicken hen, as they get too old before the turkey hen will go to +sitting. Make a board pen ten or twelve feet square and twelve or +fourteen inches high. Put a coop in it and put your hen and turkeys in +it. Feed the hen with corn and the turkeys soaked wheat bread (corn +meal will kill them), until they are a week old (I feed five or six +times a day). Then feed wheat until they are big enough to eat corn. +Give plenty of fresh water in a shallow vessel. Keep the mother in +the pen until they are large enough to fly over the top of the boards. +Let them out awhile about the middle of the day. Shut them in at +night. A turkey hen does not like to be shut up, but have a good big +coop for her and she will go in. Don't let the little turkeys get +their backs wet until they are feathered. The turkey hen will sit down +when night comes just where she happens to be, but if you drive her +home a few times she will come herself after that. Always feed them +when they come home, no matter if they are full of "hoppers." Have +your No. 2 pen in the orchard under an apple tree where it is shady. +Have the turkey hen's pen close to the chicken hen's pen, so that when +the chicken hen weans her turkeys, they will soon learn to go with the +turkey hen. Give them a dose of black pepper in their feed every cold +rain. And never, no never, get excited and in a hurry while working +with turkeys if you don't want them to get wild and fly all over the +plantation. Three or four weeks before selling, feed all the corn they +will eat. + + +FOOD HINTS. + +Restrain your desire to count your young turkeys, and let them alone +for twenty-four hours after they get into this world. Remove them to a +clean, airy, roomy coop, and give them boiled eggs, stale wheat bread +crumbs just moistened with milk or water, "Dutch" cheese, or a mixture +of all these. + +For the first two weeks feed entirely with the eggs, bread, curds, +cooked rice and cooked oatmeal. About the third week commence feeding +cooked cornmeal; and from that on they may have any cooked food that +would be suitable for chickens of the same age. Season all food +slightly with salt and pepper, and twice a week add a level +tablespoonful of bone meal to a pint of feed. Never feed any sour food +or sloppy food of any kind, except sour milk, and never feed any +uncooked food of any kind until after they have thrown out the red on +their heads. Feed often, five or six times a day, until after they are +three months old; then, if insects are numerous, you may gradually +reduce the number of meals per day to three or even two. + +After they are three months old they may be given wheat, cracked corn, +etc., but not whole corn until they are five months old. Keep the +coops dry and clean, and the turkeys out of the dew and rain until +they are fully feathered, and have thrown out the red. Dampness and +filth will kill young turkeys as surely as a dose of poison. For the +first few days confine the poults to the limits of the coop and safety +run; then, if all appear strong and well, give the mother hen and her +brood liberty on pleasant days after the dew is off. + +If they get caught out in a shower, get them to shelter as soon as +possible; and if they are chilled take them to the house and +thoroughly dry and warm them. See that the little turkeys come home +every night. The turkey mother must, for the first few nights, be +hunted up and driven home. After they are three months old, turkeys +are quite hardy, and may be allowed range at all times. If turkeys +that are well cared for, and have always seemed all right, show signs +of drooping when about six weeks or two months old, give Douglas +mixture in the drink or food, and add a little cooked meat to the food +once a day.--_The Practical Farmer._ + + +ABOUT SITTING. + +For an ordinary place, select from a good breed (I prefer the bronze) +a large gobbler and two or three hens. As soon as the warm weather +comes, place about the barn in sheltered places two or three barrels +on their sides, and in them make nice nests. In these the hens will +lay. Gather the eggs every day, keeping them in a cool place. When a +box contains 23 eggs mark it No. 1 and begin to fill a second box, and +when it contains 23 eggs mark it No. 2 and so continue. It is well to +leave turkey hens on the nest two or three days, for they often lay +one or two eggs after they begin to show signs of sitting. + +When you have decided to sit a hen, give her a good nest and 15 eggs +and at the same time give a common hen eight eggs. These, when +hatched, are all to be given to the turkey hen. Never try to raise +turkeys with a domestic fowl. If you have no place free of grass, you +can start turkeys with difficulty. Feeding is of the greatest +importance. For the first week I have found wheat bread moistened in +water the most satisfactory. If you can feed them by sunrise for the +first three or four weeks, you need lose hardly a bird. Each evening +try and call them nearer and nearer home, so that you will not be +troubled with their wandering to the neighbors'. As early as possible +train them to roost high, so as to be out of danger at night. Bird +dogs are often very destructive to turkeys, at times destroying a +whole flock in a single night. Fatten with corn. The turkey crop ought +to be one of the most profitable on our farms. + +Dr. G.G. GROFF. +Pennsylvania. + + +GRAHAM. + +Turkeys want care, especially for the first two or three weeks. I feed +graham and wheat bread, made by scalding the flour, making a very +stiff dough, and baking in a hot oven; soak over night in cold water. +I also give them plenty of young onions, cutting them up with +scissors. Be careful not to let young turkeys out in the morning while +the grass is wet. After the birds are two weeks old I feed wheat, but +no corn until they are about a month old. I like hen mothers best, for +turkey mothers are rangers, and do not take kindly to being kept in a +coop. The bread will keep a week if made right, but do not soak more +than will be wanted in a day, as it soon sours. I feed scraps from the +table, such as potatoes and bits of meat cut very fine, but not much +of the latter to young birds. I rarely lose a bird.--_Mrs. E. Reith, +in Homestead._ + + +CARE AND GENERAL MANAGEMENT. + +In turkey raising the one who is the most careful and attentive to the +small things is the most successful. The first laying of eggs should +be set under a chicken hen. The turkey hen will, after a few days' +confinement, lay another batch of eggs. A good-sized hen will cover +and care for ten eggs; a turkey hen, seventeen. Make a large, roomy +nest of soft, fine hay--straw is too brittle and slippery. If there is +danger of lice in the nest-box, sprinkle with water in which carbolic +acid has been mixed in the proportion of eight drops to a half gallon +of water. Don't wet the eggs with this. After the eggs have been sat +on one week, sprinkle with warm water every other day, until the last +week; then every day, until they hatch. Have the water clear, and use +a flower or fine rose sprinkler. Let the water be of the same +temperature as the eggs, which can be ascertained by slipping a +thermometer under the hen for a few minutes. This softens the shells, +and as a little turkey is very weak, it is helped out easily, and is +stronger than if working long to get out. + +Let the little turkeys get well dried and strong enough to climb +around the edges of their nest before taking them off. Have a pen, say +six feet square, built for them, and made tight at the sides clear +down to the ground, to keep them from getting out and being chilled. +Put sand and fine gravel over the ground, and cover enough of it to +afford shelter at night and when it rains. They may be kept in this +pen the first four or five days, then let out after dew is off, and +shut up before night. + +For the first few days' feed, nothing is better than clabber cheese or +curd made by scalding clabbered milk until the curd separates and is +cooked, then skimmed out and fed. Mix a little black pepper with this +every other day. Meal must not be fed raw for several weeks, and then +should be mixed with sour milk instead of water. Bake the meal into +bread by mixing it, unsifted, with sour milk, and adding a little soda +and pepper. Spinach, lettuce, onion tops and any other tender greens, +chopped fine, are excellent food. From the time a turkey is hatched +until it is ready for market it should have plenty of milk. Give them +clear water to drink, for milk is a food. See that the very young ones +have milk and water in quite shallow dishes, for they are in danger of +getting wet if the dish is deep. + + +GATHER THE LITTLE TURKEYS IN + +at the first signs of rain, and they will soon learn to run and fly to +their coop at the first drops. Always shut them up at night, for they +are early risers and will be out long before the dew is dried off. +Don't pen them too near the house. Feed them at or near the same place +all the time and they will learn to go there when hungry. Give them a +good feed at night and they will remember to come home for it. If the +morning is dry, feed lightly and let them hunt the rest in the orchard +and fields. Keep the grass and weeds mowed around their pen and +feeding places. Mix slaked lime in the dust for them to take their +dust bath in, and sprinkle the carbolic acid and water over and around +their roosting pen. Keep pails and kettles covered, for they will get +drowned if they have half a chance, as they begin to fly so young. Of +course a turkey hen will take her young off, and care for them after a +fashion, but the safest way to make them tame is to raise them where +they may be cared for. Even if the turkey hen hatches her last batch +of eggs, it is a good plan to have a hen ready to take the little +turkeys and slip them away at night. If she still stays on her nest +give her 20 or 25 hen's eggs, and if she hatches them let her run with +the chickens. They are not so tender or so easily led astray as +turkeys are, nor as valuable.--_Mrs. Jas. R. Hinds, in Orange Judd +Farmer._ + + * * * * * + + + + +WATER AS A THERAPEUTICAL AGENT. + +By F.C. ROBINSON, M.D. + + +My experience in the use of water in almost every disease occurring in +this climate has long since satisfied me that it is less objectionable +and produces quicker and better results than any other treatment, and +can be used when all other medication is contra-indicated. Drinking +water should be pure, uncontaminated by animal or vegetable +impurities, and given _ad libitum_, unless, in rare instances, it +should cause vomiting or interfere with the capability of digesting +food. If children are comatose or delirious, as they frequently are in +typhoid fever, give water to them regularly, or force it upon them, if +they refuse to take it, as I was obliged to do with a child of six +years just recovering from that fever. + +It is my custom to allow cold drinks of water in all cases of measles +whenever patients desire it, and I am satisfied that it aids the early +appearance of the rash, and certainly is cooling and grateful to the +patient. Hot drinks or vile and nauseous teas are unnecessary in this +disease, and should be discarded as useless, odious, and disgusting. +If congestion of the lungs or any intercurrent inflammation occurs, or +the rash is much delayed, a hot water bath or the old reliable corn +sweat will break up the complication with amazing rapidity, and if the +head is kept cool, will not generally be unacceptable to the patient. + +Hot baths reduce temperature by causing free perspiration afterward, +and cold packs reduce it by cooling the surface sufficiently long to +reduce the heat of the blood, and, if used judiciously, seldom fail of +success. I have reduced the temperature four degrees in two hours by +wrapping around a child a sheet wet with tepid water, and no other +covering. Cold packs are sometimes objectionable, because of their +depressing effects, and should only be used to reduce high temperature +and when there is no congestion or inflammation of any of the vital +organs of the body. + +Cold water poured in a small stream from a pitcher upon the head for +five or ten minutes will often relieve headache, and is a benefit in +all inflammatory brain diseases, if, at the same time, you can put the +feet into hot water containing mustard or pepper. + +Large enemas of warm water will care for spasmodic colic, and I have, +in one instance, relieved strangulated hernia by the same method, and +at another time the same result was accomplished by a large injection +of warm linseed oil. I have often applied a cloth wet with cold water +upon the throats of children suffering with spasmodic croup, with +satisfactory results. + +I have seen infants suffering with diarrhea or summer complaint, +sleepless, worrying, fretting, or crying from thirst, begging for +water, and the mother or nurse afraid to give it more than a +teaspoonful or two at a time, saying that it vomited everything it +drank as soon as taken. I have often, when visiting such cases, called +for a glass of cold water, and, to the surprise of the mother, would +allow it to take all it could drink, which usually would be retained, +and the child would soon be wrapped in a refreshing sleep. Without +medicine, a proper regulation of the child's diet would soon restore +it to health again. + +The spasms of children, from whatever causes, or the eclampsia from +uraemic poisoning, are often readily controlled when immersed in hot +water or given a hot vapor bath or corn sweat. If the convulsions of +children are accompanied by a high temperature, put them into water of +100 deg. and then gradually cool it down to 68 deg. or 70 deg., and then keep them +in a room of the same temperature, with little covering. If the +temperature rises, repeat the treatment as frequently as necessary, +and I think you will not be disappointed in the results. + +Scarlet fever and diphtheria, two of the most dreaded and formidable +diseases of children, are largely shorn of their terrors when, in +addition to an early and thorough medicinal treatment, the little +patients are bathed in as warm water as the surface will allow +frequently, or for thirty minutes wrapped in a warm, wet blanket, +followed by warm, dry coverings, to maintain the perspiration that +such treatment usually produces. It has proved to me a valuable aid in +eliminating from the blood the specific poison which causes these +diseases, and I can safely recommend it to your notice and trial. + +There is no disease more favorably influenced by this treatment than +pneumonia, and in mild cases one daily warm bath or sweat, without +medicine, will be sufficient to arrest this disease, and it is among +the first things I usually order. If I find a child or infant with a +temperature of 103 deg. to 105 deg., short, dry, and painful cough, +dyspnoea, rapid pulse, great thirst, or vomiting, with dry +crepitation in any part of the lung tissue, I order it rolled up in a +blanket or sheet coming out of hot water, and in thirty minutes change +it to warm, dry blankets, and soon the little fretful, worrying +sufferer would rest in a quiet, peaceful sleep.--_Peoria Med. Mo._ + + * * * * * + + + + +ON THE HEALTH VALUE TO MAN OF THE SO-CALLED DIVINELY BENEFICENT +GIFT, TOBACCO. + +By J.M.W. KITCHEN, M.D., New York. + + +With perhaps the exception of heredity, the question of stimulants and +narcotics in their relation to the physical welfare of the race is +second to none in importance. With trifling exceptions, the whole +world is addicted to their use. The universality of such use has led +many to consider them a necessity to man, and that they are God's +gifts to him, and, if rightly used, are of physical benefit. It may +not be a perversion of judgment to consider that their widespread +popular use is greatly due to the efforts of the race to gain +anaesthesia for, and distraction from, those pains and punishments that +are the inevitable sequence of departure from hygienic and social law +on the part of the individual, his ancestry, and society in general. + +The taste for these things is acquired, not natural, though the +acquisition may be through hereditary influence. An idea is held by a +majority of even fairly intelligent individuals that there is a +justifiable, harmless, and even beneficial use of these substances by +the general public, though acknowledging that beyond a certain +indefinite line this use becomes an abuse. + +I believe that there may occasionally be cases in which the physical +benefits derived from their use outweigh the injury they inflict, but +I think this use is very much less than is generally supposed, and if +we can judge from the preponderance of evil effected by such use, +these substances ought to be considered as the materialized curses of +God rather than as beneficent gifts. The prevalent idea as to the +beneficent nature of these substances I consider to be a delusion that +can only be explained upon the hypothesis that there is a widespread +lack of appreciation of the fact that, though they may have an +immediate pleasant and agreeable effect upon the body, their injurious +effects are cumulative, and are usually ultimate, and so distant as to +be difficult of direct connection with their cause to ordinary +observation. The more moderate the use of these substances, the more +remotely is the effect removed from the cause and more difficult of +detection. That the ordinary habitual, so-called moderate use of +stimulants and narcotics, such as tea, coffee, tobacco, and alcohol, +is, in the vast majority of cases, really an abuse, is a proposition +that I think should be admitted by all who have given the subject an +unbiased study. + +The idea that the user of tobacco and other injurious substances will +be cognizant of the injury inflicted by habitual use in moderate or +even excessive amounts is an undoubted fallacy. The daily, weekly, or +monthly injurious effect may be entirely unobservable to even trained +physicians, and yet the ultimate cumulative effect may be fatal. I can +instance numerous cases of physicians directly fatally injured by the +use of alcohol, who have never had the slightest cognizance of the +fact; and I can also instance cases of grave disease from the use of +tobacco where the patients never have believed that tobacco has been +the cause of their troubles, even after a unanimous opinion to that +effect has been expressed by a number of competent medical advisers. +The habitual consumption of opium, in doses of any amount, is +generally admitted by most people to be physically injurious outside +of its strict medicinal application. Moderate indulgence in alcohol as +a beverage is beginning to acquire a very widespread evil reputation. +But how about tobacco? Tea and coffee we can confidently leave to the +consideration of a somewhat remote posterity of a considerably +advanced intelligence and elevated hygienic ideals. + +The relation of tobacco to the physical welfare of man can only be +fairly estimated by viewing the subject in its broadest aspect; by +considering its effects upon the race as a whole rather than in +individual cases; by taking into consideration economical and other +social conditions that at first sight might be considered as having +little relevancy to the medical side of the subject. But there can be +no just consideration of the matter otherwise. The direct deleterious +effects of the immoderate use of tobacco are readily observable; but +the great bulk of the evil physical effects due to the moderate use of +this plant are of an intermediate nature and not directly noticeable; +nevertheless, they are real, and worthy of medical attention. The +plainly marked results following the use of tobacco in relatively +large amounts seem to be due to quick and extreme interference with +nutrition, and a diminution of function of all kinds, which may be +represented by anything from a slight decrease of appetite and +digestive ability up to a complete loss of function of almost any +important organ. Tobacco has stimulating as well narcotic properties, +but as ordinarily used its stimulating effect appears to be slight as +compared with its narcotic influence. In this respect it differs from +alcohol, the use of which, owing to the usual method of introduction +in large amounts through the stomach, produces directly, by +stimulation, readily noticeable structural changes. But with tobacco +the direct evil results are mostly of a functional character, and are +more generally diffused, owing to the usual slow manner of +introduction into the body. These two properties have an effect upon +the body in moderate use as well as in immoderate use, the effect +being simply in proportion to the quantity used, though the effects of +moderate use may not be measurable by ordinary means. It is easy to +see the effects of large amounts of tobacco in the stunted growth of +adolescents; in functional cardiac disorders; in intellectual +sluggishness, loss of memory, and color blindness; in loss of +appetite, and other neuroses of motion, and marked blunting of various +functions of sensation, and in degeneracy of descendants; but that +lesser evils are produced must be proved mostly by inference, +circumstantial collateral evidence, and analogy. + +The greater evils that are the outcome of a moderate use of tobacco +are probably due to prolonged slight interference with nutrition, and +consequent general decrease of vitality, which renders the individual +more susceptible through indirect influence to the invasion of +disease, and which lessens the capacity for productive effort. + +It is of course difficult, and perhaps even impossible, to accurately +estimate the value of tobacco to the race; but let us glance at the +pros and cons, and then each one can roughly estimate for himself. +Tobacco may be used medicinally, but it is a dangerous and uncertain +remedy, and it probably has not one medicinal use that cannot be more +suitably met by other remedies. One can readily imagine easier +digestion as the result of the sedative influence of the after-dinner +cigar upon a disquieted nervous system, especially if the coincident +irritation of alcohol and coffee have need of correction; but it can +also be imagined that in most of such cases the remedy has been the +cause of and will further increase the disordered condition, and that +nutrition of deficiently nourished nerve tissue is rationally +indicated rather than partial narcotization. There then remains, so +far as I can see, the solace of moderate anaesthesia and, occasionally, +of occupation for idlers, as the only items that can be placed to the +credit of tobacco. There certainly are individual cases where such +usage may be more provocative of physical benefit than evil, but, +before judging for the race as a whole, compute the other side of the +question. + +Tobacco injures the general health of the public through the economic +loss caused by its consumption. The people of our country spend +annually over seven hundred millions of dollars for tobacco--twenty +per cent. more than is spent for bread. This sum represents only a +minor part of the cost of the tobacco habit to the country. The crop +is immensely exhaustive to the soil. Its culture has blighted whole +sections of fertile territory. In the time consumed by the producer +and the trader in its production, manufacture, and sale, and by the +consumer in its use, and by the general interference with vital +activity and consequent decreased productive capacity, there is +represented an almost unimaginable sum of money. Certainly the people +at large are not so well fed both as to quantity and quality, or so +thoroughly clothed, or so hygienically housed that they can afford +this gigantic economic waste. + +There can be little doubt that if the people had sufficient +intelligence and moral strength to taboo tobacco, this comparatively +senseless outgo would be largely devoted to supplying these and other +necessities of an exalted health status. + +Tobacco injures health through its moral effects. The tobacco habit is +certainly a dirty and frequently a disgusting habit, and encourages +other dirty practices. Its use tends to make men cowardly, irritable +in temper, and low in spirits. It blunts ideas of purity and courtesy, +leading to invasion of the rights of others. It is presumed that few +medical men would visit a delicate, sensitive patient after saturation +with the "fragrant" effluvia of onions, but thousands whose systems +are saturated with nicotine and who reek with nauseating odor do not +hesitate to inflict their presence on sick or well. The time will come +when the tobacco user will not be allowed to poison the atmosphere +that is the common property of the public--will not be allowed to +force the inhalation of nicotine upon the general public, to say +nothing of being allowed to poison the infants and women in his own +family. What would be said of a man who introduced poison in any +degree into the food or drink of his child? Is the poisoning of the +household atmosphere by the ignorant, thoughtless, or selfish smoker +morally more defensible? Tobacco injures health through hereditary +influence. The tobacco user begets, more certainly than the non-user, +puny children with disordered nervous conditions. Luckily for our +race, the women, who have the most important prenatal influence in +guarding its physical well-being, are practically non-users of the +plant. The general health status of the race is improving, not because +the use of tobacco or the indulgence in other questionable practices +is harmless, but because, among other things, of the great advance in +general intelligence and knowledge of hygienic law. + +A person, or the public in general, may practice an injurious habit, +and yet more than counteract its influence by opposing beneficial +practices. + +Horace Greeley said, "Show me a drunkard who does not use tobacco, and +I will show you a white blackbird." In this country, where dietetic +drinking habits are not common in the family, the weakening of moral +fiber by indulgence in tobacco is usually the introduction into the +round of vicious indulgences, and thus directly or indirectly affects +health. Smoking induces dryness of the mucous membrane of the mouth +and consequent thirst. The partially paralyzed nerve terminals want +something more stimulating than water to afford relief. Furthermore, +blunted appetite induces deficient nutrition, and consequently there +is a call for some "pick-me-up;" hence we find that the use of tobacco +tends to the habitual use of alcoholic beverages, and there are very +few habitual users of alcohol who escape without structural injuries +to the body as well as perversion of its functions. Decrease of vital +activity in all the tissues of the body marks the use of tobacco. The +tendency is toward functional paralysis, though occasional signs of +stimulative irritation are to be noticed, especially in the +respiratory passages. The interference with intellectual activity is +marked. It is said that during a period of fifty years no tobacco user +stood at the head of his class in Harvard. The accumulated testimony +of investigating observers is conclusive that, other things being +equal, users of tobacco, in schools of all grades, never do so well in +their studies as non-users. + +One head of a public school said he could always tell when a boy +commenced to use tobacco by the record of his recitations. Professor +Oliver, of the Annapolis Academy, said he could indicate the boy who +used tobacco by his absolute inability to draw a clean, straight line. +The deleterious effects of tobacco have become so clearly apparent +that we find its sale to minors is prohibited in France, Germany, and +various sections of this country. It is somewhat a question if, at the +present time, the race is not doing itself more injury by its use of +tobacco than it is with alcohol, because of its more universal use, +particularly by youth, and because of the respectability of the habit, +which comes of its use by a certain intelligent part of the race, +including teachers of morals and physics, and even temperance +reformers. There is a widespread sentiment in existence that it is not +a respectable thing to be even partly paralyzed by alcohol, but how +few there are who consider narcosis as in any way connected with the +use of tobacco. Its effect is more diffused and masked, and is not so +acutely serious in individual cases, but through its interference with +vital activity, tobacco is probably more generally injurious to the +race than alcohol. + +The editorial fiat of "too long" prevents a full exposition of the +subject, but, in closing, let me say I hear millions of tobacco users +ask, "Why, then, was this plant given to man, if its general effects +are so decidedly evil?" The question presupposes design in creation. +Without subscribing to this theory, or pretending to have solved the +mystery of the presence of evil in the world, the answer may be +suggested that the overcoming of many seductive evils becomes to man a +means of his progressive higher development. Of one thing I am +convinced, that the physical development and welfare of man is +interfered with in strict sequence to his consumption of substances +that are unnecessary for his nutrition--stimulants and narcotics +inclusive.--_Medical Record._ + + * * * * * + + + + +ACETIC ACID AS A DISINFECTANT. + + +Dr. F. Engelmann, in _Cent. f. Gyn._, claims that acetic acid +possesses equally as good antiseptic properties as carbolic acid; in +fact, that it is to be preferred, as it is completely harmless, even +if used in concentrated solutions, and that it is a valuable +haemostatic, an advantageous addition particularly in obstetrics. +Another important property is its ease of transition into the tissues, +which, according to Engelmann's experiments, is by far greater than +that of all the other antiseptics. Of bichloride it is well known that +it forms an insoluble combination with albumen, and can therefore act +only on the surface, while acetic acid extends into the deeper tissues +with ease. + +Acetic acid also affects the metal of the instruments, but not as +severely as the bichloride; the forceps, for instance, may be placed +for a quarter of an hour in an irrigator filled with a three per cent. +solution of acetic acid without being injured. + +A pleasant effect of acetic acid is that it softens and lubricates the +skin. The author generally used a three per cent. solution; at times +he has made use of a five per cent. solution, which would easily cause +a painful burning at sore places, so that he only used the latter +strength in septic cases, as the three per cent. solution proved to be +a satisfactory antiseptic for general purposes. + + * * * * * + + + + +COUNTER-IRRITATION IN WHOOPING COUGH. + +By G.F. INGLOTT, M.D. + + +To combat this often distressing disease I have tried the +administration of several medicines, namely, bromide of potassium, +asafoetida, valerian, morphine, belladonna, etc., and I have very +closely watched their effects, but none of them proved of much use. +Having observed, however, that during the late cholera epidemic some +of the patients admitted into the hospital under my medical charge +slept well, had their anxiety improved, and some of them ultimately +recovered, after the application of a strong counter-irritation of the +pneumogastric nerves in the neck, namely, between the mastoid process +and the angle of the lower jaw, I tried the same treatment on whooping +patients, and I have no hesitation in stating that the result was very +satisfactory. I may quote one single case of the many I have had under +treatment. + +A boy, aged twelve years, of weak constitution, was suffering from +frequent and intense attacks of whooping cough. At a time the fits +were so vehement that blood came out of his eyes and mouth. The case +was a severe one, and I thought it would very likely end fatally. I +prescribed several medicines, and even subcutaneous injections of +morphine, but without any avail. I then tried for the first time the +counter-irritation on both sides of the neck, and this means acted +like magic. In four or five days the patient recovered, and was able +to go to school. Since that time I have been applying the same +treatment, either on the right side only or on both, with the greatest +benefit.--_Br. Med. Jour._ + + * * * * * + + + + +DEVELOPMENT OF THE EMBRYO. + + +At a recent meeting of the Physical Society, Berlin, Prof. Preyer +spoke on reflexes in the embryo. His researches extended over many +classes of animals. As representing mammals, guinea pigs were chiefly +used; and for reptiles, snakes; while in addition the embryos of +fishes, frogs, mollusks, and other lower animals were also employed. +But of all animals birds are most suitable for embryological +observations, inasmuch as with due precautions the development of one +and the same individual can be followed for a considerable time. +Birds' eggs can be incubated in a warm chamber, and by removing a +portion of the shell and replacing it by an unbroken piece from +another egg, it becomes possible to follow the daily development of +the chick and to experiment upon it. As early as the ninetieth hour of +incubation, spontaneous "impulsive" movements may be observed, taking +place apparently without any external stimulus as a cause, and at a +time when no muscles or nerves have as yet been developed. After the +occurrence of these spontaneous movements, and at the earliest on the +fifth day of incubation, movements are observed to result from the +application of mechanical, chemical, and electrical stimuli. In order +to observe these the eggs must be allowed to cool down until all +spontaneous movements have ceased. From the tenth to the thirteenth +day more complicated and reflex actions occur on the application of +stimuli, as, for instance, movements of the eyelids, beak, and limbs; +and if the stimuli are strong, reflex respiratory movements. These +reflexes make their appearance before any ganglia have become +differentiated. Prof. Preyer considered himself justified in +concluding from this that ganglia are not essential for the liberation +of reflex actions. He intends, on some future occasion, to give a more +detailed account of these experiments, and of the conclusions which +may be drawn from them. In the discussion which ensued the conclusions +of the speaker were contested from many sides. + + * * * * * + + + + +IRIDESCENT CRYSTALS.[1] + + [Footnote 1: Abstract of the Friday evening lecture delivered by + Lord Rayleigh, F.R.S., at the Royal Institution, on April 12, + 1889.] + +By LORD RAYLEIGH. + + +The principal subject of the lecture is the peculiar colored +reflection observed in certain specimens of chlorate of potash. +Reflection implies a high degree of discontinuity. In some cases, as +in decomposed glass, and probably in opals, the discontinuity is due +to the interposition of layers of air; but, as was proved by Stokes, +in the case of chlorate crystals the discontinuity is that known as +twinning. The seat of the color is a very thin layer in the interior +of the crystal and parallel to its faces. + +The following laws were discovered by Stokes: + + (1) If one of the crystalline plates be turned round in its own + plane, without alteration of the angle of incidence, the + peculiar reflection vanishes twice in a revolution, viz., when + the plane of incidence coincides with the plane of symmetry of + the crystal. [Shown.] + + (2) As the angle of incidence is increased, the reflected light + becomes brighter and rises in refrangibility. [Shown.] + + (3) The colors are not due to absorption, the transmitted light + being strictly complementary to the reflected. + + (4) The colored light is not polarized. It is produced + indifferently, whether the incident light be common light or + light polarized in any plane, and is seen whether the reflected + light be viewed directly or through a Nicol's prism turned in + any way. [Shown.] + + (5) The spectrum of the reflected light is frequently found to + consist almost entirely of a comparatively narrow band. When the + angle of incidence is increased, the band moves in the direction + of increasing refrangibility, and at the same time increases + rapidly in width. In many cases the reflection appears to be + almost total. + +[Illustration: FIG. 1 GENERAL SCHEME + FIG. 2 DETAIL OF LAZY-TONGS] + +In order to project these phenomena a crystal is prepared by cementing +a smooth face to a strip of glass whose sides are not quite parallel. +The white reflection from the anterior face of the glass can then be +separated from the real subject of the experiment. + +A very remarkable feature in the reflected light remains to be +noticed. If the angle of incidence be small, and if the incident light +be polarized in or perpendicularly to the plane of incidence, the +reflected light is polarized in the _opposite_ manner. [Shown.] + +Similar phenomena, except that the reflection is white, are exhibited +by crystals prepared in a manner described by Madan. If the crystal be +heated beyond a certain point the peculiar reflection disappears, but +returns upon cooling. [Shown.] + +In all these cases there can be little doubt that the reflection takes +place at twin surfaces, the theory of such reflection (_Phil. Mag._, +Sept., 1888) reproducing with remarkable exactness most of the +features above described. In order to explain the vigor and purity of +the color reflected in certain crystals, it is necessary to suppose +that there are a considerable number of twin surfaces disposed at +approximate equal intervals. At each angle of incidence there would be +a particular wave length for which the phases of the several +reflections are in agreement. The selection of light of a particular +wave length would thus take place upon the same principle as in +diffraction spectra, and might reach a high degree of perfection. + +In illustration of this explanation an acoustical analogue is +exhibited. The successive twin planes are imitated by parallel and +equidistant disks of muslin (Figs. 1 and 2) stretched upon brass rings +and mounted (with the aid of three lazy-tongs arrangements) so that +there is but one degree of freedom to move, and that of such a +character as to vary the interval between the disks without disturbing +their equidistance and parallelism. + +The source of sound is a bird call, giving a pure tone of high pitch +(inaudible), and the percipient is a high-pressure flame issuing from +a burner so oriented that the direct waves are without influence upon +the flame (see _Nature_, xxxviii., 208; Proc. Roy. Inst., January, +1888). But the waves reflected from the muslin arrive in the effective +direction, and if of sufficient intensity induce flaring. The +experiment consists in showing that the action depends upon the +distance between the disks. If the distance be such that the waves +reflected from the several disks co-operate,[2] the flame flares, but +for intermediate adjustments recovers its equilibrium. For full +success it is necessary that the reflective power of a single disk be +neither too great nor too small. A somewhat open fabric appears +suitable. + + [Footnote 2: If the reflection were perpendicular, the interval + between successive disks would be equal to the half wave-length, + or to some multiple of this.] + +It was shown by Brewster that certain natural specimens of Iceland +spar are traversed by thin twin strata. A convergent beam, reflected +at a nearly grazing incidence from the twin planes, depicts upon the +screen an arc of light, which is interrupted by a dark spot +corresponding to the plane of symmetry. [Shown.] A similar experiment +may be made with small rhombs in which twin layers have been developed +by mechanical force after the manner of Reusch. + +The light reflected from fiery opals has been shown by Crookes to +possess in many cases a high degree of purity, rivaling in this +respect the reflection from chlorate of potash. + +The explanation is to be sought in a periodic stratified structure. +But the other features differ widely in the two cases. There is here +no semicircular evanescence, as the specimen is rotated in azimuth. On +the contrary, the colored light transmitted perpendicularly through a +thin plate of opal undergoes no change when the gem is turned round in +its own plane. This appears to prove that the alternate states are not +related to one another as twin crystals. More probably the alternate +strata are of air, as in decomposed glass. The brilliancy of opals is +said to be readily affected by atmospheric conditions. + + * * * * * + + +A NEW CATALOGUE OF VALUABLE PAPERS + +Contained in SCIENTIFIC AMERICAN SUPPLEMENT during the past +ten years, sent _free of charge_ to any address. MUNN & CO., 361 +Broadway, New York. + + * * * * * + + +THE SCIENTIFIC AMERICAN + +ARCHITECTS AND BUILDERS EDITION. + +$2.50 a Year. Single Copies, 25 cts. + +This is a Special Edition of the SCIENTIFIC AMERICAN, issued +monthly--on the first day of the month. 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