154 



SCIENCE. 



[Vol. XL No. 269 



added would establish a compound which could be fired success- 

 fully in a specially constructed shell. 



" (4) The gelatine does not require a fuze or detonator of any kind. 

 " (5) It is believed the shell which destroyed the 3.2-inch breech- 

 loading gun broke from the shock of discharge, or admission of 

 powder-gas, and thus detonated the gelatine." 



In the summer of 1884 the Ordnance Board fired four cast-iron 

 screw shells from an 8-inch muzzle-loading rifle, using forty pounds 

 of powder in the gun, and from five to eight pounds of gelatine in 

 the shells, at each discharge. The gun was mounted on a cradle, 

 and directed at a target 383 feet distant. One of the shells burst 

 at or near the muzzle with little comparative violence. The other 

 three reached the target, penetrated about seven inches, and deto- 

 nated from the shock. These trials led to the making of six steel 

 shells, three of them being cast, and three forged. Analysis of the 

 facts connected with these experiments shows — 



" (i) That the 3-inch shells designed for gunpowder charge, 

 when loaded with Hill's explosive gelatine, three months old, all 

 cleared the gun without injuring it in the slightest. 



"(2) That the shells, having to be charged through the fuze- 

 holes with the dynamite, were necessarily packed loosely, thus 

 subjecting the charge to the powerful action of angular velocity. 



" (3) That in the trials made with the 3.2-inch gun, two Butler 

 shells, charged with black gunpowder, broke up ' at or near the 

 muzzle ; ' while of the two Butler shells charged with Nobel's gela- 

 tine, or dynamite, one broke up ' at or near the muzzle,' and the 

 other reached the target and exploded on impact. 



"(4) That in the trials made with the same 3.2-inch gun, using 

 thin Hotchkiss shrapnel cases, charged with Nobel's dynamite or 

 gelatine, all cleared the gun in safety (one reaching the target after 

 passing through two-inch boards) with the exception of one, which 

 the board reported on as follows : ' It either broke from the shock 

 of discharge or admitted powder-gas.' 



"(5) That a// the trials with the 8-inch shells charged with/res/t 

 Nobel's dynamite or gelatine were successful, three of the shells 

 detonating at the target, and one only exploding at or near the 

 muzzle ; that Jhe gelatine used when the premature explosion took 

 place was sixteen months on hand in this country after crossing the 

 ocean, and therefore not such as was recommended by General Ab- 

 bot, or contemplated by the board." 



Major McKee's conclusions are as follows : that the United 

 States officers undertaking the investigation of this subject were ne- 

 cessarily compelled to institute their inquiries dd novo. All foreign 

 information was so meagre, so unsatisfactory, and so shrouded in 

 mystery, in accordance, doubtless, with the policy of the European 

 governments, that it was seen, after careful investigation, that all 

 trustworthy knowledge would have to be gleaned by Americans 

 through experience. In obtaining this experience, devices have 

 been experimented with, invented by Mr. Snyder, who presented 

 several plans ; Mr. C. P. Winslow, with a nitro-glycerine shell, in 

 which the glycerine and combined nitric and sulphuric acids are 

 placed in separate glass vessels within the shells ; Mr. Garrick, 

 with a mortar and projectile for nitro-glycerine ; Mr. D. P. Hill, 

 with an 8-inch explosive gelatine shell ; Mr. Stevens, with a double 

 shell for high explosives ; Mr. Graydon, with a shell containing the 

 dynamite in capsules ; Mr. Taylor, who brought his own gun, 

 and attempted to use dynamite as a propulsive charge ; and Mr. 

 Smolianoff, experiments with whose gun were made as late as last 

 October. 



In all these trials. Major McKee said, as to the practicability of 

 using dynamite as a shell-explosive, that it was well understood by 

 the officers undertaking them that the crude blasting compound of 

 industry, which was the only available explosive attainable, was not 

 the eventual product of chemistry which would satisfactorily answer 

 this purpose. It was known that great improvements had been 

 made in the dynamites of all kinds, especially in blasting dynamite, 

 or gelatine of Nobel, and that these compounds presented in trans- 

 portation by all modern conveyances, and in all mining and other 

 industrial works, as much, if not greater, safety than the black war, 

 sporting, and blasting gunpowders of commerce. With this status 

 of dynamite apparent, it was seen that the time had arrived for 

 military men in the United States to begin experiments with it as 

 a shell-explosive, with some possibility of success. When it was 



demonstrated that the freshly prepared crude commercial dynamite 

 might be fired in a shell from an 8-inch gun with a charge of forty 

 pounds of black gunpowder, the only question that then remained 

 was as to the stability and reliability of the compound through age. 

 And when, after sixteen months' storage, it appeared to be more 

 sensitive to shock, the Ordnance Board recommended that no more 

 experiments be made with it until it was further camphorated, or 

 otherwise treated by competent chemists. And it was ascertained 

 further, in these few and inexpensive tests, that the heat developed 

 by the angular velocity was a more potent factor in detonating the 

 dynamite than was the shock of discharge. It has been seen, also, 

 that, since the comparatively recent discovery of nitro-glycerine, its 

 development has been rapid in the protean forms of dynamite. In 

 Europe experiments are being constantly conducted to perfect this 

 agent, and doubtless they will succeed. Even now they claim in 

 France and Germany to have perfected melinite and helphonite, — 

 compounds probably of nitro-glycerine and some of the ethers. Irv 

 Russia they also announce some new improvements that are not 

 known here. But in the near future there is every probability that 

 the problem will be solved in this country. 



ELECTRICAL SCIENCE. 



Electrical Testing-Laboratories in Paris and Vienna. 



The Societe Internationale des Electriciens has completed and 

 opened a laboratory whose main purpose will, for the present, be 

 the testing and calibrating of electrical apparatus. M. de Nevville 

 will be the director. The following measurements will be made : 

 resistance, capacity, electro-motive force, constants of batteries, of 

 cables and wires, insulation resistance, efficiency of dynamos (pro- 

 visionally of continuous-current machines), and co-efficients of in- 

 duction. When the means allow, purely scientific researches will 

 be carried on. The laboratory is built on a modest scale, and 

 seems to lack a few pieces of apparatus that will probably be sup- 

 plied : for example, there is no provision for measuring mechanical 

 work, — a measurement necessary in many cases for the tests of 

 dynamos and motors. 



The laboratory in Vienna is an addition to the Technological 

 Museum in that city. Herr Carl Schlenk will superintend the work, 

 which will include very much the same kind of tests as are to be- 

 made in the Paris laboratory. 



The establishment of these two laboratories is important. The 

 applications of electricity have rapidly advanced, and have assumed 

 a permanent character. The questions in many cases are not, ' Can 

 electricity do this?' but, 'How cheaply can it be done.'' and this 

 last question can only be answered by measurements. As compe- 

 tition increases, and as that part of the public looking for invest- 

 ment becomes less satisfied with the mere running of a machine, 

 and demands accurate measurement of its performance, the neces- 

 sity of some reliable means of comparing measuring-instruments 

 becomes necessary. In England the Central Institution of London 

 has undertaken the work ; in Austria, the Technological Museum at 

 Vienna; in France, the International Society of Electricians. Our 

 country lias outstripped all others in the applications of electricity. 

 Probably we will soon have some means of comparing electrical 

 apparatus, and testing the value of the numerous appliances daily 

 patented. Electrical progress has been retarded and discredited 

 by worthless patents in which a great deal of money has been in- 

 vested and lost, while a simple test, taking little time and made at 

 little expense, would have shown them valueless. 



Dujardin's Method of forming Secondary-Batterv 

 Plates. — Several methods have been tried, and some are now 

 commercially used, of obtaining a quick formation of 'active m,a- 

 terial ' — peroxide of lead and spongy lead — for secondary-battery 

 plates. The Plante process of reversing the current is employed 

 by some makers, while others deposit the peroxide and lead on 

 support plates from an alkaline solution of litharge, as in the Mou- 

 tard batteries. Dujardin's process of obtaining a deposit is as fol- 

 lows : the lead plates are put into a solution of sulphuric acid and 

 sodium nitrate in water (10 of water, 2 of sulphuric acid, i of sodi- 

 um or potassium nitrate), and a current is sent througli the cell. 

 By the passage of the current, nitrate of lead is formed, the lead 



