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SCIENCE. 



[Vol. XVI. No. 398 



also referred to at some length. The "cocoa" powder was pro- 

 duced, which is a prismatic powder containing a very slightly 

 burned charcoal of reddish-brown color, the action of which is 

 comparatively gradual and long sustained. The smoke from this 

 dififers but little in volume from that of black povs-der, but dis- 

 perses much more rapidly. Even more gradual action yet was 

 required in the case of guns of large caliber, and the brown pow- 

 der has been modified to meet the case. The desii-ability of pro- 

 ducing a smokeless powder has led many to attempt the use of 

 ammonium nitrate, in which the products of decomposition are, 

 in addition to water-vapor, enth-ely gaseous. Its deliquescent 

 character has, however, been a formidable obstacle to its applica- 

 tion as a component of a useful explosive agent. An ammonium- 

 nitrate powder has, however, been manufactured in Germany 

 which possesses remarkable ballistic proi^erties, and produces com- 

 paratively little smoke, which speedily disperses. No great ten- 

 dency is exhibited by it to absorb moisture from an ordinarily dry, 

 or even somewhat moistf, atmosphere; but it readily absorbs water 

 when the hygroscopic condition of the air approaches saturation, 

 and this greatly restricts its use. Sir Frederick next referred to 

 the introduction in France of melinite; but this has now been 

 succeeded by more than one smokeless powder, and the material 

 now in use with the Lebel rifle belongs to a class of nitro-cellu- 

 lose, or nitro-cotton preparation. 



A comparison between the chemical changes attending the 

 burning or explosion of gunpowder, and of the class of nitro- 

 compounds represented by gun-cotton, at once explains the cause 

 of the production of smoke by the former, and of the smokeless- 

 ness of the latter. While the products of explosion of the nitro- 

 compounds consist exclusively of gases and of water-vapor, gun- 

 powder, being composed of a large proportion of saltpetre or other 

 metallic nitrate, mixed with charred vegetable matter and varia- 

 ble quantities of sulphur, furnishes products of which over 50 per 

 cent are not gaseous, even ac high temperatures, and which are in 

 part deposited as a fused solid (which constitutes the fouling in a 

 fire-arm), and in part distributed in an extremely fine state of di- 

 vision through the gases and vapors developed by the explosion, 

 thus giving to these the appearance of smoke as they escape into 

 the air. 



So far as smokelessness is concerned, no material can surpass 

 gun-cotton ; but, even if the rate of combustion of the fibrous ex- 

 plosive in a fire-arm could be controlled with certainty and uni- 

 formity, its application as a safe propulsive agent is attended by 

 so many difiSculties, that the non-success of the numerous early 

 attempts to apply it to that purpose is not surprising. Those at- 

 tempts consisted entirely in varying the density and mechanical 

 condition of employment of the gun-cotton fibre. No difficulty 

 was experienced in thus exercising complete control over the 

 rapidity of burning in the open air; but when the material was 

 strongly confined, as in the bore of a gun, such methods of regu- 

 lating its explosive force were quite unreliable, as some slight 

 unforeseen variation in the amount and disposition of the air- 

 spaces in the mass would develop very violent action. Much 

 more promising results were subsequently obtained by reducing 

 the fibre to a pulp, as in the ordinary process of making paper, 

 and converting this into highly compressed, homogeneous masses. 

 But although comparatively small charges often gave high veloci- 

 ties of projection, without any indications of injury to the gun, 

 the uniform fulfilment of the conditions essential to safety proved 

 to be beyond absolute control, even in guns of small caliber; and 

 military authorities not being, in those days, alive to the advan- 

 tages which might accrue from the employment of an entirely 

 smokeless explosive in artillery, experiments in this direction were 

 not persevered in. At the same time, considerable success at- 

 tended the production of safe and uniform gun-cotton cartridges 

 for sporting-guns and the Martini-Henry rifle. 



Sir Frederick next referred to the sporting-powder of Capt. 

 Schultze, the E. C. powder, and the smokeless powder of Mr. Al- 

 fred Nobel. He also spoke of the action of camphor and liquid 

 solvents when applied to hardening compressed masses of gun- 

 cotton. The nitro-glycerine powder first produced by Mr. Nobel 

 was, he stated, almost perfectly smokeless, and developed very 

 bigh energy, accompanied by moderate pressures at the seat of 



the charge; but it possessed certain practical defects, which led 

 to the development of several modifications of that explosive and 

 various improvements in manufacture. The relative merits of 

 this class of smokeless powder, and of various kinds of nitro-cell- 

 ulose powder, were under careful investigation in this and other 

 countries, and several more or less formidable difficulties have 

 been met with in their application, in small-arms especially. 

 These arise in part from the comparatively great heat such explo- 

 sives develop, which increases the erosive effects of the products 

 of explosion, and in part from the more or less complete absence 

 of solid products. The surfaces of the barrel and of the projec- 

 tile, being left clean after the firing, are in a condition favorable 

 to then close adhesion while the bullet is propelled along the bore, 

 with the consequent establishment of very greatly increased fric- 

 tion. The latter difficulty has been surmounted by more than 

 one expedient at the cost of losing absolute smokelessness. 



Our knowledge of the results obtained in France and Germany 

 with the use of smokeless powders in the new rifles and in artillery 

 is somewhat limited. Our own experiments have demonstrated 

 that satisfactory results are attainable. The importance of in- 

 suring that the powder shall not be liable to undergo chemical 

 change detrimental to its efficiency or safety, when stored ^vhere 

 it may be subject to considerable variations of temperature, ne- 

 cessitates qualities not very easily secured in an explosive agent 

 consisting mainly of the comparatively sensitive nitro-compounds 

 to which the chemist is limited in the production of a smokeless 

 powder. It is possible, therefore, that the extent of use of such a 

 material in our ships, or in our tropical possessions, may have to 

 be limited by the practicability of fulfilling certain special condi- 

 tions essential to its storage without danger of possible deteriora- 

 tion. If, however, great advantages are likely to attend the em- 

 ployment of a smokeless explosive, it wiU be well worth while to 

 adopt such special arrangements as may be required for securing 

 these without incurring special dangers. This may prove to be 

 especially necessary in our sliips of war, where temperatures so 

 high as to be prejudicial even to ordinary black powder sometimes 

 prevail in the magazines, consequent mainly upon the positions 

 assigned to them in the ships, but which may be guarded against 

 by measures not difficult of application. 



The press and other accounts of the wonderful performances of 

 the first smokeless powder adopted by the French engendered a 

 belief that a very great revolution in the conduct of campaigns 

 must result from the introduction of such powders. It was even 

 reported very positively that noiselessness was one of the impor- 

 tant attributes of a smokeless powder; and highly colored compari-' 

 sons have, in consequence, been drawn in service periodicals, 

 and even by some military authorities, between the battles of the 

 past and those of the future. The absence of recoil when a rifle 

 was fired with smokeless powder was another of the marvels re- 

 ported to attend the use of these new agents of warfare. It need 

 scarcely be said that a closer acquaintance with them has dispelled 

 the credit given to such of the accounts of their supposed qualities 

 as were mythical. . 



The extensive use which has been made in Germany of smoke- 

 less or nearly smokeless powder in one or two special military dis- 

 plays, has, however, afforded interesting indications of the actual 

 change which is likely to be wrought by these new explosives in 

 the conditions under which engagements on land will be fought 

 in the future. Although the German powder is not actually 

 smokeless, the almost transparent film of smoke produced by in- 

 dependent rifle-firing is not visible at a distance of about 3(0 

 yards, and the most rapid salvo-flring by a large number of men 

 does not have the effect of obscuring them from distant observers. 

 When machine-guns and field artillery are fired with our own 

 almost absolutely smokless powder which we are employing, their 

 position is not readily revealed to distant observers by the momen- 

 tary vivid flash of flame and slight cloud of dust produced. In 

 the naval service, it is, especially for the quick-firing guns, so 

 important for defensive purposes, that a smokeless powder has 

 been anxiously looked for. 



The ready and safe attainment of very high velocities of projec- 

 tion through the agency of these new varieties of explosive agents, 

 employed in guns of suitable construction, would appear at first 



