354 



NA TURE 



\_Feb. 13, 1890 



the Rottweil powder-works, and appears to have been adopted 

 into the German service for a time, but its first great promise of 

 success seems to have failed of fulfilment through defects in 

 stability. 



Reference has already been made to the conversion of gun- 

 cotton (trinilrocellulose), and to mixtures of it with less explosive 

 forms of nitrated cotton (or nitrated cellulose of other descrip- 

 tion), by the action of solvents into horn-like materials. These 

 are in the first instance obtained in the form of gelatinous 

 masses, which, prior to the complete evaporation or removal of 

 the solvent, can be pressed or squirted into wires, rods, or tubes, 

 or rolled or spread into sheets ; when they have become 

 hardened, they may be cut up into tablets or into strips or pieces 

 of size suitable for conversion into charges or cartridges. 

 Numerous patents have been secured for the treatment of gun- 

 cotton, nitro-cotton, or mixtures of these with other substances, 

 by the methods indicated ; but in this direction the German 

 makers of the powder just now referred to seem to have secured 

 priority. Experiments were made about a year and a half ago 

 with powder produced in this way at Woolwich, and the Wet- 

 teren Powder Company in Belgium has also manufactured so- 

 called paper powders, or horn-like preparations, of the same 

 kind, which were brought forward as counterparts of the French 

 small-arm and artillery smokeless powder. 



Mr. Alfred Nobel, to whom the mining world is so largely 

 indebted for the invention of dynamite, and of other very effi- 

 cient blasting agents of which nitro-glycerine is the basis, was 

 the first to apply the latter explosive agent, in conjunction with 

 one of the lower products of nitration of cellulose, to the pro- 

 duction of a smokeless powder. The powder bears great 

 resemblance to one of the most interesting of known violent 

 explosives, also invented by Mr. Nobel, and called by him 

 blasting gelafine, in consequence of its peculiar gelatinous cha- 

 racter. When the nitro-cotton is impregnated and allowed to 

 dige-t with nitro-glycerine, it loses its fibrous nature and be- 

 comes gelatinized while assimilating the nitro-glycerine, the two 

 substances furnishing a product which has almost the character 

 of a compound. By macerating the nitro-cotton with from 7 to 

 10 per cent, of nitro-glycerine, and maintaining the mixture 

 warm, the whole soon becomes converted into a plastic material 

 from which it is very difficult to separate a portion of either of 

 its components. This preparation, and certain modifications of 

 it, have acquired high importance as blasting agents more 

 powerful than dynamite, and possessed of the valuable property 

 that their prolonged immersion in water does not separate from 

 them any appreciable proportion of nitro-glycerine. 



In the earlier days of the attempted application of blasting 

 gelatine to mil tary uses, in Austria, when endeavours were 

 there made to render the material less susceptible of accidental 

 explosion on active service (as by the penetration of bullets or 

 shell fragments into transport waggons containing supplies of the 

 explosive), this result was achieved by Colonel Hess by in- 

 corporating with the components a small proportion of camphor, 

 a substance which had then, for some time past, played an in- 

 portant part in the technical application of nitro-cotton to the 

 production of the remarkable substitute for ivory, horn, &c., 

 known as xylenite. By incorporating with nitro-glycerine a 

 much larger proportion of nitro-cotton than used in the produc- 

 tion of blasting gelatine, and by employing camphor as an 

 agent for promoting the union of the two explosives, as well as, 

 apparently, for deadening the violence, or reducing the lapidity 

 of explosion of the product, Mr. Nobel has obtained a material 

 of almost horn-like character, which can be pressed into pellets 

 or rolled into sheets while in the plastic condition, and which 

 compares favourably with the gun-cotton preparations of some- 

 what similar physical characters just referred to, as regards 

 ballistic properties, stability, and uniformity, besides being 

 almost absolutely smokeless. The retention in its composition 

 of some proportion of the volatile substance camphor, which 

 may gradually be reduced in amount by evaporation, renders this 

 explosive liable to undergo some modification in its ballistic 

 properties in course of time ; it is believed that this point has 

 been dealt with by Mr. Nobel, and accounts from Italy speak 

 favourably of the results of trials of his powder in small arm^, 

 while Mr. Krupp is reported to be carrying on experiments with 

 it in guns of several calibres. 



The Government Committee on Explosives, in endeavouring 

 to remedy the above defect of Nobel's original powder, were led 

 by their researches to the preparation of other varieties of nitro- 

 glycerine powder, which, when applied in the form of wires or 



rods, made up into sheaves or bundles, have given, in the 

 service small-bore rifle, excellent ballistic results. The most 

 promising of them, which fulfils, besides, the conditions of smoke- 

 lessness and of stability, so far as can be guaranteed by the 

 application of special tests of exposure to elevated temperatures, 

 &c., is now being submitted to searching experiments with the 

 view of so applying it in the arm as to overcome certain difficulties 

 attending the employment, in a very small-bore rifle, of an 

 explosive developing much greater energy than the black-powder 

 charge, which therefore gives very considerably higher velocities 

 even with much smaller charges, and consequently heats the 

 arm much more. Thus, the service black-powder charge 

 furnishes, with the small-bore rifle, an average (and variable) 

 velocity of 1800 f s., together with pressures ranging from 18 to 

 23 tons per square inch ; on the other hand, with con-^iderably 

 less of the powder referred to, there is no difficulty in securing 

 a very uniform velocity of about 2200 f.s. with pressures not 

 exceeding 17 tons, while velocities as high as 2500 f.s. are 

 obtainable with pressures not greater than the maximum allowed 

 with the black-powder charge. 



It is obvious, from what has already been said respecting the 

 causes of the erosive action of powder in guns, that compara- 

 tively considerable erosive effects would be expected to be 

 produced by powders of high energy as compared with black 

 powder. Moreover, the freedom of the products of explosion 

 from any solid substances, and consequently the absence of any 

 fouling or deposition of residue in the arm, causes the heated 

 surfaces of the projectile and of the interior of the barrel to 

 remain clean, and in a condition, therefore, very favourable to 

 close adherence together. If to these circumstances be added 

 the fact that the behaviour of the smokeless powder has to be 

 adapted to suit an arm, a cartridge, and a projectile originally 

 designed for use with black powder, it will be understood that 

 the devising of an explosive which shall be practically smokeless, 

 sufficiently stable, and susceptible of perfectly safe use in the 

 arm under all service conditions, easy of manufacture, and not 

 too costly, is, after all, but a small part of the difficult problem 

 of adapting a smokeless powder successfully to the new military 

 rifle — a problem which, however, appears to be on the near 

 approach to satisfactory solution. 



The experience already acquired in guns ranging in calibre 

 from I '85 inches to 6 inches, with the smokeless powder devised 

 for use in our service, has been very promising, and indicates 

 that the difficulties attending its adaptation to guns designed for 

 black powder are likely to prove considerably less than in the 

 case of the small arm. But here, again, the circumstances that 

 much smaller charges are required to furnish the same ballistics 

 as the service black-powder charges, and that the comparatively 

 gradual and sustained action of the new powder gives rise to 

 lower pressures in the chamber of the gun, and higher pressures 

 along the chase, demonstrate that the full utilization of the bal- 

 listic advantages, and the increase in the power of guns of a 

 given calibre and weight with the new form of powder, are only 

 attainable by some modifications in the designs of the guns- 

 such as a reduction in size of the charge- chamber, and some 

 additions to the strength, and perhaps, in some cases, of the 

 length, of the chase. 



When, however, the smokeless powder has been adapted with 

 success in all respects to artillery, from small machine-guns to 

 guns of comparatively heavy calibre, and when its ballistic ad- 

 vantages have been fully utilized in guns of suitable design, it 

 will remain to be determined how far such a powder — unde- 

 niably of much more sensitive constitution than black powder, 

 or any of its modifications — will withstand, unchanged and 

 unharmed, the various vicissitudes of climate, and the service 

 storage-conditions in ships and on land in all parts of the world 

 — a condition essential to its adaptability to naval and military 

 use, and especially to the service of our Empire ; and whether 

 sufficient confidence can be placed in its stability for long periods 

 under these extremely varied conditions to warrant the necessary 

 freedom from apprehension of possible danger, emanating from 

 within the material itself, to allow of its being substituted for 

 black powder wherever its use may present advantages. 



Possible it might be, that the storage, with perfect safety, of 

 such a powder in ships, forts, or magazines might demand 

 the adoption of precautionary measures tending to place 

 comparatively narrow limits upon the extent of its practicable 

 service applications ; even then, however, an imperative need for 

 the introduction of special arrangements to secure safety and 

 immunity from deterioration may be of small importance as 



