20 Sir FredericJc Ahel [Jan. 31, 



fulfils, besides, the conditions of smokelessness and of stability, so far 

 as can be guaranteed by tbe 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 over- 

 come certain difficulties attending the employment, in a very small- 

 bore rifle, of an explosive developing much greater energy than the 

 black-2)owder 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 20 tons per square inch ; 

 on the other hand, with considerably less of the explosive 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 comparatively 

 considerable erosive effects would be expected to be produced by 

 powders of high energy as compared wdth 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 

 devisino" of an explosive which shall be practically smokeless, suffi- 

 ciently 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 

 1 • 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 coi.siderably 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 utilisation 

 of the ballistic 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 aa 



