23 REPORT — 1895. 



But great as have been the developments of science in promoting the 

 commerce of the world, science is asserting its supremacy even to a greater 

 extent in every department of war. And perhaps this application of science 

 affords at a glance, better than almost any other, a convenient illustration 

 of the assistance which the chemical, physical, and electrical sciences are 

 affording to the engineer. 



The reception of warlike stores is not now left to the uncertain 

 judgment of ' practical men,' but is confided to officers who have receiv^ed 

 a special training in chemical analysis, and in the application of physical 

 and electrical science to the tests by which the qualities of explosives, of 

 guns, and of projectiles can be ascertained. 



For instance, take explosives. Till quite recently black and brown 

 powders alone were used, the former as old as civilisation, the latter but 

 a small modern improvement adapted to the increased size of guns. But 

 now the whole family of nitro-explosives are rapidly superseding the old 

 powder. These are the direct outcome of chemical knowledge ; they are 

 not mere chance inventions, for every improvement is based on chemical 

 theories, and not on random experiment. 



The construction of guns is no longer a haphazard operation. In spite 

 of the enormous forces to be controlled and the sudden violence of their 

 action, the researches of the mathematician have enabled the just propor- 

 tions to be determined with accuracy ; the labours of the physicist have 

 revealed the internal conditions of the materials employed, and the best 

 means of their favourable employment. Take, for example, Longridge's 

 coiled-wire system, in which each successive layer of which tlie gun is 

 formed receives the exact proportion of tension which enables all the layers 

 to act in unison. The chemist has rendered it clear that even the smallest 

 quantities of certain ingredients are of supreme importance in affecting 

 the tenacity and trustworthiness of the materials. 



The treatment of steel to adapt it to the vast range of duties it has 

 to pei'form is thus the outcome of patient research. And the use of 

 the metals — manganese, chromium, nickel, molybdenum — as alloys with 

 iron has resulted in the production of steels possessing varied and extra- 

 ordinary properties. The steel required to resist the conjugate stresses 

 developed, lightning fashion, in a gun necessitates qualities that would not 

 be suitable in the projectile which that gun hurls with a velocity of some 

 2,-500 feet per second against the armoured side of a ship. The armour, 

 again, has to combine extreme superficial hardness with great toughness, 

 and during the last few years these qualities are sought to be attained by 

 the application of the cementation process for adding carbon to one face 

 of the plate, and hardening that face alone by rapid refrigeration. 



The introduction of quick-firing guns from -303 (i.e. about one-third) 

 of an inch to 6 -inch calibre has rendered necessary the production of metal 

 cartridge-cases of complex forms di-awn cold out of solid blocks or plate 

 of the material ; this again has taxed the ingenuity of the mechanic in the 

 device of machinery, and of the metallurgist in producing a metal possessed 



