250 EXPLOSIVES : MANUFACTURK AND USE. 



Continental Powers as their propellant for large guns, and it 

 is their propellant to-day. The sporting- ballistite, which is 

 fairly well known in this country, was first made about i6 years 

 ago, and was a development of my own. 



What I have just said now is more or less introductory to 

 cordite, which you have been blazing away at your Orange 

 Free State Bislev, but at this stage I must retrace my steps a 

 little. 



About 20 years ago the different European Governments 

 were all vieing with one another as to who should have the 

 best military propellant. France had not forgotten 1870, and 

 Austria's recollections of her misadventure were still green. 

 The chemists of the British War Office were meantime quietly 

 working away on the lines indicated by Nobel a few years 

 earlier, and gradually they evoWed cordite, which is perhaps 

 the best allround military propellant. 



Now, all smokeless powders are affected by climatic con- 

 ditions, and no other Power has such a variety of those as 

 Great Britain. Cordite has successfully withstood the swelter- 

 ing heat of India and the arctic cold of Canada, the humidity 

 of West Africa, and the aridity of Aden. This may seem a 

 small thing, but it is not. We have only to think of wdiat was 

 happening regularly in the French Navy recently to realise 

 what an important thing it is. The " Jena " disaster in the 

 harbour of Toulon is only one of many similar occurrences, 

 and I have no doubt whatever that the blowing" up of the 

 American warship, the " Maine," in Havana Harbour — an 

 occurrence which brought on the Spanish-American war — was 

 not the work of the Spaniards, but the result of a defective 

 smokeless powder. 



So much for the manufacture of explosives. I now- come 

 to the use, but I must assume that you are all acquainted with 

 this in a general way, therefore I shall, as hi the case of the 

 manufacture, refer only to a few typical cases. Explosives, of 

 course, have only a value proportionate to their potential 

 power. For instance, one litre of nitro-glycerine produces 

 1,141 litres of gas on detonation, reckoned at zero and ordinary 

 barometric pressure; but as the theoretical temperature 

 of explosion is 6,980° C, and as the mechanical effect 

 is a function of the gas volume by the temperature, one can 

 easily calculate what an enormous force is developed at the 

 moment of explosion. The pressure which would be exerted 

 under these conditions is equal to 1,300 tons, not lbs., per 

 square inch. Taking equal bulks of nitro-giycerine and black 

 powder, the former produces 10 to 12 times as much gas as 

 the latter. And yet every particular application must have its 

 own particular explosive. Black powder could have no effect 

 on the rocks of the Witwatersrand, and blasting" gelatine would 

 be worse than useless for quarrying sandstone. Cordite is of 

 no use in a' shot-gun, and Schulze powder would blow the breach 

 off of a -303 rifle to pieces. Lyddite, which is merely molten 

 picric acid, must have a special primer before its potential 

 power is iilierated, and wet guncotton — the explosive for tor- 



