EXPLOSIVES : MANUFACTURE AND USE. 249 



detonator, but the underlying principle in each case is precisely 

 the same, and until a very few years ago only one body — 

 fulminate of mercury — was known to perform this very neces- 

 sary function. The first caps were made by an English gun- 

 maker in the year of the battle of Waterloo, but the idea lay 

 dormant until Nobel's intuitive mind saw their potentialities. 

 He adapted gun caps to blasting compounds, and concurrently 

 came along the development of ordinary time fuse. 



And now, ladies and gentlemen, I have very briefly reviewed 

 what might be called our raw materials, and equally briefly I 

 propose to review the processes through which these materials 

 pass, on the way towards being turned out efficient engines 

 of destruction. Time does not permit of my considering more 

 than three, viz. : — 



Blasting Gelatine, 



Safety Explosives, 



Cordite. 

 Each of these three is typical of a very large class, and all 

 are used in this Colony. I have already said that more blasting 

 gelatine is made in South Africa than in any other continent. 

 It is the strongest blasting agent known, and its manufacture 

 is exceedingly simple. Provided you have been able to follow 

 me so far I need only devote a word to it. It consists of nitro- 

 glycerine 93 per cent, and collodion cotton 7 per cent. You 

 will observe that both the ingredients are strong explosives. 



I next pass on to the so-called safety explosives, of which 

 there are scores. The name " safety " has been given because 

 of their comparative safety in coal mines, i.e., mines in which 

 there is the danger of explosions, either from accumulated gas 

 or from coal dust. We in the Transvaal are so far quite free 

 of these risks. We are free from gas on account of the geo- 

 logical formation of the overlying rocks, and we are free from 

 dust because of the very large workings, the seams not infre- 

 quently being 12 to 20 feet thick, against 24 to 30 inches in 

 England. In the northern part of your Colony, however, 

 there are two coal mines, both of which are gaseous, con- 

 sequently both safety lamps and safety explosives have to be 

 used if danger is to be avoided. These safetv explosives have 

 a comparatively low temperature of explosion, so that they do 

 not readily ignite coal gas unless when used in tremendously 

 large quantities. 



I now pass to cordite, which was the only propellant used in 

 the latter stages of the recent war. The history of the develop- 

 ment of smokeless powders is perhaps one of the most interest- 

 ing in the whole range of applied chemistry. I have already 

 referred to the early experiments of Von Link, which came to 

 nought. The name of Alfred Nobel is connected with the 

 next great advance. I have just described to you what blasting 

 gelatine is, and " ballistite," brought to the world's notice by 

 Nobel about 22 years ago, is much the same body with the 

 proportions altered. Ballistite, as produced by Nobel, con- 

 tained equal proportions of collodion cotton and nitro-glycerine, 

 and it was immediately taken up by the Germans and other 



