246 EXPLOSIVES : MANUFACTURE AND USE. 



diamonds, coal and base metals. Let me illustrate this by a 

 few official figures. 



Witwatersrand Statistics for year ending June, 1908. 



Explosives consumed : — 560,000 cases = 14,000 tons. 



Value : ;^i, 500,000. 



]\Ietals and minerals handled and won : — 



Silver . . . . 740,000 oz. Value ;£'88,297. 



Base metals . . 7,661 tons. ",, ;^i66,452. 



Coal .. .. 2,892,214 tons. ,, ^^778, 659. 



Diamonds .. .. 2,184,490 carats. ., ;£i.879,55i. 



Gold .. .. 6,711,436 oz. ,, ;^28,5o8,368. 



Total mineral output : — ;^3 1,634,000. 



Note. — During the year ending June, 1909, the above figures show an 

 overall of about 10 per cent. 



But even on its lowest basis the explosives industry is one 

 of the most important in South Africa. Over £2,000,000 are 

 invested in the three factories now working; every year these 

 three factories pay out almost £200,000 in wages, and spend 

 an additional £100,000 locally on the purchase of stores. Then 

 directly they contribute to the various administrations about 

 £250,000 in railway rates, and give direct employment to 2,000 

 people. 



If I had been lecturing" on the subject of explosives just a 

 few years ago my task would have been comparatively easy. 

 The only explosive in general use until about 30 years ago wa 

 black powder, than which perhaps no other material has played 

 a greater part in the economy of the world. This is a tall 

 statement, but if you consider only the warlike aspect of the 

 question you will see that I must be correct. We are pretty 

 certain that it was known 800 years ago, but experts are still 

 undecided as to which of the two ancient civilizations, viz., 

 those of China or Arabia, should be credited with the discovery. 

 That point need not trouble us. Five hundred years ago its 

 use was pretty general in warfare. 



It is sad to part with old friends. The days of black powder 

 are doomed, notwithstanding the fact that some old-fashioned 

 sportsmen still swear by it, but the same class of sportsman 

 swears also by the muzzle loader. For some classes of work, 

 however, such as quarrying, it will be difficult to beat. 



At this stage I might say that black powder is wdiat chemists 

 call a mechanical mixture, i.e., an ag"gregation of particles of 

 different bodies adjacent to one another, but having no interest 

 whatever in one another, until chemical reaction is started. 



Time does not permit of my dwelling longer on the past, so 

 I propose now to pass on to some of the more modern develop- 

 ments, which have not only revolutionised industry, but also 

 warfare, as we in this country know only too well. Two names 

 are most intimately associated with these developments, and 

 tney are so much alike that they are frequently confused. Thev 

 are Alfred Nobel and Sir Andrew Noble. 



Explosives, as I have already indicated, is a very wide sub- 

 ject. Under its category are included squibs, torpedoes. 



