698 



SCIENCE. 



[N. S. Vol. XVII. No. 435. 



up with shovels, then rudely washed and the 

 residue picked over by hand. The various 

 steps and stages of progress in its' treatment 

 are described, down to the wonderfully com- 

 plete, rapid and accurate machine processes 

 now employed. The rock was found to dis- 

 integrate and break up by a few months' ex- 

 posure to the air, sun and rain; and thus 

 most of the former crushing is dispensed 

 with. The rock brought out is hauled by a 

 very perfect system of traction to the ' floors ' 

 — ^large areas of smoothly rolled ground, cov- 

 <8ring several hundred acres — and there spread 

 ■•out, about a foot in thickness. Various 

 3)rocesses, of steam-harrowing, occasional 

 watering in dry times, etc., are employed to 

 .accelerate nature's effect. The removal to 

 the washing machines, and in part to crush- 

 ers, and all the devices for sorting and con- 

 «entrating, are described in detail, until the 

 last stage is reached, when the heavy con- 

 •centrates are fully separated, and ready to 

 Ibe picked by hand. Here it appeared as 

 ■though the point had been reached where 

 r.m^achine processes had to cease and liuman 

 cagency alone could avail. But no! After 

 imany years of hand-picking, the discovery 

 ~was made by one of the employees, Mr. Fred. 

 Kirsten, that diamonds would adhere to 

 grease, while the other minerals of the con- 

 centrates would not. A few experiments 

 proved conclusive; and soon all hand-sorting 

 was replaced by machinery — slightly inclined 

 tables coated with a layer of grease. These 

 are vibrated as the concentrates are made to 

 pass over them with a current of water, and 

 every diamond is retained, while the garnets 

 and other heavy minerals pass on! No more 

 simple and complete device has ever been dis- 

 covered, for the saving of time, labor and 

 loss. The diamonds thus separated are after- 

 wards boiled in a hot solution of soda, and 

 are then ready for the company's office and 

 the valuator. 



The succeeding chapter tells of ' Obstacles 

 and Perils ' encountered in the working of 

 the mines, and is a graphic presentation of 

 this aspect of the subject. The earlier dangers 

 were chiefly from reef -falls and cave-ins; after 

 the new methods were introduced these be- 



came unimportant. Occasional slight explo- 

 sions, due to carelessness of workmen, and 

 one disastrous fire, of unknovm origin, but 

 probably from the same cause, are described, 

 the latter in a very vivid and feeling way. 

 The ' mud-rushes ' are the most serious liabil- 

 ity of late; and the methods employed to pre- 

 vent them are ingenious and interesting. 



Chapter XIV., on 'The Workers in the 

 Mines,' is one of great general interest, de- 

 scribing the conditions and regulations of 

 life and work in the vast subterranean hive 

 of activity, and the arrangements for housing, 

 feeding and controlling the great heterogene- 

 ous army when above ground. About one 

 sixth of the employees are white men, largely 

 from the mining districts of England, though 

 there are many Afrikanders, and a sprinkling 

 from nearly every land on the globe. The 

 rest, some eleven thousand, are native blacks, 

 representing almost every tribe south of the 

 equator, some coming from distances as great 

 as a thousand miles. Mr. Williams gives a 

 most interesting estimate, based on conspicu- 

 ous facts, of the industrial capacity of the 

 negro — one that impresses an American with 

 surprise. The steadiness, persistence, con- 

 tentment and capacity shown by these thou- 

 sands of laborers, fresh from their native 

 savagery, is in utter contrast to the shiftless 

 and indolent character of the negro so largely 

 seen in the New World, and so generally at- 

 tributed to the race as such. As a sociological 

 study this subject of the experience of the 

 De Beers Company with African labor, on a 

 grand scale and through many years, is worthy 

 of most careful attention by anthropologists 

 and philanthropists. 



The moral and physical well-being of these 

 natives are well guarded by the company in 

 its great system of ' compounds '■ — walled en- 

 closures, carefully constructed and steadily 

 watched, where the laborers are kept in a sort 

 of paternal confinement during their period 

 of working. Every one engages freely for a 

 time not less than three months, and is then 

 at liberty to leave or renew — the great ma- 

 jority choosing the latter, and many remain- 

 ing for years. Liquor is rigorously excluded, 

 as ruinous to all steady or reliable service. 



