478 Mr. William Crookes [June 11, 



In the early part of last year, accompanied by my wife, I visited 

 some of our Colonies in South Africa, and spent a considerable time 

 in the neighbourhood of the famous Diamond Mines of Kimberley, 

 where I had an exceptionally good opportunity of studying the pecu- 

 liar geological formation, and of noting interesting facts connected 

 with the occurrence of the precious stone which forms the subject of 

 this evening's lecture. 



Although the experiments I wish to bring before you are chiefly 

 connected with the physical and chemical properties of diamonds, and 

 of the light that recent researches throws upon their probable forma- 

 tion, it will possibly act as a kind of compensation for the dryness of 

 some of the theoretical points if with the help of a few photof^raphs * 

 taken on the spot, I bring before your very eyes the general character 

 of the famous mines and their surroundings. 



The most famous diamond mines are Kimberley, De Beers, 

 Dutoitspan, Bulfontein and Wesselton. They are situated in lati- 

 tude 28° 43' South, and longitude 24° 46' East. Kimberley town 

 is 4042 feet above sea-level. Other mines in the district, as yet 

 unimportant, are worked for diamonds. Kimberley is practically in 

 the centre of the present diamond-producing area. Besides these 

 mines, there are in the Orange Free State, about 60 miles from the 

 Kimberley diamond region, two others of some importance known as 

 Jagersfontein and Coffeefontein. 



Before describing the present mode of diamond extraction followed 

 in the leading mines, I will commence with the so-called " Kiver 

 Washings," where, in their original simplicity, can be seen the 

 methods of work and the simple machinery long since discarded in 

 the large centres (Fig. 1). These drifts or "river-washings" present 

 an interesting phase of diamond industry. The work is carried out 

 in the crude fashion of early diamond discovery, every man working 

 on his own little claim, assisted by a few natives, and employing 

 primitive machinery. The chief centre of the river washings is at 

 Klipdam No. 2, about 30 miles to the north-west of Kimberley. The 

 road to Klipdam No. 2 involves a journey of about a dozen miles in 

 one of the old African coaches now becoming obsolete through the 

 spread of railways. Eoad there is none — only a track across the 

 veldt made by countless teams of oxen and mule«. 



Diamonds from the "river washings " are of all kinds, as if every 

 mine in the neighbourhood contributed. The samples are much 

 rolled and etched, and contain a fair proportion of stones of very good 

 quality, as if only the better and larger stones had survived the ordeal 

 of knocking about. 



Diamonds from the drift fetch about 40 per cent, more than those 



* Of the photographs Illustrating this lecture, Nos. 4 and 7 are from plans 

 lent by Mr. Gardner Williams, and Nos. 3, 5, 6, 8, 9, 12, 13 and 18 are copies of 

 photographs purchased at Kimberley. The remaining twenty were photographed 

 by myself. 



