The Kimberley mines were at first known as the ‘dry diggings’ on account of their arid surroundings in contradistinction to the ‘river diggings’ by the Vaal. The dearth of water was at first one of the great difficulties in the way of working the former mines, although subsequently the accumulation of underground water at lower levels proved a great obstacle to the working of the mines. The ‘river diggings’ were of a type similar to that met with in India and Brazil, the diamonds occurring in a gravelly deposit of limited thickness beneath which was barren rock, but the Kimberley mines presented a phenomenon hitherto without precedent in the whole history of diamond mining. The diamonds were found in a loose surface deposit, which was easily worked, and for some time the prospectors thought that the underlying limestone corresponded to the bedrock of the river gravel, until at length one more curious than his fellows investigated the yellowish ground underneath, and found to his surprise that it was even richer than the surface layer. Immediately a rush was made back to the deserted claims, and the mines were busier than ever. This ‘yellow ground,’ as it is popularly called, was much decomposed and easy, therefore, to work and sift. About fifty to sixty feet (15-18 m.) below the surface, however, it passed into a far harder rock, which from its colour is known as the ‘blue ground’; this also, to the unexpected pleasure of the miners, turned out to contain diamonds. Difficulties arose as each claim, 30 by 30 Dutch feet (about 31 English feet or 9·45 metres square) in area, was worked downwards. In the Kimberley mine (Plate XVI) access to the various claims was secured by retaining parallel strips, 15 feet wide, each claim being, therefore, reduced in width to 22½ feet, to form roadways running from side to side of the mine in one direction. These, however, soon gave way, not only because of the falling of the earth composing them, but because they were undermined and undercut by the owners of the adjacent claims. By the end of 1872 the last roadway had disappeared, and the mine presented the appearance of a vast pit. In order to obtain access to the claims without intruding on those lying between, and to provide for the hauling of the loads of earth to the surface, an ingenious system of wire cables in three tiers (Plate XVII) was erected, the lowest tier being connected to the outermost claims, the second to claims farther from the edge, and the highest to claims in the centre of the pit. The mine at that date presented a most remarkable spectacle, resembling an enormous radiating cobweb, which had a weird charm by night as the moonlight softly illuminated it, and by day, owing to the perpetual ring of the flanged wheels of the trucks on the running wires, twanged like some gigantic æolian harp. This system fulfilled its purpose admirably until, with increasing depth of the workings, other serious difficulties arose.