472 THE POPULAR SCIENCE MONTHLY. 



ing-table. The "pulsator" is also often so employed as to dispense 

 with the "panning" process. 



At the "river-diggings" (on the Yaal) the diamondiferous deposit 

 is imbedded between bowlders and mixed with fine red sand, and 

 sometimes with lime. The diamonds are separated by sifting the earth 

 through a machine called a " baby " — a kind of swinging sieve, which, 

 the coarser pebbles having been taken out by another sieve impending 

 above it, allows the medium-sized pebbles, supposed to contain dia- 

 monds, to roll into a tub, while the finer refuse sand passes through 

 its meshes. The contents of the tub are then gravitated, and the 

 heavier stones are turned upon a " sorting-table," and the diamonds 

 picked out by careful scraping. An experienced digger can tell at a 

 glance, from the appearance of the deposit, what chance there is of 

 " finding well " in it. He knows by sight the heavier stones that occur 

 in diamond-bearing ground, and their presence, is a sure sign of dia- 

 monds being there too. This is particularly the case with a curiously 

 marked pebble that is streaked with a succession of parallel rings, 

 from which it has received the descriptive name of "banddoom" 

 (bandround). The specific gravity of the "banddoom" is almost 

 identical with that of the diamond, and, where the former is found, 

 experience has taught that the latter may be confidently expected. 

 Beautiful agates are also found in this deposit, as well as quartz-crys- 

 tals, jaspers, chalcedony, but few garnets, and no iron pyrites or carbon, 

 which occur so plentifully in the Kimberley mines. An assortment 

 of " river-stones " forms a very pretty collection, and it is conceivable 

 enough that, prior to the opening of the diggings, diamonds should 

 have been picked up by the natives and valued as more than ordinarily 

 pretty pebbles. The river-digging is, however, not very profitable in 

 the face of the large returns given by the Kimberley mines, and is 

 now relatively of but little importance. 



The whole number of claims in the four mines of Kimberley and 

 Beaconsfield is 3,238, covering about seventy acres of diamondiferous 

 gravel. The whole property is assessed at £5,172,975, or at the rate of 

 £75,000 per acre, and is divided among ninety-eight holders, forty-two 

 of whom are joint-stock companies, and the remaining fifty-six private 

 firms and individuals. The gross capital of the joint-stock companies, 

 which hold 2,211 claims, is returned at £7,970,490; and that of the 

 private holders is estimated at £1,624,900, making the gross capital of 

 the entire mines £9,595,390. The annual expenditure in labor, ma- 

 terial, etc., is not less than two million sterling, or ten million dollars. 

 It has been estimated, by the comparison of information from various 

 official sources, that the gross value of diamonds exported from the 

 Cape Colony up to the end of 1885, exclusive of such as were not 

 reported or were illicitly taken away, amounted to £35,000,000. The 

 total yield of diamonds from the Vaal River to date has probably 

 exceeded £2,000,000. 



