594 REPORT— 1889. 



This shows that ore yielding only about 4 pennyweights of gold to the ton 

 leaves a net profit of one lialf of the gross yield. 



The mining laws of the Transvaal will not allow the miner to follow his vein 

 outside of his vertical lines. As the veins are more or less flat, the purchasers or 

 owners of mines should ascertain the extent of vein in the claims from the outcrop or 

 the point at which it enters until it leaves the claim by the side lines. This is a 

 very important factor in determining the value of the mines in this district, and has 

 heretofore been overlooked by purchasers. 



As yet nothing has been developed to indicate the depth to which the gold will 

 be found in pacing quantities. The present developed pay on the Main Reef has 

 been proved by actual work to be at least 30 miles long, with a very uniform yield 

 of gold and ore. It hardly seems possible that it will not be found to extend down 

 to a great depth. All indications so far developed are tJiat it will. 



The celebrated Oomstock mine of Nevada, United States, might well be called 

 a gold-mine, as the value of the bullion was and is about half gold. The richest 

 body of ore found there was at 1,500 feet vertical depth ; this deposit paid monthly 

 dividends of 432,000/. for several years. 



There have been a great many profitable deep gold-mines worked in the United 

 States and Australia, many being still in good pay. 



For several months past about 800 stamps have been crushing ore in this dis- 

 trict ; by the first of the year there will be probably more than double this number. 

 Say, 2,000 stamps will be at work, crushing 4,000 tons of ore and producing 3,000 

 ounces of gold xlaily, or 75,000 ounces per month. This number will have to be 

 very largely increased in order to crush in any reasonable time the ore already de- 

 veloped in the Main Reef veins, to say nothing of those required to work the ore 

 from the Black Reef, Zuur-Bult, Chimes, Botha, and other veins, that have been 

 proved already and profitably worked. 



In 1887 South Africa produced 2 per cent, of the total annual product of the 

 gold of the world — the author estimates that this year it will produce 7 per cent., 

 and next year over 15 per cent. ; this last amount will be increased proportionately 

 with the increase of additional machinery. 



This large increase in the annual production of gold may change the compara- 

 tive value between gold and silver, unless there be a corre.sponding increase in 

 the production of silver. Gold, probably, will depreciate and silver appreciate in 

 their comparative values. 



The author is aware that he is exposing himself to criticism by applying the 

 word ' basin ' to a goldfield, and estimating the yield of gold by the acre — in fact, he 

 criticised reports made in this manner before he visited this district ; but after ex- 

 amining it, and seeing how uniform the yield and thickness of the veins were, 

 and how closely they resembled coal formations, he decided that they should bo 

 estimated by the acre the same as coal. 



The author has examined closely all the principal gold and silver districts of 

 North and South America, but in no case has he seen anything approaching this 

 district in extent and uniformity of yield in ore and metal ; veins with almost 

 continuous and uniform pay for 25 miles in length being heretofore unknown in 

 mining. 



9. Third Report on the ' Manure *~Grravels of Wexford. 

 See Reports, p. 92. 



10. On Barium Sulphate, in Water-hox Deposits from the Durham Coal- 

 mine Waters and in Nottingham Sandstone. By Professor Frank 

 Clowes, D.Sc. 



At the Aberdeen meeting of the British Association I communicated a pre- 

 liminary notice of the occurrence at Bramcote, in the neighbourhood of Nottingham, 

 of red sandstone, the grains of which were found to be cemented together by barium 



