34 Scientific Proceedings, Royal Dublin Society. 



auriferous, and privately I have been interrogated to the same 

 effect. The supposition that at a given depth gold would be 

 found in comparatively great abundance is one that has received 

 some currency from the fact that certain reefs in Australia have 

 been worked with most profit at great depths. It is a supposition 

 which has proved very convenient for those companies which are as 

 yet unable to show any returns to shareholders for the large sums 

 of money which have been expended. 



Now, if we attempt to apply such an hypothesis to the region 

 in question, we find ourselves at once landed in a maze of absur- 

 dities. The only meaning that " depth" can have in this connexion 

 is the vertical distance downwards from the surface, which latter is, 

 in this particular case, a most variable datum, varying in level not 

 only by hundreds, but even by thousands of feet, since some of 

 the reefs are believed to be traceable from high elevations on the 

 Wynand plateau, 3000 feet above the sea, downwards to the low- 

 lying tracts at its foot.^ These differences in contour being mainly 

 due to subserial denudation, it stands to reason that a depth of, say 

 200 fathoms, on a reef referred to the sea-level standard, is a very 

 different thing when applied to. a mine on the top of a lofty plateau 

 to what it is when a mine at its foot is in question. 



Each mine, therefore, can only be discussed on its own merits, 

 and the outcome of all that has been done in the exploitation of 

 gold-bearing reefs may be expressed by a truism which carries 

 with it no hypothesis. It is simply this — that the richest part of a 

 reef is that which, when experimentally tried, contains most gold. 

 Similarly situated and neighbouring reefs may be found to exhibit 

 similar phenomena ; but to expect reefs situated at great distances 

 from one another, and at varied altitudes above sea level, to exhibit 

 any close resemblance in their characters, when mined to the deep, 

 is a manifest absurdity. 



Of the wide-spread distribution of auriferous rocks in certain 

 parts of India there can be no doubt ; and it is strange that we should 

 not yet, after three years, be in possession of more positive evidence 

 of their productiveness. Eighteen months ago I heard of cases of 

 managers of mines being pressed by their London directors to 

 push their works onwards to the deep, the natural conclusion being 



- King, Kecords of the Geological Survey of India, vol. viii., 1875, p. 36, 



