Notices of Memoirs — Geological Society of South Africa. 367 



in Africa, Mr. A. G. Bain, Mr. Wylie, and Mr. Stow, had opened 

 the way to the solving of many interesting- problems, such as the 

 origin of the great bed of breccia crossing the continent, known as 

 the Ecca, or Dwyka Conglomerate, and the formation of the great 

 valleys dividing the wide areas of Karoo strata, some of the latter 

 comprising rich Diamond-fields and valuable Coal-fields. Still 

 further, the consideration of the nature and origin of the backbone 

 of the Cape country and the Transvaal, whether granitic or quartzitic, 

 often highly auriferous, offer grand opportunities for geological ex- 

 planation and discussion. Nothing in the known world approaches 

 the banket reef of Witwatersrand, either in the area of country 

 through which it extends, or the average uniforniity in its mineral 

 richness. If we consider that within the past twelve months there 

 has been an output of gohl to the value of seven millions sterling, 

 and when we see from the working of new companies, and from 

 the more scientific methods of treating the ores, that this output is 

 steadily increasing, we may feel confident that these gold-fields form 

 a centre to which the whole civilized world is looking with profound 

 admiration and eager expectation. 



"But there is another factor in connection with the gold-mining 

 industry which we accept too readily as a matter of course, and that 

 is the coal supply, not considering the utter impossibility of working 

 the mines without the steam-power generated by coal ; since the 

 supply of wood for fuel (which was used in the early days of the 

 Rand) not only failed to keep pace with the growing demand, but 

 by its great expense stopped the development of the poorer mines, 

 and threatened to render the cost of production in the richer mines 

 greater than the value of the gold obtained. So far back as 1854 

 Dr. Sutherland directed attention to the existence of coal in Natal. 

 Mr. Dunn's observations, made on behalf of the Colonial Govern- 

 ment, were published in 1879, the chief results of which consisted 

 in establishing the relation of the Ecca beds and Karoo series to the 

 coal-seams of the Cape Colony. Indeed, up to 1883, so little had 

 been done by way of proving the existence of workable coal-seams 

 that Professor Green, in his Report to the Colonial Government, 

 recommended that ' suitable rewards should be offered for the 

 discovery of coal as likely to be attended with useful results.' 

 Active search has resulted in discovering the existence of coal at 

 various points over a wide extent of country. It is, of course, of the 

 highest importance that coal should be free-burning and have the 

 jDroperty of giving ont heat ; and these qualities are acknowledged 

 to have been deficient in the coal obtained from seams first opened 

 out in the colony. Professor Rupert Jones has summarized the 

 reports of Mr. Dunn, Mr. North, Professor A. H. Green, and others, 

 who all agree in attributing the deposits of coal to vegetable matter 

 subsiding in fresh-water lakes. The absence of marine fossils was 

 also noted by each observer. Subsequent flooding of such lakes 

 by currents bearing sand and mud would account for the shales 

 with which the coal is so plentifully interstratitied. Evidence of 

 the coal having been formed from drift vegetation lies in the 



