2 S. &. EMMONS 
As a rule, however, these mountains do not reach above the level 
of the high plateau, which forms an abrupt escarpment near or 
behind them, and slopes away gently toward the interior. Thus 
the drainage of the plateau region from within 100 miles or less 
of the east coast flows westward through the various tributaries of 
the Orange River into the Atlantic Ocean. The country is yet 
too new and too little explored by geologists to afford certain 
data for a physical description founded on its previous geological 
history, such as would be given by a physical geographer of the 
present school like our William M. Davis, but it is evident that 
the region presents a most interesting and fruitful field for this 
line of study. From what has already been written it is easy to 
make the preliminary deduction that the coast belt, like the east 
coast of Lower California, shows an older topography that has 
been exposed by the denudation of the more recent formations 
that constitute the plateau regions. 
Development.—The general advance of exploration, coloniza- 
tion and civilization has moved eastward and northward, instead 
of westward as with us. From the older settlements of the Cape 
1891. L. DE LauNnAy: Les mines d’or du Transvaal. Ann. des Mines, Serie 8 
Tome XIX., p. 102. 
1892. Watcor Gipson: Geology of Gold-bearing and Associated Rocks of 
the Southern Transvaal. Quar. Jour., XLVIIIL., pp. 404-437. 
_ 1894. G. A. F. MOLENGRAAF: Geologie der Umgegend der Gold-felder in Siid- 
Afrika. Neues Jahrb. f. Miner, etc., Beilage Bd. IX., p. 175. 
1894. BERGRATH SCHMEISSER: Ueber Vorkommen und Gewinnung der nutz- 
baren Mineralien in den Stid-Afrikanischen Republik. D. Reimer, Berlin, 1894. 
1894. A. PELIKAN: Goldfiihrendes Conglomerat von Witwatersrand. K. K. 
Reichsanstalt, No. 16, December 18, 1894, p. 421. 
1895. F.H. HatcuH and J. A. CHALMERS: Gold Mines of the Rand. Mac- 
millan & Co., New York and London, 1895. 
Among geologists who have written in earlier times upon the geology of the 
southern portion of Africa, but not directly upon the South African republic, may be 
mentioned A. G. BAIN (Quar. Jour., 1845), R. N. RuBIDGE (Quar. Jour., 1854-6), 
ANDREW WYLEY (1857-8), G. W. Stow and C. L. GRIEsBACH (Quar. Jour., 1870), 
E. J. DuNN, On Diamonds (Ouar. Jour., 1874, 1877 and 1881), W. H. PENNING, On 
Coal (Quar. Jour., 1884), MOULLE (Ann. des Mines, 1885), E. COHEN (Neu. Jahrb., 1887). 
The only geological map of South Africa is one made by E. J. Dunn, as Geologist 
of the Government of Cape Colony, and published in 1887. This covers most of the 
South African republic, but has no topographic base, and its geological outlines in the 
more northern portions are very sketchy. 
