Artesian Wells. 385 



Thai succeeded the period alluded to. as separating the older 

 from the younger rocks, and a glacial conglomerate was formed on or 

 near what seems to have been the shores of an inland sea. and, later, 

 through the immense space of time which stretches from the beginning 

 of the Carboniferous epoch through the Permian to the end of the 

 Triassic. this sea seems to have gradually filled up — the alternate 

 beds of sandstone and shale, full of fossil remains, pointing to long 

 continued deposition in shallow water and subsequent elevation. 



Intervals, when deposition ceased and was renewed under 

 different conditions, have divided this great mass of strata. 6.000 

 feet thick, into three well-defined series, and these have been named 

 after the places or districts in which they have been found tvpically 

 developed. The first after the Dwyka or glacial conglomerate is 

 called Ecca Beds, forming the Central Karroo, the next Karroo Beds 

 covering the Northern Karroo, and the third, spreading over the 

 Eastern Upland. Stormberg Beds. 



Excepting Bechuanaland. where there are series of rocks whose 

 relations with those in this Colony and in the Transvaal have not yet 

 been studied and defined, these eight groups of strata form the great 

 bulk of the part of the Continent called Cape Colony, which, save 

 small areas in the Southern portion of the Colony covered with 

 deposits in seas of Jurassic and more recent times, has been dry land 

 since the middle of the Mezozoic period ; that is to say, that while the 

 greater {)art of Europe, including Great Britain, and much of North 

 America, w^ere under the ocean, and the Cretaceous and Tertiary^ 

 systems of the Northern Hemisphere were in the process of forming, 

 South Africa was drv land. 



RAINFALL. 



Whatever the climate may have been like in ages gone bv. the 

 Colony, except the country near the Southern Coast and the Trans- 

 keian Territories, does not in these days enjoy sufficient rainfall to 

 make the excellent soil, which it generally possesses, productive. 

 This dr\ness is most accentuated in the North- Western areas — in fact, 

 the district near where the Orange River enters the Atlantic Ocean 

 is almost rainless — and the rainfall increases from West to East across 

 the Colon V. save in the South-West comer. A series of observations, 

 extending (-jxer many years, have been taken all over the Colony by 

 the Meteorological Cop'mission. K-hich most useful work renders it 

 possible to map out .he areas of country over which different 

 quantities of rain f?^';. 



From these duca. to give an idea of the relative dryness, it mav 

 be roughly stated that over half the Colony — which includes the 

 Northern and Central Karroos, the North- Western Coast, and a por- 

 tion of Bechuanaland — the rainfall is less than 10 inches annually; 

 over a third, which takes in the Southern Karroo, the Eastern Uplands, 

 and the rest of Bechuanaland. it is between 10 and 20 inches; and 

 onlv over the remaining sixth, consisting of the Cape Peninsula, part 



