62 
Transactio7is of the Boyal Society of South Africa. 
ment was directed towards the reduction of the Government boring 
estabhshment and the encouragement of private boring contractors — 
the general object being the gradual cessation and final abolition of 
Government aid. 
In 1910 the Government boring establishment was finally abolished, 
and the flourishing private boring industry that had sprung up was left 
to carry on the work on commercial lines. Information regarding the 
progress of boring since that date has necessarily become scanty and 
largely unreliable, as the detailed records are no longer filed in public 
of&ces. 
The general results of the work of the Government drills from 1893 up 
to the beginning of 1910 are summarised in the Annual Report of the 
Public Works Department for 1909-10 as follows : — 
Total number of holes bored by Govern- 
ment drills 5,596 holes 
Total number of feet bored 405,355 feet 
Number of holes in which water was found ... 4,326 holes 
Number of holes yielding over 1,000 galls. 
per diem 3,856 holes 
Estimated total yield of artesian or " flowing " 
water 18,663,944 galls, per day 
Estimated total yield of subartesian water 
rising to within pumping reach 35,498,775 galls, per day 
Estimated total yield of all holes 54,162,719 galls, per day 
It will be seen from the first two lines that the average depth of these holes 
is only 72 feet, and as a matter of fact very few holes of over 500 feet 
have been made in Cape Colony. The few deeper holes have in most 
cases been unsuccessful. In the selection of sites for the boreholes 
various considerations have prevailed. The convenience of the farmer 
has often been the dominant consideration. In many cases a dowser " 
has been employed by the farmer to select sites. In many other cases 
(probably about 50 per cent, of the whole) the farmer has left the selec- 
tion of the sites to the Government official in charge of the drill. These 
drill foremen all obtained a little elementary instruction in geology mainly 
directed to enable them to recognise and trace the dolerite dykes which 
play an important role in the Karroo System, and they were instructed to 
avoid boring in dolerite but to select sites if possible within a few hundred 
yards of a dolerite dyke. This principle probably guided the majority of 
their selections. 
The statistics published by the Chief Inspector of Water-Boring show 
that in general about 75 per cent, of the holes bored in the Karroo System 
