The Author's method of leak detecting had its merit therein that under certain conditions it enabled smaller leaks to be located where other analytic methods might not yield results. The writer thought that the statement enables large leaks to be located under Conclusions was misleading. Larger leaks and breaks could be readily located by water hammer methods (vide Rouse, Engineering Hydraulics, p. 482), where a pressure surge was caused to travel in the pipe-line by the rapid closure of a solenoid valve against a convenient flow rate.
Water from boreholes was so important to South Africa that, in many districts, such water was a sine qua non: Appreciation was due to the Author for his contribution to a subject which was known to be abundantly full of problems. This discussion pertains to those formations only, from which it was desirable to obtain as much water as could be found by means of jumper (percussion) drilling. Such formations were divers sedimentary deposits, bedded sandstones and shales, detrital pebbly gravels, conglomerates, granites, dolerites and basic rocks of the basalt family.