84 SCIENCE IN AFRICA 



measurements in a very satisfactory way. Since the cost of operat- 

 ing the resistivity method is neghgible compared with that of 

 drilhng, it is concluded that the savings from its use must be very 

 large. Mr. Shaw emphasizes that the success of the method in 

 locating underground water depends largely on the geological 

 interpretation of the electrical evidence by which the formations, 

 supposed to carry and yield water, may be discovered. Following 

 Mr. Shaw's work, the Irrigation Department of Southern Rhodesia 

 has carried out further electrical surveys for water, with most 

 encouraging results. 



The Department of Geophysics at Cambridge and a few other 

 centres have been actively pursuing geophysical research for 

 many years, but the facilities for training in the application of the 

 methods were restricted until the recent establishment of a School 

 of Applied Geophysics at the Imperial College of Science and 

 Technology in London. The geological departments of the Gold 

 Coast, Tanganyika, and Nyasaland, however, have already sent 

 members to London for periods of training. 



In Nigeria, where a member of the department. Dr. Tatham, 

 has studied the subject at the Colorado School of Mines, electrical 

 prospecting for water has been going on for several years. This 

 method has been used in Ijaw, Katsina and Owerri, and the last- 

 named province, where a programme of well-sinking based on the 

 geophysical survey has been put in hand, will provide a good 

 opportunity of testing the results of the electrical method. In the 

 Gold Coast, three members of the staff have received some training 

 in London, and experiments are being carried out to ascertain 

 the value of electrical methods as applied to local problems. Mag- 

 netic methods will also receive attention as soon as the necessary 

 instruments can be acquired. 



It is needless to devote much space to the merits of the divining- 

 rod and pendulum, which are believed by some exponents to be 

 capable of detecting not only water but also minerals and a variety 

 of other objects. There are scientific men who have put the methods 

 to the test and conclude that the successful diviner finds water by 

 a process of conscious or sub-conscious appreciation of topography 

 and geology, and that the activity of the actual rod is purely inci- 

 dental and of no significance; others hold that the diviner is a 



