GEOLOGY 85 



super-sensitive individual interpreting some unrecognized hygro- 

 scopic sense, and still others deny the possibility of divining on 

 general scientific principles. Divining is still employed in many 

 parts of Africa where European settlement and farming are well 

 established, but it has caused considerable disappointment and 

 waste of money. It is an occupation which allows ample scope for 

 charlatans, and the fact that the majority of diviners are ready to 

 ply their trade for absurdly small pay leads one to regard it with 

 suspicion. In addition to the human diviner, there are certain 

 instruments on the market with the same object in view. These 

 have been tested by scientists in several parts of Africa and in other 

 parts of the world, without success. The need to base methods of 

 water- and mineral-finding on irrefutable scientific principles is 

 an added reason for an increased study of geology and geophysics. 



GEOPHYSICS AND PALAEONTOLOGY 



There are certain other aspects of geology and geophysics which 

 it is easiest to regard as pure rather than applied science, but which, 

 nevertheless, have indirect bearing on development. In geophysics 

 there are the subjects of seismology, vulcanology, gravity, and ter- 

 restial magnetism, each of which has received some attention in 

 parts of Africa. In geology there is the vast subject of palaeontology 

 of which one branch deals with the interpretation of stratigraphy 

 and the age of rocks, and the rest is concerned more with under- 

 standing the evolution of organisms, including man. In this Africa 

 has already made very important contributions to knowledge. 

 This array of subjects merits at least a book in itself, but a few 

 points only are selected for mention below. 



Seismology is the recording and interpretation of earth move- 

 ments, and has been studied to a small extent. Seismographs are 

 installed and under continual observation at six places in Africa; 

 namely at Cairo, Dakar (maintained by the Meteorological Ser- 

 vice established in 1931), Lome in French Togoland, Accra in the 

 Gold Coast, Capetown, and Johannesburg. At Entebbe in Uganda 

 seismometers are also installed, but since 1931 observations have 

 had to be suspended owing to lack of staff. This was the only ob- 

 servation centre in the very important region of the rift valleys 



