SURVEYS AND MAPS 53 



Office, the scale in each case being i :2, 000,000. The best map, 

 on 1 : 1 ,000,000, was produced in 1 934-7 by the Instituto Geografico 

 Mihtare, covering all Abyssinia. The frontier areas are also well 

 covered by the series of the adjoining countries. 



Portuguese Colonies 



Angola is mapped by the Ministerio das Golonias, Lisbon, 

 1:1,500,000 being the scale adopted. 



Mozambique is mapped by the same authority. Three Inter- 

 national 1:1,000,000 sheets have appeared, but the best map is 

 by the Direcgao dos Servigos de Agrimensura, Lourengo Marques, 

 on 1 : 1,000,000. 



Portuguese Guinea is mapped on i : 500,000 by the Ministerio das 

 Colonias. 



Spanish 



For Morocco maps from 1:1,000,000 to 1:100,000 of part or the 

 whole of the territory exist, and a new i :50,ooo topographic series 

 is in rapid production. 



Rio de Oro, Ifni, and Spanish Guinea are indifferently surveyed. 

 The best maps are made by the Madrid Geographical Society. 



Liberia 



The maps of this State are not much more than skeleton in form. 

 The latest, called a preliminary base map, is published by the 

 Department of State, Monrovia, on i :6oo,ooo. 



AIR SURVEY 



Recent development in air survey has led many to suggest that 

 in it lies an obvious solution to the problem of mapping the 

 enormous unsurveyed areas of Africa, and much enthusiasm has 

 been expressed at the rapidity with which results have been 

 achieved. On the other hand some authorities, while appreciating 

 the great value that air survey can render in certain special cir- 

 cumstances, consider that general mapping programmes can be 

 carried out more efficiently and more economically by the well- 

 tested methods of ground survey. In order to appreciate air survey 



