78 SECTIONAL ADDRESSES. 



the geologist has a good deal to do with it, especially where the question of 

 dam-building and reservoir-formation is concerned. 



For the construction of a dam, and the formation of a reservoir for 

 hydro-electric purposes, it is of great importance to know the geology of 

 the area and the nature of the rocks, whether soluble (as limestones) or 

 insoluble ; porous and brittle, or impervious and firm, and all the variations 

 between ; their normal or faulted condition ; their disposition, strike and 

 dip, the latter against or with the direction of the current. 



The geologist has to help the engineer not only with regard to the 

 suitability of the rocks at the site of the dam, but also in the whole of the 

 area to be occupied by the proposed reservoir. As before mentioned, 

 where a young colony has no special department and wishes to gather 

 information respecting such water-power, it has to get help from another 

 department. What more natural than that this should come from the 

 geologist 1 



Sanitation . — Under the usual conditions for the disposal of nightsoil by 

 burial in depots in the neighbourhood, where there is no proper sewerage 

 or sterilisation system, the geological survey is able to help very con- 

 siderably in the question of sanitation. 



The glaring lack of consideration of this question, shown not infre- 

 ■quently, is a menace to the health of the people. There is an example 

 known to me where all the nightsoil from a large town was buried on the 

 ridge at the head of a valley in permeable soil, a valley in which were 

 several wells from which the people were obtaining supplies of drinking 

 water. The risk being run by using this water is illustrated by the case 

 brought under notice some years ago on the Continent. In this the cause 

 of an outbreak of typhoid fever could not be determined until a geologist 

 said it was probably due to a nightsoil depot on the side of a ridge, several 

 hundred yards distant from a spring on the opposite side of that ridge. 

 He was laughed to scorn. But, by pouring water, stained with a permanent 

 dye, on the depot he proved that the spring was taking the drainage from 

 it. The geologist showed by scientific observation of the strata, that the 

 beds were dipping through the ridge from the depot towards the spring. 



All work of this kind should have the inspection of a geologist before 

 anjrfching is done ; similarly, the sinking of wells in and near a town should 

 be subject to his approval. 



Military Training. — It may seem strange to say that geology can be 

 useful to military science, but modern warfare has shown that to be the 

 case. Prof. W. W. Watts, in his Presidential Address before this section 

 at Toronto in 1924, has brought this clearly before us. He says, ' It will 

 be readily admitted that geology has been of conspicuous service in 

 connection with military operations in such ways as the siting of camps, 

 trenches and dug-outs ; while the minute study of the water-table in 

 Northern France during the late war was not only of value in obtaining 

 water supplies, but was of conspicuous utility in mining and counter-mining.' 



Something can be said for geology in Africa in this connection. Military 

 training and manoeuvres are aided by a knowledge of the nature of the 

 soil and underlying rocks, and of water supply. Country embracing all 

 types from open to forest-capped plains, rises, hills and valleys, preferably 

 in uninhabited or sparsely populated areas, are required for these opera- 



