"14 Professor Seeley. — Some Scientific [Sept. 6, 



the intrusive sheets of lava, in which, in some instances, substantial 

 traces of gold were found, and this led us to the thought of whether 

 it would not be a matter of the greatest importance to survey the 

 whole of the sheets throughout the country, so as to ascertain which 

 are really valuable, and capable of mineral wealth, and which are 

 worth marking off so as to be avoided. 



Now our studies of gold led us to travel over a great deal 

 of country which was badly in want of water. I am sorry to 

 say that not only was the land impoverished for want of water, 

 as very much of the land we traversed frequently had had no 

 rain upon its surface for something like a year, and when after this 

 long period rain came, frequently periods approximately from threequar- 

 ters of a year or more would pass without rain again, yet I could not but 

 reflect that there were two or three things to be borne in mind in 

 relation to the geological structure of the country. In the obser- 

 vations which we had made much might be properly utilised by means 

 of a geological survey of the country, which would be of greatest 

 value. For example, wherever rocks are folded in the manner in 

 which we found them to be folded in anticlinal and synclinal folds 

 over the whole of the land every basin of this sort necessarily absorbs the 

 rain which falls upon the edges of the rock ; water, then, is stored beneath 

 the surface, and yet there is none at all upon the surface of the land 

 itself. The rocks beneath the surface are as full of water as they can 

 hold, and while the cattle on the farms are dying for want of water 

 while the land is parched up so, yet there is water in abundance 

 beneath the surface. This is pretty well-known to every geologist 

 all over the world, and I may mention that the Government of 

 Victoria, in Australia, have for a long time past made maps, in which 

 they have marked down every well which was known in the Colony, 

 for Victoria has a climate not altogether unlike your own, as the 

 evaporation is greatly in excess of the rainfall, and the water under 

 the ground has to be utilized, and so borings are made. The 

 structure of the country makes it desirable to undertake such work, 

 and when such a survey of this country is made, then every farmer will 

 readily appreciate the position in which, the structure of the country 

 enables him to relieve his pressing necessities by tapping these 

 springs. There is another source of water supply which Mr. Bain 

 fully appreciated by observing the conditions of irrigation, which I 

 may say he was ever alive to as we journeyed over the country, and 

 that is the fact of these intrusive sheets of rock which you may see all 

 all over the country, acting as a natural dam, a subterrannean dam, so 

 that if you have all the rocks possessing this common feature of contour, 

 horizontally, if you have an intrusive sheet of lava making its course to 

 the east, it is perfectly clear that all the rains which fall upon these rocks 



