TRANSACTIONS OF SECTION C. CiO 



Economics. 



While Geology Las been of direct scientific utility in topograpliy and geography 

 there is another domain, that ofEconomic Geology, which is entirely its own. The 

 application of Geology extends to every industry and occupation which has to do 

 -with our connexion with the earth on which we live. Agriculture, engineering, 

 the obtaining of the useful and precious metals, chemical substances, building 

 materials, and road metals, sanitary science, the winning and working of coal, iron, 

 oil, gas, and water, all these and many more pursuits are carried on the better if 

 founded on a knowledge of the structure of the earth's crust. Indeed a geological 

 man of this country, showing rocks, solid and superficial, of which no_ economic 

 use" could be made, would be nearly blank. Yet so much has_ this side of the 

 science been neglected of recent years that our only comprehensive text-books on 

 it are altogether out of date. 



But in teaching Geology as a technical science, or rather as one with technolo- 

 gical applications, one of the greatest difficulties before us is to steer between two 

 opposing schools, the so-called theoretical school and the practical school. 



There are those who say that there is but one geology, the theoretical, and that 

 a thorough knowledge of "this must be obtained by all those who intend to apply 

 the science. Others think that this is too much to ask— that the time available is 

 not sufficient — and that it is only necessary to teach so much of the subject as is 

 obviously germane to the question in hand. 



The best course appears to me to be the middle one between the two extremes. 

 If the engineer or miner, the water-finder or quarryman, has no knowledge of 

 principles, but only of such facts as appear to be required in the present posi- 

 tion of his profession, he will be incapable of making any improvement in his 

 methods so far as they depend upon geology. If, on the other hand, he is a purely 

 theoretical man without a detailed practical and working acquaintance with the 

 facts which specially concern him, he will be put down by his colleagues as un- 

 practical ; he will have to learn the facts as quickly as he can and buy his experi- 

 ence in the dearest market. 



It seems to me that there is certain common ground which must be acquired 

 by all types of professional men. The general petrograpkic character of the 

 common rocks, enough of their mode of origin to aid the memory, the principle of 

 order and age in the stratified rocks, the use of fossils and superposition as tests 

 of age, the nature of unconformities, the relation of structure to the form of the 

 ground, the occurrence of folds and faults, and above all the reading of maps and 

 sections, and sufficient field work to give confidence in the representation of 

 facts on maps — these things are required by everybody who makes any use of 

 geology in his daily life. 



But when so much has been acquired it should be possible to separate out the 

 students for more special treatment. The coal-miner will require especially a full 

 knowledge of the coal-bearing systems, not in our own islands merely, but all over 

 the world ; a special acquaintance with the eHects of folds and faults, and an 

 advanced training in the maps and sections of coal-bearing areas. The vein-miner 

 should be well up in faulting and all the geometrical problems associated with it, 

 and he should have an exhaustive acquaintance with the vein and metalliferous 

 minerals. 



The water engineer needs to know especially well the porous and impervious 

 rock types, the texture and composition of these rocks, the nature of their cements 

 and joints, and the distribution of water levels in them. Further, he must know 

 what there is to be known on the problems of permeability and absorption, the 

 relation of rain to supply, the changes undergone by water and the paths taken by 

 it on its route underground, and the varying nature of rocks in depth. He must 

 also understand the effects of folds and faults on drainage areas and on underground 

 watercourses, the special qualities of water-yielding rocks, of those forming the 

 foundation of reservoir sites, and those suitable for the construction of dams. 



The sanitary engineer will need to be acquainted with the same range of 



