Vol. XIX.J 
[Part I. 
PROCEEDINGS 
OF THE 
YORKSHIRE GEOLOGICAL SOCIETY. 
Edited by W. LOWER CARTER, M.A., F.G.S. 
1914. 
some remarks ox geology ix relation' to the exact sciexces, 
with ax excursus ox geological time. 
by alfred harker, m.a,. f.r.s., f.g.s. , 
presidext of the yorkshire geological society. 
(Address Delivered 21st November, 1912). 
Although the constitution of this Society enjoins us to confine 
our serious labours to a definite geographical field, it may still, I 
hope, be permissible upon occasion to vary the programme by dis- 
cussing some general geological question or some particular aspect 
of the science. Assuming this liberty, I propose to offer a few remarks 
on the subject of geology in its relation to the exact sciences. 
I take it as undisputed that, in the rough classification which 
serves the purpose of his catalogues, the book-seller is justified in 
ranking geology with the descriptive," not with the " exact " 
sciences. We are nevertheless free to inquire to what extent the 
quantitative element may legitimately enter to strengthen geological 
methods and add precision to the results. Connected with this 
question is another, perhaps more elusive but certainly more funda- 
mental : to what extent, and with what precautions, can the geologist 
admit deductive reasoning into his discussions ? 
