2 ©. EF. Dutton—Lfect of a warmer Climate upon Glaciers. 
tions would be required by the other seals or even whether 
any such modifications were at all necessary. conspicuous 
instance cf this faulty method is furnished by those who argue 
that in order to account for more extended glaciers than we 
now have we must infer that a more copious snowfall prevailed 
in the Glacial period; that to provide this more copious snow- 
fall we must infer that the air was more moist, the evaporation 
greater and o temperature of the atmosphere at large higher 
than now; in brief, that the climate of the earth was then 
warmer thnk: a present : probably by reason of a greater rate 
of solar radiation. The questions which this hypothesis raises 
are much more limited and less complex than those brought 
up by other theories of a glacial climate, though even core the 
complexity is considerable. I believe that it can be brought 
late In that conviction the following argument is sub- 
mitt te 
will question the assumption that a warmer climate will 
increase the annual liquefaction and evaporation. It remains 
to inquire whether it will also increase the snowfall; and 
increase it to an extent which shall more than compensate the 
increased dissipation 
Se ) It is sufliciently obvious that the amount of snowfall in 
mount of ‘sn nowfall, and the question is fie resolved into the 
vd beldiary ones: Ist, will a warmer climate canse in any local- 
ity any increment in the time of snow precipitation in an av- 
erage year; 2d, will it cause any increase in the average rate? 
These will, so far as practicable, be considered separately. It 
will be most convenient to examine. first, the rate of precipita- 
tion. But before doing so it will be well to advert to two or 
three familiar but most essential facts. They are truisms, 
never otherwise. If the two limiting temperatures between 
which cooling takes place are both above zero (centigrade) the q 
