C. FE. Dutton—Lffect of a warmer Climate upon Glaciers. 5 
There is no doubt that the faster saturated air is supplied to a 
locality where it is cooled the faster (ceteris paribus) the rain or 
snow will fall. But the ratio of increment of wind velocity to 
increment of precipitation is not a simple one. It will be given 
farther on. Just here we are merely concerned with the 
inquiry, How would this air-supply or wind-velocity be affected 
y a warmer climate? Would it be increased? and, if so, in 
what ratio? Undoubtedly it would be increased. As regards 
the ratio, an answer will be attempted presently. The velocity 
of the wind is intimately associated with the second factor, rate 
of cooling, and it is first necessary to have the entire range of 
facts before us so as to dispose of the matter in its entirety. 
(8.) Let us, then, consider the second factor which affects the 
rate of precipitation, viz: the rate at which air cools; and let 
us afterwards inquire how it would be affected by a change of 
climate consequent upon increased solar radiation, There are 
four known ways in which the cooling of air oceurs: (1) by the 
work done in expansion; (2) by contact with colder surfaces ; 
(3) by commingling with colder air bodies; (4) by excess of 
radiation over absorption of heat. 
-) A moment's reflection will convince us that the first 
three modes of cooling are dependent altogether upon move- 
ment, and, therefore, velocity. The rates of expansion, contact 
unequally at any instant upon different places. It falls une 
Statical equilibrium of the air; and further consequent is the 
rush of air to find a new equilibrium. Any disturbance of a 
