G. EF. Becker—Influence of Convection on Glaciation. 475 
If a comparison is made between a warmer and cooler period, 
the conditions otherwise being equal, it will not be denied by 
any one that the lower strata of the warmer atmosphere contain 
a greater absolute amount of moisture than the lower strata of 
must be a minute evaporation during their passage. It seems, 
however, hardly possible to maintain that this addition to the 
* Tt is of course supposed here that the sea-level temperature remains constant. 
