4 
G. F. Becker—Injfluence of Convection on Glaciation. 473 
Art. LVITI.—The influence of Convection on Glaciation; by 
Gro. F. Brecker. 
increase the accumulation of ice a it? In this form the 
question is one of great complexity, for it involves a knowledge 
h 
Sr understand Captain Dutton, he would reply to this 
latter question that the accumulation in each period would be 
the same, the whole excess of moisture of the warmer period 
falling as rain below the snow-line, His statement might have 
been made somewhat more broadly, for the same argument 
shows that upon his suppositions the precipitation above any 
isotherm is independent of the temperature at sea-level. If, for 
example, the characteristic temperature at sea-level in the cooler 
period were 10° and in the warmer period 20°, then the entire 
excess of moisture evaporated during the warmer period would 
*This Journal, vol. xxvii, p. 1. + This Journal, vol. xxvii, p. 167, 
Am. Jour. Scr.—Thirp Series, Vou. XXVIL. No. 162.—June, 1884, 
32 : 
