T. S. Hunt on the Earth’s Climate in Paleozoic Times. 397 
represented by 70 or 80. Air saturated with moisture at the 
ordinary temperature absorbs more than five hundredths of the 
heat radiated from a metallic vessel filled with boiling water, 
and T'yndall calculates that, of the heat radiated from the earth’s 
surface warmed by the sun’s rays, one-tenth is intercepted by the 
aqueous vapor within ten feet of the surface. Hence the power- 
ful influence of moist air upon the climate of the globe.’ Like 
a covering of glass, it allows the sun’s rays to reach the earth, 
but prevents to a great extent the loss by radiation of the heat 
thus communicate , 
greatly to produce the elevated big eden that prevailed at 
carbon which was afterwards condensed in the forms of coal and 
surrounding the earth, and pee. it like a dome of glass, 
To this effect of carbonic acid it is possible that other gases may 
absorptive power, have very well aided to maintain at the earth’s 
ce that 
Montreal, August Ist, 1863. 
