The vapor- 
carrying 
capacity of 
air. 
CHAPTER V 
RAIN AND SNOW 
In order to understand the phenomena of 
rain and snow we must consider for a mo- 
ment some facts established by the weather 
men. I have no notion of trenching upon the 
domain of the meteorologist. Indeed, I had 
thought to write a book that would suggest 
some of nature’s beauties rather than its bare 
facts, but I find it continually necessary to ex- 
plain beauty by first showing structural char- 
acter. 
The capacity of air for receiving and holding 
vapor depends upon temperature. It is small 
at low temperatures ; it is large at high tem- 
peratures. That is to say, the vapor-carrying 
capacity of a cubic foot of air is ten times as 
large at 100° Fahrenheit as at 32°. At either 
temperature, when the cubic foot has all the 
vapor it can carry, it is called ‘ saturated.” 
When more vapor is crowded in than the cubic 
foot can carry the result is condensation of the 
surplus into cloud and rain. Perhaps this can 
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