60 TRANSACTIONS OF THE 
of these long wave radiations; and carbon dioxide and 
other constituents of the lower also absorbs them readily. 
The heat radiations do not escape readily from the earth 
and lower atmosphere then, but only step by step until they 
reach the diathermous layer, where the radiations are re- 
latively unimpeded. 
It is thought that the air in the upper inversion layer 
gets its heat by radiations from the earth and from the 
layer of water vapor. 
Now, the upper air is composed of part oxygen which 
absorbs a large part of the ultraviolet and a small part of 
the red. Besides causing heating, chemical and electrical 
effects are produced. The air there is ionized, and both 
ozone and nitrogen pentoxide are formed, and as ozone 
absorbs energy from a large portion of the spectrum the 
air there is heated both by radiations from the sun and also 
those from the water-vapor below which does not happen 
with the diathermous region as that is not rich in ozone. 
