AMERICAN JOURNAL OF SCIENCE. 
[THIRD SERIES.] 
ABT, AIX On the Existence in both Hemispheres of a Dry Zone, 
and its cause; by ARNOLD GuYoT. 
(Read before the National Academy of Science, Nov., 1882.) 
the causes of these extraordinary variations. 
_ One of the general laws already recognized is that the quan- 
tity of rain, on the whole, decreases with the temperature, 
that is, from the equatorial belt toward the poles. This was to 
WwW 
xperiences a remarkable interruption a little beyond either 
tropic, where the quantity of rain is ee to a 
_ It we find the 
Jour. Scr.—Tarep Senies, Vor. XXVI, No. 153.—Surr., 1888. 
