Distribution of Land and Water. 317 
to fall below that of the superincumbent air; the coldest stratum 
of the lower portions of the atmosphere being in contact with 
the ground, the equilibrium of those above is not so much dis- 
turbed. Yet, even in this case, causes exist which tend to pro- 
duee a series of actions and reactions between the upper and 
lower strata of air, by which a process of convection will 
t+ durin 
°ver Immense surfaces of ( 
trast to the southwesterly winds which at the same season trav- 
se the ocean 
€m which e writer, “cannot be solved 
* 
de Taylor's Scientific Memoirs, vol. ¥, pp- 458 and 530; and Annales de Chimie et 
Fees for February and April, igs. m5 
Metéorologie, French edit., p. 45. 
