PERIODICAL WINDS. 
123 
toward tlie land. During the night the sea is warmer 
than the land, because it cools more slowly, and hence 
the wind is reversed. The wind blowing off the sea 
is known as a sea breeze, and that off the land as a 
land breeze. For the same reason currents of air 
may exchange between a forest or grass-covered plain 
and an arid region. 
The ‘‘ sirocco ” of Algiers and Italy and the “ so- 
lano” of Spain are hot, tiresome winds which have 
blown off the deserts of I^orth Africa across the 
Mediterranean to the Alps. They have such a wear¬ 
ing effect on both man and beast that the Spaniards 
have a proverb, “ Ask no favor during the solano.” 
These winds usually come in the van of cyclones. 
There are many other disturbances of this charac¬ 
ter in different parts of the world. They have re¬ 
ceived local names; some of them are interesting, 
as the United States “ blizzard,” the Texan “ norther ” 
(Fig. 62), the southerly bursters ” of Australia, the 
“pampero” of Mexico and the Argentine Republic, 
and the “mistral” of southeast France. These usu¬ 
ally come in as the tail of the cyclone. The mon¬ 
soons are nothing but exaggerated sea breezes which 
blow off the Indian Ocean across southern Asia during 
the season when the land is much heated by a torrid 
sun. The monsoons are sO strong that they interrupt 
the trade-wind on the Indian Ocean. Mountains and 
valleys, forests, plains, lakes, each has a disturbing 
influence on the regular flow of the air currents. 
