128 , THE WORLD. 



during its past existence, we shall have occasion to refer to their 

 agency ; no power can resist the combined action of winds and 

 waves. Hurricanes and high winds are generally characterized by 

 a whirling motion producing the phenomena called whirlwinds, 

 these often exhibit the most incredible power,- uprooting huge 

 trees, and whirling their dismembered fragments into the air, 

 unroofing houses, and even raising aloft animals, and heavy carts. 

 The great gales of the ocean manifestly exhibit more or less of 

 this rotary motion. Such are the the hurricanes whioh annually 

 sweep over the Indian seas and along the Atlantic coast. 



Our limits will not permit us to be very extended upon this sub- 

 ject, and we shall therefore briefly notice some of the more pecu- 

 liar winds, and we commence with the land and sea breezes. 

 These are occasionally met with in every latitude, but are con- 

 stantly observed near the shores of the continent, and of the lar- 

 ger islands within the tropics. In these sultry regions, as the 

 day advances, a refreshing wind blows from the sea, and is suc- 

 ceeded by an opposite current from the interior of the land on the 

 approach of evening. The cause of these diurnal winds is obvi- 

 ous. The change of temperature between the night and day on 

 land often varies more than 40 or 50 Fahr., while at the same 

 time on the water it seldom varies more than 1 or 2. The 

 large body of heated air over the land, rising continually during 

 the day, a denser and colder portion rushes in from over the wa-" 

 ter to supply its place, causing the sea breeze. During the night 

 the ground cools much more rapidly than the water, and the lower 

 stratum of atmosphere thus soon becomes colder than at sea, 

 consequently a stream of air thus flows toward the sea, displacing 

 the lighter and warmer air, producing the land breeze. This breeze 

 is never as powerful as the sea breeze, but is much colder. Every 

 oij.3 who is familiar with these breezes must have noticed the pe- 

 riod of peculiar languor and depression, between the change from 

 the sea to the land breeze. 



Dr. Robinson mentions an experiment which illustrates the 

 cause of land and sea breezes very prettily. If we place a hot 

 stone in a room, and hold near it a candle just extinguished, w r e 

 will see the smoke move toward the stone, and then ascend up 



