INTRODUCTION. 



35 



Waterspout. 



\ 1 . Lund and Sea Breezes. There is another Idnd of periodical winds, common on islands 

 and coasts in tropical countries. During the day, when the air over the land is heated by the 

 sun, a cool bi-eeze sets in from the sea; this blows from about 10 A. M. to 6 P. M. At ni_^ht, 

 on the contrary, a land-breeze prevails, that is, the wind sets off from the land till about 8 

 A. M., when it dies away. 



12. Hurricanes, Whirlwinds, Waterspouts, &c. Hurricanes are violent storms of wmd, 



blowing with great fury, often from 

 opposite points of the compass, 

 and causing dreadful devastations. 

 They are rare beyond the tropics. 

 Whirlwinds are sometimes caused 

 by two winds meeting, each from 

 diflerent directions, and then turn- 

 ing rapidly round upon a centre ; 

 and sometimes by the form of 

 mountains, which occasions gusts 

 of wind to descend with a spiral 

 or whirling motion. Waterspouts 

 which are met with at sea, and are 

 dangerous to ships, have been sup- 

 posed to be formed by the raising 

 up of water from the sea by whirl- 

 winds. This opinion, however, 

 seems to be doubtful ; for accord- 

 ing to some observers, the water 



discharged on the bursting of a waterspout is always fresh, and therefore must have passed into 

 the air in the form of vapor. The simoom of the desert of Sahara, the samiel of the Arabian 

 deserts, the chamseen of Egypt, and the harmattan of Guinea, the soJano of Spain, the sirocco 

 of Italy, and the northwest wind of New South Wales, are noxious, hot winds, some of which 

 merely produce languor, while others, if admitted into the lungs, cause suffocation. 



13. Clouds. Every part of the land and water is constantly imparting to the atmosphere 

 portions of its substance, in the form of vapor. This is condensed by cold, and formed into 

 mists and clouds. In ascending to the summits of high mountains, the traveller sometimes passes 

 through a zone of clouds, and beholds the extensive vapors of which it is composed stretched 

 under his feet, like a vast plain covered with snow. He will, however, discover other clouds 

 far above the tops of the loftiest peaks. There is na part of nature which more adorns the 

 universe than the clouds. The beauty of their various tints, the variety of their forms, the 

 sublimity of their masses, the grandeur of their movements, are all calculated to afl'ect the 

 imagination, and direct the attention to their great Author. 



The utility of the clouds is no less obvious than their beauty. They scatter over the land 

 the dew, rain, snow, and hail ; all of which contribute to refresh and fertilize the earth. We 

 observe all nature to languish, when the clouds retain their stores too long ; plants fade and 

 droop ; animals feel their strength failing them ; man himself, breathing nothing but dust, can 

 with difficulty procure shelter from the sultry heat, by which his frame is ))aiched and overpow- 

 ered. No sooner has the water fallen from the clouds, than all living things begin to revive, 

 the fields resume their green attire, the flowers their lively tints, animals the sportive freedom 

 of their motions, and the elements of the air their healthful equilibrium. 



The association of certain forms of clouds with the state of the weather has long been ob- 

 served, and meteorologists have divided them into seven species : 1 The cirrus, resembling a 

 lock of hair or a feather ; it is high and indicates a breeze ; 2. The cumulus, a dense cloud 

 nearer the earth, the prognostic of settled weather ; 3. The stratus, a low, continuous, level 

 sheet of cloud, indicative of serene weather ; 4. The cirro-cumulus consists of dense rounded 

 masses, at different heights, also a sign of fine weather ; 5. The cirro-stratus is long and nar- 

 row, but changeable, often high, but descends to the earth as a soaking dense mist ; when 

 stationary it indicates rain or snow ; 6. The cumulo-stratus, in which the cumulus is mixed 

 with the cirro-stratus or cirro-cumulus ; the thunder-cloud is of this species ; 7. The nimbus 

 is a shower seen in profile ; the thunder-cloud, on discharging its electricity, generally passes 

 into the nimbus. 



