Physical Geography of Hindostan. 349 



east and south-west, which change their direction as the 

 sun passes the latitude of the place. On the Malabar Coast, 

 as the sun approaches from the southward, clouds and 

 variable winds attend him, and his transit northward is in a 

 week or ten days followed by that furious burst of thunder 

 and tempest which heralds the rainy season. His southward 

 transit is less distinctly marked ; it is the sign of approach- 

 ing fair weather, and is also attended by thunder and storm. 

 The alternating land and sea-breezes are occasioned by the 

 alternate heating and cooling of the soil, the temperature of 

 the sea remaining nearly uniform. At present, when most 

 powerfully felt, the earth by noon will often be found to have 

 attained a temperature of 120°, while the sea rarely rises 

 above 80°. The air, heated and expanded, of course ascends, 

 and draws from the sea a fresh supply to fill its room ; the 

 current thus generated constitutes the breeze. During the 

 night the earth often sinks to a temperature of 50° or 60°, 

 cooling the conterminous air, and condensing in the form 

 of dew, the moisture floating around. The sea is now from 

 15° to 20° warmer than the earth, — the greatest difference 

 between the two existing at sunrise ; and in then rushes the 

 air, and draws off a current from the shore. 



We have not noticed the Tides, which, obedient to the sun 

 and moon, daily convey two vast masses of water round the 

 globe, and which twice a month, rising to an unusual height, 

 visit elevations which otherwise are dry. During one-half of 

 the year the highest tides visit us by day the other half by 

 night : and at Bombay, at springs, the depths of the two dif- 

 fer by two or three feet from each other. The tides simply 

 rise and fall in the open ocean, to an elevation oP two or three 

 feet in all ; along our shores, and up gulfs and estuaries, 

 they sweep with the violence of a torrent, having a general 

 range of ten or twelve feet, — sometimes, as at Fundy in 

 America, at Brest and Milford Haven in Europe, to a height 

 of from forty to sixty feet. They sweep our shores from filth, 

 and purify our rivers and inlets, affording to the residents of 

 our islands and continents the benefit of a bi-diurnal ablution, 

 and giving health and freshness and purity wherever they 

 appear. Obedient to the influences of bodies many millions 



VOL. LVI. NO. CXII. — APRIL 1854. - 2 A 



