Sciences of Meteorology and Terrestrial Magnetism. 179 



than on the Styehead Pass, distant a mile and a-half. Passing from 

 the sea level up the valleys ahove mentioned, the quantity of rain 

 increases rapidly, and at the heads of the valleys augments im- 

 mensely (Philosophical Transactions, 1849, Part II). Thus the quantity 

 is one-fourth greater at the head of Eskdale than in the middle of 

 the valley; at Ennerdale it is nearly double the amount at a farm 

 house three miles west. As the heads of the vallej's are reached, a few 

 hundred yards make a remarkable difference. The amount goes on 

 inci-easing up to 2,000 feet, and then begins to diminish, the air at this 

 altitude being about saturation ; getting colder upwards, it holds a less 

 tjuantity of vapour in solution. 



(22.) Not less remarkable are the prodigious quantities of rain which 

 have been recently ascertained to fall in some parts of India, exposed to 

 the full influence of the south-west Monsoon. The meteorology of India 

 is fully considered by Colonel Sykes, in a long paper in the Philosophi- 

 cal Transactions for 1S50, Part II. We have here only to consider the 

 rainfall. The amount annually deposited on the AVest Ghauts, against 

 which the warm winds, loaded with moisture, first impinge, is very great. 

 The quantity which falls at Cape Comorin — a low point — is very sUght ; 

 but a few miles north, where hills rise to 2,000 feet, it is 112 inches 

 annually. Colonel Sykes considers that the chief rain-bearing current 

 is seldom much higher than 2,000 feet ; for, standing on heights greater 

 than this, he has often seen the rain-clouds below ; but, when driven 

 by the west winds they strike against the steep wall-hke barrier 

 fronting in that direction, they rise to heights very much greater, and 

 suddenly cooled by the lofty summits rising above the general level of 

 the Kange, deposit a prodigious quantity. The maximum fall yet 

 recorded on the West Ghauts takes place at Uttray Mullay in Travan- 

 core, latitude 9"^, where the amount was 263 '21 inches, the mean of two 

 years. At Mahabuleshwar, latitude 18°, the rainfall was 254'84 inches, 

 the mean of fifteen years ; and of this quantity 134!'2 inches fell in the 

 month of July alone. The mountains here attain an elevation of 

 4,500 to 4,700 feet, 2,300 higher than the Deccan plateau inside the 

 Range. At places where valleys, or rather guUies, opening from the 

 low tract seaward, cut the Range deeply, the quantity is much less, 

 because the rain-clouds escape eastward across the Deccan, and deposit 

 their load of moisture gradually. The maximum fall he places at about 

 4,.500 feet ; the quantity above and below this plane being less. Thus 

 at different elevations on the Travancore Range, the quantities are as 

 follows:— At 500 feet, base of Range, 99 inches; at 2,200 feet, 170 

 inches ; at 4,500 feet, 250 inches ; at G,200 feet, 194 inches. The fall 

 at Bombay is 7608 inches, the mean of thirty years ; and at other 



