110 



DR MILLER ON THE METEOROLOGY OF 



a mountain, as 2000 feet, is lower, and the condensation and precipitation of the 

 warm oceanic vapour will be more rapid and copious, than at an equal height in 

 the surrounding atmosphere. 



On the other hand, when a Pluviometer is merely removed from a lower to a 

 higher position in the atmosphere, as from the bottom to the top of a building, the 

 quantity of rain is found to diminish with the elevation. Thus, the gauge on the 

 tower of St James's Church, Whitehaven, on an average of 10 years, has received 

 12-1 inches, or 28 per cent, less rain than a precisely similar instrument stationed 

 in a garden, near to and on the same level with the base of the building. 



The explanation seems to be, that as in most heavy and continuous rains, the 

 whole atmosphere up to a great height is charged with and precipitates vapour, 

 the drops are enlarged by accretion after leaving the summit of the tower. It is 

 only during heavy showers, when the drops are formed at a great altitude, that 

 the upper gauge is in excess. In this case, the drops have probably been sub- 

 jected to evaporation in passing through the comparatively warm and dry stratum 

 of air intervening between the two instruments. 



Among the mountain chains of the Indian Peninsula, Colonel Sykes finds the 

 maximum fall of rain at 4500 feet, and that above this level the supply is 

 diminished. The following tables and remarks are extracted from Colonel Sykes's 

 valuable " Discussion of Meteorological Observations taken in India," published 

 in the Philosophical Transactions, Part ii., for 1850. 



Fall of Rain at various Heights in India. (Western Coast.) 



Inches. 



Mean of Seven Stations on Western Coast, at Sea level, . . 81-70 



At 150 feet, Rutnagherry, in the Konkun, .... 114*55 



900 ... Dapoolee, Southern Konkun, .... 134-96 



1740 ... Kundalla, the Pass from Bombay to Poona, . . 141-59 



4500 ... Mahabuleshwur, mean of 15 years, . . . 254-05 



4500 ... Mercara, in Coorg, mean of 3 years, . . . 143-35 



4500 ... Uttray Mullay, Travancore, mean of 2 years, . 263-21 



6100 ... Kotergherry, on the Neelgherries, 1 year, . . 81*71 



8640 ... Dodabetta, highest point of Western India, 1 year, . 101-24 



Uttray Mullay Range — for 1849. 



Inches. 



99 



170 

 250 

 194 



At 500 feet, Base of range, ...... 



... 2200 ... Attagherry, ...... 



... 4500 ... Uttray Mullay, ...... 



...6200 ... Agusta Peak ...... 



Shewing at 6200 feet, 46 inches less rain than at 4500 feet.* 



[The greatest depth at Mahabuleshwur in 21 years, was 338-38 inches, in 1849; 



* From returns recently published by Dr Buist of Bombay, it appears that in Eastern India 

 also, the maximum deposit of rain is found at 4500 feet, at which elevation, the annual quantity 

 amounts (at Cheerapoong) to no less than 610 inches ! ! At Sylhet, 5000 feet above sea level, the 

 fall is 209 inches ; and, at Darjeeling, at 7000 feet, it is 125 inches. At Bombay, on an average of 

 30 years, the annual rain fall is 76-08 inches, and at Calcutta and Madras, for 8 years, it is 66- 59 

 and 52-27 inches, respectively. 



