OBSERVATIONS TAKEN IN INDIA. 
365 
Surveyor-General’s Ofl&ce, similar observations were made at the respective heights 
of 4 feet and 40 feet, and I have inserted the results in the general rain-fall Table for 
four years. The sums were respectively 261’97 inches and 247*41 inches, and the 
annual means 65"49 inches and 6r85 inches. 
Dr. Buist states that at the observatory in Bombay, in two rain-gauges, one at 
3 feet from the ground, and the other above the observatory at 32 feet, the 
Lower gauge for 1843 . 
Upper gauge for 1843 . 
Lower gauge for 1844 . 
Upper gauge for 1844 . 
inches. 
=5624 
=49*07 
= 66-51 
= 66*08 
These results therefore are in accordance with Professor Phillips and Mr. Miller’s 
observations, taken at limited heights, but entirely antagonist to Mr. Miller’s own 
observations and those I have supplied in this paper from India for heights exceeding 
a few hundred feet. The supposed law may hold good for small differences in eleva- 
tion on the plains, but the law is reversed in mountainous districts. 
Two great features of my Rain-table demand express notice, the paucity of rain at 
Cape Comorin and at Kurrachee, at the extremities of nearly the same meridional 
line, and the prodigious fall of rain at the elevation of 4500 feet at three stations dif- 
fering greatly in latitude, but situated nearly in the same meridian. I have not any 
satisfactory explanation to offer of the want of rain either at Cape Comorin or at 
Kurrachee. I am not at all acquainted with the physical character of the country 
about Cape Comorin, and cannot therefore express an opinion how far local circum- 
stances occasion the phenomenon. I had thought that a very high mean tempera- 
ture, with a limited range of the thermometer, might account for the want of rain 
at Kurrachee on the Indus, the vapour from the ocean not coming into an air cold 
enough to condense it; but the register of the thermometer for 1847 at Kurrachee 
shows that I could not found a satisfactory argument upon its records, for the 
maxima are not so great as at Calcutta, Madras and Bombay ; the minima are lower, 
and the mean temperature is lower than at either of the places ; some other cause 
therefore must be looked for than a high mean temperature. The clouds which con- 
stantly pass over Kurrachee, would appear not to be condensed until they impinge 
upon the Sulimanee Mountains, which run parallel to the right bank of the Indus. 
The explanation of the prodigious fall of rain at the level of 4500 feet is simple and 
satisfactory. The chief stratum of aqueous vapour brought from the equator by the 
S.W. monsoon is of a high temperature, and floats at a lower level than 4500 feet ; indeed 
I have looked over, or upon the upper surface of the stratum at 2000 feet. It is dashed 
with considerable violence against the western mural faces of the Ghats, and is thrown 
up by these barriers in accumulated masses into a colder region than that in which it 
naturally floats ; it is consequently rapidly condensed and rain falls in floods. The 
uncondensed vapour which escapes up the chasms and over the crest of the Ghats, 
