Taz METEOROLOGY or ruz PLAINS ayy MOUNTAINS or N.W. INDIA. xxxi* 
Thermometer never rose above 89°, or sunk below 71°, and the mean temperature deduced from the 
means of the extremes is 80° 04 in all the years. 
Jan. Feb. March April May June July Aug. Sept. Oct. Nov. Dec, 
Maximum .ecoooe 845 85 87 87 89 88 8 888 88 86 8&6 
Minimum ..... ae Te oe ww eS ee Ae ae ee en 
75 795 8 85 B B BLS SIS BIS BIS 80 80=804 
This degree of equability is found near the Equator only, but an approach is made to it during the 
rainy season of the year, both in higher latitudes and at considerable elevations, within the influence of 
the tropical rains, though the general characteristics of these situations is that of variableness of climate, 
or of a great range of the thermometer, both daily and annual. The result is the production, not only 
of great cold, but also of great heat, so that the thermometer is found to rise much higher at, and a little 
beyond the tropics, than in the neighbourhood of the Equator. This is accounted for, in some measure, by 
what has been observed by astronomers, that the sun, in his progress from the Equator towards the Tropic, 
advances in the first month 12°, and in the second 8°, so that at the end of the second month he is 20° 
from the Equator, and takes a month to advance the remaining 34°, and an equal time to return, so that 
during the whole of this period the solar rays must fall nearly perpendicularly at noon on all places 
between 20° and 233° of latitude, while a place situated under the Equator has the sun only during six 
days, as near the zenith, as the above places near the tropics have it for near two months ; and, therefore, 
we may expect a greater degree of heat, which is moreover increased by the greater length of the days. 
The larger proportion of land near and beyond the tropic of Cancer, as well as the sandy barren nature 
of the soil, perhaps originally a consequence of, but now acting as a cause, in increasing the heat, together 
with the dryness of the air, all contribute, as causes, in increasing the absorption of, and the subsequent 
radiation of the heat imparted by, the nearly perpendicular solar rays. Thus Ritchie and Lyon state, 
that during whole months the thermometer stood at 117°, and at 128° in the Oasis of Mourzouk ; Dr. 
Coulter mentions having observed it at 140° on the banks of the Rio Colorado, 32° 30’ N. lat., and we 
have it often stated as being 120°. Mr. Everest gives 111° as the highest at Ghazeepore; Mr. Prinsep 
as its being 114° at Benares. I have observed it at 107° at Saharunpore. The free radiation of the same 
open plains in the clear still nights of the winter months, causes a degree of cold which one is surprised 
to hear of as occurring in situations where the summer heat is so intense ; hence the coldness experienced. 
in some of the deserts of Africa, also by Lieut. Burnes, as well as in the plains of India. — 
The climate of many places in low latitudes has been ascertained, but of these we can only state the 
mean temperatures: as of places in Ceylon, from lat. 6° to 83°; of Point de Galle, 81°10’; of Colombo, 
80° 75’; and of Trincomalee, 80° 56’; while the temperature of Madras, in lat. 13° 5’, has been ascer- 
tained, by numerous observations, to be 80° 42’. Pondicherry, on the dry and hot part of the Coroman- 
del Coast, and in N. lat. 11° 58’, has the highest observed mean temperature, this having been found to 
be 85° 28’. Seringapatam, in lat. 12° 45’ N. long. 76° 51’ E., and elevated about 2,412 feet above 
the level of the sea, has a mean temperature of 77° 06’; the mean at sunrise is 63° 17’; at 3 p.m., 
90° 95’; of the day, 84°; of the night, 70° 11’; the highest temperature observed was 115°, and the 
lowest 48°. At Bangalore, the mean temperature is about 74° 39/. 
My friend Mr. James Prinsep, whose lamented illness all friends of science and of literature equally 
deplore, published, in the year 1882, the results of my observations, and as he has united them with 
others, I give his tables for the sake of comparison. 
« The whole presents a convenient epitome of meteorological phenomena between 12° and 30° of north 
latitude. Of the climate of Madras, the minutest details are recorded in the voluminous and careful soe 
reports of the late astronomer, Mr. Goldingham, whose results merely required to be reduced to the 
freezing point. The Ava tables are abstracted from Major Burney’s Registers, published - in a ee ae 
‘ Gleanings ;’ the Benares tables are taken from the Oriental Magazine, 1820 ; = the Sa hat un) 
results we are indebted to Dr. aoe who allowed us to look through his der a -gisters 
