OBSERVATIONS TAKEN IN INDIA. 
323 
and the minimum pressure from December to January inclusive. On referring to the 
St. Helena observations for 1843 this is very nearly the case, the maximum pressure 
and minimum temperature being in August instead of July, and the minimum pres- 
sure and maximum temperature in February to March instead of January. 
Meteorological Observations at St. Helena, 1843. 
January . . 
Barom. 
in. 
. 28-238 
Therm. 
64-76 
February . . 
. 28-214 
66-25 
March . . . 
. 28-214 
65-35 
April . . . 
. 28-251 
64-93 
May .... 
. 28-292 
6T53 
June . . . 
. 28-335 
58-88 
July .... 
. 28-341 
57-43 
August . . . 
. 28-358 
56-71 
September . . 
. 28-328 
56-92 
October . . 
. 28-279 
57-23 
November. . 
. 28-250 
59-54 
December . . 
. 28-251 
62-44* 
From the occurrence of the maxima and minima of the horary oscillations of the 
barometer at the same local hours in different meridians, these phenomena also would 
seem to be connected with the sun’s action upon the atmosphere. 
In the fitful movements of the atmosphere beyond the northern tropic the sun’s 
influence would not appear to be similarly felt, as the maximum pressure at Green- 
wich is in October, with a second maximum in December, and the minimum pressure, 
instead of being when the sun is at the northern tropic, is in November. 
Tem'perature. 
The hourly observations at Madras for four years afford the most complete and 
trustworthy data for determining at that place the fluctuations of temperature, the 
exact diurnal and annual range, and the exact periods of the fluctuations in the oc- 
currence of the maxima and minima, which cannot be satisfactorily shown by any 
observations short of hourly record. For Bombay I have only such records made by 
Dr. Buist for the years 1843 and 1844. Those at Calcutta were two-hourly only 
during the daytime, and those at Dodabetta were made but twice a day, with the 
exception of twenty-four hours once a month between the 21st and 22nd, when the 
observations were taken hourly. For exact determinations I am constrained to 
abandon many proposed comparisons, and in many instances to use less frequently 
recorded observations to express general features. The following Table shows the 
monthly means and annual temperatures at Madras and Bombay from hourly observa- 
tions. For the other localities the means are derived from less frequent observations, 
and are therefore only approximations to the truth. 
* The above table is confirmed by the Mauritius and Cape observations ; the minimum pressure being from 
January to February inclusive, and the maximum July to September inclusive. 
3 T 2 
