OBSERVATIONS TAKEN IN INDIA. 
331 
curves of temperature at the different places, which might be expected otherwise to 
coincide with the sun’s path in the ecliptic ; but further observations from the hill 
stations may modify these conclusions. 
Range of Temperature and Hours of Maxima and Minima. 
Unless where hourly observations are taken, the exact periods of the occurrence of 
the maxima and minima cannot be determined ; and though a self-registering thermo- 
meter will determine the range of temperature, yet the hours of the turning-points 
cannot be learnt from it. For the hours of the occurrence of the maxima and minima, 
therefore, I am limited to the hourly observations taken at Madras and Bombay; 
but for the range of temperature, without reference to specific times, I can avail my- 
self of a maximum thermometer registered at Aden for 1848, and one at Calcutta 
registered since June 1848. 
Madras. — Hours of Maximum and Minimum Temperature. 
The usual impression in India is, that the maximum heat occurs about 2 p.m., and 
the minimum a little after sunrise. The Madras hourly observations for four years, 
from which the following Table is prepared, exhibit great anomalies in the hours of 
the occurrence of the maxima and minima. In the forty-eight months of monthly 
range there are seventeen records of the greatest heat occurring about noon (between 
llh 4 jin | 2 h 4 im). eighteen records between 1 and 2 p.m., and thirteen records 
between 2 and 3 p.m. In 1842 the maximum daily heat occurred only 07 ice about noon 
(I 2 h 4 imj 20th of April (96°*5). In 1843 it occurred at the same hour, or be- 
fore it, in January, February, March, May and November. In 1844, at the same 
hour, in January, April, November and December. In 1845, in March, April, May, 
September, October, November and December ; so that in fact the maximum 
daily heat, although it took place only at noon in the month of April in 1842, in the 
other three years, either in one year or the other, occurred at noon in all the months. 
There is not a single instance of the maximum daily heat occurring after 2^‘ 41“ p.m. 
The minimum heat of the month, in 1842, occurred in May at 2*^ 41“ a.m. (81°‘1), 
the only record of the kind in the year. In 1843 there is no similar record, but 
in 1844 there are two instances of the least heat taking place in July and August 
at 41“ past midnight, and one instance at 2^‘ 41“ a.m. in September. In 1845 
there is a solitary case of the lowest temperature at 2** 41“ a.m. In the whole 
four years there are only three instances of the minimum heat being at 3^ 41“ a.m., 
two at 4^ 41“ A.M., twenty-five at 5^ 41“ a.m., and twelve at 6*’ 41“ a.m.; and one 
singular instance of the greatest cold in the month being as late as 7'* 41“ a.m. on 
the 14th of May 1844. It may be affirmed, therefore, that the greatest cold occurs 
at Madras most often at 5'' 41“ a.m. The monthly range of the thermometer does 
not differ very much in the different months of the year, nor does the range of the 
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