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Remarks on the Preceding Observations. By Professor J. D. ForBss. 
Mr CaLDECOTT’s observations possess an extraordinary interest from being 
the first of the kind prosecuted between the tropics, from the great care and ex- - 
tent of the observations, and from the circumstances being altogether comparable 
with those of observations lately made in Europe. [The depths of the thermo- 
meters are the same as those at Brussels, Edinburgh, and Greenwich. ] 
In conformity with Mr Ca.LpEcott’s suggestion, I have had the corrected 
means. of 1843—4—5 united, so as to give the mean temperature of each month 
(the observations of 1842 being omitted). The results are given in the following 
Table. The readings of Nos. 1 and 2 are deficient in some of the months, owing 
to the liquid having risen above the scale :— 
MEAN OF THREE YEARS, 1843—5. 
No. 1. No. 2. No. 3. 
12 feet Thermo- 6 feet Thermo- 3 feet Thermo- 
meter. meter. meter. 
Air 
Temperature. 



January 85° 85618 84:954 78°930 
February : 86°625 86°838 80°386 
March i 88°110 88°789 82-730 
April ; 88°527* 89°614 83°370 
May 88°224F 88°413 81-603 
June 86:878F 86°883 85°012 79°023 

July 86°537 85°114 83°250 78°450 
August 85°894 84°736 83°566 78:990 
September 85°633 85°133 84°575 79973 
October 85°680 85°632 84°722 79-076 
November 85°651 85:271 84°622 79°750 
December 85°607 85°303 84228 78:030 
Means 86:043 86°264 85°715 80°025 




* Mean of Two Years only. t Result of 1843 only. 

The following conclusions are plainly deducible :— 
I. The Temperature of the ground at Trevandrum is from 5° to 6° Fahr. 
higher than that of the air. This result is confirmed by observations on the tem- 
perature of springs and wells at Trevandrum, which have been obligingly com- 
municated to me by Major-General Cutten of the Madras Artillery. These 
observations are printed in the “ Proceedings” of this Society. 
II. When the monthly means of the thermometers are projected, so as to 
shew the curves of annual temperature, they are found to have one great inflection 
and a smaller one. The principal maximum of the temperature of the air occurs 
about the beginning of April, after which the rainy season sets in, and the annual 
