On the Mean Temperature of Bombay. 21 



The slightest examination of the preceding observations is 

 sufficient to convince us that the mean temperature of Bombay 

 for 1827 must be considerably less than 80°98, which is the 

 mean of five ordinates of the daily curve. Three of the or- 

 dinates, viz. that of 11 a. m., 1^ p. m., and 4^ p. m. are taken 

 during the warm part of the day. The ordinate of Q'^ p. m. 

 is very little above the mean ordinate ; so that in the preced- 

 ing series of observations there is really only one ordinate, 

 namely, that before sunrise, which is near the lowest part of the 

 curve, and decidedly below the mean temperature. Two or- 

 dinates, therefore, or observations at 12 p. m. and about S^ 

 A. M. are wanting to enable us to deduce from the series the 

 accurate mean temperature of Bombay. 



Taking the mean temperature before sunrise as the lowest 

 during the day, we have by the Leith observations the follow- 

 ing correction : — * 



Deviation from 

 Mean Temp. 



Before sunrise, - — 2°873 



11 o'clock A. M. - +1 



I p. M. - + 2 



4 P. M. - + 2 97^ 



9 p. M. - — 438 



Sum of deviations from the mean, - + 4^^226 



Hence we have 



Observed mean temperature, - 80°98 



Correction, - - - —* 4.226 



Corrected mean temperature, ^Q'^lQ^i 



If we now compute the mean temperature of Bombay in 

 N. Lat. 18°58' and east Long. 19P^&, by Dr Brewster's Ge- 

 neral Formula for the Eastern Hemisphere of the Globe we 

 shall find : — 



« See this Jovrnal, vol. v. No. ix. p. 30. 



