TRANSACTIONS OF THE SECTIONS. 567 



been cloudless all day, and the sun intensely hot; a decided 

 change of temperature took place about sunset, at which time 

 a fine breeze from E.S.E. sprung up, gradually increasing, 

 rendering the evening and night cold. At sunset the sky was 

 clear, except towards the north and west, where dense masses 

 of cloud rose a few degrees above the horizon ; and also in the 

 intermediate part above the sun, where streaks of thin haze 

 were rendered visible by its light : upon these a narrow but 

 slightly expanding vertical band of well-defined light, having 

 the sun for its base, was again exhibited. 



It had occurred to Professor Christie, after he had first 

 observed this light on the 30th June, that it might be due to a 

 succession of images of the sun imperfectly reflected by strata 

 of thin vapour, and all the appearances which he observed on 

 this second occasion tended to impress this notion more strongly 

 on his mind ; but he thinks repeated observation of the phaeno- 

 menon will be required before it can be decided whether this be 

 the correct explanation. On both occasions, the position in 

 which Mr. Christie saw the light, was looking almost immediately 

 across some extent of sea, the sun setting behind the Hants 

 and Dorsetshire hills. The light was most brilliant very shortly 

 after sunset, and gradually declined in brightness till it wholly 

 disappeared, about half an hour afterwards ; but its direction 

 was invariable, and its general character the same during the 

 whole time of its continuance. Early on the morning of the 

 18th July there was thunder and lightning, with rain, which 

 continued more or less until the middle of the day. 



Notes on mean Temperatures in India. By Lieut. Col. 

 Sykes, F.R.S. 



The author states the results of several observations of mean 

 temperature in India, at different elevations above the sea, 

 between 10° and 25° N. lat., and 70° and 82° E. long., for 

 comparison with the formulae of Meyer, and the generalizations 

 of Humboldt and others. 



Mhon, in Malwa, in lat. 22° 23' is 2000 ft.^ ^ 

 above the sea ; the mean temperature ob- > 74-00 



served by Dr. Craw J 



Calculated by Meyer's formula, and adopting"! ^q q^. 

 the correction of 1° Fahr. for 300 ft. ascent J ^'^^ 

 Calcutta is in nearly the same lat. (22° 35') and"^ 



its mean temp, as determined in 1781, and > 78*13 



again after a lapse of 52 years J 



There is therefore a difference of 4° 13' between the mean 



