72 S. A. Hill— /Solar Thermometric Observations. [May, 



suture, of the median thoracic portion of the cephalothorax, and of the 

 rostrum, which gradually tapers to a longer point, and in colour, which 

 is throughout a brilliant scarlet-lake. I propose to call the new species 

 clothed in a white uniform with red facings, N. carpenteri, after the 

 commander of the vessel. 



Full comparative descriptions of the two species, together with an 

 account of the structure of the respiratory organs and of the larvae, which 

 leave the huge egg, in a condition closely resembling fig, E. of S. I. 

 Smith's plate representing the early stages of the American lobster, will 

 be published with illustrations in the Journal. 



In reply to a question by Mr. Cotes, the speaker explained that no 

 trace of the outer remus of the thoracic limbs was preserved in the adults. 



The following papers were read — 



1. Ohservations of the Solar Thermometer at Luclcnow, — By S. A. 

 Hill, B. Sc, A. R. S. M., Meteorological Reporter for the N. W. Pro- 

 vinces and Oudh. (Postponed from last Meeting.) 



(Abstract.) 



This paper has been compiled with a view to test the soundness 

 of the conclusions arrived at by the author from a discussion of seven 

 years' observations at Allahabad, published in the Journal, Vol. LI, 

 Part II. 



The data on which the paper is founded are hourly observations of 

 a non-registering black-bulb thermometer in vacuo. These observations 

 were made on four days in each month during the eight years 1877-84, 

 but only such as were recorded at times when the sky was free or nearly 

 free from cloud have been made use of. The reductions have been 

 effected b}^ means of Ponillet's formula. 



The deduced mean values of the constant of solar radiation in 

 degrees of the thermometer employed are the following : — 



Tear. 1877. 1878. 1879. 1880. 1881. 1882. 1883. 1884. 

 Solar Const. 80-1 86-7 80-4 76-7 74-7 74-6 76-4 77-2 

 These results strongly support the conclusion derived from the Allahabad 

 observations that the solar radiation is most intense when there are 

 fewest spots on the sun's surface, the last sunspot minimum having 

 occurred in 1878 and the maximum probably in 1881 or 1882. 



The author then proceeds to show that though there is a rather 

 strong presumption in favour of the variation in the sun's heat indicated 

 by the figures above given, the range indicated is doubtless much too 

 great. The thermometer having a globular bulb receives radiation from 

 all sides ; and therefore in dry weather, when the ground under it is 

 bare and the air over it dusty, it receives much more reflected heat than 



