1882 J H. F. Blaiiford — SomcfiirtJier results of tlic sun-iJiermometer 83 



of the intensity of the solar radiation, in the registers of insolation tem- 

 peratures, or even those of actinoraetric observations on the plains of India ; 

 but this I think would be a hasty conclusion. The effect of cloud reflection 

 may be pretty well eliminated by careful selection, and even although 

 the effect of the solar variation (supposing such to exist) may be small 

 in comparison with those effects which depend imYnediately on atmos- 

 pheric absorption, since in comparing the registers of different year&, 

 the former must affect all stations simultaneously and similarly, whereas 

 the latter vary indefinitely at different stations, it may yet be possible by 

 taking the mean result of a large number of stations in different parts of 

 the country, to eliminate such atmos}>heric effects, as continue to manifest 

 themselves prominently in the individual registers, after taking such 

 obvious precautions as have been specified above ; and I am the more encour- 

 aged to entertain this view, by the very striking coincidence between inso- 

 lation and sun-spot frequency which resulted from my former investigation. 

 And the results of the present attempt, though less striking than the former 

 investigation had led me to anticipate, are, still, not such as to discourage 

 further enquiry in this field. They must however be regarded, at present, 

 as provisional only ; and, indeed, the number of stations here considered is 

 too small to admit of any other estimate of their validity. 



Table V. — Progressive differences of insolation temperatures on clear 

 days from the montldy means of Table II. 





1875-6. 



1876-7. 



1877-8. 



1878-9. 



1879-80. 



1880-81. 





1 



i • 



o 



ft 



1 



o 



CO 



g 

 3 



ft 



03 



ft 



i 



o 



S 

 W. 



i 

 ft 



d 

 .2 



1 



January 





 

 

 

 3 

 3 

 3 

 14 



+ 0-3 



— 0-8 



— 0-2 



— 2 3 

 + 4-3 



+ 12-7 

 + 8-8 

 + 5-4 

 + 28-2 

 + 2-0 



4 

 4 

 4 

 5 

 5 

 1 

 

 

 

 6 

 6 

 6 

 41 



— 4-9 



— 4-7 



— 1-3 

 + 10-3 

 + 1-6 

 + 0-1 



—1*3.4 

 —21-8 

 —220 

 —561 



— 1-4 



6 



8 

 8 

 8 

 8 

 3 

 2 

 1 

 2 

 8 

 8 

 8 

 70 



— 8-3 

 -29^2 

 —20-5 

 -14-3 



— 7-7 



— QQ 



— 6 9 



— 8-5 



— 1-4 

 —130 

 + 22 

 + 79 

 -1063 



— 1-5 



7 

 7 

 7 

 6 

 6 

 3 

 2 

 1 

 2 

 6 

 6 

 6 

 59 



— 4-3 

 + Q-Q 



+ 4-1 

 -18-8 

 -14-9 



— 21 

 + 02 

 + 1-9 

 + 02 



— 4-9 



— 4-8 

 —10-7 

 -47-5 



— 0-8 



6 

 6 

 6 

 6 

 6 

 3 

 2 

 1 

 2 

 6 

 6 

 6 

 56 



— 9-6 



— 1-9 

 —181 





 + 5-6 

 + 5-6 

 + 3-5 

 + 4-2 

 + 62 

 + 4-4 



— 2-2 



— 55 



— 7-8 



— 0-1 



6 

 6 

 6 

 6 

 6 

 3 

 2 

 1 

 2 

 5 

 5 

 5 

 53 



— 0-7 



February 



March 



— 9-3 

 + 11-6 



April >. ..<.>•<«. 



+ 61 



May , 



— 9-4 



June 



— 0-3 



July 



+ 3-2 



Aus'ust , 



+ 21 



September 



October 



— 1-4 



— 5 3 



November 



December 



Sums 



— 3 7 



— 5-8 

 —12-9 



Means 



— 0-2 



12 



