1884.] President's Bemarks on Sun-spot Cycle. 169 



and went through a double oscillation in two succeeding cycles ; and I 

 may add that since his paper was written, his conclusion has been con- 

 firmed by the fall in the average temperature of India from the last 

 sun-spot minimum to the present maximum. In the case of barometric 

 pressure there was a very well marked oscillation during three sun- 

 spot cycles in Western Siberia and European Russia, and a smaller but 

 still decided oscillation of the opposite character in the Indo-Malayan 

 region during about 2 sun-spot cycles (the whole period for which evi- 

 dence was forthcoming) . The evidence that Mr. Meldrum has adduced 

 of the frequency of cyclones in the Indian Ocean, shows too I think a 

 distinct periodical variation according to the sun-spot cycle. The evi- 

 dence of a similar oscillation in the case of rainfall is more conflicting, 

 but in certain regions there does seem to be such a periodical variation, 

 although it is overlaid and much obscured by irregularites arising from 

 other causes. 



" Although therefore, the variation of meteorological phenomena in 

 accordance with the sun-spot cycle has sometimes been unduly exag- 

 gerated, the evidence of its reality is cumulative, and is such as to war- 

 rant for it a high degree of probability. And if we are justified in assum- 

 ing that the solar radiation is subject to a cyclical variation concurrently 

 with the variable changes of photosphere, bearing in mind the maxim 

 emphatically laid down by the younger Herschell, that any periodical 

 oscillation in a cause, must be repeated and reproduced in every effect 

 of that cause, however remote, we should have a priori grounds for 

 asserting that the oscillation must make itself felt in all meteorological 

 phenomena, since the sun's heat is the motive power of all, and the only 

 issue open to discussion would be whether the effects are of such mag- 

 nitude that we can hope to detect them with our present means and 

 appliances. 



" I have said nothing of the supposed manifestation of the sun-spot 

 cycle in certain economic matters, as I am less able to form an opinion 

 on the value of the evidence adduced in support of it. In so far as 

 these economic conditions are dependent on meteorological conditions, 

 assuming the fundamental postulate, Herschell's maxim of course holds 

 good, but the more remote the effect, the greater is the likelihood of its 

 becoming inappreciable to observation." 



5. Note on the Abstract of Mr. Blanford's Paper on the Theory 

 of the Winter Bains of Northern India. — By Feedeeick Chambees, 

 Meteorological Beporter for Western India. 



In the abstract of the paper entitled " The Theory of the Winter 

 Rains of Northern India," published in the Proceedings of the Asiatic 



