50 H. I. JENSEN. 



very largely depends on solar conditions, being large at 

 sunspot maxima, deficient at sunspot minima ; some also 

 believe that the mean atmospheric pressure is somewhat 

 increased during minimum years and diminished in maxi- 

 mum years. 



Before proceeding it might be well to mention that 

 meteorologists are by no means unanimous on this question, 

 but if a connection between sunspots and climate can be 

 definitely proved, it is reasonable to suppose that earth- 

 quakes which are known to be influenced by weather are 

 also influenced at any rate indirectly by sunspots. 



According to Professor Schuster "the difference between 

 the average temperature in years of maximum and years 

 of minimum amounts to the considerable amount of 0*73° O. 

 in tropical, and over 0*5° in extra-tropical parts of the world; 

 and Gautier has shown that the temperature curve displays 

 the same characteristics in period as the sunspot curve." 1 



Carpenter and Balfour Stewart found "that sunspot 

 inequalities, whether apparent or real, seemed to have 

 nearly the same periods as terrestrial inequalities as 

 exhibited by the daily temperatures at Toronto and Kew." 2 



Mr. Blandford's observations in India, as well as spectro- 

 scopic investigations by Roscoe and Balfour Stewart, show 

 that solar radiation in years of sunspot maximum is greater 

 than in minimum years. 



The great Austrian meteorologist, Halm, has paid special 

 attention to abnormal temperatures, and has observed that 

 the summers were hotter at or near a time of sunspot 

 minimum, while colder and wetter summers and winters 

 obtained at a maximum. 



1 Article by Professor Schuster in "Report of Brit. Assoc, for the 

 Advancement of Science, 1884." 



2 See Schuster and also Rev. A. L. Cortie's paper on " Sunspot Spectra'* 

 — Memoirs Roy. Astro. Soc, 1890-1, Vol. l. 



