132 



MR. JOSEPH BAXENDELL 



A projection of these numbers^ and of the corresponding 

 ratios of solar radiation, to the oscillation of mean daily 

 g temperatiore is shown in diagram B : 



No. I is the curve of sun-spot fre- 

 quency, and No. 2 that of the ratios ; 



^■^■^M ^^^ ^* ^^^^^ ^^ ^^^^ ^^^* *^^ similarity 



I^I^H^I in form of the two curves is remark- 

 H^l^l ably striking, and apparently con- 

 H^H^H elusive, as to the connexion between 

 im^H^H the two classes of phenomena. 

 ^|H Assuming that changes in the 

 0|^| heating power of the sun^s rays fol- 

 ||n^| low the coiirse of the changes in 

 IH|H solar-spot frequency, it seemed pro- 

 flB^fl bable that the ratio of the difference 

 0MH between the maximum temperature 

 IMH in the shade and in the sun, to the 

 H|^ difference between the mean daily 

 ^B9 temperature (or better, perhaps, the 

 temperature of evaporation) and the 

 maximum temperature in the shade, would also exhibit 

 corresponding changes. It will be seen that the following 

 results strongly support this view : — 



Max. temp, in sun, 

 less max. temp, 

 in sliade. 



Max. temp, in shade, 



less mean temp, of 



evaporation. 



Ratio. 



1859 

 i860 

 1861 

 1862 

 1863 

 1864 



12-85 

 1078 

 1 1*24 



9*37 

 978 

 9-81 



io'o6 

 8-63 



9*52 

 9-28 



10-38 



io"57 



i*Z7 

 1-25 

 ri8 

 I 09 



0-94 

 o'93 



The line No. 3 in diagram B is a projection of these 

 ratios. It would probably be better to employ the maxi- 

 mum instead of the mean temperature of evaporation, but 

 this is not given in the printed observations. 



