231 



surface very differently in some places from others, so as to cause 

 here and there completely opposite states of weather.* For if 

 ■we suppose a tropical or sub-tropical region to be overheated 

 through an increase of the sun's activity, the immediate effect 

 would be a more exhausting evaporation of the moisture in the 

 soil ; and an increased quantity of vajjour would consequently be 

 taken up by the atmosphere, to be carried by winds far elsewhere, 

 where the sun's influence is less, and there condensed into rain. 



But to all this inquiry as to sun-spot influence there is a previous 

 question, which has hitherto, I believe, received no decided answer. 

 Does the actual amount of heat and light radiated out from the sun 

 to our earth vary from year to year 1 On putting this question to 

 a distinguished Professor of Astronomy at Cambridge, ■with whom 

 I had conversation on the subject last summer, he replied that he 

 knew of no evidence to show that it did vary. Of course such 

 evidence may be forthcoming hereafter, but if it be unfavourable, 

 the hypothesis of sun-spot influence on our seasons falls to the 

 ground. 



Setting aside, then, for the present, all further consideration of 

 this matter, I pass on to other causes which have been adduced as 

 aff"ording an explanation of our long protracted cold weather. One 

 of these is a suggested deviation of the gulf stream from its usual 

 course, some imsuspected agency taking it away further from our 

 shores, and thereby depriving us of its accustomed ameliorating 



• See an article on "The Weather and the Sun" in "Nature," vol. 20, p. 

 626. See also another article on " Sun-spots and the Rainfall of Paris," which 

 has appeared in " Nature " (vol. 21, p. 166), since the reading of this paper, 

 giving full details on the subject, and leading to the belief that a connection 

 will eventually be found to exist between sun-spots and rainfall generally^ 

 though not capable of proof from the observations of a single locality. The Author 

 thinks that "the general rainfall cycle for the whole globe might be conceived 

 to be made up of a number of local cycles differing more or less among them- 

 selves land from the general cycle, according to local conditions, and in soma 

 places the general cycle might be reversed,'^ 

 D 2 



