76 METHODS AND RESULTS OF TORONTO OBSERVATIONS. 



Another singular point is on record which adds to the weight of 

 proof that the condition of the sun's outer envelope bears its couter- 

 part in the magnetic condition of the earth. It was witnessed on 

 September 1, 1859, by Mr. Carrington, at Redhill, England, while 

 observing the sun's disc. He was taking observations of the forms 

 and positions of the solar spots, the sun's image being projected on 

 on a plate of glass, coated with distemper of a pale straw color, at a 

 distance, and under a power which presented a picture of about 1 1 

 inches in diameter. Suddenly within the area of the largest group 

 there broke out two patches of intensely white light. The outburst 

 after increasing for some seconds rapidly died away, the whole dur- 

 ation of the phenomenon being not more than five minutes. In 

 this interval the two patches had traversed a space of about 35,000 

 miles. On visiting the Observatory at Kew a few days later he found 

 that at the instant when he had observed the phenomenon the three 

 magnetic elements were simultaneously disturbed, the time of dura- 

 tion of the disturbance being about ten minutes. 



The above incident taken with the almost exact coincidence 

 between the periods and turning points in three classes of phenomena 

 so widely different as the magnetic disturbances, the diurnal range 

 and the frequency of the solar spots, leaves, I think, little doubt that 

 the coincidence is not accidental but causal. 



Professor Balfour Stewart, of Owen's College, Manchester, has 

 lately been investigating the observations of temperature taken at the 

 Toronto observatory with a view to determining the existence of a 

 thermometric period similar to the sun spot period. His results are 

 published in appendix G to the report of the committee to advise 

 on the methods of carrying on observations in solar physics. I shall 

 now quote from the concluding portion of Professor Stewart's re- 

 port : 



" In the course of this paper I have given evidence which tends 

 to show that there are in all probability solar variations of short 

 period, and that these are connected with variations in the tempera- 

 ture range. Toronto was chosen as a station from which accurate 

 information, with regard to temperature, was to be obtained, and 

 also as one which, being in America, may be supposed to be influ- 

 enced more directly and immediately by solar changes than an 

 equally good station in Europe." 



