1904.] Astrophysical Frohlems. 435 



WEEKLY EVENING MEETING, 



Friday, January 22, 1904. 



His Grace The Duke of Northumberland, K.G. D.C.L, F.R.S., 

 President, in the Chair. 



The Eev. Walter Sidgreaves, S.J. F.R.A.S., Director. 



Spectroscopic Studies of Astrophysical Problems 

 at Stonyhurst College Observatory. 



I HOLD in ray hand two papers, prints of the Royal Institution, 

 kindly sent me by my friend Professor Dewar. The first bears 

 the date 24th May, 1889, and is a discourse by my predecessor, 

 Fr. Perry. In it he says : " For the last ten years I have been 

 anxiously endeavouring to make Stonyhurst as efficient an obser- 

 vatory for solar physics as the means at my disposal would admit." 

 It was the last time he addressed you in this hall, for the close of 

 that year was the close of his life, and found him struggling in the 

 discharge of a duty he had accepted, which pressed upon his sensitive 

 nature so far as to hide from him the real danger in which he was on 

 the eve of the Solar Eclipse of December 1889. 



It would be right on this occasion to take up the narrative where 

 he left it ; and this was made more easy for me by the second paper, 

 bearing a later date, April 11th, 1902, by Professor Dewar, ' On 

 Problems of the Atmosphere.' In his concluding paragraph he 

 draws attention to a definite and rational answer of Arrhenius to the 

 question : " What is the cause of the electric discharges which are 

 generally believed to occasion auroras ? " There is much in the 

 answer to favour an alternative hypothesis : and it would have been 

 congenial to a combative nature to have placed before you my 

 reasons for preferring a theory of my own to that of Arrhenius. 

 And I feel that I owe an apology to Professor Dewar for not accept- 

 ing in full the suggestion contained in his presentation of the two 

 papers. My apology is this : In October last two great spots crossed 

 the solar disc. The greater spot was associated with a smaller 

 magnetic disturbance, and the smaller spot with the greatest magnetic 

 storm recorded by the Stonyhurst magnetographs. This contrast 

 was all in my favour ; but the facts brought out so much sun-spot 

 literature, that I was frightened by the thought that the subject could 

 not be divested of its worn-out attire, and would not afford that 

 interest which is the one encouragement of a stranger in my position 

 this evening. 



Nevertheless, I am able to take up the narrative in another 

 direction. Fr. Perry had provided the Observatory with two costly 

 spectrometers : a Rowland grating on a massive stand, with circles 



