342 ANNUAL EEPOBT SMITHSONIAN INSTITUTION, 1910. 



constantly increasing, this one, though very small and just, will prob- 

 ably be set aside. Still, it must be said, civilized man of to-day, and 

 he of the city especially, thinks little about the sun ; he notices it less 

 than primitive man and the savage who had neither watch nor alma- 

 nac. The carrying out of my idea must be reserved for future citi- 

 zens and for a social state more perfect than our own. 



This recourse to the Government or to associations of men is a 

 French custom. It would be better to proceed as the English do, 

 and appeal to private support, to the initiative of enlightened, gen- 

 erous individuals. In this way the Royal Institution was founded 

 which has seen mature so many beautiful discoveries and so many 

 illustrious scientists. This good example should be followed by all. 

 We know how liberally it has been followed in America, where the 

 greatest qbservatories and especially those devoted to the study of 

 the sun have been due to private munificence. 



Indeed, during the last 50 years, thanks to great discoveries, thanks 

 to the support of our Governments and private patrons, the study of 

 the sun has made remarkable progress. Little by little, astronomers 

 have developed for it a zealous and permanent organization, and 

 have extended their study to the entire and hitherto inaccessible 

 atmosphere of this star. 



The principal discovery was the periodic variations of the sun 

 spots, variations which are also undergone by the brilliant facula? 

 of the surface and, indeed, by all of its far-extending atmosphere. 

 The sun, in its entirety undergoes a great periodic variation; and 

 what is yet more interesting, this variation extends to the earth and 

 affects its magnetic elements. 



This connection of solar phenomena with the earth is of capital 

 importance. It implies almost necessarily a novel, special action 

 exercised by the sun upon our globe ; whence comes the practical pop- 

 ularity which solar research now enjoys. Following the discovery 

 by Sabine and Lamont of the coincidence between the earth's mag- 

 netic variation and the variation of the sun, the English have given 

 very great attention to the study of sun spots; and they were the 

 first to establish the photographic registration of the spots and the 

 magnetic elements at various places on the earth. The collection of 

 all these records in one observatory, where they were accurately 

 compared, followed. The works of Ellis and Maunder relative to 

 these discoveries are well known. In this connection it is fitting to 

 mention the researches of Lockyer and Schuster, who have recently 

 noted variations of the spots in periods greater and smaller than 

 the principal cycle of 11 years. 



The action produced upon the earth by the sun is generally at- 

 tributed to the sun spots, but it may as well have its cause in the 

 solar atmosphere, which undergoes the same variation ; whence comes 



