ASTRONOMY ON THE PACIFIC COAST 211 



with the proviso, however, that " the same must be located within the 

 state of California." 



Just why Lick provided for this telescope and observatory will prob- 

 ably never be known. While I can not recall my authority, I have a 

 very distinct recollection of having heard it stated that the idea was 

 first suggested to him and frequently urged upon him by Professor 

 George Davidson, Concerning this point, however, the director of the 

 Lick Observatory writes/ 



The question, " What induced Lick to provide for a great telescope? " 

 has never been satisfactorily answered; but there is no reason to doubt that he 

 eame to this determination without conscious suggestion from others. 



After having several sites tested the trustees decided upon Mount 

 Hamilton, California, as the best location for the observatory. Active 

 work was begun in 1879, and the observatory was completed and ready 

 for regular work in 1888. The plant cost all but $90,000 of the amount 

 set aside for it. The observatory and this balance were turned over to 

 the regents of the University of California by the trustees June 1, 1888 ; 

 and since then it has been an integral part of the university. 



The principal instruments of this observatory are the great 36-inch 

 refractor, a 6-inch Eepsold meridian circle, provided by the Lick Trust, 

 and the 36|-inch reflector, a gift from Edward Crossley, Esq., of Eng- 

 land. Besides these there is a host of smaller instruments and auxiliary 

 apparatus. I can not go into details here concerning the instruments, 

 but I wish to mention one which has an important bearing upon the 

 subject of this article. It is that the magnifying power of the great 

 refractor may be made to be as much as 3,000 diameters. When one 

 considers that ever}i;hing in the line of sight of the telescope is magni- 

 fied by this amount, it becomes evident that, to be efficient, the telescope 

 must be located at a site where the atmosphere through which the line 

 of sight passes is extremely steady, for any little atmospheric disturb- 

 ance will be magnified to this amount and destroy what is called the 

 "seeing," giving a poorly defined image of the star or object under 

 observation. And it is principally on account of the splendid atmos- 

 pheric conditions on the Pacific coast, especially on some of the moder- 

 ately high mountains, which make excellent "seeing" possible that 

 observational astronomy here has been able to make such tremendous 

 strides. 



For the efficient use of a great telescope its location must be in a 

 region of great atmospheric calm, where the sky is clear and trans- 

 parent, with little wind, and where the number of days and nights of a 

 year during which such conditions do not exist is small. For some 

 reason, the " seeing " conditions at Mount Hamilton during the day are 

 not of the best; but at night excellent conditions are found on a large 



1 " A Brief Account of the Lick Observatory of the University of Califor- 

 nia, " prepared by the Director of the Observatory. Fourth edition, 1914. 



