Winchester Observatory was also in the possession of several blank glass 

 discs: a 29-inch diameter flint, and two flint and two crown pieces 10 

 inches wide. In 1875 these pieces were given to the Clarks for examina- 

 tion and safe storage. Extant correspondence indicates that, had money 

 been available, the Yale astronomers would have asked the Clarks to 

 figure a 29-inch achromatic objective. 267 Money to work the lenses, 

 however, was not found during the Clarks' lifetimes. 



The last objective made by the Clarks is at the Yerkes Observatory 

 of the University of Chicago. In respect to both the figure of the lens, 

 and the form of the Warner & Swasey mount, the Yerkes telescope is 

 similar to the Lick instrument (q.v.). Like the Dearborn telescope 

 (q.v.), the 40-inch went to Chicago by default. While in California in 

 1888-89, Alvan Graham discussed the possibility of a large refractor for 

 Wilson's Peak with representatives of the University of Southern Cali- 

 fornia; and he received authorization to place an order with Mantois 

 of Paris for the 40-inch crown and flint discs. Soon thereafter the Cali- 

 fornians found themselves without the funds necessary for purchase of 

 such a telescope. Although there were frequent notices in newspapers 

 and scientific journals of the existence of these discs, and of the Clarks' 

 desire to figure them, no definite bids were made until Alvan Graham 

 met George Ellery Hale at the September 1892 meeting of the AAAS. 268 

 The persuasive Hale quickly talked C. T. Yerkes into paying for an ob- 

 servatory and a mount, as well as for the great objective. 



The 40-inch lens, the largest one made by the Clarks, is as yet the 

 largest one ever made and mounted. Had Alvan Graham lived longer — 

 he died in June 1897, shortly after delivering the objective to the ob- 

 servatory at Williams Bay, Wisconsin — lenses of even greater aperture 

 might have been made. The often mentioned problems of adequate sup- 

 port and absorption of light through the glass seemed trivial to him. In 

 1893, wne n visited by Edward Emerson Barnard, Alvan Graham ex- 

 pressed his readiness, as soon as the 40-inch was figured, to begin work on 

 a 5-foot objective. 269 



267 See H. A. Newton to Prof. Lyman, 12 August 1884 (letter in Yale University 

 Archives). 



268 Edwin B. Frost, An Astronomer's Life (Boston, 1933), p. 97. 



269 Edward E. Barnard, "Nearer to the Stars," English Mechanic, vol. 60 (1894- 

 l8 95)> PP- 495-496. 



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