Ohservations of tlic Trrnisif of Venus. ;5.S5 



The instrument used in the observations was an e<)uatorially 

 mounted refractor, made b}' Alvan Clark & Sons. Aperture, 

 5.09 inches ; focal length of object-glass, 74.3 inches. The 

 magnifying poAvers used were 48 on first contact ; 165 on second 

 and third contacts ; 95 on fourth contact. 



The telescope was moved by clock-work, and was similar in 

 all respects to the instruments nuide for the transit of Venus 

 exiieditions of 1874. 



In making chronometer comparisons, the sidereal chronome- 

 ter Avas left at the College, and the mean-time chronometer was 

 carried to the instruments on which si^'nals were to be received. 



CHRONOMETER COMPARISONS. 



December 5th, P. M., at the College. 

 Negus, Sidereal. P. & F. Mean-Time. 



h. in. s. h. ni. s. 



21 39 14.0 = 4 26 15.0 



21 42 4.5 = 4 29 5.0 



December 5ih, P. M., at 42d Street Depot. 



West'n Union Time Signals Mean-Time Chronometer. P. &F. 

 in N. Y. City Hall time. 



4 



41 



0.0 



4 



43 



2.0 



4 



42 



0.0 



4 



44 



2.1 



4 



43 



0.0 



4 



45 



2.0 



4 



44 



0.0 



4 



46 



2.0 



4 



45 



0.0 



4 



47 



2.0 



December 5th, P. M., at the College. 



NeCtUs, Sidereal. P. & F. Mean-Time. 



22 20 27.5 = 



22 23 18.0 = 



22 26 30.0 = 



5 



i 



25.0 



5 



10 



15.0 



5 



13 



26.5 



