256 NATIONAL ACADEMY OF SCIENCES 



COMMITTEE ON THE TRANSIT OF VENUS. 1871 AND 1881 



Two transits of Venus across the sun's disc have occurred 

 since the foundation of the Academy fifty years ago. These 

 took place in 1874 and in 1882. No more will occur until the 

 year 2002. As early as 1870, or even before that date, plans 

 began to be formulated for observing these rare celestial phe- 

 nomena. At the session of the Academy held in Washington 

 in April, 1870, Simon Newcomb read a paper, " On the coming 

 transits of Venus and the mode of observing them," in which he 

 said: 



" . . . . Although the next transit does not occur for four years, the pre- 

 liminary arrangements for its observation are already being made by the govern- 

 ments and scientific organizations of Europe. It is not likely that our govern- 

 ment will be backward in furnishing the means to enable its astronomers to take 

 part in this work. The principal dangers are, I apprehend, those of setting out 

 with insufficient preparation, with unmatured plans of observation, and without a 

 good system of cooperation among the several parties. For this reason I beg leave 

 to call the attention of the Academy to a discussion of the measures by which we 

 may hope for an accurate result." 



After explaining the methods which it was necessary to 

 employ, he remarked: 



" .... I have endeavored to show that no valuable result is to be expected 

 from hastily-organized and hurriedly-equipped expeditions; that every step in 

 planning the observations requires careful consideration, and that in all the pre- 

 paratory arrangements we should make haste very slowly. I make this presenta- 

 tion with the hope that the Academy will take such action on the matter as may 

 seem proper and desirable." 70 



At the same session a committee was appointed by the Presi- 

 dent of the Academy to secure the successful observation of the 

 transit. It consisted of Benjamin Peirce, Superintendent of the 

 Coast Survey, Rear-Admiral Charles H. Davis, at that time in 

 charge of the Naval Station at Norfolk, and Commodore B. F. 

 Sands, Superintendent of the Naval Observatory. 



In his report for the year 1870, the Secretary of the Navy, 

 George M. Robeson, remarked : 



Amer. Journ. Sci., ser. 2, vol. 50, 1870, pp. 74-83. On the mode of observing the coming 

 Transits of Venus. By Simon Newcomb. Read before the National Academy of Sciences, 

 April 13, 1870. 



