304 NATIONAL ACADEMY OF SCIENCES 



The committee consisted of F. A. P. Barnard (chairman), A. 

 Graham Bell, J. D. Dana, S. P. Langley, Theodore Lyman, E. C. 

 Pickering, and C. A. Young. 



Of the three subjects presented for its consideration, the com- 

 mittee gave its attention principally to the question of the erec- 

 tion of a new observatory building. 



THE ASTRONOMICAL DAY 



As regards the change in the astronomical day proposed by 

 the International Meridian Conference, to make it conform to 

 the civil day, the committee recommended that it be carried into 

 effect as soon as there should be a general agreement among 

 astronomers and astronomical establishments to adopt it, and 

 preferably in 1890 or in 1900. It is well known that from the 

 earliest times astronomers have been accustomed to reckon the 

 day as beginning when the sun is on the meridian, or in other 

 words, at noon; while for ordinary purposes among modern na- 

 tions the day begins at midnight. In the case of a phenomenon re- 

 ported as occurring on a certain day between noon and midnight 

 there is, therefore, room for uncertainty as to the real date, unless 

 the kind of day be specified. If the astronomical day should be 

 made to conform to the civil day, this uncertainty would dis- 

 appear but, on the other hand, there would be a lack of uni- 

 formity between ancient and recent astronomical records. The 

 committee considered these difficulties and decided that the 

 advantage of having a single system of reckoning time over- 

 balanced the inconvenience of a discrepancy among astronomical 

 records. This view has not, however, prevailed up to the present 

 time, and, with few exceptions, astronomers have continued to 

 regard the day as beginning at noon. 



THE SOLAR ECLIPSE OF AUGUST 29, 1886 



This eclipse was visible in the tropics and the committee, after 

 looking into the matter, concluded that it would be observed to 

 the best advantage in Benguela, West Africa, but as a consider- 



