624 



SCIENCE. 



[N. S. Vol. VIII. No. 201. 



papers nor their excellence. Forty papers 

 were offered, of which twenty-six were read 

 in full. As two days only were given to 

 meetings for the reading of papers, a sub- 

 section was organized on the second day, to 

 which were referred the papers in. abstract 

 mathematics. There were also four valuable 

 reports on recent progress, two of which 

 were read before the mathematical sub- 

 section and two before a joint session of 

 Sections A and B. 



Of the strictly astronomical papers, three 

 were concerned with the teaching of the 

 science; two each with subjects relating to 

 stellar positions, to the work of observa- 

 tories and to the study of planetary details; 

 and one each with the subjects of photom- 

 etry, personal equation, variation of latitude 

 and solar eclipses. The short time allowed 

 for these papers, which were all of interest 

 and without exception well presented, pre- 

 vented their discussion, as there was a per- 

 ceptible feeling of hurry due to the desire 

 to complete the program. This lack of 

 discussion is to be lamented in scientific 

 gatherings. Fortunately it did not exist 

 at the Conference at Cambridge, where the 

 discussions called out by the papers were a 

 marked feature. 



THE ASTEROID DQ. 



The discovery by Herr Witt at Berlin, 

 August 13th, of a minor planet whose mean 

 distance fi-om the sun places it between 

 the Earth and Mars is of great interest. 

 It was detected by photography and given 

 especial attention because of its rapid mo- 

 tion. Provisional elements were calculated 

 by Herr Berberich, who has made a spe- 

 cialty of asteroid orbits, and were pub- 

 lished in the Astronomisclie Nachrichten. The 

 observations made since their publication 

 show but small departures from the calcu- 

 lated positions, and confirm the substan- 

 tial accuracjr of the provisional orbit. Mr. 

 A. C. D. Crommelin, of the Greenwich Ob- 



servatory, published in the Observatory for 

 October the results of calculations which 

 assume the accuracy of the first orbit, but 

 which can x^robably be relied on. As the 

 perihelion distance is 1.13 and the eccen- 

 tricity 0.23, the least distance of the planet 

 from the Earth is 0.15 (about 14,000,000 

 miles), while that of Venus is 0.27 and of 

 Mars 0.38. The planet, therefore, comes 

 nearer the Earth than any other planet ex- 

 cept the moon, and can be used with great 

 advantage for observations to determine the 

 solar parallax. Its sidereal period is 644.- 

 734 days and its mean synodic period 2.- 

 30692 years. It is approximately 17 miles 

 in diameter and was of the 7th magnitude 

 in 1894. It is surprising that it has not 

 been detected before, but Mr. Crommelin is 

 of the opinion that it has not been intro- 

 duced into the system bj^ the action of any 

 other planet (the nearest approach to Ju- 

 piter is 3.2) , but has always been one of the 

 solar family. It will be interesting to learn 

 if the photographs made so abundantly in 

 recent years at Cambridge and elsewhere 

 do not contain it, and undoubtedly they will 

 be examined when the planet's positions in 

 former times are determined. 



The Earth passes the longitude of the 

 planet's perihelion January 22d. The next 

 opposition of the planet comes in ISTovem- 

 ber, 1900, the perihelion passage occurring 

 February 12, 1901. The opposition in 1894 

 was a very favorable one, unfortunately 

 lost; another will come in 1924, but that 

 of 1900 will be sufficiently good to warrant 

 careful observations for the solar parallax. 

 In Circular 31,. of the Harvard College Ob- 

 servatory Professor Pickering gives the re- 

 sults of determinations of its brightness. 

 Mr. Wendell's observations with the visual 

 photometer give the mean 12.13 ± 0.04, 

 which corresponds with the 11.39 at the 

 distance 1. The photographic determina- 

 tion of its brightness is difficult, because an 

 exposure of sufficient length to give any 



