296 Astronomical Socictij. 



ducing and arranging them. He therefore took the rough observa- 

 tions with him, and availed himself of an interval of leisure to arrange 

 them in the same form as his other catalogues. The stars observed 

 are less in number than those of his former catalogues, but they are 

 in some respects more interesting, from the greater number of deli- 

 cate and difficult objects comprised ; the measures of which, with 

 those in Struve's great work on Double Stars (said to be in course of 

 publication), it will be important to compare. The catalogue con- 

 tains 105 new double stars, as well as the observations of several 

 others that were previously known ; the positions and distances of 

 which, as observed by Sir J. Herschel, are here recorded: some of 

 the stars, however, inserted in Struve's catalogue, be has been unable 

 to find in this review of the heavens. 



Sir J. Herschel states, that he has nearly gone over the whole south 

 circumpolar region, to 60° from the pole ; the observations of which 

 are in the course of arrangement. He is somewhat surprised at the 

 extraordinary paucity of close double stars, which cannot arise from 

 want of power in the telescope, or from the nature of the climate : for 

 he considers his mirrors as perfect as it is possible to make them ; 

 and he represents the beauty and tranquillity of the climate to be 

 such, that the stars are reduced to all but mathematical points, and 

 thus allow of their being viewed like objects under a microscope. But 

 although the number of double stars is so small, considering the 

 richness of the southern heavens in stars, yet he represents the ne- 

 hulce as very copious ; and has accordingly collected a numerous list, 

 which will doubtless, in due time, be laid before the public. 



n, A Letter from tlie Superintendent of the Nautical Almanac to 

 the Secretary, of which the following is a copy : 



" Naulical Almanac Office, Dec. 6, 1835. 



" My DEAR Sir, — I have the pleasure of forwarding, for distribu- 

 tion, some copies of an Ephemeris of Halley's Comet, founded on the 

 revised elements of the orbit, which appear, as far as 1 have yet 

 tested them, to represent the observations very well; so well, indeed, 

 that I shall not hesitate to adopt them as the basis of my future pro- 

 ceedings with the cometary calculations. 



" An accurate Ephemeris for the period of the Comet's apparition 

 is now absolutely necessary, to enable observers to identify the stars 

 with which the Comet has been compared, to determine parallax, and, 

 finally, to settle their observations. It may, therefore, be as well to 

 apprise you, that such an Ephemeris, founded upon the revised ele- 

 ments, and embracing the period between Aug. 1, 183.5, and March 

 31, 1836, is now in progress, and will be published next week.* 



" It is my intention afterwards to determine, for the same period, 

 the effects produced upon the right ascension and declination by a 

 minute variation of each of the elements of the orbit; and, finally, to 

 compute the effects of the disturbing forces of the old planets. These 

 tables will be prepared and published with all possible dispatch. We 



* This Ephemeris has since been completed and printed. — Sec. 



