350 Clusters and Nebulae — Double Stars. 



observers, far surpasses in completeness everything that has 

 hitherto appeared, and will hereafter be universally referred to 

 as the standard authority upon the subject. It was presented 

 to the Royal Society, October 16, 1863, and has been printed 

 in their Transactions for the present year. It combines all the 

 previous catalogues and descriptions of Messier, Mechain, La 

 Caille, Herschel I., Dunlop, Secchi, Bond, Mason, D J Arrest, 

 Auwers, Lassell, and the Earl of Bosse, and contains 5079 

 objects, of which, however, some few may have been comets or 

 mistaken entries. They are arranged in order of Right 

 Ascension, which, as well as North Polar Distance (more con- 

 venient for such a purpose than Declination in European lati- 

 tudes, as reckoned all one way) is computed for 1860, with 

 columns for Precession to 1880. The corresponding synonyms 

 are all given, and references to other authorities : the num- 

 ber of observations specified, and a summary description 

 added of each nebula or cluster, from a comparison of all 

 previous observations and remarks. The place of every object 

 has been independently calculated both by Sir J. Herschel and 

 Mr. Kerschner, one of the occasional computists at Greenwich, 

 specially employed by the Astronomer Royal for the purpose; 

 — a truly laborious task, comprising between nine and ten 

 thousand entries separately computed by each party. The 

 value of this noble contribution to science will not be esti- 

 mated by the remark, however true in itself, which the 

 author makes with characteristic modesty, when he says that 

 <l for the want of such a general catalogue ... a great many 

 nebulae have been, from time to time, in the Astronomische 

 Nachrichten and elsewhere, introduced to the world as new 

 discoveries, which have since been identified with nebulas 

 already described and well-known. Many a supposed comet, 

 too, would have been recognized at once as a nebula, had 

 such a general catalogue been at hand, and much valuable 

 time thus saved to their observers in looking out for them 

 again." 



A mass of valuable notes is prefixed to the catalogue, 

 from which some extracts of especial interest will be laid 

 before our readers in a future number. 



DOUBLE STARS. 



Our search among the nebulas has brought before us two 

 interesting pairs, which have been already mentioned as lying 

 sp from our No. 26 (81 M.). The nearer, smaller, and more 

 open of these is 



125. 1387 2, who calls it 8""93. 269°-6. Equal, 9*5 mag. 

 of his scale, equivalent to about 10 of Smyth's (1832-97). 



