Xll NOTES BY THE EDITORS 



of Venus, in connection with the National Observatory at Washington. 

 This expedition was placed under the charge of Lieut. Gilliss, U. S. Navy. 

 Suitable buildings were shipped to Chili, as well as two telescopes equa- 

 torial ly mounted, a meridian circle, a clock, and three chronometers. The 

 expedition sailed several months since, and at the last accounts observa- 

 tions had already been commenced at Santiago. The observations espe- 

 cially contemplated consist of differential measurements during certain 

 portions of 1849, 1850, 1851, and 1852, upon Mars and Venus, with certain 

 stars along their paths. In spite of bad weather, Lieut. Gilliss had in ten 

 nights in June, with eight zones, made 444 observations ; in sixteen nights 

 in July, with nine zones, 528 observations ; in twenty nights in Atigust, 

 with ten zones, 576. From the middle of February to September 22d, not 

 much short of 5,000 stars had been observed, and this number would 

 probably be increased to 20,000 during the ensuing season. 



A new wing is in process of construction at the Observatory at Cam- 

 bridge, which is to be devoted in part to astronomical, and in part to me- 

 teorological purposes. It is to contain a comet-seeker constructed upon a 

 new plan, by which it is expected that the labor of searching for these 

 transient visitors to our sphere will be considerably diminished. A set of 

 self-registering photographic instruments will be placed in the basement, 

 from which important results may be expected. In the remainder of the 

 building there will be a computing room and a library, to the collection of 

 which a very liberal sum can now be annually devoted. If it is deemed 

 advisable, other instruments can be introduced. The expense of the build- 

 ing is defrayed by a subscription raised through the efforts of J. Ingersoll 

 Bowditch, Esq., of Boston. 



During the past year such measures have been adopted as will, it is be- 

 lieved, secure the erection of an observatory at Brooklyn, N. Y. Over 

 $ 20,000 have been already subscribed, but nearly as much more is re- 

 quired. It is proposed to procure a first-class refracting telescope, a me- 

 ridian-circle, a clock, and various smaller instruments. 



The longitude of Cambridge Observatory Avest from Greenwich, as 

 deduced from a comparison of 116 chronometers conveyed from Liver- 

 pool to Boston in thirty-four voyages of the Cunard steamers, in 1848, is 

 4 h - 44 m - 30 S> .5 ; that deduced from lunar occupations and solar eclipses is 

 4 h. 44111. sp.y^ w hile that deduced from 87 additional comparisons of 

 chronometers in 1849 differs nearly two seconds of time from that pre- 

 viously obtained by astronomical observations. 



The volume containing the observations made at the National Observa- 

 tory in 1846 embraces a catalogue of some 12,000 or 15,000 stars, most of 

 them unknown to any existing catalogues. It forms a quarto of not less 

 than 1,000 pages, and is the largest work of the kind ever published by 

 any observatory as the result of a single year's labor. 



Nowhere has more activity been displayed during the past year than in 



