ASTRONOMICAL PUBLICATIONS. 371 



to the sixth magnitude, for nearly twenty years, has been 

 made by Messrs. Walker, Downes and Paine. Mr. 

 Downes' computations for the years 1848, 1849, 1850 

 and 1851, have been published by the Smithsonian 

 Institution. They contain the times of all the occulta- 

 tions visible at "Washington, and elements for facilitating 

 a similar computation for any part of North America. 



During the session of 1849, Congress made an ap- 

 propriation of $6,000 for the commencement of an 

 American Nautical Almanac. Lieutenant (now Com- 

 mander) Charles H. Davis, of the United States Navy, 

 was appointed superintendent, and the preparation of 

 different parts of the work was assigned to a corps of 

 computers. Lieutenant Davis secured the valuable 

 services of Professor Peirce as consulting astronomer; 

 the theoretical part of the work was placed under his 

 direction; and most of the calculations pass under his 

 final revision. 



The first volume was published in 1852, being the 

 almanac for 1855, consisting of 552 octavo pages. The 

 first part of the work is appropriated to nautical purposes, 

 and is calculated for the meridian of Greenwich. The 

 second part is designed for the promotion of astronomi- 

 cal science, and is adapted to the meridian of Wash- 

 ington. The nautical part consists of an ephemeris of 

 the sun and moon, and of the planets Venus, Mars, Ju- 

 piter and Saturn, together with tables of lunar distances. 

 The ephemeris of the moon is calculated from new tables 

 founded on Plana's theory. The ephemeris of Mercury 



