21 [ 1 ] 



■will be presented to the Institution in the form of a memoir for the Smith- 

 sonian Contributions to Knowledge. 



COMPUTATIONS. 



Ocadtations for 18-51. — For the purpose of facilitating the accurate 

 determination of geographical points in the United States, a list of occul- 

 tntions and the co-ordinates of reductions for the years 1848, 1849, and 

 1850, was prepared and published at the expense of the Smithsonian In- 

 sititution. Congress has since ordered the publication of an American 

 Nautical Almanac, and as lists of occultations will form a part of this 

 cphemeris, Mr. Preston, late Secretary of the Navy, directed that the 

 expense of computing these tables for 1850, should be defrayed from the 

 appropriation for the almanac, provided the printing and distribution were 

 at the expense of the Smithsonian Institution. The same course has been 

 authorised by Mr. Graham, the present Secretary of the Navy. 



Copies of these tables computed by John Downes, of Pliiladelphia, have 

 been sent to all persons known to the Institution, who would probably 

 make use of them in the way of improving our knowledge of the geog- 

 raphy of this country. They have been furnished particularly to officers 

 e.f the United States Army, and other persons engaged in exploring our 

 new possessions and determining their boundaries. All persons, to whoiri 

 thesetables were presented, have been requested to send the result of their 

 observations, made in connection with the use of them, to this Institution, 

 or to publish them in some accessible journal. 



Epiicmeris of JVeptune. — It w^as stated, in the last report, that the orbit 

 of the planet Neptune, established by the researches of Mr. Walker, and 

 comprised in his memoir published by the Institution, gives the data for 

 calculating an ephemeris or tables of the daily position of this planet, 

 rivaling in precision the tables for any of the older jdanets. Sets of 

 these tables were computed and published for 1848 and 1849, at the expense 

 of the Smithsonian Institution, but those for 1850 and 1851, have been 

 computed under the direction of Lieutenant Davis, superintendent of the 

 Nautical Almanac, and ;it the expense of the appropriation under liis 

 charge, while the expense of printing the tables has been borne by this 

 Institution. 



These ta1)les are corrected for the perturbing influence of the planets 

 Jupiter, Saturn and Uranus, by deductions from mathematical investiga- 

 tions of Professor Peirce, of Harvard University. They have been used 

 in following the motion of Neptune, by all the principal astronomers of 

 the world, and have every where received the highest commendation, re- 

 llecting honor on the Institution and on the science of the country. 



MUSEUM. 



The act of Congress authorizing the establishment of the Smithsoni;in 

 Institution, contemplates the formation of a Museum of Natural History. 

 It would not, however, be in accordance with the spirit of the organization, 

 to expend the income in the reproduction of collections of objects which 

 are to be found in every museum of the country. Naturiil History can be 

 nmch more effectually promoted, by special collections ot new objects, by 

 appropriations for original explorations and researches, and above all, by 



