THE SMITHSONIAN INSTITUTION. 193 



applicable to his system of stereotyping catalogues of libraries, by sepa- 

 rate titles ; and in this way it will certainly be of great value, even 

 should it fail in other respects to realize the sanguine expectations of its 

 inventor. 



The result of the experiments will be submitted to a commission of 

 persons properly qualified to judge of its merits; and if their report be 

 favorable, a small sum will be allowed for the use of it. 



Besides the experiments mentioned under the head of meteorology, 

 made by Mr. Espy, on the cold produced by the rarefaction of air, Dr. 

 Hare, of Philadelphia, is employing articles of apparatus belonging to 

 the Institution, in a series of researches on the phenomena exhibited in 

 the air and in a vacuum by rubbing silicious minerals against each 

 other. The results of these experiments, with the drawings of the 

 apparatus employed, he intends to present to the Institution in the form 

 of a memoir for the Smithsonian Contributions to Knowledge. 



•t> v 



Computations. 



Occultations for 1851. — For the purpose of facilitating the accurate 

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

 cultations and the co-ordinates of reductions for the years 1848, 1S49, and 

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

 Institution. Congress has since ordered the publication of an Ameri- 

 can Nautical Almanac ; and as lists of occultations will form a part of 

 this ephemeris, 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 distribu- 

 tion were at the expense of the Smithsonian Institution. The same 

 course has been authorized by Mr. Graham, the present Secretary of 

 the Navy. 



Copies of these tables, computed by John Downes, of Philadelphia, 

 have bee^sent to all persons known to the Institution, who would pro- 

 bably make use of them in the way of improving our knowledge of the 

 geography of this country. They have been furnished particularly to 

 officers of the United States army, and other persons engaged in ex- 

 ploring our new possessions and determining their boundaries. All 

 persons to whom these tables were presented, have been requested 

 to send the result of their observations, made in connexion with the use 

 of them, to this Institution, or to publish them in some accessible 

 journal. 



Ephemeris of Neptune. — It was 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, rivalling in precision the tables for any of the older planets. 

 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 at the expense of the ap- 

 propriation under his charge, while the expense of printing the tables 

 has been borne by this Institution. 

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