46 REPORT OF THE SECRETARY. 



After minute inspection lie was led to conclude that one of the stars 

 which had been observed by Lalande in 1795 was the planet Nep- 

 tune, He was thus supplied with the amount of its motiou for up- 

 wards of fifty years, from which he deduced a much more perfect 

 orbit, and was enabled to construct an ephemeris giving the place of 

 the planet for several years in succession. These investigations, so 

 interesting to astronomy and honorable to this country, were prose- 

 cuted and published at the expense of the Institution, the name of 

 which will be further connected with the planet Neptune by the pub- 

 lication, now in press, of a new discussion of all the observations which 

 have been made on this body for the last fifteen years. This work, 

 which is by Professor Newcomb, of the United States navy, will 

 furnish not only the means of determining the exact position of Nep- 

 tune for years to come, but also the data for ascertaining whether it 

 is affected by other bodies than those now known to astronomers. 



To render more generally accessible to practical astronomers in 

 this country the theory of the motion of the heavenly bodies by the 

 celebrated Gauss, the Institution shared the expense of publishing a 

 translation of this treatise by Admiral C. H. Davis, U. S. N., from 

 the Latin. It furnishes a complete system of formulas for computing 

 the movements of a body in any of the curves belonging to the class 

 of conic sections, and a general method of determining the orbit of a 

 planet or a comet from three observations, as seen from the earth. 



For a number of years aid was afforded to the publication of Gould's 

 American Astronomical Journal, which rendered good service to the 

 science by making promptly known to foreign observers the results of 

 the labors of their contemporaries in America. It has also had re- 

 duced by Mr. Charles A. Schott, and published at its own expense, 

 the astronomical observations made by Dr. Kane in the arctic regions, 

 and has. now in hand those which were made in the same regions by 

 Dr. Hayes. 



Congress having authorized in 1849 an astronomical expedition 

 under Lieutenant Gilliss to the southern hemisphere for the purpose 

 of determining the parallax of the planets, and consequently their 

 distance from the sun, by observations on Venus and Mars, accident- 

 ally failed to make the appropriation for instruments. This omission 

 was supplied by the Institution, which was subsequently indemnified 

 for the expense by the Chilian government. 



In the observation of all the larger solar eclipses which have hap- 

 pened since the date of its organization the Institution has actively 



