THE SMITHSONIAN INSTITUTION. 19 



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 Institu- 

 tion shared the expense of publishing a translation of this treatise from the Latin, 

 by Admiral Davis. 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 contempo- 

 raries in America. It has also reduced and published at its own expense the as- 

 tronomical observations made by Dr. Kaue in the Arctic regions, aucl lias also 

 published those made in the same regions by Dr. Hayes. 



Congress having authorized, in 1849, an astronomical expedition under Lieuten- 

 ant Gilliss to the Southern Hemisphere, for the purpose of determining the paral- 

 lax of the planets, and consequently their distance from the sun, by observations 

 on Venus and Mars, accidentally 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 large solar eclipses which have happened since the 

 date of its organization, the Institution has actively and efficiently co-operated by 

 publishing projections of the phases and times of their occurrence in diffiirent parts 

 of America. 



Under its auspices, and partly at its expense, an expedition was inaugurated to 

 observe the great eclipse of 1858 in Peru, from which data of value for the im- 

 provement of solar and lunar tables were determined, besides facts of interest in 

 regard to the physical constitution of the sun. 



Assistance was also rendered to the expeditions under the direction of the Coast 

 Survey, to observe the eclipse of July 18, 18G0, one of which was sent to Labrador, 

 under the charge of Professor S. Alexander, of New Jersey, and the other to 

 Washington Territory, under that of Lieutenant Gilliss. 



To these may be added an account of an instrument invented by Rev. T. Hill, 

 President of Harvard College, for the projection of eclipses. 



Physics and Chemistry. — The Institution has fostered these sciences in many 

 different ways ; among others, by importing models of the most approved articles 

 of apparatus, and making them known to scientific men through lectures and 

 otherwise. 



It has instituted an extensive scries of experiments on building materials, par- 

 ticularly in reference to those employed by the government in the construction of 

 the Capitol and other public edifices; also a like series on acoustics, as applied to 

 public halls, and the principles deduced from these practically applied in the con- 

 struction of a model lecture room. It has made a very extended series of experi- 

 ments on different substances employed for light-house illumination, from which 



