REPORTS OF AMERICAN OBSERVATORIES. 571 



IY. Work proposed for the coming year (1879-80) : 

 The same as in former years. 



V. Principal publications of the Observatory: 

 Report on the Transit of Mercury, 1878. 



EASTMAN, Meteorological Observations, 187(i. 

 Eastman, Meteorological Observations, 1877. 



VI. Additional information: 



[The following is a short abstract of the annual report of the Superin- 

 tendent of the Observatory to the Chief of the Bureau of Navigation, 

 and in it will be found details additional to the information presented 

 above.— E. S. II.] 



United States Naval Observatory, 



Washington, October 20, 1879. 



" I strongly recommend the removal of the institution to a better site. 

 The present grounds are malarious, the river fogs obscure the vision, 

 rendering it less clear than in a position more removed from the water. 

 When the contemplated improvements are made on the river front, 

 which seem only the question of a short time, when the marsh, partly 

 encircling the observatory, is filled in, and the hill on which the build- 

 ings rest is used as a top-dressing to the land thus acquired, this part 

 of the city will be the center of its water commerce, and its value to the 

 government will be greater than the cost of a new situation for the ob- 

 servatory. It thus seems that when the hill is cut down the selection of 

 a new site will be imperative. It will be better to select this new site 

 now, for the cost will be greater in the future."* 



THE 2G-INCH EQUATORIAL. 



The observers on this instrument have been the same as in the pre- 

 ceding year, namely, Prof. Asaph IIall, in charge, and Prof. Edavard 

 S. HOLDEN, assistant. This instrument is now in good order, and is in 

 constant use. The principal work done; with it by the astronomers dining 

 the year is as follows : 



The satellites of Saturn were observed until December 24, 1878. We 

 have now accumulated a large number of observations of the threeouter 

 satellites of Saturn; and these observations ought to be completely re- 

 duced and discussed lor the purpose of determining more accurately the 

 orbits of these, satellites and the mass of the planet. 



The principal series of observations with this instrument are the ob- 

 servations of double stars by Professor Hall. The thirty stars selected 

 by Struvi; for the comparison of micrometrical measurements by various 

 observers have each been observed eight nights on an average. This 

 work may now he considered as finished. 



*Notk. — An appropriation of §75,000 has been made I" purchase a n>-\\ site. 



