ASTRONOMY. 437 



former years, and a catalogue of 900 sets of measures has been published 

 in the Memoirs of the Eoyal Astronomical Society. 



United States Naval Observatory. — The report of the Superintendent 

 bears the date of October 5, 1885. Eear-Admiral S. E. Franklin, U. S. 

 Kavy, was detached March 31 and ordered to the command of the 

 European squadron. From that date to the 1st of June Commander 

 A. D. Brown acted as Superintendent, when he was relieved by Commo- 

 dore George E. Belknap. 



The 26-inch equatorial, in charge of Professor Hall, has been em- 

 ployed on satellites and double stars. The dome, 43 feet in diameter, 

 is now revolved with great ease by means of a 4 horse-ijower gas engine. 

 The observations of the satellite of Neptune and those of the two outer 

 satellites of TJranus have been discussed and the results published. 

 The observations of lapetus have been published since the report 

 closed. 



The transit circle has been employed in the same class of work as in 

 the preceding years. Since the last report 5,520 observations have been 

 made. Of these, 90 were of the sun, 70 of the moon, 156 of the major 

 planets, and 64 of the minor planets. 



The 9-6-inch equatorial : Professor Frisby was placed in charge April 

 2, 1885. The work of the instrument has been confined to : (1) Obser- 

 vations of comets, six of which have been systematically observed during 

 the year. These observations have all been reduced to date, and pub- 

 lished in various astronomical journals in this country and Europe. (2) 

 Observations of asteroids, principally of such as could not be observed 

 with the transit circle on account of their faintness or their position ; 

 thirty-five regular observations of asteroids were made, and twenty-one 

 approximate positions of other asteroids obtained, so that they could 

 readily be observed with the transit circle. (3) Occultations of stars by 

 the moon, whenever practicable. (4) Doubtful observations of stars and 

 asteroids made with other instruments were looked up and decided, 

 this being probably one of the most important uses of the equatorial. 

 A few observations have been made of the variable star in the nebula 

 of Andromeda, which show that the star is decreasing in brightness. 

 Assistant Astronomer Winlock has made several observations of 

 comets, with drawings of their physical peculiarities and changes of 

 appearance. 



The prime vertical instrument : The work of reducing the observa- 

 tions made in 1883-'84 by Lieut. C. G. Bowman and Ensign H. Taylor, 

 U. S. Navy, for the determination of the constant of aberration, has 

 been pursued. In July of last year a communication was received from 

 the president of the International Geodetic Conference, asking the co- 

 operation of this Observatory with the Eoyal Observatory at Lisbon in 

 the determination of the problem of the change of latitudes, the obser- 

 vations to be taken with the prime vertical instruments of the two 

 observatories. Communication was opened and correspondence is still 



