REPORTS OF ASTRONOMICAL OBSERVATORIES. 649 



Authority for latitude and longitude, United States Coa-st Survey. 

 Director : E. E. Baknaud. 



Instruments: 



((?) Equatorial imtrument : a simple eciuatorial; ai)erture of object- 

 ive, 5 inches ; nniynifying powc^-s of eye-pieces, 52 to ry>,{). (c') A small 

 2h inches alt-azimuth telescope with good rack-work; all the eye-pieces 

 of large telescope flt it. 



(/) Miscellaneous : In use also a small instrument. The base of this 

 instrument is divided to degrees and read by vernier to 3' of arc. An 

 upright pdlar carries a semi-circle of altitude ; this is divided to degrees 

 and read to 3' of arc by a vernier. Attached to the semi-circle of alti- 

 tude is an hour-circle divided to 4"^ of time and read to single minutes 

 by vernier. Upon the hour-circle rests a semi-circle of declination 

 divided to degrees and read to 3' of arc by vernier. On the base are two 

 levels, the instrument being leveled by three adjusting screws, which 

 also serve as feet. The declination semi-circle carries a very small tel- 

 escope about .4 inch diameter of objective. The telescope has a diago- 

 nal eye-piece with metal reflector and single lenses and vertical and 

 horizontal hairs. The instrument was made by W. & S. Jones, London. 

 It is used for identifying stars in comet observations by setting the alti- 

 tude semi-circle for the latitude, thereby converting the instrument into 

 an equatorial. 



Observations during the past year : 



(c) (c') Observations of the planets and comets. 

 Work proposed for the coming year : 



Continuation of the work of last year. 



Principal publications of the observatory during the 



YEAR : 



The only publications have been : Letters to the English Mechanic 

 (Loudon), Science (of Kew York), &c. 

 Additional information : 



Observations have been from June, ISSO, to Jaiuiary, 1881. These 

 observations have consisted chiefly in watching the changes on Ju])iter ; 

 getting positions of comets, and making drawings of Saturn. From 

 July 11 to January 7 about fifty transits of the great red spot on Jupiter 

 recorded and some seventy-five sketches and drawings made of the cou- 

 figuration of his surface. Transits of a ]niml)er of s])ots, &c., on Jupiter 

 also observed. One black transit of Satellite III and four dark (brown- 

 ish) transits of Satellite 1 also noted. 



A very good set of drawings made of the remarkable black spots 

 which brolce out just north of Jupiter's great equatorial baiul, in the 

 iatter part of October (1880). These drawings show the remarlcalde 

 transformations of these spots until their fiually encircling the planet 

 with a beautiful scolloped belt. 



The comets of which positions have been obtained are Swift's (the 

 first position of this comet on October 21), and I»echiile's. 



