ASTRONOMY. 423 



Observations have been taken as often as practicable, to obtain each 

 day the correction of the standard mean-time clock for setting to correct 

 time the transmitting clock, which is used in sending out the time sig- 

 nals from the chronometer room and in rating the chronometers. 



Harvard College Observatory. — The annual report of the director of 

 Harvard College Observatory, for 18S3, was submitted on the occasion 

 of the annual inspection by the visiting committee. It is a document 

 of considerable length, and reviews in detail the doings of the year. 

 The report begins with a statement that the annual donation or sub- 

 scription of $5,000, which has continued for a term of five years, has 

 now ceased. An attempt has been made to supply its place by a per- 

 manent fund. For this $50,000 have been subscribed, and it is hoped 

 that this will be increased to $100,000, so that the activity of the ob- 

 servatory may be maintained. The working force of the institution now 

 consists of the director and sixteen assistants of various grades, six of 

 whom are womeu and ten men. The photometric determinations of the 

 times of eclipse of Jupiter's satellites have been continued. The eclipses 

 thus observed since October, 1882, have been 55, and from the begin- 

 ning 210. . Experimental observations of occultations and transits of 

 the satellites have also been made with a double-image micrometer. 

 A part of the zone observations made under Professor Bond's directions 

 has been revised for the purpose of detecting cases of proper motion 

 among small stars, for which this early work of the observatory fur- 

 nishes valuable data. The present revision also includes photometric 

 determinations with a wedge of tinted glass. 



The construction of charts of small stars near certain selected bright 

 stars, in accordance with a plan adopted some years ago by a committee 

 of the Association for the Advancement of Science, has been begun. 

 Similar charts of the neighborhood of variable stars have also been 

 undertaken. Reference is made to successful distribution of early coin- 

 etary intelligence through the observatory. By this arrangement, the 

 first accurate observations of the two comets discovered this year were 

 made at this observatory, and the positions obtained were extensively 

 used in the computation of orbits. Experimental work has been done 

 in anticipation of a systematic investigation of the spectra and color of 

 the stars. Between February 8 and November 1 Professor Rogers made 

 2,640 observations of fundamental stars with the meridian circle, in- 

 cluding 136 of Polaris and 121 of the sun. Mention is made of the 

 determination during the year through observations at Cambridge of the 

 longitude of McGill Observatory, in Montreal. In order to complete 

 the series of zone observations which formed an important part of the 

 work of the meridian circle from 1870 to 1879, it became necessary to 

 reobserve a large number of stars, and to observe others which were 

 found to have escaped notice previously. The faintness of many of these 

 required a different system of illumination, which was successfully ar- 



