426 SCIENTIFIC RECORD FOR 1885. 



and advice of one of its most cordial friends, who had been a member 

 of the visiting committee from the time of its original organization, forty 

 years ago. Mr. Paine has perpetnated his services to his favorite science 

 by the bequest to the observatory of his entire fortune, amountiug to 

 more than a quarter of a million of dollars. Upon the settlement of 

 the estate, one-half of this sum will become immediately available. 



The devotion of the observatory mainly to photometry continues, and 

 the large equatorial has been occupied in observations of the eclipses of 

 Jupiter's satellites, faint stars selected as standards of magnitude, com- 

 parison stars for variables, and of the temporary star in the nebula of 

 Andromeda. Mr. Chandler has continued his observations with the 

 new instrument of his invention called the almncaniar, which in his 

 hands exhibits, Professor Pickering says, a surprising efficiency and 

 accuracy. The meridian photometer shows a large increase of work 

 over previous years, the number of separate settings somewhat exceed- 

 ing 50,000. The list of objects observed has been somewhat extended, 

 and the accordance of the results continues satisfactory. The height 

 and velocity of clouds have been the subject of study with Mr. W. M. 

 Davis, about three hundred series of measures being obtained at a pair 

 of stations connected by telephone. The measured altitudes varied 

 from 2,000 to 25,000 feet. The observatory remains the American center 

 of telegraphic distribution of important astronomical announcements, 

 the discovery of nine small planets, five comets, and one new star being 

 promulgated during the year. By the aid of the Bache fund of the 

 National Academy of Sciences, an important investigation in stellar 

 photography has been undertaken. Many photographs of the trails left 

 by stars have been taken with the camera stationary ; and an equatorial 

 star no brighter than the sixth magnitude leaves its mark in this way, 

 while stars much fainter near the pole will leave an impression, since 

 their motion is slow. Stars as faint as the fourteenth magnitude have 

 thus been photographed without clock-work to move the instrument. 

 The trails of the faint polar stars are very well defined and minute, and 

 afford an excellent measure of stellar brightness, besides furnishing the 

 means of determining the stars' positions with great accuracy. Also, 

 the attempt has been made to prepare star charts by photography ; but 

 the most striking results have been obtained with stellar spectra. By 

 means of a large prism mounted in front of the lens, photographs of 

 spectra have been obtained of stars as faint as the eighth magnitude, 

 in which lines are shown with sufficient distinctness to be clearly seen 

 in a paper positive. As all the stars in a large region are thus obtained 

 with one exposure, more than a hundred spectra have been secured on 

 a single plate. 



The work done with the meridian circle by Professor Eogers has 

 largely consisted in the determination of the graduation of the instru- 

 ment. Tlie work performed for this purpose is equivalent to the read- 

 ing of a microscope forty thousand times. A second revision of the zone 



