612 



SCIENCE. 



[N. S. Vol. XVII. No. 433. 



approaching and colliding with enormous 

 relative speed, Avould be converted into 

 heat in sufficient quantities to transform 

 the dax'k bodies into incandescent gases. 

 The history of previous new stars had led 

 us to expect that the spectrum would grad- 

 ually change into that of a nebula, and in 

 this we were not disappointed. For a 

 suitable study of the present nebular 

 spectrum of the new star it was necessary 

 that fui'ther and more accurate investiga- 

 tions be made upon the spectra of the well- 

 known nebulse. These investigations were 

 undertaken with great success by Assistant 

 Astronomer Wright. He determined the 

 positions of many well-known nebular lines 

 more accurately than had previously been 

 done, and a number of very interesting 

 new lines were detected. 



Very little attention has been given to 

 the subject of comet-seeking, on account 

 of pressure of work in other lines. 



Micrometer observations of comets in the 

 past two years have been secured, as fol- 

 lows: 



Comet a 1900, Aitken 3 nights, Perrine 4 nights. 

 6 1900, " 10 " " 3 " 



c 1900, " 6 " 

 a 1901, " 2 " 

 a 1902, " 2 " 



Valuable photographs of comet a 1901 

 were secured by Mr. Perrine at the Eclipse 

 Station in Sumatra. An orbit of comet 

 h 1900 was computed by Mr. Perrine, and 

 of comet c 1900 by Mr. Aitken. Some very 

 interesting photograplis of comet 6 1900 

 were secured by Mr. Palmer. 



Extensive series of measures of satellites 

 of planets were obtained by various mem- 

 bers of the staff, observations being limited 

 in all cases to those most desired by investi- 

 gators of their orbits. 



Two hundred and fifteen observations of 

 the relative positions of the satellites of 

 Saturn were made by Mr. Hussey with the 

 thirty-six-ineh equatorial. 



Mr. Aitken made the following observa- 

 tions with the thirty-six-inch equatorial: 



Satellites of Uranus, 27 nights. 



" " Neptune, 13 " 



" " Mars, 7 " 



Fifth satellite of Jupiter, 2 " 



At the request of Professor Newcomb, 

 Mr. Perrine photographed the planet Nep- 

 tune and its satellite on thirty plates, in 

 January, 1902, with the Crossley Reflector. 

 The measurements of these plates furnish 

 fifty-one determinations of the position of 

 the satellite, with reference to its primary. 

 Photographic methods have been but little 

 used in this line of work, and it is interest- 

 ing to note that the smallness of the errors 

 of observation justifies the application of 

 the method in all possible cases. 



The work with the meridian circle has 

 been most efficiently proseciited. Since 

 July 1, 1900, Mr. Tucker has obtained 

 6,500 complete observations. These in- 

 clude observations of Eros comparison 

 stars ; of Eros itself ; of Nova Persei ; and 

 of zodiacal stars, greatly needed at the pres- 

 ent time, to be used as a basis for improv- 

 ing the orbits of the major planets. 



The manuscript for 'Lick Observatory 

 Publications, ' Volume VI., is entirely ready 

 for the printer. The volume will contain 

 results of meridian circle work from July, 

 1896, to March, 1901, and will include 

 about 14,000 complete observations of 

 4,500 stars. 



Fellow R. T. Crawford assisted in merid- 

 ian circle work during the years 1898-1901. 

 At the end of his service he received the 

 degree of doctor of philosophy, having 

 taken for his thesis the subject of 'The Re- 

 fraction Constant at Mt. Hamilton.' 



The department of astronomy known as 

 double stars has been most ably advanced 

 by Messrs. Hussey and Aitken. Their 

 programs have been admirably devel- 

 oped and systematized, and results of 

 prime importance have been surprisingly 



