40 



ASTRONOMY, PROGRESS OF, IN 1892. 



his (on these occasions) great southern declina- 

 tion. The astronomers of the Lick Observatory, 

 with its great elevation above the sea and its 

 lower latitude, have observed this planet under 

 more favorable auspices than those at any north- 

 ern observatory, but published unofficial ac- 

 counts from this point are conflicting as to the 

 success in verifying the duplication of Schiapa- 

 relli's network of canals. The snow-cap sur- 

 rounding the south pole has been conspicuously 

 visible even in small telescopes. At the Warner 

 Observatory both satellites have been seen fre- 

 quently. On several occasions a small, circular, 

 black spot has been noticed partly on the follow- 

 ing edge of the snow-cap, resembling in appear- 

 ance the shadow cast on Jupiter by one of his 

 satellites. At the Lick Observatory the satel- 

 lites were seen to disappear in eclipse on reach- 

 ing the line of shadow in two tenths of a sec- 

 ond, consequently, as the extent of their orbits 

 is known, and their orbital motions cover a space 

 equal to their diameters in two tenths of a sec- 

 ond of time, Prof. Edward S. Holden, the di- 

 rector, has computed their diameters as follows: 

 That of Phobos. the inner satellite, about eight 

 miles ; that of Deimos, the outer, about twenty 

 miles. These values differ from those of many 

 authorities. M. Perrotin has announced that 

 with the great equatorial telescope at Mont Gros 

 the luminous projections seen at the Lick Ob- 

 servatory have been observed since June 10. The 

 shifting of the southern snow-cap has also been 

 noticed, and some of the canals are apparent 

 enough to convince the most prejudiced observer. 

 In a letter to the New York " Herald " of Sept. 

 1, Prof. W. H. Pickering, of Arequipa, Peru, 

 claims the discovery of two mountain ranges on 

 Mars, north of the green patch near the planet's 

 south pole. In the equatorial mountain regions 

 snow fell on Aug. 5, covering two mountains. 

 On Aug. 7 the snow had melted. He says in a 

 later letter : " I have seen forty lakes varying in 

 size. They branched out in dark lines, connect- 

 ing them with two large, dark areas like seas, 

 though not blue. Many of the canals mentioned 

 by Schiaparelli were also seen, but they were 

 found to be single and not double." 



Algol and Other Variables. Prof. S. C. 

 Chandler, an authority on variable stars, has 

 made thorough investigation of the complex 

 changes in the variability of the light of Algol, 

 and he declares the star to be not only a double 

 but a triple: that it has a dark spectro-photo- 

 graphic companion, unseen by any eye, which 

 revolves round its primary, partly occulting it, 

 thus producing the long known variability of its 

 light in 2 (l 20>> 8 m , and contends that it 'is sub- 

 ject to still another orbital motion of a very dif- 

 ferent kind. Both have a revolution about a 

 third bodv a large, distant, dark companion 

 in a period of about one hundred and thirty 

 years. He thinks the size of its orbit around 

 the common center of gravity is about equal to 

 that of Uranus around the sun. The plane of 

 the orbit is inclined about 20 to our line of 

 vision. Algol transited the plane, passing 

 through the center of gravity perpendicular to 

 this line of vision in 1804, going outward, and 

 in 1869 coming inward. Mr. Chandler's paper 

 on the subject will be found in " Astronomical 

 Journal." No. 15, Vol. XL 



Mr. A. W. Roberts, of Alice, South Africa, 

 announced the discovery of a short-period vari- 

 able in Argo Navis which changes from magni- 

 tude 7'5 to 8'5 in a period of 4'6 days, increasing 

 in brilliancy for l - 8 day, and decreasing for 2'8 

 days. It is in It. A. 8 h 33 m 37% Dec. south 46 

 55-4' (1875-0). 



Mr. Espin, of Wolsingham, during 1891, dis- 

 covered 120 new third-type stars, 1 fourth-type, 

 and 5 variable stars, bringing the total number 

 of the latter class up to 627. 



Examination by Mrs. M. Fleming of photo- 

 graphs of stellar spectra taken at Arequipa has 

 resulted in the detection of five new variable 

 stars. Two are within 4 of the south pole. 



Asteroids. Since Vol. XVI went to press, 

 15, perhaps 16, of these small planets have been 

 discovered visually and several photographically. 

 The number now recognized as belonging to this 

 group is uncertain, but is probably 340. The 

 names given them since last report, are : 



805. Gordonia. 

 307. Nike. 

 80S. Polyxo. 

 810. Margarita. 



811 Claudia. 



312. Pierretta. 



815. Constancia. 



822 I-haeo. 



823. Bmcia. 

 825. Heidelberga. 

 330. Alimtar. 

 832. Columbia. 



The names of the discoverers are : 



The numbers and their discoverers are so con- 

 fusing that it has been decided, until all doubts 

 are removed, to number them A, 13, C, etc., giv- 

 ing the year of discovery. 



Discovery of Nebulae. In Astronomiscfie 

 Nachrichten, No. 3094, Dr. Lewis Swift has 

 chronicled a list of 60 new nebulae found at the 

 Warner Observatory during 1891. This cata- 

 logue is in continuation of the series of 9 pre- 

 vious ones of 100 each discovered at the Warner 

 Observatory and published in the same journal. 

 Owing to adverse conditions in the surroundings 

 of the observatory introduced within the year, 

 and to sky illumination from electric street lights, 

 the quest has ceased, and the observatory is to 

 be moved to Colorado. 



In "Monthly Notices" for April, 1892, Mr. 

 Burnham gives a list of nebute covering 21 pages 

 of those discovered by himself, by Barnard, and 

 others, and of many additional ones selected 

 from Dreyer's New General Catalogue of Nebu- 

 lae, because of some uncertainty in description 

 or doubt concerning place or actual existence. 

 He has settled many disputed points, and the 

 notes appended to the nebulre are very interest- 

 ing and valuable. His discoveries and observa- 

 tions were made with the 36-inch telescope dur-_ 

 ing September and October, 1891. 



Catalogues. In the " Astronomical Journal." 

 No. 268, Prof. J. C. Porter, of the Cincinnati 

 Observatory, has a catalogue of 301 stars having 

 a proper motion of a half-second and over. He 

 hopes soon to publish a more extensive record 

 of stellar proper motions. 



The second installment of the Paris Catalogue 

 has recently been issued. This volume contains 

 the reduction of 7,538 stars within the limits of 



