ASTRONOMY, PROGRESS OF, IN 1894. 



long period, on approaching the planet Jupiter 

 was diverted and not only changed in orbit, but 

 became entangled in his satellites for 2*65 days, 

 during which time the comet made a complete 

 revolution around Jupiter, passing over an arc 

 of 313 3 of longitude. Previous to this approach 

 to the great disturbing planet, he ascribes to 

 comet Brooks a period of 31-38 years, with an 

 utuvrtainty of 1-2 year. The tendency of the 

 iv-oarch is' to disprove the identity of this comet 

 with that of Lexel, though the latter passed also 

 between Jupiter and his satellites; but the mat- 

 ter has boon much discussed, and the suspected 

 identity will probably never be either substan- 

 tial od or disproved. 



Spectrum of Comet b 1894 (Gale). With 

 a narrow slit, Prof. Campbell saw a bright line 

 at wave length 563, terminating the yellow 

 band; another at 474, terminating the blue 

 band : and two bright lines in the green band 

 were measured at wave lengths 5,163-5 and 

 5,124. His conclusion was that the four lines 

 were the edges of carbon bands at wave lengths 

 5,635, 4, 737, 5.165-3, and 5,129, which in every re- 

 spect seemed to agree with the observations of 

 Prof. Vogel. The spectrum was photographed 

 on several nights, with long exposures. On one 

 evening 6 bright lines were recorded ; on 

 another, 15 bright lines and the unresolved 

 band at wave length 47 were depicted, and, 

 later, with greatly extended exposure, 22 bright 

 lines were photographed. Comparison of this 

 spectrum with that of comet b 1893 shows the 

 two to be identical. The conclusion arrived at 

 is that the principal lines are due to the pres- 

 ence in both comets of carbon and cyanogen, but 

 the origin of several of the fainter lines is un- 

 known. The spectrum of comets more nearly 

 resembles that of a burning compound of car- 

 bon than one of carbon made incandescent by 

 electricity. 



Jupiter's Family of Comets. Nearly all, if 

 not every one, of the comets of short period 

 were made thus by the perturbing influence of 

 Jupiter, and hence their paternity is ascribed to 

 him. In their journey to the sun they traveled 

 near the giant planet, whose superior attraction 

 changed their orbits from ellipses of long period, 

 or perchance parabolas, to ellipses of short pe- 

 riod. The appended list is his family record so 

 far as known. Nearly all have been observed at 

 more than one apparition: Lexel's of 1770, De 

 Vico's, D' Arrest's, Finlay's, Denning's I, Den- 

 ning' s II, Faye's, Tempel's I, Tern pel's II, 

 Swift's I, Swift's II, Barnard's I, Barnard's 

 II, Brooks's I, Brooks's II, Encke's, Spitaler's, 

 Brorson's, Wolf's, Holmes's, Winnecke's, Tut- 

 tle's, Biela's (lost). 



There are a few others having short computed 

 periods, but too much uncertainty attaches to 

 them to warrant their introduction into this 

 table. 



Asteroids. This year there has been a lull 

 in the discovery of these little planets, and but 

 few new members have been added to the aster- 

 oid group. In March, 1893, as many, less one, 

 were found as have boon discovered in tho past, 

 eleven months. But astronomy is tho gainer by 

 the infrequency of their detection. The follow- 

 ing list comprises all those to be added to the 

 catalogue incorporated in the last volume : 



Date. 



Nov. 6, 1893 

 Dec. 6, iv. 

 Jan. 8, 1894 

 Jan. 8, Is94 

 Jan. 10, 1894 

 Jan. 29, 1894 

 Jan. 29, 1894 

 Feb. 11, 1S94 

 Jan. 8d, 1894 

 Mar. 1, 1894 

 Mar. 1, 1894 

 Mar. 5, 1894 



Symbol. 

 AO 

 AP 

 AQ 

 AK 

 AS 

 AT 

 AU 

 AV 

 AW 

 AX 

 AY 

 AZ 



Discoverer. 



Wolf. 



< 'harlois. 



Charlois. 



Charlois. 



(harlois. 



Charlois. 



Charlois. 



Courty. 



Wilson. 



Wolf. 



Wolf. 



Courty. 



So far as known, not one of these has received 

 a name, nor have any names been given, save 

 a few, to those found in 1891-'93. The entire 

 number of these bodies is a little uncertain, but 

 will not vary much from 388. 



Diameters of Asteroids. As is well known, 

 measurement of the diameters of the asteroids 

 has been deemed impossible, but Dr. Barnard 

 thinks the brightest of them easily measurable 

 with the 36-inch telescope of the Lick Observa- 

 tory. " Astronomy and Astro-Physics " for May, 

 1894, contains a history of the determination by 

 several astronomers of the diameters of Ceres, 

 Pallas, and Vesta, but the results are very dis- 

 cordant. All measurements hitherto have given 

 the largest diameter to Vesta ; but Dr. Barnard, 

 with the great telescope, using a power of 1,000, 

 has made micrornetrical measures of Ceres, Pal- 

 las, and Vesta, and has found the diameter of 

 Ceres twice as large as either of the others. 

 Subjoined are his filar-micrometer measures of 

 these three planetoids : 



Diameter. * Miles. No. of nights observed. 



Ceres = 1 -330" 0'064" =* 599 29 B 



Pallas - 0-605" 0-026" = 273 12 

 Vesta = 0-527" 0-033" = 23T 15 

 All at distance unity. 



The disks, which were uniformly round, gave 

 no suggestions of an atmosphere. An inspec- 

 tion of Juno, without measures, shows it to be 

 comparable in size to Pallas and Vesta. From 

 consideration of the amount of light emitted by 

 these asteroids, Argelander derived their diame- 

 ters as follow : 



Ceres = 230 miles. 



Pallas = 162 " 



Juno = 108 " 



Vesta = 275 " 



Meteors. While information has been had 

 from various parts of the world of about the 

 usual number of bolides, yet, as usual, the ac- 

 counts are so at variance that it is difficult to 

 obtain data of sufficient exactness for computa- 

 tion of reliable orbits. A gratifying exception 

 is the report of a meteor of this sort seen at and 

 in the vicinity of Grahamstown, Cape of Good 

 Hope, on the evening of April 6, 1894, which is 

 thus described by Mr. L. A. Eddie, F. R. A. S. : 

 " When first seen it was about 6 above the 

 western horizon, moving very slowly to the east, 

 having in its wake a brilliant train some 30 in 

 length and 2 or 3 in width, much resembling 

 a bright comet with a long tail. When nearing 

 the eastern horizon the flame was extinguished 

 and it resumed the appearance of a glowing ball 

 of molten matter, as it had on its first appari- 

 tion in the west. It was visible for thirty sec- 

 onds. The cause of its slow motion was, doubt- 

 less, its direction of motion, that having been 

 from west to east, the same as that of the earth." 

 He adds: " I had never before seen a fire ball rise 

 and set as this one did. There was no accom- 



