ASTRONOMICAL PHENOMENA AND PROGRESS. 



Periodicity of Comets. At the session of the 

 Paris Academy of Sciences on January 8, 1883, 

 M. Zenger read a paper on the periodicity of 

 comets. The theory proposed includes the fol- 

 lowing propositions : 



1. Comets have originated in the sun. 



2. Their origin has been in some way con- 

 nected with the sun's rotation. 



3. Portions of the matter forming the solar 

 protuberances have been thrown out into space 

 by enormous explosive force. From the mat- 

 ter thus ejected large meteorites might gather 

 about them such quantities of the coronal sub- 

 stance as to constitute comets. 



4. The periods of comets are multiples of 

 half the rotation period of the sun. 



M. Zenger has collected a number of facts 

 which he regards as evidence in favor of his 

 hypothesis. 



The Great Comet of 1882, and the Speetroseopic 

 Method of determining Motions in the Line of Sight 

 This comet afforded an excellent opportunity 

 for testing the accuracy of the spectroscopic 

 method of finding the rate of approach or re- 

 cession of the heavenly bodies. M. Thollon, 

 observing the comet's spectrum on September 

 18th, found the bright lines of sodium displaced 

 by an amount indicating a recession at the rate 

 of forty-seven miles a second. After the comet 

 had been observed for a sufficient length of time 

 to determine its orbit, its true rate of motion in 

 the line of sight was found to have been forty- 

 five miles a second. As the amount of dis- 

 placement was only estimated by M. Thollon, 

 not accurately measured, the agreement be- 

 tween the observed and calculated rates is 

 quite satisfactory. The comet's rate of reces- 

 sion, September 18, 1882, was about equal to 

 that of Vega as determined by the spectro- 

 scope. 



Meteors. The following large meteors were 

 observed during the year ending December 1, 

 1883: 



On December 12, 1882, a large meteor was 

 seen from the United States steamer Alaska, 

 westward from San Francisco, latitude 38 21', 

 longitude 134 7' west; when about 10 above 

 the horizon it exploded with a loud detona- 

 tion, the glowing fragments plunging into the 

 ocean. 



At Concord, N. H., one of the largest and 

 most brilliant meteors ever observed there was 

 seen on the afternoon of December 20, 1882, 

 between four- and five o'clock. It passed from 

 west to east, and was as plainly visible as me- 

 teors usually are after dark. 



Payne's "Sidereal Messenger" for March, 

 1883, contains an account of a very brilliant 

 meteor which passed over Central Indiana. on 

 the evening of January 3d. From observations 

 at numerous points in Indiana and Illinois it 

 is concluded that the meteor first became visi- 

 ble over Grant county, Indiana, at a height of 

 about 85 miles, that it passed very nearly over 

 Kokomo and Lafayette, its height at the latter 

 place being 53 miles ; that its course was south 



78 west, and that the length .of its visible track 

 was about 140 miles. 



About six o'clock on the evening of February 

 5th a meteor three or four times as large as 

 Venus was seen at several points in Indiana. At 

 Bloomington, when first noticed, it was a few 

 degrees east of south, 18 or 20 above the 

 horizon. It disappeared behind a building, the 

 length of its visible track having been nearly 

 20. At Martins ville, Morgan county, it was 

 first seen 5 west of south at an apparent eleva- 

 tion of 18. 



On the 16th of February a large meteoric 

 stone fell, a little before three o'clock in the 

 afternoon, between Cremona and Brescia, sink- 

 ing more than three feet into the earth. The 

 explosion was heard at a distance of 12 or 13 

 miles. 



At Norwich, Conn., a meteor of great mag- 

 nitude was seen on the evening of February 

 27th. Its path was from the northeast to the 

 northwest. 



Early on the morning of March 4th an im- 

 mense fire-ball darted across the heavens at Pe- 

 tersburg, Va., brilliantly illuminating the city. 

 Its course was northwest, and an explosion was 

 heard shortly after its passage. 



At the meeting of the Royal Academy of 

 Vienna, on the 14th of June, 1883, Prof. G. von 

 Niessl read an elaborate discussion of the ob- 

 servations of a meteoric fire-ball seen at Brunn 

 and elsewhere, at about 7 h ' 30 m - on the even- 

 ing of March 13, 1883. Dr. von Niessl finds 

 the radiant point of this meteor to have been 

 in right ascension 148 30' and in south dec- 

 imation 9. Its mean altitude was about 61 

 English miles, and its heliocentric velocity was 

 estimated at 50 miles a second. The meteor's 

 orbit about the sun was, therefore, an hyper- 

 bola. If it belong, then, to a meteoric cluster, 

 no member of the group can be expected to 

 return. Several other large meteors are known 

 to have appeared at nearly the same epoch. 



On the evening of April 14th, at 7 h- 30 m a re- 

 markably fine meteor was seen at Wooster, O. 

 When first noticed, its direction from the point 

 of observation was east-southeast, about 45 

 above the horizon. It had at least twice the 

 apparent magnitude of Venus, and the line of 

 its motion would have cut the horizon a little 

 north of east. After a brief visible flight as a 

 single body, it suddenly burst into fragments 

 twenty or more all brilliant and pursuing the 

 same direction, but more slowly, and falling 

 somewhat below the line which the meteor 

 seemed at first to pursue. 



At about 10 h - 45 m - on the evening of June 

 3d, a meteor whose apparent magnitude was 

 several times that of Venus was seen at sev- 

 eral points in England. At Ripon its length 

 of path while visible was about 120, with the 

 middle point due east; direction of motion, 

 parallel to the horizon ; elevation, 20 ; length 

 of train, 25. Another large meteor was seen 

 later in the same evening. 



A splendid meteor was seen in the evening 



