ASTRONOMY AND METEOROLOGY. 359 



able extent, a more systematic form, by a previous mapping of the 

 stars up to a certain magnitude, and contained within a belt of a few 

 degrees in breadth on either side of the ecliptic. Any small planet will 

 in the first instance be inserted in the map as a small star, but will on 

 the re-examination of the same area some time afterwards, be recog- 

 nized in its true character, from the fact of its having moved from the 

 place in which it was first observed. This mapping of the ecliptic stars 

 from the eighth to higher magnitudes, is still comparatively limited ; 

 nor has the length of time during which any one portion, perhaps, of the 

 space has been thus mapped, been sufficiently great to ensure the pas- 

 sage through it, within that time of any planet whose period is as long 

 as the possible periods of those which may yet remain unknown to us. 

 Analogy would therefore lead us to conclude in favor of the probability 

 of their number being much greater than that at present recognized. 

 All those which are now known lie between the orbits of Mars and 

 Jupiter, but many may exist more distant and of much smaller appar- 

 ent magnitudes ; and thus almost the same careful telescopic research 

 may be necessary to make us acquainted with our planetary neigh- 

 bors as with the remoter regions of space. Nor is the telescopic mode 

 the only one by which we may detect the existence of remoter planets ; 

 for as Uranus betrayed the existence of Neptune, so may the latter 

 hereafter reveal to us the retreats in which some more distant member 

 of tlje system has hitherto hidden himself from- the observation of 



man." 



The period of Massilia, the 20th asteroid, differs but 21 days from 

 that of Parthenope, the former being 1422 days nearly. The inclina- 

 tion is less than that of any known planet or comet, which renders the 

 computation of the orbit by the method of Gauss extremely tedious and 

 imperfect. 



COMETS OF 1853. 



A telescopic comet was discovered near star 63, in the constellation 

 Eridanus, March 8th, 1853, by Mr. Charles Tuttle, of the Cambridge, 

 Mass., Observatory. This comet was considerably condensed towards 

 the center, but no definite nucleus was noticed. This comet was first 

 discovered by Prof. Secchi, of the Observatory of the Collegio Ro- 

 mano, on the 6th of March, and was also independently by Schweitzer, 

 at Moscow, on the 8th, and by Dr. Hartwig, on the 10th. There is 

 some reason for supposing this comet to be identical with that of 1664. 



Prof. Schweitzer, at Moscow, discovered the second comet of 1853, 

 on the 4th of April, 1853. It was extremely minute and faint. 



The most remarkable comet of the year was discovered on the 10th 

 of June, by M. Klinkerfues, of Gottingen. This comet was clearly 

 visible to the naked eye, and had a well defined nucleus and tail. On 

 the 2 3d of August, the diameter of the nucleus, as measured at the 

 Washington Observatory, was eleven seconds of arc, and the length 

 of the coma, fifty-two minutes. Its passage of the perihelion was 

 made on the 27th of August. This comet has not been identified with 



