ASTRONOMY AND METEOROLOGY. 391 



attended with similar results on comets, the influence of electricity must be 

 most decided on these bodies when they are nearest to the solar orb; the 

 attractive power between the nucleus and envelop will be then greatest, and 

 the compression on the latter must confine it to the most limited space. In 

 this manner we may account for the fact that the heads of comets gradually 

 become small as they approach the sun, and regain their size when retiring 

 from him. The consequences of electrical action is also indicated by the 

 commotions to which these bodies appear to be subject, and by the dismem- 

 berment which Biela's comet experienced during the present century. In 

 another place I have shown that this wonderful catastrophe was such as 

 might be expected to result from a great electrical disturbance, and the con- 

 sequent occurrence of an extensive storm in the atmosphere of the cometary 

 mass. (See Annual of Scientific Discovery for 1858, page 405.) 



VARIABLE STARS. 



The fine double star y Virginis, is one of the most remarkable specimens 

 of a binary system in the sidereal regions, and has been watched with great 

 assiduity for several years past by Admiral Smyth, of England, and several 

 other astronomers. At the last meeting of the British Association (Leeds), 

 Admiral Smyth stated that its observed and computed places have generally 

 been found to agree within the limits assigned to probable errors of obser- 

 vation, and that it now presents a system which affords, by actual changes 

 both in angular velocity and distance the former varying inversely as the 

 square of the latter, with the elliptical orbital elements deducible therefrom 

 incontrovertible evidence of the physical connection of its constituent mem- 

 bers. These results are converting probability into demonstration respecting 

 its being subject to the same dynamical forces which govern our own system. 

 Every advance tends to prove the universality of the Newtonian influence of 

 attraction, obeying the Keplerian law of areas. In a word, by warranting 

 the conclusion of the inconceivable extent of the controlling agency of grav- 

 itation, it forms a wonderfully sublime truth in astronomical science. 



Some interesting observations have also been made recently upon Antares, 

 the nearest of the double stars of the first magnitude. From these, the color 

 of the smaller companion was ascertained to be of a blue-green, the star An- 

 tares itself being of a brilliant deep red; and there are traces of change in 

 the angle and distance since 1849. With regard to another double star, a 

 Centauri, the distance has little altered for a long time, but the angular mo- 

 tion is increasing. 



Attention has also been recently directed to the star B, A, C, 3345, whose 

 variability seems very great. In 1856 several attempts were made at Green- 

 wich to observe it, amongst other moon-culminating stars set down in the 

 Nautical Almanac for 1859, but in every instance without success. In its 

 stead, 19- Leonis which precedes it by a few seconds of time, was observed 

 four times; and a star which precedes 19 Leonis by ten seconds was observed 

 twice, while nothing whatever was visible at the exact position of the star 

 sought for. The observers reported the circumstance, and were directed to 

 keep a vigorous watch for the missing star. In 1857-8 no difficulty in ob- 

 serving it has been reported, its appearance being that of the 7th magnitude. 

 The star is identical with Lalande 19,197, who marks it as of the 9th magni- 

 tude. In Mayer's Catalogue, as revised by Mr. Baily (Mem. R.A.S. vol. iv.), 

 it is No. 420. It is also identical with Piazzi IX. 176, and is marked of the 



