ASTRONOMY AND METEOROLOGY. 333 



New Relation of Periodic Times. Mr. Finlaysan, of Dover, Eng., 

 points out the fallowing singular proportion : The period of rotation of 

 the earth on its axis is in the same proportion to the periodic time of the 

 moon round the earth, as that of the period of rotation of the sun on its 

 axis is to the periodic time of Mars round the sun. 



Nebula of Eta Argus and Southern Double Stars. Mr. Powell, ob- 

 serving at Madias, confirms his own and Mr. Abbot's previous suspicions 

 of the changes in the nebula surrounding Eta Argus. He states that 

 since 1860, the whole nebula has faded away very considerably, and has 

 also altered its form ; the star now being left quite isolated, and out of 1 he 

 n -bilious nutter altogether. It is to be remembered that the star is one 

 of the most remarkable variabl ones, and the phenomenon of the star 

 and nebula varying in brightness at the same time resembles that of the 

 disappearance of the small star and telescopic nebula of Taurus a few 

 years since. Mr. Powell has also made some good observations on the 

 remarkable star, Alpha Centauri, which is now at an interesting part of its 

 orbit, as the distance is now decreasing. Gamma Coronas Australia he 

 finds has described 20 during the last four years. 



New Nebulce. Mr. Lassel, the celebrated English Astronomer, who 

 has for some time located his fine telescope in the Island of Malta, an- 

 nounces the discovery of nearly 200 new nebula? during the last year. 



Orbits of Binary Stars. Prof. Kirkwood in a recent communication 

 to S Human's Journal, directs attention to the fact that the orbits of 

 Binary Stars, so far as observed, are much more elliptical than those 

 of the planets, Of the whole number of apparently double stars known 

 to us, about 6,000, no less than 650 have changed their relative posi- 

 tion. The almost circular path of planets around the sun and the 

 extremely elliptic motions of the self-luminous stars are both accounted 

 for by the theory of Laplace, as explained by Prof. K. For if a mass 

 of nebulous matter in which the process of condensation has com- 

 menced, has a very slow rotation, and if instead of a single center of 

 attraction, two distinct nuclei be formed, the consequence may be its 

 complete separation into two bodies, while the rotation is yet so slow 

 that, the centrifugal force, as compared with centripetal, is too feeble to 

 produce a nearly circular motion. While, therefore, orbits of small 

 eccentricity must characterize planets formed from the abandoned 

 equatorial rings of a condensing nebula, orbits highly elliptical may be 

 regarded as the probable consequence of a separation in the earlier 

 stages of its physical history. 



Thoughts on the Influence of Ether in the Solar System, its Relation 

 to the Zodiacal Light, Comets, and Seasons, and periodical Shooting- 

 Stars. In a communication to the American Philosophical Society by 

 Dr. A. Wilcocks, the author advances the hypothesis that there is a 

 constant circulation of ether induced by the heat of the sun ; that the 

 cold ether descends near the poles of the sun, and that heated ether 

 ascends from the sun's equator, or rather from a parallel of solar 

 latitude just north of the equator ; that this heated current as it rises 

 is compressed by the cold ether into a thin conical sheet ; that the 

 ether bears with it matter capable of reflecting light, and thus causes 

 the zodiacal light ; that the tails of the comets are lighter than the 

 ether, and arise for that reason from the sun, except when near the 

 poles of the sun, when they are made to descend in the vortices of 



