ASTRONOMY AND METEOROLOGY. 319 



three nebulas as clearly established ; and mentions, as a curious fact, 

 that they are all situated in the same celestial region, and in the 

 vicinity of the Pleiades. 



ANNULAR NEBULA. 



In a letter read before the French Academy, October, 1862, Mr. 

 Lassell, the English astronomer, who has located his observatory at 

 Malta, describes a new and marvellous nebula, situated in the 20th 

 hour at 101 degrees 56 minutes from the pole. A 1480 magnifying 

 power reveals inside the nebula an elliptical ring, perfectly well de- 

 fined, and without any apparent connection with the surrounding 

 nebulous matter. This last, says Mr. Lassell, is like a thin veil of 

 vapor, and not confounded with the margin of the ring, whose splen- 

 dor it diminishes very little. The nebulous envelope, a little more 

 removed from the extremity of the. conjugate axis than from the ex- 

 tremity of the transverse axis, is in reality very fully prolonged, and 

 it is difficult to follow its traces amongst the stars that precede and 

 follow it. There is a star near its northern border in the prolonga- 

 tion of its conjugate axis. The breadth or thickness of the ring 

 differs from that of Saturn in being nearly uniform throughout. It 

 appears, therefore, that if its form is really elliptical, we must see it in 

 a direction almost perpendicular to its plane ; while, if it is actually 

 circular, it is presented to us a little foreshortened. A section passing 

 through any portion of the space between its inner and outer sides 

 would be circular. In other words, it is like a cylinder bent round 

 till both ends meet. 



At first I was inclined to refer it to the same class as the annular 

 nebula of Lyra, chiefly on account of its central star, which was, 

 however, of greater brilliance ; and, besides this, the resemblance is 

 incomplete, for the ring is much more symmetrical, and better defined 

 at its edges. It suggests the idea of a compact assemblage of bril- 

 liant stars, like the milky-way. The brightness of the ring is not 

 strictly uniform, the south preceding position being slightly more 

 luminous. Mr. Lassell proceeds to remark that observations on this 

 nebula are extremely difficult, and that it was only when the fine 

 climate of Malta afforded him a night of unusual clearness, and per- 

 mitted the employment of a power of 1,480, that its details were re- 

 vealed. He concludes thus: "I confess I was strongly impressed 

 with the appearance of this marvel, situated, without doubt, at the 

 extreme limit of the regions accessible to our investigation, and 

 affording reason to believe that the heavens that are invisible to us 

 are peopled with systems more splendid than any which we are per- 

 mitted to contemplate." 



SATURNIAN PHENOMENA. 



One of the most interesting astronomical phenomena of the past 

 year has been the temporary disappearance of the ring of Saturn, 

 that is, from May to August. The cause of this phenomenon is gen- 

 erally understood ; but it may be well to refer to it in this place on 

 account of some curious details connected with it. The position of 

 this great plane (or rather assemblage of planes, the only fiat surface 

 that we know of in the universe) does not coincide with the plane of 



