The Daily Herald

The Comet.--On Saturday evening, the 17th, Encke's Comet presented an interesting spectacle to our large telescopes, and was distinctly visible even to the naked eye. It was situated, from 6 to 8 o'clock, in the western sky, between the bright star Lyra, and a point of the horizon a few degrees north of west, forming an isosceles triangle with the shoulders of Hercules, its vertex being midway between the three bright stars Alpha, Beta, Delta, of that constellation.

To the naked eye, it would hardly be distinguished from a faint star: but in Clarke's telescope, its appearance was that of a large nebulous body, of a globular figure; of a pale light towards the margin, but much brighter and more condensed towards the center.

Encke's Comet was so named from Mr. Encke of Berlin, one of the most distinguished astronomers of the age, who was the first to determine its elements and the period of its revolution. This period is the least belonging to any known Comet, being only 1208 days, or about 3 years. Hence it is called the Comet of short period. It descends within the orbit of Mercury, but, unlike every other Comet whose orbit has been determined, it retreats from the sun only a little farther than the orbit of Jupiter. The attraction of this large planet, also, greatly disturbs its motions.

It has long been a question with astronomers, whether the planetary spaces were a perfect void, or whether an ethereal medium of extreme tenuity, were diffused through them. Such a resisting medium could never be detected by its effect on the motions of the planets, but it might still be obvious on those of a comet: a feather, or tuft of down, might meet with sensible resistance in a medium which would not apparently affect the motions of a cannon ball. Encke's Comet has settled this question, and revealed to us the important fact, of the existence of a resisting medium in the planetary regions, the effect of which is to bring the Comet at every revolution a little nearer to the sun, thus to increase its velocity, and finally to precipitate it upon that luminary. These considerations, as well as the frequency with which this body is presented to our notice, render it one of the most interesting members of the solar system.

O.