Again; in _Hamlet_ (Act i., sc. 1) we find:—
“As stars with trains of fire, and dews of blood, Disasters in the Sun.”
Once more; in the _Taming of the Shrew_ (Act iii., sc. 2) we have the more general, but still emphatic enough, idea expressed by the simple words of reference to—
Shakespeare may be said to have lived at the epoch when astrology was in high favour, and it may be that he only gave utterance to the current opinion prevalent among all classes in those still somewhat “Dark Ages” (so called). This, however, can hardly be said of the author of my next quotation—John Milton (_Paradise Lost_, bk. II.):—
“Satan stood Unterrified, and like a Comet burned, That fires the length of Ophiuchus huge In th’ Arctic sky, and from its horrid hair Shakes pestilence and war.”
Jumping over a century we find the ancient theory still in vogue, or Thomson (_Seasons_, Summer) would never have written:—
“Amid the radiant orbs That more than deck, that animate the sky, The life-infusing suns of other worlds; Lo! from the dread immensity of space, Returning with accelerated course, The rushing comet to the sun descends; And, as he sinks below the shading earth, With awful train projected o’er the heavens, The guilty nations tremble.”
Even Napoleon I. had servile flatterers who, as late as 1808, tried to extract astrological influence out of a comet by way of bolstering up “Old Bony.” But enough of poetry and fiction, let us hasten back to prosaic fact.
[Illustration: Fig. 19.—Telescope Comet with a nucleus.]
Comets as objects to look at may be classed under three forms, though the same comet may undergo such changes as will at different epochs in its career cause it to put on each variety of form in succession. Thus the comet of 1825 seen during that year as a brilliant naked-eye object, after being lost in the sun’s rays, was again found on April 2, 1826 by Pons. Lamentable were his cries at the miserable plight it was in. He described it as totally destroyed: without tail, beard, coma or nucleus, a mere spectre. The simplest form of comet is a mere nebulous mass, almost always circular, or perhaps a little oval, in outline. It may maintain this appearance throughout its visibility; or, growing brighter may become a comet of the second class, with a central condensation, which developing becomes a “nucleus” or head. It may retain this feature for the rest of its career, or may pass into the third class and throw out a “coma” or beard, which will perhaps develop into a tail or tails. Doing this it will not unfrequently grow bright enough and large enough to become visible to the naked eye. In exceptional cases the nucleus will become as bright as a 2nd or even 1st magnitude star, and the tail may acquire a length of several or many degrees. In the last named case of all the comet becomes, _par excellence_ according to the popular sentiment, “a comet.” It will now be readily inferred that the astronomer in his observatory has to do with many comets which the public at large never hear of, or if they do hear of, treat with contempt, because they are destitute of tails.