Page:Popular Science Monthly Volume 14.djvu/685

Rh from the moon, nor had it any annular structure: it looked like a radiated luminous cloud behind the moon." The long streamers manifestly require a different explanation.

We can not but think that the true explanation of these streamers, whatever it may be (we are not in the least prepared to say what it is), will be found whensoever astronomers have found an explanation of comets' tails. These singular appendages, like the streamers seen by Professor Abbe, extend directly to the sun, as if he exerted some repellent action on the matter forming the heads of comets. Indeed, Sir John Herschel did not hesitate to say that the existence of such a repulsive force was, to all intents and purposes, demonstrated by the phenomena of comets' tails. Now we know that meteors and comets are in some way associated, though the actual nature of the connection between them is not clear. It is certain that the November meteors, the August meteors, and other such systems, follow in the track of known comets. We know that when, in 1862, the earth passed through the region of space along which Biela's comet had recently traveled, there was a display of thousands of meteors, all radiating from just that part of the heavens from which bodies traveling parallel to the orbit of Biela's comet would have seemed to radiate. It follows from this association between comets and meteors, and from the fact that probably thousands of meteoric and cometic systems travel close to the sun, that in all probability there must exist generally, if not always, in the sun's neighborhood, enormous quantities of the substance whence comets' tails are formed by the sun's repellent action. This being so, we should expect to find generally, if not always, long streams of matter extending from the sun's immediate neighborhood, in the same way that comets' tails extend from comets' heads. Whether the repulsive force is electrical, magnetic, or otherwise, does not at present concern us; or rather it does concern us, but at present we are quite unable to answer the question. All that we know certainly is that, in the first place, the sun does in some way cause streams of luminous matter to appear beyond the heads of comets, in a direction opposite to his own, and to enormous distances; and, in the second place, that the matter forming comets' heads is probably present at all times, in large quantities, in the sun's immediate neighborhood. We can hence infer, with extreme probability, that such long streamers as Abbe saw last July, Myer in August, 1869, Feilitzsch in June, 1860, and several Swedish observers during the eclipse of 1733, are produced in the same way as comets' tails, and therefore really extend (as they seem to do) radially from the sun. It is also certain that if they did not really extend radially from the sun, their always seeming to do so would be altogether inexplicable. So that the theory to which we are led in one direction leads us also out of what would else be a very perplexing difficulty in another direction.—Cornhill Magazine.