And it is supposed that this monster of 1843, which was first seen in 1668, returned, and was seen in the southern hemisphere in 1880--that is to say, it came back in thirty-seven years instead of one hundred and seventy-five years. Whereupon Mr. Proctor remarked: "If already the comet experiences such resistance in passing through the corona when at its nearest to the sun that its period undergoes a marked diminution, the effect must of necessity be increased at each return, and after only a few, possibly one or two, circuits, the comet will be absorbed by the sun." On October 10, 1880, Lewis Swift, of Rochester, New York, discovered a comet which has proved to be of peculiar interest. From its first discovery it has presented no brilliancy of appearance, for, during its period of visibility, a telescope of considerable power was necessary to observe it. Since this comet, when in close proximity to the earth, was very faint indeed, its dimensions must be quite moderate. The illustration on page 88 gives the orbit of the earth and the orbit of this comet, and shows how closely they approached each other; when at its nearest, the comet was only distant from the earth 0.13 of the distance of the earth from the sun. It comes back in eleven years, or in 1891. On the 22d of June, 1881, a comet of great brilliancy flashed suddenly into view. It was unexpected, and advanced with tremendous rapidity. The illustration on page 89 will show how its flight intersected the orbit of the earth. At its nearest point, June 19th, it was distant {p. 88} from the earth only 0.28 of the distance of the sun from the earth. Now, it is to be remembered that great attention has been paid during the past few years to searching for comets, and some of the results are here given. As many as five were discovered during the year 1881. But not ### ORBIT OF EARTH AND COMET a few of the greatest of these strange orbs require thousands of years to complete their orbits. The period of the comet of July, 1844, has been estimated at not less than one hundred thousand years! Some of those that have flashed into sight recently have been comparatively small, and their contact with {p. 89} ### THE EARTH'S ORBIT the earth might produce but trifling results. Others, again, are constructed on an extraordinary scale; but even the largest of these may be but children compared with the monsters that wander through space on orbits {p. 90} that penetrate the remotest regions of the solar system, and even beyond it.