Page:Popular Science Monthly Volume 3.djvu/367

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that have succeeded one another hitherto, the transformation now in progress is but an advance from a lower form, no longer fit, to a higher and fitter form; and neither will this transformation, nor kindred transformations to come hereafter, destroy that which is transformed anymore than past transformations have destroyed it.


By R. A. PROCTOR, B. A.,


EACH evening during the month of April the planet of Love could be seen in the west for a few hours after sunset. She set earlier and earlier each successive night—overtaking the sun, as it were—and toward the end of April she could no longer be detected. On the 5th of May she had overtaken the sun, passing him at a distance of about three times his own breadth above or to the north of his disk. When these lines appear she will be a morning star. This passage by the sun is the last made by Venus (at least when on the hither side of him) before the long-desired and now famous transit of December 9, 1874, when, instead of passing by the sun, either above or below his disk, as she usually does, she will pass right across his face.

So much has been said of late respecting this approaching phenomenon, and so much importance is deservedly attached to it, that my readers will probably be interested by a brief and simple account of the matter. In particular, some may desire to know what has been the special aim of the controversy recently and still in progress. Before entering on these matters, I shall make a few remarks on the history of former transits.

The first occasion on which Venus was ever seen on the sun's face was on November 24, 1639 (Old Style), corresponding to December 4th (New Style). It is rather singular that then, somewhat as at present, doubts had arisen, owing to a difference of opinion between an astronomer of established reputation and one less known to the scientific world. The Belgian astronomer Lansberg had stated in his "Tables of the Motion of Venus" that no transit would occur in 1639. Young Horrox, while preparing himself for practical observation, undertook (apparently from sheer love of science) the computation of Venus's motions from the tables of Lansberg. These tables were so highly valued by their author that he had spoken of them as superior to all others—"quantum lenta solent inter viburna cupressi." But Horrox recognized many imperfections in them, and at length, as he says, "broke off the useless computation, resolved for the future with my own eyes to observe the positions of the stars in the heavens; but,