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Rh for by others. He had time only to warn a friend of the expected event, then close at hand, and prepared himself to observe it, by forming, through a small aperture in a darkened room, an image of the sun upon a sheet of paper. This he watched continuously on the important day, a Sunday, till the time came for church. Though knowing that the opportunity, which would not occur again to any one then living, might pass in his absence, he left it for what he deemed a religious duty, and did not resume his observation till late in the afternoon. "At this time," said he, "an opening in the clouds, which rendered the sun distinctly visible, seemed as if Divine Providence encouraged my aspirations, when, oh, most gratifying spectacle! the object of so many earnest wishes! I perceived a new spot of unusual magnitude and perfectly round, which had just entered on the left limb of the sun." His friend had been equally fortunate, "and thus," says Mr. Grant, in his "History of Physical Astronomy," whence this account is taken, "did two young men, cultivating astronomy together in a state of complete seclusion in one of the northern counties of England, enjoy the privilege of witnessing a phenomenon which human eyes had never before beheld, and which no one was destined again to see till more than a hundred years had passed away." Horrocks attempted to obtain the sun's parallax, but without much success; good results from such observations requiring, as will be inferred from what has been said, to be made by a pair of observers removed from each other, nearly as far as the limits of the earth will allow.

In 1761 and 1769 astronomers were fully aware of the importance of the occasion. Special preparations were made by different European governments, especially for the latter year, when parties were sent, as now, to various portions of the illuminated hemisphere of the globe. Among the names of those employed are the familiar ones of Captain Cook, who made his first voyage to Tahiti for this purpose, and of Mason and Dixon, the surveyors of the "line" which bore their name, and which was once so frequently heard of in our own affairs.

One, who is less known, but whose singularly bad luck deserves sympathy, was Le Gentil. Sailing for Pondicherry, where he expected to observe the transit of 1761, he was unable to land, and got no other observations than such as could be made at sea. A voyage from Europe to the Indies in those days was something so formidable, that Le Gentil, who was resolved to see the transit of 1769, decided on waiting for it abroad through eight years of voluntary exile, but, by a cruelly hard fortune, when the long-expected day came, the sun was shut out from his view by clouds which had left the sky clear till the eventful occasion.

It is perhaps worth while to recall such a disappointment, to remind us that all the skill, means, and labor, which have gone to fit out the expeditions now absent, are equally liable to frustration by