Page:Popular Science Monthly Volume 76.djvu/22

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THE POPULAR SCIENCE MONTHLY

attraction of other comets or even of some planet, too far removed from the sun to be even perceived. It should be remembered that nothing was known at this time of Uranus and Neptune. The actual time of perihelion passage was March 13, just within the limit.

The history of its discovery is interesting. Though astronomers everywhere were looking forward with great interest to the event, the most elaborate attack was made at Paris. This was planned by De Lisle, but the work of searching for the body fell to Messier, whose name is familiar to astronomers everywhere in connection with the discovery of numerous comets, nebulæ and clusters. He had a genuine

The Path of Halley's Comet and its Conjunction with the Earth's Orbit.

passion for this class of work, but no taste whatever for theoretical research. At this time he was living in the house of De Lisle, who seemed to think that he had a property right in Messier's observations, which Delambre tells us he hoarded as a miser does his wealth, neither using them himself nor allowing any one else to do so.

De Lisle planned a systematic siege of the stronghold. Assuming limits which he believed wide enough for the purpose, he prepared charts on which lines were drawn for convenient dates, the supposition being that the comet would be found somewhere on the line. Night after night for eighteen months, Messier carried on the siege until, finally, on January 21, 1759, he was rewarded with his first sight of the comet. It was doubtless humiliating to all concerned to learn that on Christmas eve, previous, the comet had been seen by a peasant named Palitzsch. Delambre states that he saw it with the naked eye, without previous knowledge of its existence, but this is not the true history. The account given by Palitzsch is quite different. He states that he was engaged in observing the variable star, Omicron Ceti, with his nine foot tube, and that he found between Delta and Epsilon Ceti a nebulous