remote observation made by an astronomer who might have entered the place of the planet in his catalogue as a fixed star. Mr. Adams led the way in the computation of the elements of the orbit of the new planet from actual observation, and was followed by many other computers,-among them Mr. S. C. Walker, then of the Washington Observatory, United States.

Having obtained an approximate orbit, Mr. Walker computed backwards the places of the new planet for more than fifty years

and then examined the late catalogues, in the hope of finding its place on some of them as a fixed star. Among recent catalogues there was no success; but in an examination of Lalande's Catalogue, he found an observation on a star of the eighth magnitude, made May 10th, 1795, which was so near the place which his computation assigned the planet at the same date, that he was led to suspect that this star might indeed prove to be the new planet. In case his conjecture were true, on turning the telescope to the place occupied by the star, it would be found blank, as its planetary motion would have removed it very far from the place which it occupied more than fifty years before. The experiment having been made, no star could be found; and strong evidence was thus presented that Mr. Walker had actually found an observation of the new planet, giving its position in 1795; but in consequence of the great discrepancy between

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the period of M. Leverrier and that which would result from a reliance on this observation of the new planet Neptune, Mr. Walker's discovery was at first received with great hesitation. A greater doubt was thrown over the matter from the fact that Lalande had marked the observation as uncertain; and it was only by reference to the original manuscripts preserved in the Royal Observatory of Paris that the doubts could be removed.

The discovery of Mr. Walker was subsequently made by Mr. Petersen, of Altona; and the results of these astronomers reached Paris on the same day. A committee was at once appointed to examine the original manuscript of Lalande, when a most remarkable discovery was made. This astronomer had observed a star of the eighth magnitude on the evening of the 8th of May, 1795; and on the evening of the 10th, not finding the star as laid down, but observing one of the same magnitude very near the former place, he rejects the observation of the 8th of May as inaccurate, and enters the observation of the 10th, marking it doubtful.

On close examination, this star proves to be the planet Neptune; and by this discovery we are placed in possession of observations which render it possible to determine the elliptic elements of the new planet with great precision. These differ so greatly from those announced by Leverrier and Adams previous to the discovery, that Professor Pierce, of Cambridge, Massachusetts, pronounces it impossible so to extend fairly the limits of Leverrier's analysis as to embrace the planet Neptune; and that, although its mass, as determined from the elongation of its satellite, renders it possible to account for all the perturbations of Uranus by its action, in the most surprising manner, yet, in the opinion of Professor Pierce, it is not the planet to which geometrical analysis directed the telescope. Leverrier rejects absolutely the result reached by the American geometer, and claims Neptune to be the planet of his theory, in the strictest and most legitimate sense.

Time and observation will settle the differences of these distinguished geometers; and truth being the grand object of all research, its discovery will be hailed with equal enthusiasm by both of the disputants. In any event, the profound analytic research of Leverrier is an ever-during monument to his genius, and his name is for ever associated with the most wonderful discovery that ever marked the career of astronomical science.

NOTE.-In the above historical account of the discovery of the planet Neptune, it appears to us that sufficient justice has not been done to the share which our countryman, Mr. Adams, of Cambridge, had in the discovery. It was stated by Professor Challis, of Cambridge, that Mr. Adams, Fellow of St. John's College, showed him a memorandum made in the year 1841, recording his intention of attempting to solve the problem arising out of the perturbations of Uranus, as soon as he had taken his B.A. degree. Accordingly, after graduating in 1843, he obtained an approximate solution, and afterwards pursued the subject to that extent, as actually to place in the hands of the Astronomer Royal, and of Professor Challis, the elements of the then unknown planet, before any elements of this planet had been obtained, or at least published, by M. Leverrier.

Mr. Adams.

On July 29th, 1847, Professor Challis commenced observing, and by October 1st he had then registered 3150 positions of stars. On this day he heard that Dr. Galle had discovered the planet at Berlin, on September 23rd. It afterwards appe that Professor Challis himself had observed the planet on A 4th, and again on August 12th.

Professor Challis adds, that it was impossible that any one could have comprehended the problem more fully than Mr. Adams did; " that he carefully considered all that was necessary for its exact solution, and that he had a firm conviction, from the results of his calculations, that a planet was to be found."

Whatever honour is, therefore, due to M. Leverrier,-and it is certainly great,-equal honour and praise are due to Mr. Adams. The former gentleman has had some rewards for his labours; we believe that the latter gentleman's honours are yet to come.

The attempt to fix the name of the discoverer upon new planets has been unsuccessful in every instance. The planet discovered by Herschel is called Uranus; Piazzi gave to Ceres the name "Ferdinandea,” in honour of the King of Naples; yet, Ceres is the name by which it is known. Harding, Olbers, Hencke, and Hind, all discoverers of planets, followed the long-established custom of selecting names from the Heathen Divinities. Immediately after the planet beyond Uranus was discovered, M. Leverrier, in letters addressed to several persons, said, the "Board of Longitude" has decided in favour of “ Neptune,” with the sign of the trident. And this name "Neptune," is the one generally adopted.

THE wonderful characteristics which mark the flight of comets through space; the suddenness with which they blaze forth; their exceeding velocity, and their terrific appearance; their eccentric motions, sweeping towards the sun from all regionr and in all directions; have rendered these bodies objects of terror and dread in all ages of the world. While the plane pursue an undeviating course round the sun, in its orbits circular and almost coincident with the plane of the