the Earl of Darlington, who engaged him to superintend and instruct a military band at the time forming for the Durham militia. After fulfilling this engagement, he passed several years in Yorkshire, in the capacity of teacher of music. He gave lessons to pupils in the principal towns, and officiated as leader in oratorios or concerts of sacred music-a kind of employment in which the Germans are eminently skilled, from their love of musical performances. Herschel, however, while thus engaged in earning an honourable livelihood, did not allow his professional pursuits to engross all his thoughts. He sedulously devoted his leisure hours in improving his knowledge of the English and Italian languages, and in instructing himself in Latin, as well as a little Greek. At this period he probably looked to these attainments principally with a view to the advantage he might derive from them in the prosecution of his professional studies; and it was no doubt with this view also that he afterwards applied himself to the perusal of Dr Robert Smith's "Treatise on Harmonics"-one of the most profound works on the science of music which then existed in the English language. But the acquaintance he formed with this work was destined ere long to change altogether the character of his pursuits. He soon found that it was necessary to make himself a mathematician before he could make much progress in following Dr Smith's demonstrations. He now, therefore, turned with his characteristic alacrity and resolution to the new study to which his attention was thus directed; and it was not long before he became so attached to it, that almost all the other pursuits of his leisure hours were laid aside for its sake.

Through the interest and good offices of a Mr Bates, to whom the merits of Herschel had become known, he was, about the close of 1765, appointed to the situation of church-organist at Halifax. Next year, having gone with his elder brother to fulfil a short engagement at Bath, he gave so much satisfaction by his performances, that he was appointed organist in the Octagon chapel of that city, upon which he went to reside there. The place which he now held was one of some value; and from the opportunities which he enjoyed, besides, of adding to its emoluments by engagements at the rooms, the theatre, and private concerts, as well as by taking pupils, he had the certain prospect of deriving a good income from his profession, if he had made that his only or his chief object. This accession of employment did not by any means abate his propensity to study for mental improvement. Frequently, after the fatigue of twelve or fourteen hours occupied in musical performances, he sought relaxation, as he considered it, in extending his knowledge of the pure and mixed mathematics. In this manner he attained a competent knowledge of geometry, and found himself in a condition to proceed to the study of the different branches of physical science which depend upon the mathe

matics. Among the first of these latter that attracted his attention, were the kindred departments of astronomy and optics. Some discoveries about this time made in astronomy awakened his curiosity, and to this science he now directed his investigations at his intervals of leisure. Being anxious to observe some of those wonders in the planetary system of which he had read, he borrowed from a neighbour a two-feet Gregorian telescope, which delighted him so much, that he forthwith commissioned one of larger dimensions from London. The price of such an instrument, he was vexed to find, exceeded both his calculations and his means; but though chagrined, he was not discouraged he immediately resolved to attempt with his own hand the construction of a telescope equally powerful with that which he was unable to purchase; and in this, after repeated disappointments, which served only to stimulate his exertions, he finally succeeded.

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Herschel was now on the path in which his genius was calculated to shine. In the year 1774, he had the inexpressible pleasure of beholding the planet Saturn through a five-feet Newtonian reflector made by his own hands. This was the beginning of a long and brilliant course of triumphs in the same walk of art, and also in that of astronomical discovery. Herschel now became so much more ardently attached to his philosophical pursuits, that, regardless of the sacrifice of emolument he was making, he began gradually to limit his professional engagements and the number of his pupils. Meanwhile, he continued to employ his leisure in the fabrication of still more powerful instruments than the one he had first constructed; and in no long time he produced telescopes of seven, ten, and even twenty feet focal distance. In fashioning the mirrors for these instruments, his perseverance was indefatigable. For his seven-feet reflector, it is asserted that he actually finished and made trial of no fewer than two hundred mirrors before he found one that satisfied him. When he sat down to prepare a mirror, his practice was to work at it for twelve or fourteen hours, without quitting his occupation for a moment. He would not even take his hand from what he was about, to help himself to food; and the little that he ate on such occasions was put into his mouth by his sister. He gave the mirror its proper shape more by a certain natural tact than by rule; and when his hand was once in, as the phrase is, he was afraid that the perfection of the finish, might be impaired by the least intermission of his labours.

It was on the 13th of March 1781 that Herschel made the discovery to which he owes, perhaps, most of his popular reputation. He had been engaged for nearly a year and a-half in making a regular survey of the heavens, when, on the evening of the day that has been mentioned, having turned his telescopean excellent seven-feet reflector, of his own constructing-to a particular part of the sky, he observed among the other stars

one which seemed to shine with a more steady radiance than those around it; and, on account of that, and some other peculiarities in its appearance, which excited his suspicions, he determined to observe it more narrowly. On reverting to it after some hours, he was a good deal surprised to find that it had perceptibly changed its place-a fact which, the next day, became still more indisputable. At first he was somewhat in doubt whether or not it was the same star which he had seen on these different occasions; but after continuing his observations for a few days longer, all uncertainty upon that head vanished. He now communicated what he had observed to the astronomerroyal, Dr Maskelyne, who concluded that the luminary could be nothing else than a new comet. Continued observation of it, however, for a few months, dissipated this error; and it became evident that it was, in reality, a hitherto undiscovered planet. This new world, so unexpectedly found to form a part of the system to which our own belongs, received from Herschel the name of Georgium Sidus, or Georgian Star, in honour of the king of England; but by continental astronomers it has been more generally called either Herschel, after its discoverer, or Uranus. He afterwards discovered, successively, no fewer than six satellites or moons belonging to his new planet.

The announcement of the discovery of the Georgium Sidus at once made Herschel's name universally known. In the course of a few months the king bestowed upon him a pension of £300 a-year, that he might be enabled entirely to relinquish his engagements at Bath; and upon this he came to reside at Slough, near Windsor. He now devoted himself entirely to science; and the constructing of telescopes, and observations of the heavens, continued to form the occupations of the remainder of his life. Astronomy is indebted to him for many other most interesting discoveries besides the celebrated one of which we have just given an account, as well as for a variety of speculations of the most ingenious, original, and profound character. But of these we cannot here attempt any detail. He also introduced some important improvements into the construction of the reflecting telescope, besides continuing to fabricate that instrument of dimensions greatly exceeding any that had been formerly attempted, with powers surpassing, in nearly a corresponding degree, what had ever been before obtained. The largest telescope which he ever made was his famous one of forty feet long, which he erected at Slough, for the king. It was begun about the end of the year 1785, and on the 28th of August 1789 the enormous tube was poised on the complicated but ingeniously-contrived mechanism by which its movements were to be regulated, and ready for use. On the same day a new satellite of Saturn was detected by it, being the sixth which had been observed attendant upon that planet. A seventh was afterwards discovered by means of the same instrument. This telescope has since been

taken down, and replaced by another of only one-half the length, constructed by the distinguished son of the subject of our present sketch.

So extraordinary was the ardour of this great astronomer in the study of his favourite science, that for many years, it has been asserted, he never was in bed at any hour during which the stars were visible; and he made almost all his observations, whatever was the season of the year, not under cover, but in his garden, and in the open air-and generally without an attendant. By these investigations Herschel became acquainted with the character of the more distant stars, upon which he wrote a variety of papers. In 1802, he presented to the Royal Society a catalogue of five thousand new nebulæ, nebulous stars, planetary nebulæ, and clusters of stars; thus opening up a boundless field of research, and making the world aware of the sublime truth of there being an infinitude of heavenly bodies far beyond the reach of ordinary vision, and performing in their appointed places the offices of suns to unseen systems of planets.

These discoveries established Herschel's claims to rank amongst the most eminent astronomers of the age, and amply merited the distinctions conferred upon him by learned bodies and the reigning prince. In 1816, George IV., then prince regent, invested him with the Hanoverian and Guelphic order of knighthood. He was now, from being originally a poor lad in a regimental band, rewarded for his long course of honourable exertion in the cause of a science upon which so much of our national welfare depends. Herschel (now Sir William) did not relinquish his astronomical observations until within a few years of his death, which took place on the 23d of August 1822, when he had attained the age of eighty-three. He died full of years and honours, bequeathing a large fortune, and leaving a family which has inherited his genius.

Besides the eminent men of whose lives we have thus presented an outline, there are others who, since the time of Copernicus, have contributed materially to the advancement of astronomical science, but to whose labours our space will admit only of the briefest allusion. Foremost among these, both in point of time and merit, may be mentioned the Cassinis, father and son, who flourished in the seventeenth century; Delisle, a French savan (1675-1768), alike distinguished in natural science, geography, and astronomy; our revered countryman Bradley, who died in 1762; Lalande (1732-1807), another Frenchman of well-known fame; the celebrated La Place; and, of more recent reputation, Our countrymen Sir John Herschel, Professor Airy, Sir J. South, and Lord Rosse; and the continental philosophers, Bode,

Encke, Bessel, Biot, Arago, and others, by whom important contributions have been made, and from whom much is yet expected. To these may be added the names of such men as Dr Thomas Dick, Professor Nichol, Sir J. Herschel, and others, who, by their general treatises, have brought the sublimest truths of the science to the level of the popular capacity; thereby not only extending its range, but eliciting, it may be, new observers and discoverers from among those to whom astronomy and all its glorious revelations would have otherwise remained uncared for and unknown. To each and all of these is astronomy less or more indebted for its present perfection and universal esteem as a science. Governed by laws now known, every planet and system holds on its course through space with undeviating regularity; their distances, dimensions, times of revolution, appearance and disappearance, are things ascertained with as much certainty as the commonest fact in terrestrial measurement; the most extraordinary phenomena of the heavens are things now familiar to the eye of science and reason, evincing in all their phases the most perfect beauty and harmony; and appearances under which ignorance formerly cowered in superstitious fear, are now regarded as additional themes of human adoration for the wisdom, power, and goodness of a common Creator.