Sir William, an illustrious astronomer, and inventor of the telescope which bears his name, was born at Hanover on the 15th of November 1738. He was the second of four sons, all of whom were brought up to their father's profession, which was that of musician. As he evinced a peculiar taste for intellectual pursuits, his father provided him with a French tutor, who instructed him in the rudiments of logic, ethics, and metaphysics, and under whom he made considerable progress. But, owing to the untoward circumstances of his family, his studies were soon interrupted, and, at the age of fourteen, he was placed in the band of the Hanoverian regiment of guards, a detachment of which he accompanied to England in 1757, or, as some say, in 1759. His father came with him to England, but after the lapse of a few months he returned home, leaving the young musician to push his fortune, as he best could, in London. After struggling with many difficulties, he attracted the notice of the Earl of Darlington, who engaged him to superintend and instruct a military band then forming for the Durham militia. Having ful- Herschel filled this engagement; he passed several years in the west riding of Yorkshire, giving lessons to pupils in the principal towns, officiating as leader in oratorios and public concerts, and employing his leisure hours in improving his knowledge of English, acquiring the Italian language, which he considered as necessary to the exercise of his profession, and instructing himself in Latin, as well as learning a little Greek.

About the close of the year 1765, he was appointed to the situation of organist at Halifax, which he obtained through the good offices of Mr. Joah Bates, and there continued to give instructions in music, though with what success does not appear. Anxious to make himself master of the theory of harmony, he studied Dr. Smith's treatise on that subject; in connection with this science he also cultivated the mathematics, and thus, perhaps unconsciously, prepared himself for those sublime investigations which were destined to open a new field of discovery, and to confer immortality on his name. In the year 1766 he and his elder brother repaired to Bath, where they were both engaged by Mr. Linley for the Pump-room band; but the principal object which attracted him to that place was the advantageous situation of organist to the Octagon Chapel, which opened to him a profitable range of engagements at the concerts, the rooms, the theatre, and the oratorios, besides affording him an opportunity of obtaining many private pupils. This accession of employment, however, was so far from abating his propensity to study, that frequently, after the fatigue of twelve or fourteen hours occupied in professional avocations, he sought relaxation (for to him it was really such) in extending his knowledge of the pure and the mixed mathematics.

Some discoveries then recently made having awakened his curiosity, he next applied himself to the study of astronomy, and to that of the auxiliary science of optics, in which he laboured with indefatigable perseverance during every interval of leisure. Anxious to observe with his own eyes the wonders of which he had read, he borrowed from a neighbour in Bath a two-feet Gregorian telescope, which delighted him so much that he commissioned a friend in London to purchase for him one of larger dimensions. The price demanded, however, exceeded both his calculation and his means; but, far from being discouraged, he resolved to attempt with his own hands the construction of that complicated instrument which he had found himself unable to purchase; and in this, after successive disappointments, which served only to stimulate his exertions, he at length succeeded. In the year 1774, he had the inexpressible gratification of beholding the planet Saturn through a five-feet Newtonian reflector constructed by himself, and, with the prophetic instinct of genius, already discerned the path of discovery opening before him. Encouraged by this success, he extended his operations; constructed telescopes of seven, ten, and even twenty feet in length; and worked with such indefatigable perseverance that, in perfecting the parabolic figure of a seven-feet reflector, he finished two hundred specula before producing one which answered his purpose in a satisfactory manner. Becoming more and more attached to astronomy, he now limited his professional engagements, restricted the number of his pupils, and, about the end of the year 1779, commenced a regular survey of the heavens by means of a seven-feet reflector. In the course of his observations, which were continued during eighteen months, he remarked that a star, which had been recorded by Bode as fixed, was progressively changing its position; and prolonged attention to it enabled him to ascertain, beyond all doubt, that it was an hitherto undiscovered planet. Having determined the mean and periodic motions, and the orbit of this body, he communicated the particulars to the Royal Society, who, in return, awarded him their annual gold medal, and unanimously elected him a fellow. This important discovery he made on the 13th of March 1781, and, in compliment to the king of England, bestowed on the planet the name of Georgium Sidus; but the Continental astronomers chose to honour the discoverer by calling it Herschel, an appellation subsequently changed to that of Uranus, which was considered as more consistent with the received astronomical nomenclature.

This discovery at once established the fame of Herschel as an astronomical observer; and the king having bestowed on him a handsome salary, he was enabled to relinquish his profession as musician, and to devote the remainder of his life exclusively to astronomy. Accordingly he quitted Bath; and having fixed his residence first at Datchet and afterwards at Slough, he resumed the career of discovery on which he had so auspiciously entered. His first undertaking was to construct a telescope forty feet in length, which he completed in 1787; but this huge instrument disappointed the expectations he had formed from it; and it was by instruments of a more manageable size that he perused the great volume of the heavens, and derived from it new contributions to enrich the records of science. In these researches, and in the laborious calculations to which they led, he was assisted by his sister Miss Caroline Herschel, whose indefatigable assiduity and devotion in the performance of a task usually considered as incompatible with female habits excited equal surprise and admiration. The discoveries of Herschel were communicated, as they occurred, to the Royal Society, and constitute an important part of the printed transactions of that body during a period extending from 1782 to 1818. In 1783 he announced the discovery of a volcanic mountain in the moon; and four years afterwards he communicated an account of two other volcanoes in the same orb, which appeared to be in a state of eruption. In prosecuting his observations on the planet discovered by himself, he ascertained that Uranus was surrounded with rings, and had six satellites. Although the results obtained by means of the forty-feet telescope were not such as to realize the expectations he had formed, yet they were too considerable to justify the somewhat contemptuous allusion made to them by Lalande in his History of Astronomy. By means of this instrument he discovered the sixth and seventh satellites of Saturn; and in observing the quintuple belt of Saturn, he was enabled to demonstrate the length of its day, and to determine its diurnal rotation. Amongst the papers communicated by this great astronomer, was a memoir on the power of telescopes to penetrate into space, or to render sensible distant and faint objects, which would be imperceptible without the aid of such instruments; and his opinion was, that the greatest amplification cannot exceed that produced by a telescope of from twenty to twenty-five feet. In 1802, he presented to the Royal Society a catalogue of five thousand new nebular, nebulosus stars, planetary nebulae, and clusters of stars; preceded by a view of the sidereal bodies composing the universe, in which he enumerated twelve species of stars that enter into the composition of the heavenly host.

By these and other scientific labours he established his claim to rank amongst the most eminent astronomers of the age, and amply merited the distinctions which were conferred on him. Oxford had previously done itself honour by bestowing on him the honorary degree of doctor of laws; and in 1816, George IV., then prince regent, invested him with the Hanoverian and Guelphic order of knighthood. Sir William Herschel did not relinquish his astronomical observations until within a few years of his death, which took place on the 23rd of August 1822, at the advanced age of eighty-three. He expired full of years and honours, leaving behind him a considerable fortune, and, what is of far greater importance, a son who inherited his father's genius, under more favourable auspices for its early development, and who unquestionably ranks in the first class of the scientific men of his day.

name by which the French, and most other European nations, call the planet discovered by Dr Herschel in the year 1781. The Italians call it Uranus, and the British Georgium Sidus.