“Coelorum perrupit claustra.” HERSCHEL’S _Epitaph_. 251. _Frederick William Herschel_ was born at Hanover on November 15th, 1738, two years after Lagrange and nine years before Laplace. His father was a musician in the Hanoverian army, and the son, who shewed a remarkable aptitude for music as well as a decided taste for knowledge of various sorts, entered his father’s profession as a boy (1753). On the breaking out of the Seven Years’ War he served during part of a campaign, but his health being delicate his parents “determined to remove him from the service—a step attended by no small difficulties,” and he was accordingly sent to England (1757), to seek his fortune as a musician. After some years spent in various parts of the country, he moved (1766) to Bath, then one of the great centres of fashion in England. At first oboist in Linley’s orchestra, then organist of the Octagon Chapel, he rapidly rose to a position of great popularity and distinction, both as a musician and as a music-teacher. He played, conducted, and composed, and his private pupils increased so rapidly that the number of lessons which he gave was at one time 35 a week. But this activity by no means exhausted his extraordinary energy; he had never lost his taste for study, and, according to a contemporary biographer, “after a fatiguing day of 14 or 16 hours spent in his vocation, he would retire at night with the greatest avidity to _unbend the mind_, if it may be so called, with a few propositions in Maclaurin’s Fluxions, or other books of that sort.” His musical studies had long ago given him an interest in mathematics, and it seems likely that the study of Robert Smith’s _Harmonics_ led him to the _Compleat System of Optics_ of the same author, and so to an interest in the construction and use of telescopes. The astronomy that he read soon gave him a desire to see for himself what the books described; first he hired a small reflecting telescope, then thought of buying a larger instrument, but found that the price was prohibitive. Thus he was gradually led to attempt the construction of his own telescopes (1773). His brother Alexander, for whom he had found musical work at Bath, and who seems to have had considerable mechanical talent but none of William’s perseverance, helped him in this undertaking, while his devoted sister _Caroline_ (1750-1848), who had been brought over to England by William in 1772, not only kept house, but rendered a multitude of minor services. The operation of grinding and polishing the mirror for a telescope was one of the greatest delicacy, and at a certain stage required continuous labour for several hours. On one occasion Herschel’s hand never left the polishing tool for 16 hours, so that “by way of keeping him alive” Caroline was “obliged to feed him by putting the victuals by bits into his mouth,” and in less extreme cases she helped to make the operation