George III. took the new astronomer under his protection, and attached him to his court, bestowing on him the title of astronomer to the king, with a salary of 400_l._ a year. It is difficult to estimate the amount of benefit thus conferred on astronomy by the award of this pension; for nothing short of the entire devotion of a lifetime, could have produced such results as we owe to Herschel. His contributions to the 'Philosophical Transactions' alone amount to sixty-nine in number, and may give some idea of the unwearied activity of the author; they range over a period of thirty-five years, commencing in 1780 and terminating in 1815. The numerous bodies which he added to the solar system, make that number half as large again as he found it. Including Halley's comet, and the four satellites of Jupiter and five of Saturn, the number previously known was eighteen, to which Herschel added nine--namely Uranus and six satellites, and two satellites of Saturn. His discovery of the rotation of Saturn's ring, his measurements of the rotation of Saturn and Venus, his observations of the belts of the former, and his conjectural theory--derived from observation--of the rotation of Jupiter's satellites, with a large number of minor observations, prove that no one individual ever added so much to the facts on which our knowledge of the solar system is founded. His leading discoveries in siderial astronomy include--the discovery of binary systems of stars, and the orbits of several revolving stars; the discovery and classification of a prodigious multitude of nebulæ; the law of grouping of the entire firmament, and its connection with the great nebula of the Milky Way; and lastly, the determination of the motion of our sun and system in space, and the direction of that motion. Herschel's magnificent speculations on the Milky Way, the constitution of nebulæ, &c., first opened the road to the conception, that what was called the universe was, in all probability, but a detached and minute portion of that fathomless series of similar formations which ought to bear the name. Imagination roves with ease upon such subjects; but before Herschel's observations, even that daring faculty would have rejected ideas which afterwards proved to be but sober philosophy. These great and arduous enquiries occupied Herschel during nearly the whole of his scientific career, extending to almost half a century, and, excepting the continuation of his labours by his illustrious son, Sir John, little has been added to our knowledge of 'the constitution of the heavens' since his death.