Page:Encyclopædia Britannica, Ninth Edition, v. 11.djvu/804

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HERSCHEL
was, we are disposed to regard it as among the least of his great works. On the day that it was finished (August 28, 1789) Herschel saw at the first view, in a grandeur not witnessed before, the Saturnian system with all its six satellites, five of which had been discovered long before by Huygens or Cassini, while the sixth, latterly named Enceladus, he had, two years before, sighted by glimpses in his exquisite little telescope of 6} inches aperture, but now saw in unmistakable brightness with the towering giant he had just completed. On the 17th of September he discovered a seventh, which proved to be the nearest of all the satellites of Saturn. It has since that time received the name of Mimas. It is somewhat remarkable that, notwithstanding his long and repeated scrutinies of this planet, the eighth satellite, Hyperion, and the crape ring should have escaped him.

Herschel married the widow of Mr John Pitt, a wealthy London merchant, on May 8, 1788, by whom he had an only son, John Frederick William. The prince regent conferred a Hanoverian knighthood upon him in 1816. But a far more valued and less tardy distinction was the Copley medal assigned to him by his associates in the Royal Society in 1781].

He died at Slough on August 25, 1822, in the eighty- fourth year of his age, and was buried under the tower of St Laurence Church, Upton, within a few hundred yards of the old site of the 40-foot telescope. A mural tablet on the wall of the church bears a Latin inscription from the pen of the late Dr Goodall, provost of Eton College. A collected edition of his astronomical memoirs would speak of his genius in unmistakable language; but this has not yet been published.

(c. p.)

HERSCHEL, Sir Jonn Frederick William, Bart. (1792–1871), the illustrious astronomer, the only son of Sir F. William Herschel, was born at Slough, Bucks, in the year 1792. His early home was a singular one, and eminently adapted to nurture into greatness any child born, as he was, with natural gifts capable of wide development. The examples about him were those of silent but ceaseless industry, busied about things which, at the first view, scemed to have no apparent connexion with the world outside the walls of his abode, bnt which, at a mature period of his life, he, with rare eloquence, taught his countrymen to appreciate as foremost among those influences which satisfy and exalt the nobler instincts of our nature.

His scholastic education commenced at Eton, but maternal fears or prejudices soon removed him to the house of a private tutor. Thence, at the early age of seventeen, he was sent to St John’s College, Cambridge, and the form and method of the mathematical instruction he there received exercised a material influence on the whole com- plexion of his scientific career. In due time the young student acquired the highest academical distinction of his year, graduating as senior wrangler. It was during his undergraduateship that he and two of his fellow-students who subsequently attained to very high eminence in their respective careers of life, Dean Peacock and Mr Babbage, entered into a sort of moral compact that they would “do their best to leave the world wiser than they found it,’—a compact loyally and successfully carried out by all three to the end. As a commencement of this laudable attempt we find Herschel associated with these two friends in the production of a work on the differential calculus, and on cognate branches of mathematical science, which changed the whole style and aspect of mathematical learning in England, and brought it up to the level of the Continental methods. Two or three memoirs communicated to the Royal Society on new applications of mathematical analysis at once placed him in the front rank of the cultivators of this branch of knowledge. Of these his father had the gratification of introducing the first, but the others were presented in his own right as a fellow.

His first intention had been to study for the bar, and with this view he left the university, and placed himself under the guidance of an eminent special pleader of that day. Probably this ‘temporary choice of a profession arose from the extraordinary success which for some time had attended the efforts of so many eminent Cambridge mathe- maticians in legal pursuits. Be that as it may, an early acquaintance with Dr Wollaston in London soon changed the direction of his studies. In 1820, assisted by his father, he completed a mirror of 18 inches diameter and 20 feet focal length, for a reflecting telescope. This, subse- quently improved by his own hands, became the instrument which enabled him to effect the astronomical observations which, more than any other of his great works, form the basis of his fame. In 1821-23 we find him associated with Mr South in the re-examination of his father’s double stars, by the aid of an achromatic telescope and other appliances, the like of which for excellence and power had not hitherto been collected. For this work in 1826 he received the recognition of the Astronomical Society by the award of their gold medal; the French Insti- tute also presented him with the Lalande medal for the same contribution to astronomical science. It ought also to be mentioned that in 1821 the Royal Society had presented him with the Copley medal for his mathematical contributions to their 7ransactions. From 1824 to 182 he held the distinguished and responsible post of secretary to that society. In 1827 he was elected to the chair of the Astronomical Society, which office he also filled on two subsequent occasions, In the course of the discharge of his important offices in the last-named society he ennobled its literature by his memorable presidential addresses and obituary notices of deceased fellows, which, it is not too much to say, are, by their combination of eloquence and wisdom, the chief adornments of their printed memoirs. In 1831 the honour of knighthood was conferred on him by William IV., and two years later he again received the recognition of the Royal Society by the award of one of their medals for his memoir “ On the Investigation of the Orbits of Revolving Double Stars.” There isa significance in this award ; the father had been the original discoverer of the extension of gravitation to the remotest boundarics of the visible universe, and the son had now put the crown- ing stone to this edifice of discovery by the invention of a graphical method whereby the eye could as it were sce the two component stars of the binary system revolving before it, after the regularity of the Newtonian law.

Before the end of the year 1833, being then about forty years of age, Sir John Herschel had re-examined all his father’s discoveries of double stars and nebule, and had added many similar bodies to his own list ; this alone con- stituted a gigantic work even for the lifetime of any astro- nomer in that day. For it should be remembered that the astronomer was not as yet provided with those curious and valuable automatic contrivances for observing and for recording observations which at present most matertally abridge the labour and increase the accuracy of astronomi- cal work such as that in which Sir John had been engaged. And he had no assistant. Equatorial clocks for turning the telescope, electrical chronographs for recording the times of the phenomena observed, were at that date unknown.

His scientific life now entered another and very char- acteristic phase. The bias of his mind, as he subsequently was wont to declare, was towards chemistry and the pheno- mena of light, rather than towards astronomy. Indeed, very shortly after taking his academical degree at Cam- bridge, he proposed himself as a candidate for the vacant