HERSCHEL, WILLIAM. 



HERSCHEL, CAROLINE LUCRETIA. 



408 



About 1766 he was organist of the Octagon chapel at Bath; in 

 which place he began to turn his attention to astronomy. How well 

 his talents suited that pursuit was afterwards seen, and his preliminary 

 studies had been amply sufficient for the purpose. Though not a 

 mathematician of the first order, his attainments in that science were 

 more than respectable, and his power of applying his knowledge was, 

 like that of Thomas Young, so great as to make it a source of regret 

 that he did not pay special attention to the exact sciences. The 

 earliest writing of Herschel which has come to our knowledge is the 

 answer to the prize question in the ' Ladies' Diary ' for 1779, proposed 

 by Peter Puzzlem (a name which the celebrated Landen always 

 adopted in his contributions to that work), namely, 'The length, 

 tension, and weight of a musical string being given, it is required to 

 find how many vibrations it will make in a given time, when a small 

 given weight is fastened to its middle and vibrates with it.' 



His astronomical pursuits led him to desire a telescope, and as the 

 purchase of a good reflector was ' fortunately ' beyond his ability, he 

 resolved to make one for himself. After many trials he succeeded in 

 making a Newtonian telescope of five feet focal length, and we find 

 him before long not only in possession of adequate means, the work 

 of his own hands, but employing those means with a true perception 

 of the field in which his services were wanted, and a persevering deter- 

 mination to throw light upon our knowledge of the organisation of 

 the universe. 



There are two great branches of astronomy; the first consisting of 

 those investigations, theoretical and practical, by which the mighty 

 clockwork of the heavens is made our measure of time, and our means 

 of settling the relative positions of places on the earth, and of guiding 

 a vessel from one port to another ; the second consisting of inquiries, 

 theoretical and practical, into those phenomena which guide us to 

 such knowledge as we can obtain of the constitution of the heavenly 

 bodies. The study of the science of optics, the improvement of 

 telescopes, the application of sound reasoning to the collective phe- 

 nomena pointed out by such instruments, and, subordinate to the last, 

 a knowledge of the past history of observation, are the keys to the 

 advance of this part of the science. Herschel devoted himself sedu- 

 lously to every part of this task, and the consequence was success 

 such as the world had hardly seen before, and a reputation of twofold 

 splendour, appreciable in its different parts by men of the lowest as 

 well as of the highest order of cultivation. 



Herechel began to contribute to the ' Philosophical Transactions ' 

 in 17SO, and in 1781 announced to the world his discovery of a sup- 

 posed comet, which soon turned out to be a new planet. We have 

 not here to describe the details of this discovery, the merit of which 

 in itself is small. It is the method which gave rise to it on which 

 this part of Herschel's fame must rest. Perceiving how much 

 depended upon an exact knowledge of telescopic phenomena, and a 

 perfect acquaintance with the effect produced by differences of instru- 

 mental construction, he commenced a regular examination of the 

 heavens, taking tlie stars systematically in series, and using one tele- 

 scope throughout. If an indifferent person were by accident to pick 

 up a manuscript out of a large number lying in a library, and were to 

 find it on examination to be a lost classic author, he would be entitled 

 to praise, since it is not every one who would know what he had got 

 hold of, even when the writing was in his hands ; but if the same 

 person were to make the same discovery while voluntarily engaged in 

 the formation and classification of an immense catalogue requiring 

 knowledge of ancient and modern languages and literature, the credit 

 due to the discovery would be very much increased. This case is 

 analogous with that of Herschel, who was not a mere dilettante star- 

 gazer, but a volunteer carrying on with no great pecuniary means a 

 laborious and useful train of investigation. 



The announcement of this comet or (as it turned out) planet drew 

 Herschel immediately into the full blaze of fame ; and George III. 

 honoured his reign by immediately attaching the new astronomer to 

 his court under the title of private astronomer to the king, with a 

 salary of 4001. a year. Herschel fixed his residence first at Datchet, 

 and afterwards at Slough, near Windsor, and his abode became, as 

 Fourier remarks, one of the remarkable spots of the civilised world. 

 His family consisted at first of one of his brothers, and his sister, 

 Kin Caroline Herschel, who was his coadjutor and assistant in his 

 computations and reductions, and also actively employed in observa- 

 tion, having been, among other things, the discoverer of more than 

 one comet. [See notice of CAROLINB HERSCHEL below.] 



Herschel married a widow lady, Mrs. Mary Pitt, and left one son, 

 whose name has long been known to the public as one of the most 

 active and successful adherents of science that our day has produced. 

 [HlBSCHBL, SIB JOHN.] The deficiency of authentic information 

 leaves us little more to say on the private life of Herschel. He was 

 knighted, and received the degree of Doctor of Laws from the Univer- 

 sity of Oxford. He was soon in affluent circumstances, partly by the 

 profits arising from the sale of his mirrors for reflecting telescopes, and 

 partly by the jointure of his wife, which was considerable, and he died 

 wealthy. His death took place on the 23rd of August 1822. 



Henchel's papers in the ' Philosophical Transactions ' exhibit the 

 unwearied activity of their author. They are sixty-nine in number, 

 and range from the 70th volume, in 1780, to the 105th volume, in 1815. 

 He also wrote a paper entitled ' On tho Places of 145 New Double 



Stars,' published in the first volume of the ' Memoirs of the Astrono- 

 mical Society ' in 1822. 



Hersehel must be remembered by the number of bodies which he 

 added to the Solar System, making 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 he added nine, namely, Uranus and six satellites, and two 

 satellites to Saturn. His discovery of the rotation of Saturn's ring, 

 his measurements of the rotation of Saturn and Venus, his observa- 

 tions 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 

 grounded. To this we must add, that his announcement (in 1803) of 

 the motions of binary stars round each other was accompanied by the 

 first proof that there exist in the universe organised systems besides 

 our own ; while his magnificent speculations on the Milky Way, the 

 constitution of nebulae, &c. <fec., first opened the road to the conception 

 that what was called the universe might be, and in all probability is, 

 but a detached and minute portion of that interminable series of 

 similar formations which ought to bear the name. Imagination roves 

 with ease upon such subjects ; but even that daring faculty would have 

 rejected the ideas which, after Herschel's observations, became sober 

 philosophy. 



The instrument by which this great work was achieved was the 

 reflecting telescope, the second reflecting surface which is found in the 

 constructions of Newton, Gregory, and Cassegrain having been rejected, 

 and the eye-piece applied directly to the image produced from the Urge 

 mirror, which is the distinguishing feature of the Herschelian telescope. 

 Herschel had constructed more than one such instrument of 20 feet 

 focal length before he attempted the enormous one of 40 feet, which 

 he erected iu the grounds of his house at Slough. This instrument 

 was begun in 1785, and Herschel dates the completion from August 28, 

 1789, on which day he discovered with it the sixth satellite of Saturn. 



The catalogues of double stars, nebulas, &c., and of the comparative 

 brightness of stars, would alone constitute a title to the name of a 

 distinguished astronomer ; and the optical researches, with those on 

 the refrangibility of heat, are highly valuable ; while the papers ou 

 the power of telescopes should be read by all who wish to understand 

 those instruments. 



HERSCHEL, CAROLINE LUCRETIA, the sister of the great 

 astronomer Sir William Herschel, was born at Hanover on the 16th 

 of March 1750. Till her twenty-second year she lived with her parents 

 hi her native place ; after which she came over to England to reside 

 with her brother, then established as an organist at Bath. When Sir 

 William exchanged his profession as a musician for those astronomical 

 labours which were to immortalise his name, his sister became his 

 constant and most valuable helpmate. " From the first commencement 

 of his astronomical pursuits," says an authority who writes from inti- 

 mate knowledge, " her attendance on both his daily labours and nightly 

 watches was put In requisition, and was found so useful that, on his 

 removal to Datchet and subsequently to Slough, she performed the 

 whole of the arduous and important duties of his astronomical assist- 

 ant not only reading the clocks and noting down all the observations 

 from dictation, as an amanuensis, but subsequently executing the 

 whole of the extensive and laborious numerical calculations necessary 

 to render them available for the purposes of science, ns well as a 

 multitude of others relative to the various objects of theoretical and 

 experimental inquiry in which, during his long and active career, he 

 was at any time engaged." For these important services she was in 

 receipt of a moderate salary allowed her by George III. But, in 

 addition to these labours performed expressly as her brother's assistant 

 and amanuensis, she found time to perform others of a similar character 

 on her own account. Though sitting up frequently all night till day- 

 break, more especially in winter, while her brother required her help, 

 she was able, by snatching such intervals of time as her brother's 

 occasional absences permitted, to conduct a series of observations of 

 her own with a small Newtonian telescope, which he had constructed 

 for her. Her special employment with this instrument was to sweep 

 the heavens for comets; and so successful was she in this employment 

 that she discovered seven comets, of at least five of which she was 

 entitled to claim a clear priority of discovery. The dates of the 

 discoveries of the seven comets were as follows: August 1, 1786; 

 December 21, 1788 ; January 9, 1790 ; December 15, 1791 ; October 7, 

 1793; November 7, 1795; August 6, 1797. Besides the discovery of 

 these comets, she had the merit of having made original observations 

 of several remarkable nebulw and clusters of stars, included iu her 

 brother's catalogues. Iu 1798 she published, with an introduction by 

 her brother, an astronomical work of great value, entitled ' Catalogue 

 of Stars taken from Mr. Flamsteed's Observations, contained in tho 

 second volume of the Historia Ccelestis, and not inserted in the 

 British Catalogue, with au Index to point out every observation iu 

 that volume bilonging to the stars of the British Catalogue : to 

 which is added a collection of Errata that should be noticed iu the 

 same volume.' In this work, which was published at the expense of 

 the Royal Society, no fewer than 561 stars observed by Flamsteed, but 

 which had escaped the notice of the framers of tho ' British Catalogue,' 

 were pointed out. During the whole of her brothers career Miss 



