NA TURE 



361 



THURSDAY, MARCH 9, 1876 



CAROLINE HERSCHEL 



Memoir and Correspondence of Caroline HerscJul. By 

 Mrs. John Herschel. (London : John Murray, 1876.) 



ASTRONOMY may justly claim to be one of the 

 most comprehensive branches of human know- 

 ledge, not merely from the immeasurable extent of the 

 region v,hich it undertakes to investigate, but from its 

 embracing in a common boundary, and directing towards a 

 common end, mental processes and lines of study which 

 otherwise would have found but little ground for con- 

 vergence and combination. It is, perhaps, not generally 

 understood how varied are the courses, or how distinct the 

 attainments, of those who are comprehended under the 

 general title of "astronomers," or how strong, more 

 especially, is the demarcation between the pursuit of 

 theory and the practice of observation. Very different 

 are the requirements of Greenwich and Parsonstown. 

 The collection of facts, and the investigation of the laws 

 which are gathered from those facts, are entirely distinct 

 processes, and though the qualifications demanded sepa- 

 rately for each have occasionally been found in combina- 

 tion, yet more frequently they have existed in individuals 

 who have had little in common besides the general end 

 of their pursuit. Laplace or Clairaut would have exhibited 

 but little aptitude for wielding the instruments of Slough, 

 and many an eye that has rested with the liveliest interest 

 on the magnificence of the lunar scenery, or the mysterious 

 glories of those regions where the great Creator has 

 " sowed with stars the heaven thick as a field," would 

 pore in vain on a page of intricate analytical formulae, or 

 perhaps turn from it with a feeling of positive dislike and 

 annoyance. 



At the head of the observing class in his own day 

 everyone will recognise the name of William Herschel. 

 He did not, indeed, stand as prominently alone as was 

 formerly supposed in the adopted country which was so 

 justly proud of him, for he had left a worthy rival in his 

 native land, where Schroter, armed at first with his 

 opponent's instruments, and afterwards with those of 

 Schrader of Kiel, was doing most earnest and faithful 

 work in his own way. On the moon, indeed, and on 

 I Venus and some of the planetoids, Schroter not only held 

 ': his own, but gained an advantage which has been more 

 fully appreciated as years have passed away. But in the 

 starry heavens, where Schroter was inefficient, Herschel 

 was supreme ; and in his hands sidereal and nebular 

 astronomy started out at once into a prominence which 

 it has since fully maintained. Before his time some forty 

 double stars had been casually noticed ; his catalogues 

 comprised about 700 ; and the host of nebulae grew in 

 far higher proportion, from 103 in Messier's list, to 2,500, 

 a great part of them most delicate and difficult objects. 

 Nor was our own system without its corresponding 

 enlargement, in a new and important planet at an unsus- 

 pected distance, with a train of most minute attendants, 

 to say nothing of two additional satellites of Saturn : nor 

 lad the solar phenomena ever been so fully investigated 

 ! 5r so clearly described. No wonder that the records of 



Ii You XIII.— No. xrz 

 \ 



English science should adorn the name of Herschel with 



a pre-eminent glory — 



" Gloria sideribus quam coavenit esse coaevam, 

 Et tantum ccelo commoriente mori." 



But other talents, and those of a high order, were com- 

 bined in the case of this illustrious man. Inheriting a 

 family gift, he had been originally a musician of con- 

 siderable eminence — not only the organist of a fashion- 

 able chapel in Bath, and sometimes giving thirty-five and 

 thirty-eight lessons per week to lady-pupils, but rising 

 above the ordinary level as a writer of good music. It 

 is matter of great regret that much of his composition 

 has been irrecoverably lost : but a portion seems to be 

 still existing, and we earnestly hope may yet appear in a 

 public form. It was, however, of more importance to one 

 of the very first astronomers that he should also be one 

 of the very first opticians of the age, and in Sir W. 

 Herschel this was fully carried out. In him a consum- 

 mate knowledge of practical optics aided the keen vision 

 of the observer. Others had indeed attained great and 

 perhaps equal perfection in the manufacture of reflecting 

 telescopes. Those of the celebrated Short, though on the 

 inferior Gregorian construction, were remarkable for their 

 distinctness ; nor had he shrunk from 1 2-inch apertures, 

 or nominal powers, even in this case, of loo per inch, 

 though it may be feared that actual measurement would 

 have considerably reduced their value. And as regards 

 mere size, the French optician Noel, after many attempts, 

 succeeded, in 1772, with a mirror of 2 feet, which, mounted 

 as a Cassegrain, bore a power of 528, though with what 

 distinctness does not appear, nor where the remains of 

 this Colossus may be now. But the multitude of specula 

 that Herschel had wrought — more than 400 of 7, 10, and 

 20-feet focus — before he succeeded to his satisfaction, and 

 the wholly unprecedented effort that placed the 40-foot 

 telescope at his command, merely constituted him the 

 chief optician of his day ; to this was added the special 

 talent of acute and most persevering obsen'ation, which 

 he possessed in very full development, and employed to 

 the utmost, even to a very advanced age, and with a 

 result exceeding all anticipation. 



Any one, however, who has some practical acquaint- 

 ance with the labour of observation with the larger class 

 of telescopes, wiU readily perceive that such researches, 

 especially when combined with such heavy and con- 

 tinuous optical work, could never have been accomplished 

 alone. This must be eminently the case when far- 

 stretching tracts of sky have to be explored for unknown 

 objects ; the distinct and equally important tasks of 

 observing and recording are so incompatible as to be 

 beyond the grasp of the most accomplished astronomer. 

 Assistance must be had, and that no ordinary kind of 

 assistance, but such as may really answer to its name — 

 carelessness, or tardiness, or awkwardness being fatal in 

 such a case to the idea of effectual aid. That Sir W. 

 Herschel found in his sister Caroline such an assistant as 

 materially contributed to his own success has long been 

 familiarly known ; but it has not been so generally under- 

 stood how able was her co-operation, how laborious her 

 night- watchings, how persevering her attention, how 

 utterly unselfish in its absorbing and generous attach- 

 ment her devotion to her brother's pursuits. It was to 

 bring into due notice so uncommon a character, which 



