Chapter 20

If after having, from a sense of duty, expatiated upon anarchical, odious, and sanguinary scenes, the historian of our civil discords has the good fortune to meet on his progress with an incident that gratifies the mind, raises the soul, and fills the heart with pleasing emotions, he stops there, Gentlemen, as the African traveller halts in an oasis!

HERSCHEL.

William Herschel, one of the greatest astronomers that ever lived in any age or country, was born at Hanover, on the 15th of November, 1738. The name of Herschel has become too illustrious for people to neglect searching back, up the stream of time, to learn the social position of the families that have borne it. Yet the just curiosity of the learned world on this subject has not been entirely satisfied. We only know that Abraham Herschel, great-grandfather of the astronomer, resided at Mähren, whence he was expelled on account of his strong attachment to the Protestant faith; that Abraham's son Isaac was a farmer in the vicinity of Leipzig; that Isaac's eldest son, Jacob Herschel, resisted his father's earnest desire to see him devote himself to agriculture, that he determined on being a musician, and settled at Hanover.

Jacob Herschel, father of William, the astronomer, was an eminent musician; nor was he less remarkable for the good qualities of his heart and of his mind. His very limited means did not enable him to bestow a complete education on his family, consisting of six boys and four girls. But at least, by his care, his ten children all became excellent musicians. The eldest, Jacob, even acquired a rare degree of ability, which procured for him the appointment of Master of the Band in a Hanoverian regiment, which he accompanied to England. The third son, William, remained under his father's roof. Without neglecting the fine arts, he took lessons in the French language, and devoted himself to the study of metaphysics, for which he retained a taste to his latest day.

In 1759, William Herschel, then about twenty-one years old, went over to England, not with his father, as has been erroneously published, but with his brother Jacob, whose connections in that country seemed likely to favour the young man's opening prospects in life. Still, neither London nor the country towns afforded him any resource in the beginning, and the first two or three years after his expatriation were marked by some cruel privations, which, however, were nobly endured. A fortunate chance finally raised the poor Hanoverian to a better position; Lord Durham engaged him as Master of the Band in an English regiment which was quartered on the borders of Scotland. From this moment the musician Herschel acquired a reputation that spread gradually, and in the year 1765 he was appointed organist at Halifax (Yorkshire). The emoluments of this situation, together with giving private lessons both in the town and the country around, procured a degree of comfort for the young William. He availed himself of it to remedy, or rather to complete, his early education. It was then that he learnt Latin and Italian, though without any other help than a grammar and a dictionary. It was then also that he taught himself something of Greek. So great was the desire for knowledge with which he was inspired while residing at Halifax, that Herschel found means to continue his hard philological exercises, and at the same time to study deeply the learned but very obscure mathematical work on the theory of music by R. Smith. This treatise, either explicitly or implicitly, supposed the reader to possess some knowledge of algebra and of geometry, which Herschel did not possess, but of which he made himself master in a very short time.

In 1766, Herschel obtained the appointment of organist to the Octagon Chapel at Bath. This was a more lucrative post than that of Halifax, but new obligations also devolved on the able pianist. He had to play incessantly either at the Oratorios, or in the rooms at the baths, at the theatre, and in the public concerts. Then, being immersed in the most fashionable circle in England, Herschel could no longer refuse the numerous pupils who wished to be instructed in his school. It is difficult to imagine how, among so many duties, so many distractions of various kinds, Herschel could continue so many studies, which already at Halifax had required in him so much resolution, so much perseverance, and a very uncommon degree of talent. We have already seen that it was by music that Herschel was led to mathematics; mathematics in their turn led him to optics, the principal and fertile source of his illustrious career. The hour finally struck, when his theoretic knowledge was to guide the young musician into a laborious application of principles quite foreign to his habits; and the brilliant success of which, as well as their excessive hardihood, will excite reasonable astonishment.

A telescope, a simple telescope, only two English feet in length, falls into the hands of Herschel during his residence at Bath. This instrument, however imperfect, shows him a multitude of stars in the sky that the naked eye cannot discern; shows him also some of the known objects, but now under their true dimensions; reveals forms to him that the richest imaginations of antiquity had never suspected. Herschel is transported with enthusiasm. He will, without delay, have a similar instrument but of larger dimensions. The answer from London is delayed for some days: these few days appear as many centuries to him. When the answer arrives, the price that the optician demands proves to be much beyond the pecuniary resources of a mere organist. To any other man this would have been a clap of thunder. This unexpected difficulty on the contrary, inspired Herschel with fresh energy; he cannot buy a telescope, then he will construct one with his own hands. The musician of the Octagon Chapel rushes immediately into a multitude of experiments, on metallic alloys that reflect light with the greatest intensity, on the means of giving the parabolic figure to the mirrors, on the causes that in the operation of polishing affect the regularity of the figure, &c. So rare a degree of perseverance at last receives its reward. In 1774 Herschel has the happiness of being able to examine the heavens with a Newtonian telescope of five English feet focus, entirely made by himself. This success tempts him to undertake still more difficult enterprises. Other telescopes of seven, of eight, of ten, and even of twenty feet focal distance, crown his efforts. As if to answer in advance those critics who would have accused him of a superfluity of apparatus, of unnecessary luxury, in the large size of the new instruments, and his extreme minutiæ in their execution, Nature granted to the astronomical musician, on the 13th of March 1781, the unheard-of honour of commencing his career of observation with the discovery of a new planet, situated on the confines of our solar system. Dating from that moment, Herschel's reputation, no longer in his character of musician, but as a constructor of telescopes and as an astronomer, spread throughout the world. The King, George III., a great lover of science, and much inclined besides to protect and patronize both men and things of Hanoverian origin, had Herschel presented to him; he was charmed with the simple yet lucid and modest account that he gave of his repeated endeavours; he caught a glimpse of the glory that so penetrating an observer might reflect on his reign, ensured to him a pension of 300 guineas a year, and moreover a residence near Windsor Castle, first at Clay Hall and then at Slough. The visions of George III. were completely realized. We may confidently assert, relative to the little house and garden of Slough, that it is the spot of all the world where the greatest number of discoveries have been made. The name of that village will never perish; science will transmit it religiously to our latest posterity.

I will avail myself of this opportunity to rectify a mistake, of which ignorance and idleness wish to make a triumphant handle, or, at all events, to wield in their cause as an irresistible justification. It has been repeated to satiety, that at the time when Herschel entered on his astronomical career he knew nothing of mathematics. But I have already said, that during his residence at Bath, the organist of the Octagon Chapel had familiarized himself with the principles of geometry and algebra; and a still more positive proof of this is, that a difficult question on the vibration of strings loaded with small weights had been proposed for discussion in 1779: Herschel undertook to solve it, and his dissertation was inserted in several scientific collections of the year 1780.

The anecdotic life of Herschel, however, is now closed. The great astronomer will not quit his observatory any more, except to go and submit the sublime results of his laborious vigils to the Royal Society of London. These results are contained in his memoirs; they constitute one of the principal riches of the celebrated collection known under the title of _Philosophical Transactions_.

Herschel belonged to the principal Academies of Europe, and about 1816 he was named Knight of the Guelphic order of Hanover. According to the English habit, from the time of that nomination the title of Sir William took the place, in all this illustrious astronomer's memoirs, already honoured with so much celebrity, of the former appellation of Doctor William. Herschel had been named a Doctor (of laws) in the University of Oxford in 1786. This dignity, by special favour, was conferred on him without any of the obligatory formalities of examination, disputation, or pecuniary contribution, usual in that learned corporation.

I should wound the elevated sentiments that Herschel professed all his life, if I were not here to mention two indefatigable assistants that this fortunate astronomer found in his own family. The one was Alexander Herschel, endowed with a remarkable talent for mechanism, always at his brother's orders, and who enabled him to realize without delay any ideas that he had conceived;[15] the other was Miss Caroline Herschel, who deserves a still more particular and detailed mention.

Miss Caroline Lucretia Herschel went to England as soon as her brother became special astronomer to the king. She received the appellation there of Assistant Astronomer, with a moderate salary. From that moment she unreservedly devoted herself to the service of her brother, happy in contributing night and day to his rapidly increasing scientific reputation. Miss Caroline shared in all the night-watches of her brother, with her eye constantly on the clock, and the pencil in her hand; she made all the calculations without exception; she made three or four copies of all the observations in separate registers; coördinated, classed, and analyzed them. If the scientific world saw with astonishment how Herschel's works succeeded each other with unexampled rapidity during so many years, they were specially indebted for it to the ardour of Miss Caroline. Astronomy, moreover, has been directly enriched by several comets through this excellent and respectable lady. After the death of her illustrious brother, Miss Caroline retired to Hanover, to the house of Jahn Dietrich Herschel, a musician of high reputation, and the only surviving brother of the astronomer.

William Herschel died without pain on the 23d of August 1822, aged eighty-three. Good fortune and glory never altered in him the fund of infantine candour, inexhaustible benevolence, and sweetness of character, with which nature had endowed him. He preserved to the last both his brightness of mind and vigour of intellect. For some years Herschel enjoyed with delight the distinguished success of his only son,[16] Sir John Herschel. At his last hour he sunk to rest with the pleasing conviction that his beloved son, heir of a great name, would not allow it to fall into oblivion, but adorn it with fresh lustre, and that great discoveries would honour his career also. No prediction of the illustrious astronomer has been more completely verified.

The English journals gave an account of the means adopted by the family of William Herschel, for preserving the remains of the great telescope of thirty-nine English feet (twelve metres) constructed by that celebrated astronomer.

The metal tube of the instrument carrying at one end the recently cleaned mirror of four feet ten inches in diameter, has been placed horizontally in the meridian line, on solid piers of masonry, in the midst of the circle, where formerly stood the mechanism requisite for manoeuvring the telescope. The first of January 1840, Sir John Herschel, his wife, their children, seven in number, and some old family servants, assembled at Slough. Exactly at noon, the party walked several times in procession round the instrument; they then entered the tube of the telescope, seated themselves on benches that had been prepared for the purpose, and sung a requiem, with English words composed by Sir John Herschel himself. After their exit, the illustrious family ranged themselves around the great tube, the opening of which was then hermetically sealed. The day concluded with a party of intimate friends.

I know not whether those persons who will only appreciate things from the peculiar point of view from which they have been accustomed to look, may think there was something strange in several of the details of the ceremony that I have just described. I affirm at least that the whole world will applaud the pious feeling which actuated Sir John Herschel; and that all the friends of science will thank him for having consecrated the humble garden where his father achieved such immortal labours, by a monument more expressive in its simplicity than pyramids or statues.

FOOTNOTES:

[15] When age and infirmities obliged Alexander Herschel to give up his profession as a musician, he quitted Bath, and returned to Hanover, very generously provided by Sir William with a comfortable independence for life.

[16] Sir W. Herschel had married Mary, the widow of John Pitt, Esq., possessed of a considerable jointure, and the union proved a remarkable accession of domestic happiness. This lady survived Sir William by several years. They had but this son.--_Translator's Note_.

CHRONOLOGICAL TABLE

OF THE MEMOIRS OF WILLIAM HERSCHEL.[17]

1780. _Philosophical Transactions_, vol. lxx.--Astronomical Observations on the Periodical Star in the Neck of the Whale.--Astronomical Observations relative to the Lunar Mountains.

1781. _Phil. Trans._, vol. lxxi.--Astronomical Observations on the Rotation of the Planets on their Axes, made with a View to decide whether the Daily Rotation of the Earth be always the same.--On the Comet of 1781, afterwards called the _Georgium Sidus_.

1782. _Phil. Trans._, vol. lxxii.--On the Parallax of the Fixed Stars.--Catalogue of Double Stars.--Description of a Lamp Micrometer, and the Method of using it.--Answers to the Doubts that might be raised to the high magnifying Powers used by Herschel.

1783. _Phil. Trans._, vol. lxxiii.--Letter to Sir Joseph Banks on the Name to be given to the new Planet.--On the Diameter of the Georgium Sidus, followed by the Description of a Micrometer with luminous or dark Disks.--On the proper Motion of the Solar System, and the various Changes that have occurred among the Fixed Stars since the Time of Flamsteed.

1784. _Phil. Trans._, vol. lxxiv.--On some remarkable Appearances in the Polar Regions of Mars, the Inclination of its Axis, the Position of its Poles, and its Spheroïdal Form.--Some Details on the real Diameter of Mars, and on its Atmosphere.--Analysis of some Observations on the Constitution of the Heavens.

1785. _Phil. Trans._, vol. lxxv.--Catalogue of Double Stars.--On the Constitution of the Heavens.

1786. _Phil Trans._, vol., lxxvi.--Catalogue of a Thousand Nebulæ and Clusters of Stars.--Researches on the Cause of a Defect of Definition in Vision, which has been attributed to the Smallness of the Optic Pencils.

1787. _Phil. Trans._, vol. lxxvii.--Remarks on the new Comet.--Discovery of Two Satellites revolving round George's Planet.--On Three Volcanoes in the Moon.

1788. _Phil. Trans._, vol. lxxviii.--On George's Planet (Uranus) and its Satellites.

1789. _Phil. Trans._, vol. lxxix.--Observations on a Comet. Catalogue of a Second Thousand new Nebulæ and Clusters of Stars.--Some Preliminary Remarks on the Constitution of the Heavens.

1790. _Phil. Trans._, vol. lxxx.--Discovery of Saturn's Sixth and Seventh Satellites; with Remarks on the Constitution of the Ring, on the Planet's Rotation round an Axis, on its Spheroïdal Form, and on its Atmosphere.--On Saturn's Satellites, and the Rotation of the Ring round an Axis.

1791. _Phil. Trans._, vol. lxxxi.--On the Nebulous Stars and the Suitableness of this Epithet.

1792. _Phil. Trans._, vol. lxxxii.--On Saturn's Ring, and the Rotation of the Planet's Fifth Satellite round an Axis.--Mixed Observations.

1793. _Phil. Trans._, vol. lxxxiii.--Observations on the Planet Venus.

1794. _Phil. Trans._, vol. lxxxiv.--Observations on a Quintuple Band in Saturn.--On some Peculiarities observed during the last Solar Eclipse.--On Saturn's Rotation round an Axis.

1795. _Phil. Trans._, vol. lxxxv.--On the Nature and Physical Constitution of the Sun and Stars.--Description of a Reflecting Telescope forty feet in length.

1796. _Phil. Trans._, vol. lxxxvi.--Method of observing the Changes that happen to the Fixed Stars; Remarks on the Stability of our Sun's Light.--Catalogue of Comparative Brightness, to determine the Permanency of the Lustre of Stars.--On the Periodical Star _a_ Herculis, with Remarks tending to establish the Rotatory Motion of the Stars on their Axes; to which is added a second Catalogue of the Brightness of the Stars.

1797. _Phil. Trans._, vol. lxxxvii.--A Third Catalogue of the comparative Brightness of the Stars; with an Introductory Account of an Index to Mr. Flamsteed's Observations of the Fixed Stars, contained in the Second Volume of the Historia Coelestis to which are added several useful Results derived from that Index.--Observations of the changeable Brightness of the Satellites of Jupiter, and of the Variation in their apparent Magnitudes; with a Determination of the Time of their rotary Motions on their Axes, to which is added a Measure of the Diameter of the Second Satellite, and an Estimate of the comparative Size of the Fourth.

1798. _Phil. Trans._, vol. lxxxviii.--On the Discovery of Four additional Satellites of the Georgium Sidus. The retrograde Motion of its old Satellites announced; and the Cause of their Disappearance at certain Distances from the Planet explained.

1799. _Phil. Trans._, vol. lxxxix.--A Fourth Catalogue of the comparative Brightness of the Stars.

1800. _Phil. Trans._, vol. xc.--On the Power of penetrating into Space by Telescopes, with a comparative Determination of the Extent of that Power in Natural Vision, and in Telescopes of various Sizes and Constructions; illustrated by select Observations.--Investigation of the Powers of the Prismatic Colours to heat and illuminate Objects; with Remarks that prove the different Refrangibility of radiant Heat; to which is added an Inquiry into the Method of viewing the Sun advantageously with Telescopes of large Apertures and high magnifying Powers.--Experiments on the Refrangibility of the Invisible Rays of the Sun.--Experiments on the Solar and on the Terrestrial Rays that occasion Heat; with a comparative View of the Laws to which Light and Heat, or rather the Rays which occasion them, are subject, in order to determine whether they are the same or different.

1801. _Phil. Trans._, vol. xci.--Observations tending to investigate the Nature of the Sun, in order to find the Causes or Symptoms of its variable Emission of Light and Heat; with Remarks on the Use that may possibly be drawn from Solar Observations.--Additional Observations tending to investigate the Symptoms of the variable Emission of the Light and Heat of the Sun; with Trials to set aside darkening Glasses, by transmitting the Solar Rays through Liquids, and a few Remarks to remove Objections that might be made against some of the Arguments contained in the former paper.

1802. _Phil. Trans._, vol. xcii.--Observations on the two lately discovered celestial Bodies (Ceres and Pallas).--Catalogue of 500 new Nebulæ and Clusters of Stars, with Remarks on the Construction of the Heavens.

1803. _Phil. Trans._, vol. xciii.--Observations of the Transit of Mercury over the Disk of the Sun; to which is added an Investigation of the Causes which often prevent the proper Action of Mirrors.--Account of the Changes that have happened during the last Twenty-five Years in the relative Situation of Double Stars; with an Investigation of the Cause to which they are owing.

1804. _Phil. Trans._, vol. xciv.--Continuation of an Account of the Changes that have happened in the relative Situation of Double Stars.

1805. _Phil. Trans._, vol. xcv.--Experiments for ascertaining how far Telescopes will enable us to determine very small Angles, and to distinguish the real from the spurious Diameters of Celestial and Terrestrial Objects: with an Application of the Result of these Experiments to a Series of Observations on the Nature and Magnitude of Mr. Harding's lately discovered Star.--On the Direction and Velocity of the Motion of the Sun and Solar System.--Observation on the singular Figure of the Planet Saturn.

1806. _Phil. Trans._, vol. xcvi.--On the Quantity and Velocity of the Solar Motion.--Observations on the Figure, the Climate, and the Atmosphere of Saturn and its Ring.

1807. _Phil. Trans._, vol. xcvii.--Experiments for investigating the Cause of the Coloured Concentric Rings, discovered by Sir Isaac Newton between two Object-glasses laid one upon another.--Observations on the Nature of the new celestial Body discovered by Dr. Olbers, and of the Comet which was expected to appear last January in its Return from the Sun.

1808. _Phil. Trans._, vol. xcviii.--Observations of a Comet, made with a view to investigate its Magnitude, and the Nature of its Illumination. To which is added, an Account of a new Irregularity lately perceived in the Apparent Figure of the Planet Saturn.

1809. _Phil. Trans._, vol. xcix.--Continuation of Experiments for investigating the Cause of Coloured Concentric Rings, and other Appearances of a similar Nature.

1810. _Phil. Trans._, vol. c.--Supplement to the First and Second Part of the Paper of Experiments for investigating the Cause of Coloured Concentric Rings between Object-glasses, and other Appearances of a similar Nature.

1811. _Phil. Trans._, vol. ci.--Astronomical Observations relating to the Construction of the Heavens, arranged for the Purpose of a critical Examination, the Result of which appears to throw some new Light upon the Organization of the Celestial Bodies.

1812. _Phil. Trans._, vol. cii.--Observations of a Comet, with Remarks on the Construction of its different Parts.--Observations of a Second Comet, with Remarks on its Construction.