"_March 22nd_.--He (Sir William) went for the first time into his library, but could only remain for a few moments."
[Footnote 1: Afterwards Sir John Herschel.]
From this dangerous attack Sir William recovered, but thenceforth it was clear to his friends that his strength gradually decreased, though not his enthusiasm or his industry. He persevered in his life-long labours with all his old intellectual force. What failed him was neither his tender affections nor his mental powers; but his body refused to answer all the demands made upon it by the resolute will,--the sword was slowly but surely wearing out the scabbard. Under the date of April 2, 1819, we meet with an ominous entry in his loving and faithful sister"s diary:--
"My brother left Slough, accompanied by Lady Herschel, for Bath, he being very unwell; and the constant complaint of giddiness in the head so much increased, that they were obliged to be four nights on the road both going and coming. The last moments before he stepped into the carriage were spent in walking with me through his library and workrooms, pointing with anxious looks to every shelf and drawer, desiring me to examine all, and to make memorandums of them as well as I could. He was hardly able to support himself; and his spirits were so low, that I found difficulty in commanding my voice so far as to give him the a.s.surance he should find on his return that my time had not been misspent.
"When I was left alone, I found that I had no easy task to perform, for there were packets of writings to be examined which had not been looked at for the last forty years. But I did not pa.s.s a single day without working in the library as long as I could read a letter without candlelight, and taking with me papers to copy, which employed me for best part of the night; and thus I was enabled to give my brother a clear account of what had been done at his return. But (May 1) he returned home much worse than he went, and for several days hardly noticed my handiwork."
To this same year of decay and decline (1819) belongs a small slip of yellow paper, inscribed with the following lines in a tremulous and feeble handwriting, which is jealously preserved by the ill.u.s.trious astronomer"s descendants:--
"LINA,--There is a great comet. I want you to a.s.sist me. Come to dine, and spend the day here. If you can come soon after one o"clock, we shall have time to prepare maps and telescopes. I saw its situation last night,--it has a long tail.
"_July 4, 1819_."
Then follows:--
"I keep this as a relic! Every line _now_ traced by the hand of my dear brother becomes a treasure to me.
"C. HERSCHEL."
We know of nothing more touching in literary history than this n.o.ble, self-sacrificing, generous affection of the sister towards her eminent brother. Such instances of absolute self-denial and all-absorbing love elevate our opinion of human nature generally, and prove that something of the Divine image lingers in it still.
Herschel was now bordering upon the ripe old age of eighty, and it is no wonder that, after a life of incessant study, his strength should daily diminish. In 1822 it became painfully evident to his attached relatives and friends that the end was not far off; and on the 25th of August he pa.s.sed away to his rest. We owe an account of his last days to his sister, but for whose pious care, indeed, very little of his private life would have been known, and Herschel could have been judged only from the recorded results of his immense labours.
"_May 20th_.--The summer proved very hot; my brother"s feeble nerves were very much affected, and there being in general much company, added to the difficulty of choosing the most airy rooms for his retirement.
"_July 8th_.--I had a dawn of hope that my brother might regain once more a little strength, for I have a memorandum in my almanac of his walking with a firmer step than usual above three or four times the distance from the dwelling-house to the library, in order to gather and eat raspberries, in his garden, with me. But I never saw the like again.
"The latter end of July I was seized by a bilious fever, and I could for several days only rise for a few hours to go to my brother about the time he was used to see me. But one day I was entirely confined to my bed, which alarmed Lady Herschel and the family _on my brother"s account_. Miss Baldwin [a niece of Lady Herschel] called and found me in despair about my own confused affairs, which I never had had time to bring into any order. The next day she brought my nephew to me, who promised to fulfil all my wishes which I should have expressed on paper; he begged me not to exert myself, for his father"s sake, of whom he believed _it would be the immediate death if anything should happen to me_."
Afterwards she wrote:--
"Of my dear nephew"s advice I could not avail myself, for I knew that at that time he had weighty concerns on his mind.
And, besides, my whole life almost has pa.s.sed away in the delusion that, next to my eldest brother, none but Dietrich was capable of giving me advice where to leave my few relics, consisting of a few books and my sweeper [that is, the seven-foot telescope with which she was accustomed to sweep the heavens for comets]. And for the last twenty years I kept to the resolution of never opening my lips to my dear brother William about worldly concerns, let me be ever so much at a loss for knowing right from wrong."
Miss Herschel proceeds to note that on the afternoons of the 11th, 12th, 13th, and 14th of August, she, "as usual," spent some hours with her brother.
On the 15th she hastened to the accustomed place, where she generally found him, with the newspaper which she was to read aloud for his amus.e.m.e.nt. But, instead, she found a.s.sembled there several of his nearest friends, who informed her that her aged brother had been compelled to return to his room. She lost no time in seeking him. He was attended by Lady Herschel and his housekeeper, who were administering everything which was likely to keep up his failing strength.
Miss Herschel observed that he was much irritated, with the irritation natural to old age and extreme bodily feebleness, at his inability to grant a friend"s request for some token of remembrance for his father.
No sooner did he see Miss Herschel, the loving companion and fellow-worker of so many years, than he characteristically employed her to fetch one of his last papers, and a plate (or map) of the forty-foot telescope. "But, for the universe," says Miss Herschel, "I could not have looked twice at what I had s.n.a.t.c.hed from the shelf; and when he faintly asked if the breaking up of the Milky Way[1] was in it, I said, "Yes," and he looked content." I cannot help remembering this circ.u.mstance; it was the last time I was sent to the library on such an occasion. That the anxious care for his papers and workrooms never ended but with his life, was proved by his frequent whispered inquiries if they were locked and the key safe; of which I took care to a.s.sure him that they were, and the key in Lady Herschel"s hands.
[Footnote 1: The _Via Lactea_, or "Milky Way," had long been supposed to consist of a nebulous, vague, luminous matter, but Herschel showed that it was really made up of stars and systems of stars.]
After struggling for some thirty minutes against his rapidly increasing weakness, the great astronomer, bowed by his burden of years and labours, was forced to retire to his bed, with little hope that he would ever rise from it again. For ten days and nights his wife and sister watched by his side in painful suspense, until, on the 25th of August, the end came. Peacefully closed a life which had pa.s.sed in a peace and quietness not often vouchsafed to man.
Herschel, says a brother astronomer, will never cease to occupy an eminent place in the small group of our contemporary men of genius, while his name will descend to the most distant posterity. The variety and the magnificence of his labours vie with their extent. The more they are studied, the more they are admired. For it is with great men as it is with great movements in the Arts and in national history,--we cannot understand them without observing them from different points of view.
What a brilliant roll of achievements is recalled to the mind by the name of William Herschel! The discovery of Ura.n.u.s, and of its satellites; of the fifth and sixth satellites of Saturn; of the many spots at the poles of Mars; of the rotation of Saturn"s ring; of the belts of Saturn; of the rotation of Jupiter"s satellites; of the daily period of Saturn and Venus; and of the motions of binary sidereal systems,--added to his investigations into nebulae, the Milky Way, and double, triple, and multiple stars;--all this we owe to his patient, his persevering, his daring genius! He may almost be styled the Father of Modern Astronomy.
CHAPTER IV.
We now propose to furnish a brief sketch of the life of Sir John Frederick William Herschel, the only son of Sir William, and not less ill.u.s.trious as a man of science.
He was born at Slough, in the year 1792. Evincing considerable talents at a very early age, he received a careful private education under Mr.
Rogers, a Scottish mathematician of distinguished merit; and afterwards was sent to St. John"s College, Cambridge, always famous as a nursery of mathematical and scientific prodigies! Here he pursued his studies with remarkable success, suffering no obstacles to daunt him, and wasting no opportunities of improvement. His fellow-collegians regarded him as one who would add to the high repute of the college, and rejoiced at the brilliant ease with which he pa.s.sed every examination. In 1813 he took his degree of B.A., and consummated a long series of successes by becoming "senior wrangler," and "Smith"s prizeman;" these being the two highest distinctions to which a Cambridge scholar can attain.
In the same year, when he was hardly twenty-one, he published a work ent.i.tled, "A Collection of Examples of the Application of the Calculus to Finite Differences." To our young readers such a t.i.tle will convey no meaning; and we refer to it here only to ill.u.s.trate the industry and careful thought of the young student, which had rendered possible such a result.
Returning to Slough, he continued his studies in mathematics, chemistry, and natural philosophy, and in various publications exhibited that faculty of observation and a.n.a.lyzation, that intelligence and scrupulousness in collecting facts, and that boldness in deducing new inferences from them, which were characteristic of his ill.u.s.trious father. The subjects he took up were so abstruse, that we could not hope to make our readers understand what he accomplished, or how far he excelled his predecessors in his grasp and comprehension of them. For instance: if we tell them that in 1820 he wrote a paper "On the Theory and Summation of Series;" communicated to the Cambridge Philosophical Society his discovery that the two kinds of rotatory polarization in rock crystal were related to the plagihedral faces of that mineral; and issued an able treatise "On Certain Remarkable Instances of Deviation from Newton"s Tints in the Polarized Tints of Uniaxal Crystals,"--they will gain no very distinct idea of the significance or value of these researches. Again: it will not be very intelligible to them to be informed that, in 1822, he communicated to the Royal Society of Edinburgh a paper "On the Absorption of Light by Coloured Media", in which he enunciated a new method of measuring the dispersion of transparent bodies by stopping the green, yellow, and most refrangible red rays, and thus rendering visible the rays situated rigorously at the end of the spectrum. But they will understand that these results could have been attained only by the most a.s.siduous industry and the most unflinching perseverance. And it is on account of this industry and this perseverance that we recommend Herschel as an example to our readers. They may not make the same progress in science, or achieve the same reputation. It is not necessary they should. Humble work is not less honourable, if it be done conscientiously, and with a sincere desire to do the best that it is in our power to do.
An interesting feature in the younger Herschel"s character was his loving care for his father"s fame. He was ever most anxious that the full measure of his services to science should be recognized and appreciated. Thus, in 1823, he writes to his aunt:--
"I have been long threatening to send you a long letter, but have always been prevented by circ.u.mstances and want of leisure from executing my intention. The truth is, I have been so much occupied with astronomy of late, that I have had little time for anything else--the reduction of those double stars, and the necessity it has put me under of looking over the journals, reviews, &c, for information on what has already been done, and in many cases of re-casting up my father"s measures, swallows up a great deal of time and labour. But I have the satisfaction of being able to state that our results in most instances confirm and establish my father"s views in a remarkable manner.
These inquiries have taken me off the republication of his printed papers for the present.
"I think I shall be adding more to his fame by pursuing and verifying his observations than by reprinting them. But I have by no means abandoned the idea. Meanwhile, I am not sorry to hear they are about to be translated into German.... I hope this season to commence a series of observations with the twenty-foot reflector, which is now in fine order. The forty-foot is no longer capable of being used, but I shall suffer it to stand as a monument."
In reference to this famous telescope, we may digress to state that its remains have been carefully preserved.
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 piles of masonry, in the midst of the circle where the apparatus used in manoeuvring it was formerly placed. On the 1st of January 1840, Sir John Herschel, his wife, their seven children, and some old family servants, a.s.sembled at Slough. Exactly at noon the party walked several times in procession round the instrument; they then entered the gigantic tube, seated themselves on benches previously prepared, and chanted a requiem with English words composed by Sir John Herschel himself. Then issuing from the tube, they ranged themselves around it, while its opening was hermetically sealed.
In March 1821, the younger Herschel, in conjunction with Sir James South, undertook a series of observations on the distances and positions of three hundred and eighty double and triple stars, by means of two splendid achromatic telescopes of five and seven focal length. These were continued during 1822 and 1823, and have proved of great service to astronomers.
Having pursued with much zeal the study of optics, and experimented largely and carefully on the double refraction and polarization of light, he compiled a treatise on the subject for the "Encyclopaedia Metropolitana" It has been translated into French by M. Quetelet; and both foreign and English men of science have been accustomed to regard it as indicating a new point of departure in the important branch of science to which it is devoted.
Astronomy, however, became for him, as for his father, the great pursuit of his laborious life; and having constructed telescopes of singular magnitude and power, he entered upon a study of the Sidereal World. In 1825 he commenced a careful re-examination of the numerous nebulae and starry cl.u.s.ters which had been discovered by his father, and described in the "Philosophical Transactions," fixing their positions and investigating their aspects. He devoted eight years to this _magnum opus_, completing it in 1832. The catalogue which he then contributed to the "Philosophical Transactions" includes 2306 nebulae and star-cl.u.s.ters, of which 525 were discovered by himself. While engaged in this difficult task, Herschel discovered between three and four thousand double stars, which he described in the Memoirs of the Astronomical Society. His observations were made with an excellent Newtonian telescope, twenty feet in focal length, and eighteen and a half inches in aperture; and having obtained, to use his own expression, "a sufficient mastery over the instrument," the idea occurred to him of making it available for a survey of the southern heavens. Accordingly, he left England on the 13th of November 1833, and arrived at Cape Town on the 16th of January 1834. Five days later he wrote to his aunt as follows:--
"Here we are safely lauded and comfortably housed at the far end of Africa; and having secured the landing and final storage of all the telescopes and other matters, as far as I can see, without the slightest injury, I lose no time in reporting to you our good success _so far_. M----[1] and the children are, thank G.o.d, quite well; though, for fear you should think her too good a sailor, I ought to add that she continued sea-sick, at intervals, during the whole pa.s.sage. We were nine weeks and two days at sea, during which period we experienced only one day of contrary wind. We had a brisk breeze "right aft" all the way from the Bay of Biscay (which we never entered) to the "calm lat.i.tudes;" that is to say, to the s.p.a.ce about five or six degrees broad near the equator, where the trade-winds cease, and where it is no unusual thing for a ship to lie becalmed for a month or six weeks, frying under a vertical sun.
Such, however, was not our fate. We were detained only three or four days by the calms usual in that zone, but never _quite_ still, or driven out of our course; and immediately on crossing "the line" got a good breeze (the south-east trade-wind), which carried us round Trinidad; then exchanged it for a north-west wind, which, with the exception of one day"s squall from the south-east, carried us straight into Table Bay. On the night of the 14th we were told to prepare to see the Table Mountain.
Next morning (_N.B._, we had not seen land before since leaving England), at dawn, the welcome word land" was heard; and there stood this magnificent hill, with all its attendant mountain-range down to the farthest point of South Africa, full in view, with a clear blue ghost-like outline; and that night we cast anchor within the Bay. Next morning early we landed, under escort of Dr. Stewart, M----"s brother, and you may imagine the meeting. We took up our quarters at a most comfortable lodging-house (Miss Robe"s), and I proceeded, without loss of time, to unship the instruments. This was no trifling operation, as they filled (with the rest of our luggage) fifteen large boats; and, owing to the difficulty of getting them up from the hold of the ship, required several days to complete the landing. During the whole time (and indeed up to this moment) not a single south-east gale, the summer torment of this harbour, has occurred. This is a thing almost unheard of here, and has indeed been most fortunate, since otherwise it is not at all unlikely that some of the boats, laden as they were to the water"s edge, might have been lost, and the whole business crippled.