A common two-foot telescope falling into his hands, revealed to him the wonders of the heavens. His imagination was inspired by their contemplation; with ever-increasing enthusiasm he gazed on the revolving planets, on the flashing stars; he determined to fathom more profoundly the constellated depths. A larger instrument was necessary, and Herschel wrote to London for it; but the price demanded proved far beyond the resources of the sanguine organist. What should he do? He was not the man to be beaten back by a difficulty: as he could not buy a telescope, he resolved to make one; an instrument eighteen or twenty feet long, which would reveal to him the phases of the remotest planets. And straightway the musician entered on a multitude of ingenious experiments, so as to discover the particular metallic alloys that reflected light with the greatest intensity, the best means of giving the parabolic figure to the mirrors, the necessary degree of polish, and other practical details. In his eager pursuit he enlisted the services of his loving and intelligent sister. "I was much hindered in my musical practice," she writes, "by my help being continually wanted in the execution of the various contrivances; and I had to amuse myself by making the tube of pasteboard for the glasses which were to arrive from London—for at that time no optician had settled at Bath. But when all was finished, no one besides my brother could get a glimpse of Jupiter or Saturn, for the great length of the tube would not allow it to be kept in a straight line. This difficulty, however, was soon removed, by substituting tin tubes."
The work went on famously, as might be expected from so much ardour, perseverance, and ingenuity. Of a Quaker resident at Bath, the musician-astronomer purchased a quantity of patterns, tools, hones, polishers, and unfinished mirrors. Every room in the house was converted into a workshop. In a handsomely-furnished drawing-room might be seen a cabinetmaker constructing a tube and stands of all descriptions; while Herschel's brother Alex was engaged in a bedroom in putting up a gigantic turning-machine. Meantime, the claims of music could not be ignored: there were frequent rehearsals for the public concerts; lessons to pupils; the composition of glees and catches, and the like; the superintendence of the practice of the chapel choir; and the study of sonatas and concertos for public performance. But all the leisure that could be made or stolen was occupied in labours which proved their own reward. Straight from the concert-platform rushed the musician to his workshop, and many a lace ruffle was torn by nails or bespattered by molten pitch; to say nothing of the positive danger to which Herschel continually exposed himself by the precipitancy of his movements. For example: one Saturday evening, when the two brothers returned from a concert between eleven and twelve o'clock, William amused himself all the way home with the idea of being at liberty to spend the next day, except the few hours' duty at chapel, at the turning-bench; but recollecting that the tools wanted sharpening, they ran with them and a lantern to their landlord's grindstone in a public yard, where, very naturally, they did not wish to be seen on a Sunday morning. But William was soon brought back by his brother, almost swooning with the loss of one of his finger-nails.
This incident took place in the winter of 1775, at a house situated near Walcot turnpike, to which Herschel had removed in the summer of the previous year. Here, on a grass plot behind the house, he made active preparations for the erection of a twenty-foot telescope. So assiduous was his devotion to this work, that while he was engaged in polishing the mirror, his sister was constantly obliged to feed him by putting his victuals into his mouth. Otherwise he would have reduced himself to a condition of positive emaciation! Once, when finishing a seven-foot mirror, he did not take his hands from it for sixteen consecutive hours; for in these days machinery had not been devised as a substitute for manual toil. He was seldom unemployed at meals; but at such times employed himself in contriving or making drawings of whatever occurred to his fertile fancy. Usually his sister Caroline read to him while he was engaged at the turning-lathe, or polishing mirrors; choosing such books as "Don Quixote," the "Arabian Nights," the novels of Sterne and Fielding; and tea and supper were served without any interruption to the task in which Herschel was absorbed.
In Miss Herschel's charming letters we find a vivid sketch of the family avocations at this period:—-
"My brother applied himself to perfect his mirrors, erecting in his garden a stand for his twenty-foot telescope: many trials were necessary before the required motions for such an unwieldy machine could be contrived. Many attempts were made by way of experiment against a mirror before an intended thirty-foot telescope could be completed, for which, between whiles (not interrupting the observations with seven, ten, and twenty-foot, and writing papers for both the Royal and Bath Philosophical Societies), gauges, shapes, weights, &c., of the mirror were calculated, and trials of the composition of the metal were made. In short, I saw nothing else and heard nothing else talked of but about these things when my brothers were together. Alex was always very alert, assisting when anything new was going forward; but he wanted perseverance, and never liked to confine himself at home for many hours together. And so it happened that my brother William was obliged to make trial of my abilities in copying for him catalogues, tables, &c, and sometimes whole papers which were lent [to] him for his perusal. Among them was one by Mr. Michel, and a catalogue of Christian Mayer in Latin, which kept me employed when my brother was at the telescope at night. When I found that a hand was sometimes wanted when any particular measures were to be made with the lamp micrometer, or a fire to be kept up, or a dish of coffee necessary during a night's long watching, I undertook with pleasure what others might have thought a hardship."
The astronomer-musician's patient survey of the heavens was rewarded, on the 13th of March 1781, by the discovery of a new planet, situated on the borders of our Solar System. In every way this was a discovery of signal importance. It broke up the traditional conservatism of astronomers, which had almost refused to regard as possible the existence of any planets beyond the orbit of Saturn, because for so many years none had revealed themselves to the watchful gaze. Men's minds were widened, so to speak, at a bound; their conceptions strengthened and enlarged; for the discovery of Georgium Sidus—as the new planet was designated by its discoverer, in honour of George III.—rendered possible and probable the discovery of other planets, and thus extended immeasurably the limits of the Solar System. Herschel, whose reputation as a musician had hitherto been local, now sprang into world-wide fame as an astronomer. George III., who was a true lover of science, and not disinclined to bestow his patronage on men and things of Hanoverian origin, summoned him to his presence; and was so much pleased with his modest and interesting account of the long labours which had led to the great result, that, after a brief interval, he bestowed upon him an annual pension of three hundred guineas, and a residence, first at Clay Hall, and then at Slough.
But before this well-deserved good fortune fell to him, Herschel continued his industrious career as both musician and astronomer. During the concert season, which lasted five or six months, he had never a night disengaged, but was conducting oratorios at Bath or Bristol, arranging for public concerts, attending rehearsals, and superintending the performances of his choir. As soon as a lull came, the indomitable man, assisted by his faithful sister, returned to his astronomical pursuits. To gain a fuller and clearer knowledge of the starry worlds scattered over the vast fields of space, Herschel from the first had seen that instruments of much greater power were necessary than any hitherto used by astronomers. He set to work, therefore, on the construction of a thirty-foot telescope; the metallic mirror of which must, of course, be of proportionate dimensions. This huge mirror was to be cast in a mould of loam prepared from horse-dung, of which an immense quantity was to be pounded in a mortar, and sifted through a fine sieve; an arduous and almost endless task, undertaken by Caroline Herschel and her brother Alex. Then a furnace was erected in a back-room on the ground-floor; and every preparation having been made, a day was set apart for the casting. The day came, and Herschel and his collaborateurs looked forward to the consummation of their hopes. The metal was placed in the furnace; but, unfortunately, just when it was ready for pouring in a molten stream into the mould, it began to leak, and both the Herschels, and the caster with his men, were compelled to fly from the apartment, the stone flooring exploding, and flying about in all directions, as high as the ceiling. The astronomer, exhausted with heat and exertion, fell on a heap of brickbats; exhausted, but not dismayed. The work was renewed; and a second casting being attempted, it proved entirely successful, and a very perfect metal was formed in the mould.