At that epoch new planets had not yet begun to be found by the dozen. Five, besides the earth, had been known from the remotest antiquity. Five, and no more, seemed to have a prescriptive right to exist. The boundaries of the solar system were of immemorial establishment. It was scarcely conceivable that they should need to be enlarged. The notion did not occur to Herschel. His discovery was modestly imparted to the Royal Society as “An Account of a Comet.” He had, indeed, noticed that the supposed comet moved in planetary fashion from west to east, and very near the ecliptic; and, after a few months, its true nature was virtually proved by Lexell of St. Petersburg. On November 28th, Herschel measured, with his freshly-invented “lamp-micrometer,” the diameter of this “singular star;” and it was not until a year later, November 7th, 1782, that he felt sufficiently sure of its planetary status to exercise his right of giving it a name. Yet this, in the long run, he failed to accomplish. The appellation “Georgium Sidus,” bestowed in honour of his patron, George III., never crossed the Channel, and has long since gone out of fashion amongst ourselves. Lalande tried to get the new planet called “Herschel;” but the title “Uranus,” proposed by Bode, of Berlin, was the “fittest,” and survived.
This discovery made the turning-point of Herschel’s career. It transformed him from a music-master into an astronomer. Without it his vast abilities would probably have been in great measure wasted. No man could long have borne the strain of so arduous a double life as he was then leading. Relief from it came just in time. It is true that fame, being often more of a hindrance than a help, brought embarrassments in its train. In November, 1781, Herschel was compelled to break the complex web of his engagements at Bath by a journey to London for the purpose of receiving in person the Copley Medal awarded to him by the Royal Society, of which body he was, some days later, elected a Fellow. At home, he was persecuted by admirers; and they were invariably received with an easy suavity of manner that gave no hint of preoccupation. Everyone of scientific pretension who visited Bath sought an interview with the extraordinary man who, by way of interlude to pressing duties, had built telescopes of unheard-of power, and performed the startling feat of adding a primary member to the solar system. Among the few of these callers whose names have been preserved were Sir Harry Englefield, Sir Charles Blagden, and Dr. Maskelyne, then, and for thirty years afterwards, Astronomer-Royal. “With the latter,” Miss Herschel relates, “he (William) was engaged in a long conversation which to me sounded like quarrelling, and the first words my brother said after he was gone were, ‘That is a devil of a fellow!’” The phrase was doubtless meant as a sign of regard, for the acquaintance thus begun ripened into cordial intimacy. And William Herschel never lost or forgot a friend.
As regards music alone, the winter of 1781–82 was an exceptionally busy one. He had arranged to conduct, jointly with Rauzzini, a Roman singer and composer, a series of oratorios; undertaking, besides, pecuniary responsibilities which turned out little to his advantage. The labour, vexation, and disappointment involved in carrying out this unlucky plan can readily be imagined. But neither the pressure of business, nor the distractions of celebrity, checked the ardour of his scientific advance. The review which afforded him the discovery of Uranus, and the materials for his first catalogue of 269 double stars, was completed in 1781; and a third, made with the same beautiful instrument, bearing the high magnifying power of 460, was promptly begun. This had for one of its special objects the ascertainment of possible changes in the heavens since Flamsteed’s time; and in the course of it many thousands of stars came under scrutiny, directed to ascertain their magnitude and colour, singleness or duplicity, hazy or defined aspect.
The first of Herschel’s effective twenty-foot telescopes was erected at 19, New King Street, in the summer of 1781. Enclosing a mirror twelve inches in diameter, it far surpassed any seeing-machine that had ever existed in the world. Yet its maker regarded it as only marking a step in his upward progress. A speculum of thirty-feet focus was the next object of his ambition. For its achievement no amount of exertion was counted too great. Its composition was regulated by fresh experiments on various alloys of copper and tin. Its weight and shape were again and again calculated, and the methods appropriate to its production earnestly discussed. “I saw nothing else,” Caroline Herschel tells us, “and heard nothing else talked of but these things when my brothers were together.”[B]
[B] In borrowing Miss Herschel’s lively narratives and comments, some obvious slips in grammar and construction have been corrected. Quotations, too, from the writings of Sir William and Sir John Herschel are often slightly abridged.
“The mirror,” she continues, “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. It was an endless piece of work, and served me for many an hour’s exercise; and Alex frequently took his turn at it, for we were all eager to do something towards the great undertaking. Even Sir William Watson would sometimes take the pestle from me when he found me in the work-room.”
The matter was never out of the master’s thoughts. “If a minute could but be spared in going from one scholar to another, or giving one the slip, he called at home to see how the men went on with the furnace, which was built in a room below, even with the garden.”
At last, the concert season being over, and everything in readiness for the operation of casting, “the metal,” we hear from the same deeply-interested eyewitness, “was in the furnace; but, unfortunately, it began to leak at the moment when ready for pouring, and both my brothers, and the caster with his men, were obliged to run out at opposite doors, for the stone flooring, which ought to have been taken up, flew about in all directions, as high as the ceiling. My poor brother William fell, exhausted with heat and exertion, on a heap of brickbats. Before the second casting was attempted, everything which could ensure success had been attended to, and a very perfect metal was found in the mould, which had cracked in the cooling.”
This second failure terminated the enterprise. Not that it was abandoned as hopeless, but because of a total change in the current of affairs. Herschel’s fame had stirred the royal curiosity, and rumours had now and again reached Bath that he was to be sent for to court. In the spring of 1782 the actual mandate arrived; and on May 8th, leaving his pupils and his projects to shift for themselves, he set out for London. He carried with him his favourite seven-foot reflector, and all the apparatus necessary for viewing double stars and other objects of interest. On May 25th he wrote to his sister:—
“I have had an audience of His Majesty this morning, and met with a very gracious reception. I presented him with the drawing of the solar system, and had the honour of explaining it to him and the Queen. My telescope is in three weeks’ time to go to Richmond, and meanwhile to be put up at Greenwich.... Tell Alexander that everything looks very like as if I were to stay here. The King enquired after him, and after my great speculum. He also gave me leave to come and hear the Griesbachs (Herschel’s nephews) play at the private concert which he has every evening.... All my papers are printing, and are allowed to be very valuable. You see, Lina, I tell you all these things. You know vanity is not my foible, therefore I need not fear your censure. Farewell.”