You will remember that Herschel while still a boy had deserted from the army, many years previously. It appears that the King had learned this fact in some way, so that when Herschel was ushered into his presence his Majesty said that before the great astronomer could discuss science there was a little matter of business that must be disposed of. The King accordingly handed Herschel a paper, in which he was, I dare say, greatly surprised to find a pardon to the deserter written out by the King himself.
Then Herschel unfolded his wonderful discovery, which the King thoroughly appreciated, and in the evening the telescope was set up in the gardens, and the glories of the heavens were displayed. Herschel made a most favorable impression on his Majesty, and when the King told the ladies of the Castle next day of all that Herschel had shown him, their astronomical ardor was also aroused, and they asked to see through the marvellous tube. Of course Herschel was ready to comply, and the telescope was accordingly carried to the windows of the Queen’s apartments at Windsor, which would have commanded a fine view if the clouds had not been in the way, which they unfortunately were. Even for royalty the clouds would not disperse, so what was to be done? Herschel was equal to the occasion. He specially wanted to exhibit Saturn, for it is one of the most beautiful objects in the sky, and will fascinate any intelligent beholder. No astronomers would have been able to see Saturn through the clouds, but Herschel did not disappoint his visitors; he directed the instrument, not to the sky (nothing was there to be seen); he turned it towards a distant garden wall. Now what would you expect to see by looking through a telescope at a garden wall—bricks, perhaps, or ivy? What these ladies saw was a beautiful image of Saturn, his globe in the centre and his rings all complete, forming so true a resemblance to the planet that even an experienced astronomer might have been deceived. In the afternoon Herschel had seen that the clouds were thick, and that there would be little probability of using the telescope properly. Accordingly he cut out a little image of Saturn, illuminated it by lamps, and set it up at a suitable distance on a garden wall.
Herschel’s visit to Windsor was productive of important consequences. The King said it was a pity that so great an astronomer should devote himself to music, and that it would be far better for him to give up that profession and come and live at Windsor. His Majesty promised that he would pay him a salary, and he also undertook to provide the cost of erecting great telescopes. His faithful sister Caroline came with him as his assistant, and also received some bounty from the King. From that moment Herschel renounced all his musical business, and devoted himself to his great life-task of observing the heavens.
He built telescopes of proportions far exceeding those that had ever been then thought of. He used to stand at night in the open air from dusk to dawn gazing down the tube of his mighty reflector, watching the stars and other objects in the heavens as they moved past. He would dictate what he saw to Caroline, who sat near him. It was her business to write down his notes and to record the position of the objects which he was describing. Sometimes, she tells us, the cold was so great that the ink used to freeze in her pen when she was at this work. Until he became a very old man, Herschel devoted himself to his astronomical labors. His discoveries are to be counted by thousands, though not one of them was so striking or so important as the detection of the new planet which first brought him fame.
The question of a name for the addition to the sun’s family had, of course, to be settled. Herschel had surely a right to be heard at the christening, and as a compliment to his Majesty he named the stranger the Georgium Sidus. So, indeed, for a brief while, the planet was actually styled. The Continental astronomers, however, would not accept this designation; all the other planets were named after ancient divinities, and it was thought that the King of England would seem oddly associated with Jupiter and Saturn; perhaps also they considered that the British dominions, on which the sun never sets, were already quite large enough, without further extension to the celestial regions. Accordingly a consultation was held, the result of which was that George III. was deprived of his planetary honors, and the body was given the name of Uranus, which, by universal consent, it now bears.
The planet Uranus lies just on the verge of visibility with the unaided eye. It can sometimes be glimpsed like a faint star, and, of course, with a telescope it is readily perceived. Many generations of astronomers before Herschel’s time had been observing the heavens, making maps of the stars, and compiling great catalogues in which the places of the stars were accurately put down. It often happened that Uranus came under their notice, but it never occurred to them that what seemed so like a star was really a planet. I have, no doubt, said that Uranus looked unlike a star when Herschel examined it; but then that was because Herschel was a particularly skilful astronomer. To an observer of a more ordinary type Uranus would not present any very remarkable appearance, and would be passed over merely as a small star. In fact, the planet was thus observed not once or twice, but no fewer than seventeen times, before the acute eye of Herschel perceived its true character. On many previous occasions the planet had been noted as a star by astronomers who are in every way entitled to our respect. It required a Herschel, determined to see everything in the very best manner, to grasp the discovery which eluded so many others.
When Uranus was observed on these former occasions and mistaken for a star, its place had been carefully put down. These records are at present of the utmost use, because they show the past history of the planet; and they appear all the more valuable when we remember that Uranus requires no less than eighty-four years to accomplish a single revolution around the sun. Thus, since the planet was discovered in 1781, it had completed one revolution by 1865, and is now (1899) about one-third of the way around another. The earlier observations extend backwards almost 200 years, so that altogether we have more or less information about the movements of the planet during the completion of two circuits and a half.
Uranus is a great deal bigger than the earth, as you will see in the view of the comparative sizes of the planets ([Fig. 47]). It appears to be of a bluish hue, but we cannot tell whether it turns round on its axis, or rather, I should say, we are not able to see whether it turns round on its axis; for we can hardly doubt that it does so.
Notwithstanding that Uranus is at so great a distance from the earth, we have been able to put this planet, no less than the nearer ones, in the weighing scales, and we assert with confidence that Uranus is fifteen times as heavy as our earth. We are indebted to the satellites for this information.