THE FIRST KALEIDOSCOPE.
When, by a happy accident, Sir David Brewster had discovered the leading principles of the kaleidoscope while repeating Biot's experiments on the action of fluids upon light, he constructed an instrument in which he fixed permanently, across the ends of the reflectors, pieces of coloured glass, and other irregular objects. But it was not till some time afterwards that the great step towards the completion of the instrument was made, in the idea of giving motion to these objects, which were placed loosely in a cell at the end of the instrument. When this idea was carried into execution, the kaleidoscope in its simple form was completed. The next and by far the most important step of the invention was, to employ a draw tube and lens, by means of which beautiful forms could be created from objects of all sizes, and at all distances from the observer. In this way, the power of the kaleidoscope was indefinitely extended, and every object in nature could be introduced into the picture, in the same manner as if these objects had been reduced in size, and actually placed at the end of the reflector.
FERGUSON AND HIS WIFE.
James Ferguson and his wife led a cat-and-dog life, and she is not once alluded to in the philosopher's autobiography. About the year 1750, one evening, while he was delivering to a London audience a lecture on astronomy, his wife entered the room in a passion, and maliciously overturned several pieces of the apparatus; when all the notice Ferguson took of the catastrophe was the observation to the audience—"Ladies and gentlemen, I have the misfortune to be married to this woman."
A DESCENT IN A DIVING-BELL.
Sir George Head, in his shrewdly humorous Home Tour, gives an amusing picture of a pair of operative divers whom he saw in the Hull docks. Sir George was passing as the workmen were raising the diving-bell, when he stepped into the lighter to observe the state of the labourers on their return from below. He had a remarkably good view of their features, at a time when they had no reason to expect any one was looking at them; for, as the bell was raised very slowly, he had an opportunity of seeing within it, by stooping, the moment its side was above the gunwale of the lighter. But, Sir George shall relate what he saw:—
"A pair of easy-going, careless fellows, each with a red nightcap on his head, sat opposite one another, by no means over-heated or exhausted, and apparently with no other want in the world than that of 'summut to drink;' they had been under water exactly two hours. I asked them what were their sensations on going down? They said that, before a man was used to it, it produced a feeling as if the ears were bursting; that, on the bell first dipping, they were in the habit of holding their noses; at the same time of breathing as gently as possible, and that thus they prevented any disagreeable effect: they added, the air below was hot, and made a man thirsty;—the latter observation, though in duty bound I received as a hint, I believe to be true; nevertheless, the service cannot be formidable, as the extra pay is only one shilling per day. Had there been any thing extraordinary to see below, I should have asked permission to go down; but the water was by no means clear, and the muddy bottom of the docks was not a sufficient recompence for the disagreeable sensation. Two men descend at a time, and four pump the air into the bell through the leathern hose; the bell is nearly a square, or rather an oblong, vessel of cast-iron, with ten bull's-eye lights at the top, which lights are fortified within by a lattice of strong iron wire, sufficient to resist an accidental blow of a crowbar, or other casualty.—Notwithstanding the great improvements made in diving-bells since their invention, after all precautions, a man in a diving-bell is, certainly, in a state of awful dependence upon human aid: in case of the slightest accident to the air-pump, or even a single stitch of the leathern hose giving way, long before the ponderous vessel could be raised to the surface, life must be extinct."