This hypothesis, however, like a thousand others, when it happened that they engaged no durable sympathy from his nursery audience, he did not pursue. For some time he turned his thoughts to philosophy, and read lectures to us every night upon some branch or other of physics. This undertaking arose upon some one of us envying or admiring flies for their power of walking upon the ceiling. "Poh!" he said, "they are impostors; they pretend to do it, but they can't do it as it ought to be done. Ah! you should see _me_ standing upright on the ceiling, with my head downwards, for half an hour together, and meditating profoundly." My sister Mary remarked, that we should all be very glad to see him in that position. "If that's the case," he replied, "it's very well that all is ready, except as to a strap or two." Being an excellent skater, he had first imagined that, if held up until he had started, he might then, by taking a bold sweep ahead, keep himself in position through the continued impetus of skating. But this he found not to answer; because, as he observed, "the friction was too retarding from the plaster of Paris, but the case would be very different if the ceiling were coated with ice." As it was _not_, he changed his plan. The true secret, he now discovered, was this: he would consider himself in the light of a humming top; he would make an apparatus (and he made it) for having himself launched, like a top, upon the ceiling, and regularly spun. Then the vertiginous motion of the human top would overpower the force of gravitation. He should, of course, spin upon his own axis, and sleep upon his own axis--perhaps he might even dream upon it; and he laughed at "those scoundrels, the flies," that never improved in their pretended art, nor made any thing of it. The principle was now discovered; "and, of course," he said, if a man can keep it up for five minutes, what's to hinder him from doing so for five months?" "Certainly, nothing that I can think of," was the reply of my sister, whose scepticism, in fact, had not settled upon the five months, but altogether upon the five minutes. The apparatus for spinning him, however, perhaps from its complexity, would not work--a fact evidently owing to the stupidity of the gardener. On reconsidering the subject, he announced, to the disappointment of some amongst us, that, although the physical discovery was now complete, he saw a moral difficulty. It was not a _humming_ top that was required, but a peg top. Now, this, in order to keep up the _vertigo_ at full stretch, without which, to a certainty, gravitation would prove too much for him, needed to be whipped incessantly. But that was precisely what a gentleman ought not to tolerate: to be scourged unintermittingly on the legs by any grub of a gardener, unless it were father Adam himself, was a thing that he could not bring his mind to face. However, as some compensation, he proposed to improve the art of flying, which