"The difference," said the Professor calmly, with a glance of affection at his large-skulled hat, which was rolling on the floor without taking any harm, "according to my very humble opinion, is not so much of kind as of degree, my Tommy. It has long been well known that the various families of the human race--as we may venture still to call it--differ very greatly in specific gravity; the Celt, for instance, is especially heavy in proportion to his size, and the Jute the opposite. There was, I believe, an exceptionally light and buoyant race in North America, aboriginal so far as we know; and the lightest member of that race, Tommy, would probably have despised your highest flight. At the same time, and although I have met with a case of almost equal levity--the example being, I regret to say, feminine--you must not imagine that I am endeavouring to disparage your exploits, my dear Tommy. Don't cry, my dear child; I had no idea that you were so sensitive upon this matter. Your admirable master has always told me, that your main desire is to stop upon the ground, and that both your parents wish it. You nod your head, as if I understood your feelings. Then why are your blue eyes full of tears?" "If you please, sir, I wasn't at all longing to go up. Only I didn't know anybody else had done it. And I shan't care to go up any more, after that." "Well!" cried the Professor, with his great rich smile; "human nature has no exceptions half so wonderful as its laws are. My good little friend, allow me to comfort you, and to restore your self-respect. It is not by any means a common thing for members of the English race to fly--excuse me for using the popular, but incorrect word, to describe your exploits. But there is a power that beats you, Tommy, in your own province, and that is Time. At three o'clock I have a lecture to deliver upon your antitype, the apteryx, a bird that has abdicated the rights, which some of us desire to usurp." "Oh, sir, do let me come and hear it, if old Rum will let me go. Bill Chumps has heard you lecture, and he says----"