"Gracious, what a memory that boy has!" exclaimed his uncle. "Well; now this water in the kettle—eh?—why, this is not above one hundred and fifty degrees. There, sir, now set it on the fire, and don't bring me up cold water to make tea with again; or else," added Mr. Bagges, making a vague attempt at a joke, "or else—eh?—you will get yourself into hot water."
Mr. Thomas was seized with a convulsion in the chest, which he checked by suddenly applying his open hand to his mouth, the effort distending his cheeks, and causing his eyes to protrude in a very ridiculous manner, while Mr. Bagges disguised his enjoyment of the effects of his wit in a cough.
"Now let me see," said the old gentleman, musingly contemplating the vessel simmering on the fire; "how is it, eh, Harry, you said the other day that a kettle boils?"
"La!" interrupted Mrs. Wilkinson, who was of the party, "why, of course, by the heat of the coals, and by blowing the fire, if it is not hot enough."
"Aha!" cried her brother, "that's not the way we account for things, Harry, my boy, eh? Now, convince your mother; explain the boiling of a kettle to her: come."
"A kettle boils," said Harry, "by means of the action of currents."
"What are you talking about? Boiling a plum-pudding in a tea-kettle!" exclaimed the mystified mamma.
"Currents of heated particles—of particles of hot water," Harry explained. "Suppose you put your fire on your kettle—on the lid of it—instead of your kettle on your fire—- what then?"
"You would be a goose," said his mother.
"Exactly so—or a gosling"—rejoined her son; "the kettle would not boil. Water is a bad conductor of heat. Heat passes through the substance of water with very great difficulty. Therefore, it would have a hard matter to get from the top of a kettle of water to the bottom. Then how does it so easily get from the bottom to the top?"