Q. Why would not the hearth-stone feel cold, when it is of the same temperature as our feet?
A. Because the heat would no longer rush out of our feet into the hearth-stone, in order to produce an equilibrium.
Q. Why does the hearth-stone (when the fire is lighted) feel so much hotter than the hearth-rug?
A. The hearth-stone is an excellent conductor; and, therefore, parts with its heat more readily than the woollen hearth-rug; which (being a very bad conductor) parts with its heat reluctantly.
Q. Why does parting with heat rapidly make the hearth-stone feel warm?
A. As the heat of the stone rushes quickly into our foot, it raises its temperature so suddenly, that we cannot help perceiving the increase of heat.
Q. Why does the non-conducting power of the hearth-rug prevent its feeling so hot as it really is?
A. Because it parts with its heat so slowly and gradually, that we scarcely perceive its transmission into our feet.
Q. When we plunge our hands into a basin of water, why does it produce a sensation of cold?
A. Though the water (in which we wash) is really warmer than the air of our bed-room; yet because it is a better conductor, it feels colder.