Mother: Yes, when we move quickly, we breathe faster, and the blood goes bounding through every part of the body, so the fire inside burns brightly. Sawing wood is a good way to warm a cold boy, and a broom is a fine helper to warm a cold girl.
“A good way to warm a cold boy.”
Amy: When it is frosty, we can see our breath. Is that the smoke coming from the fire inside, mother?
Mother: You may call it that if you like. When a candle burns, it gives off what we call carbonic acid gas, and we breathe out some of the same kind of gas. Water also comes out in the breath like steam from an engine, half a pint or a pint each day.
Elmer: Do some kinds of food make more heat than others?
“A fine helper to warm a cold girl.”
Mother: Yes; all kinds of fatty foods make heat. In very cold countries people can eat more fat and keep well than in warm climates. Esquimaux eat a great deal of fat. A little Esquimau child would eat a tallow candle and enjoy it as much as you would an orange. I once read of some sailors who made a Christmas tree for some of those children in the frozen north. The tree was made of walrus bones tied together, and, instead of popcorn, fruit, and sweetmeats, they hung balls of fat on the tree. The children thought it a great treat, and ate them as quickly as you would eat peaches.
Amy: How funny! But, mother, are not our bodies warmer in summer than in winter?