A. As they do not come in contact with the fire, they cannot absorb heat; and (being bright) they will not suffer the heat to escape by radiation.
Q. In what state should a saucepan be, in order that it may boil quickly?
A. All those parts which come in contact with the fire should be covered with soot, to absorb heat; but all the rest of the saucepan should be as bright as possible, to prevent the escape of heat by radiation.
Q. Why is it said that “Saturday’s kettle boils the fastest?”
A. Because on Saturday the front and top of the kettle are generally cleaned and polished; but the bottom and back of the kettle are never cleaned.
Q. Why should not the bottom and back of a kettle be cleaned and polished?
A. Because they come in contact with the fire, and (while they are covered with black soot) absorb heat freely from the burning coals.
Q. Why should the front and top of a kettle be clean and well polished?
A. Because polished metal will not radiate heat; and, therefore, (while the front and top of the kettle are well polished) the heat is kept in, and not suffered to escape by radiation.
Q. Why is the inside of a kettle and saucepan white?