Reflection.
When a piece of bright tin is held near the fire, does the tin become hot?
No; the tin is scarcely warmed.
What does the tin do with the rays of heat from the fire?
The tin throws them back from its surface.
What is this called?
It is called Reflection of heat.
Do all substances reflect heat equally well?
No; some reflect much more heat than others.
What kind of objects reflect heat the best?
Those with bright and smooth surfaces.
What kind of objects reflect heat the least?
Those with rough and dark surfaces.
Does bright tin reflect heat better than glass?
Yes; bright tin reflects about eight times as much heat as glass does.
Why does it take so long to heat water in a new tin cup?
Because the bright tin is a good reflector, and throws off the greater part of the rays of heat that come to it from the fire.
Why does a piece of tin or other bright metal, placed under a stove, protect the carpet from burning?
Because the tin being a good reflector, remains cool, and cannot burn the carpet under it.
Why will not a piece of iron protect the carpet from burning?
Because the iron, being a poor reflector, soon becomes heated, so as to burn the carpet under it.