In 1693, the postage rate of a letter was determined by how much light went through the letter. The less the light went through the letter the more expensive the rate would be. This technique was referred to as candling.

One acre of wheat can produce enough bread to feed a family of four people for about ten years.

There are 21 "secret" highways that are part of the Interstate Highway System. They are not identified as such by road signs.

AMAZING FACTS