The first envelopes with gummed flaps were produced in 1844. In Britain, they were not immediately popular because it was thought to be a serious insult to send a person's saliva to someone else.

Most people fail in adhering to their stated New Year's resolutions. Specifically, 22% fail after one week, 40% after one month, 50% after three months, 60% after six months, and 81% after twenty-four months.

One hundred years ago, visitors to Cave of the Winds in Colorado carried candles and lanterns along ghostly, dark halls that seemed to have no end. Today, cave enthusiasts can spend an hour or more with an authentically ...Read More

The Liberty Bell was not made in the United States and it was not rung on the first Fourth of July. It was cast in London in 1752, cracked in 1835, and was not named "Liberty" until the 1830s in memory of slaves seeking ...Read More

Recycled glass uses only two-thirds the energy needed to manufacture glass from scratch. That means for every soft drink bottle that is recycled, enough energy is saved to run a television set for an hour and a half.

Among his many achievements, the astronomer Johannes Kepler chalked up one about man's inner world. It was Kepler who realized that man's visual apparatus is so constructed that it can produce only inverted images.