Over 100 years ago, felt hat makers in England used mercury to stabilize wool. Many of them were poisoned by the fumes, which cause erethism, a disorder characterized by nervousness, irritability, and strange personality changes as demonstrated by the Mad Hatter in Alice in Wonderland.

The Hawaiian Islands are the projecting tops of the biggest mountain range in the world. Mauna Kea, on the island of Hawaii, is the largest mountain on Earth - though partially submerged, it is 4,000 feet taller than Mount Everest.

Bavarian immigrant Charles August Fey invented the first three-reel automatic payout slot machine, the liberty bell, in San Francisco in 1899.

The sting of a Box Jelly can kill a human within three minutes.

Mysterious disappearances have occurred in the Bermuda Triangle and the Devil's Sea off the east coast of Japan.

Edward Drinker Cope, in his rush to beat Othniel Marsh as the collector and publisher of the most dinosaurs, reconstructed one dinosaur so that its head was placed at the end of its tail instead of its rightful place on its neck. Unsympathetic colleagues suggested that it be named "Strepsisaurus" ("twisted lizard").

A bubble is round because the air within it presses equally against all its parts, thus causing all surfaces to be equidistant from its centre.

The Goltzschtal Railway Bridge in Plauen, Germany was built in 1900 and is the worlds longest stone bridge.

Mars is only half as wide as the Earth and has only about a tenth of its mass.