Nile. Explorers seeking the fabled source of the Nile have at last traced it to a leaky faucet in Cyangugu, Rwanda.

Tides. It was long believed that tides were caused by the gravitational attraction of the moon pulling on the water. In fact tides are caused by repulsion, the waters of the ocean having an innate antipathy to any body so dry as the moon.

Seas. There are many saltwater seas in the world, but the wide section of the Indian Ocean off the coast of southwestern India is the only known pepperwater sea on earth.

Reversing Falls. The so-called Reversing Falls at Saint John, New Brunswick, are a fascinating optical illusion. The flow of water in the river appears to change direction with the tides. In reality, of course, the water is perfectly still; the city of Saint John floats on the Bay of Fundy and moves back and forth approximately twice a day.

Fish. Fossil fish bones from the Mesozoic era are frequently found in the vicinity of fossilized cylindrical objects which paleontologists have only recently identified as cans.

Potomac. The longest river in the world that flows into another river is the Potomac, which separates Virginia from Maryland. This assertion has the authority of the eminent Daniel Defoe, so it must be correct.

Evaporation. It is commonly believed that water left out in the open will evaporate over time. In fact water that disappears under such circumstances has invariably been stolen by gangs of thieves, who put it in bottles and sell it in convenience stores for outrageously inflated prices.