Canals are man-made channels for water. There are two types of canal:
Many decades ago, it was thought by some astronomers, such as the American Percival Lowell (1855 - 1916), that there were thousands-of-miles-long canals on the planet Mars that had been constructed by intelligent beings there. They were thought to be used by the Martians to carry water from the ice caps to martian farmland closer to the equator. However, this notion has been co...
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Canals are man-made channels for water. There are two types of canal:
Many decades ago, it was thought by some astronomers, such as the American Percival Lowell (1855 - 1916), that there were thousands-of-miles-long canals on the planet Mars that had been constructed by intelligent beings there. They were thought to be used by the Martians to carry water from the ice caps to martian farmland closer to the equator. However, this notion has been completely overthrown, especially with pictures taken by spacecraft that were sent to Mars. It has been found that the appearance of martian canals through telescopes was merely an optical illusion formed in the minds of dozens of astronomers such as Lowell.
The word "canal" is also used for a city-canal (gracht) in Dutch cities.
Some canals are part of an existing waterway. This is usually where a river has been canalised: making it navigable by widening and deepening some parts (by dredging, weirs or both), and providing locks with "cuts"...
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