As everybody knows, mud is heavier than water, and when time has been given to muddy water, the mud sinks to the bottom.

But why should mud ever be able to float? The following from the Independent shows how heavy bodies may be lifted - but long after they have been lifted, and velocity is no power in the case, mud will swim :

"The power which water has to transport or carry, is not usually appreciated. This power increases as the sixth power of the velocity, so that a stream flowing six times as fast as another will be able to transport 46,656 times more matter. The flowing data are often used by engineers in calculating the scouring effects of water on the bottoms of rivers. Fine clay is hardly affected by a velocity of 3 inches a second. Fine sand is raised by 6 inches per second, while a velocity of 8 inches will raise sand as coarse as linseed. Fine gravel is swept away at 12 inches per second, and 24 inches per second (1 1/3 miles an hour) takes off pebbles about 1 inch in diameter. When the velocity gets up to 36 feet per second, or about 2 miles per hour - and this is about two-thirds the rate of an ordinary walker - pieces of rock as large as an egg are carried off".