An Etymological Dictionary of Astronomy and Astrophysics

In fluid dynamics, a theorem that relates the speed of fluid flowing out of an opening to the height of fluid above the opening: v = (2gh)^1/2, where v is the exit velocity of the water, h is the height of the water column, and g is the acceleration due to gravity (9.81 m/s²). It was later shown to be a particular case of → Bernoulli’s theorem.

See also: After the Italian scientist Evangelista Torricelli (1608-1647), who found this relationship in 1643.