Every part of enclosed water desires to fall along a perpendicular line. Being impeded, it always exerts force and loads upon its support; and that support will be the more burdened which is touched by the longer line of water.

A system of communicating vessels, with: water that presses the water — b n a / a b are of equal weight, and here it performs the office of a balance, whose pole is n.

g f / I ask whether f g are equal in weight.

c — f — r / When the water r is like f in height, m will perform between these two channels the office of the pole of a balance, and the water r m will weigh as much as the water m f; and the water of the vessel e will settle on the bevels of its bottom, and where that vessel is unbottomed, the water will fall into r.

b — S a — water / The water a h S will have no movement, because the water a h weighs as much as the water h S, and the line a S is level, and level water does not move of itself.

b S — r / The water will make such movement through the siphon S b r as it would make if it ran along the line r S.

l — n — o / The water of the siphon o l n will not make lasting motion because ...

Without good effect.

f — K — l / This will perform such office as if the line f K were somewhat shorter than the line l f; and it makes that line f K as if it were straight, of the length that is from K to l.

a — t m / Some have held the opinion that, since the water in the pipe m a weighs more than that in the pipe a t, m ought to let its water fall continually.

f — S — h / This one has believed that the water S f, weighing more than that of f h, when the holes S are unstopped, would let the water fall without admitting air; and the water S f will indeed fall, but the water f h will not