THE PRINCIPLES

OF HYDROSTATICS

DESCRIBED BY

SIMON STEVIN.

Definitions

FIRST, THE DEFINITIONS.

Known heaviness is what we call here that whose known size is expressed through known weight.

Equally heavy substances are those whose equal volumes are of equal weight in the air.

But the heaviest substance is that which is the heaviest of those with equal volumes.

And the lightest substance is that which is the lightest of those with equal volumes.

And as many times as the heaviest of equal volumes is heavier than the lightest, so many times heavier in substance do we say one is than the other.

A rigid body is one whose substance does not flow, through which neither water nor air penetrates.

Geometrica superficies Geometrical surface.

A surface original: "Vlacvat" is the entire geometrical plane of a body, separable from it in thought.