The principles of mechanics. [electronic resource] : Explaining and demonstrating the general laws of motion, the laws of gravity, motion of descending bodies, projectiles, mechanic powers, pendulums, centers of gravity, &c. strength and stress of timber, hydrostatics, and construction of machines. A work very necessary to be known by all gentlemen and others that desire to have an insight into the works of nature and art: and extremely useful to all sorts of artificers; particularly to architects, engineers, shipwrights, millwright's, watchmakers, &c. or any that work in a mechanical way.