Inventor who developed the double-acting water pump in 1716. This seemingly simply invention produces a continuous stream of water by pumping on both the "up" stroke and the "down" stroke. Previous pumps, using a handle attached to a piston, would suck water into the pump while pulling a handle up, then discharge it into a pail while pushing the handle down. By discharging water on both strokes, de la Hire's pump greatly improved efficiency. Variants of this type of pump are still in use.