First pump
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Some three thousand years ago, the ancient Romans and Greeks understood the hydraulic laws that govern today’s modern pumps. They had already calculated the physics and math required to bring water from the mountain streams, down through giant aqueducts and underground clay pipes, and spray a stream of water 12 feet up into the air in the fountain at the public square. They understood the laws of gravity and the concept of atmospheric pressure. They knew at what volume, and at what speed, the water had to fall through the troughs in the aqueducts, to arrive into the heart of the cities and supply the needs of the growing population. About 2,200 years ago, a Grecian named Archimedes, developed the first practical pump. He took a hollow tree trunk, and carved an internal spiral corkscrew type groove from one end of the trunk to the other. By lowering one end of the tree trunk into a mountain lake and rotating the trunk (on its axial centreline), the water flowed upward through the spiral groove and dropped out of the upper end of the tree trunk. By positioning the upper end of the tree trunk over a trough of an aqueduct, the water began flowing down the aqueduct to irrigate crops, or to supply the city below with fresh water. In those days, there were no oil refineries, nor bottlers of carbonated soda, nor sulphuric acid plants. There was only one liquid to consider, and move in large quantities ... fresh water from the mountains. With only one liquid under consideration, fresh water, and no sophisticated instrumentation, they measured the water’s force, or pressure, in terms of elevation. It is for this reason that today all over the world, pump manufacturers use the term ‘Head’ measured in meters or feet of elevation to express pressure or force. The term ‘flow’ expresses volumeover time, such as gallons per minute, or cubic meters per second.
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