AMERICAN ORIGINS 1928, Volumetric pumps - But the visible pumps were slow: once the vessel had emptied, one had to wait for it to fill up again. And they were even a bit dangerous: if the vessel broke, the service area would be instantly drenched by a cascade of flammable liquid. When at the end of the Twenties there appeared a new means of measuring fuel flow, the era of the visible pump ended almost instantly. The new electric-powered volumetric pumps delivered the fuel to a measuring chamber, a complex mechanism with many moving parts. The chamber, under the pressure of the liquid, and proportionally to the quantity that entered it, rotated on an axis, along which was mounted a spindle that transmitted the degree of rotation to a clock-face dial. The measuring chamber was much more precise than the previous system, and the dial indicated the amount dispensed to both customer and attendant with great clarity. Those nostalgic for the old visible pumps could still monitor the fuel flow through a transparent gauge on top of the hose if they wished; meanwhile the trigger of the pistol nozzle mounted at the end of the hose was far more efficiently controlling the pump and the rate and quantity of fuel flow by means of electricity. Much more precise and also much faster, the volumetric pump was the instrument that everyone had always dreamed of. Since then, much has changed as far as the appearance and the precise details of its mechanical function, but the basic principles of the most modern gasoline pump are essentiallythose of 1928. 8/20