Clemens Herschel

An American hydraulic engineer, Herschel invented the Venturi meter in 1887, applying Bernoulli's principle to measure flow in a pipe by the pressure drop across a constriction — still one of the most common flow measurements in industry.

The orifice and flow tools here descend from his insight. He was also a scholar of ancient Roman water law, bridging engineering and history.

Portrait: a stylized blueprint-line rendering, not a photograph.