Giovanni Battista Venturi. Portrait of the Italian physicist, Giovanni Battista Venturi (1746-1822). In 1773 Venturi was made the Professor of Geometry and Philosophy at the University of Modena in Italy, before becoming a professor at Pavia, also in Italy. He did research on sound and colours, but is most famous for his work on hydraulics. This work, published in 1797, described the fact that the pressure of a fluid in a pipe decreased where the width of the pipe had been reduced by a gradual taper. The Venturi flow-meter, invented by the American engineer Clemens Herschel, was based on this principle.