Henry Darcy and His Law

Henry Darcy and the Pitot Tube

Henry Darcy Main

I wrote a short paper and presented a poster at the 2001 ASCE National Convention held in Houston, Texas on Darcy's improvements to the Pitot tube and expanded on it for the 2003 Darcy Symposium. The symposium paper's abstract follows. If your interested, download the PDF or check your library for the proceedings.


Starting in 1856 Henry Darcy, with the assistance of Henry Bazin, published four works that show various forms of an improved Pitot tube design. Although Henri Pitot had invented the device in 1732, theoretical and design weaknesses had kept it little more than a scientific toy. Darcy's improved instruments provided accurate and easy measurements of point velocity for the first time, which allowed advances in open channel and pipe flow hydraulics. His final design for the instrument tip is reflected today in all of our modern instruments. A reproduction of Darcy's published 1858 design was completed and shown to work as reported. Darcy's contribution to the development of the device equaled or exceeded Pitot's initial work, thus making it appropriate to refer to the modern instrument as the "Pitot-Darcy tube".


Download PDF (0.6 MB)


Brown, G., 2001. Darcy and the Pitot tube, in International Engineering History and Heritage, J. R. Rogers and A. J. Fredrich Editors, ASCE, Reston, VA, 360-366.

Brown, G. O., 2003. Henry Darcy's perfection of the Pitot tube, in Henry P. G. Darcy and Other Pioneers in Hydraulics: Contributions in Celebration of the 200th Birthday of Henry Philibert Gaspard Darcy, G.O. Brown, J.D. Garbrecht, and W.H. Hager (eds), ASCE, Reston, VA. pg. 14-23.