Menabrea’s Note on Waterhammer: 1858

The earliest analysis of waterhammer is frequently attributed to Jules Michaud in 1878, but in 1858 the Italian engineer, L.F. Menabrea, published a short note on the calculation of water pressures. This little known contribution is, for its time, a remarkable and innovative study, introducing the technique of energy analysis and describing the phenomenon with singular clarity. As it thus appears to deserve wider recognition in the history of waterhammer, the note is translated and an explanatory introduction is provided. The introduction is intended: (1) To demonstrate how close Menabrea came to the derivation of the formula generally attributed to Joukowsky; (2) to pinpoint the errors and failures in his analysis; and (3) to examine briefly the reception at the turn of the century of the ideas he first proposed some 40 years earlier.