(b. Lampertsloch, Alsace, France, 9 September 1805; d. Lorient, France, 6 May 1884)
After graduating sixth in a class of ninety-five from the Ecole Polytechnique, Reech entered the Ecole du Genie Maritime at Brest in 1825. Upon completion of his naval training he worked at the port of Brest and was promoted to the rank of lieutenant in 1829. After brief service at the arsenal of Cherbourg, he was assigned to Lorient, where the Ecole du Genie had just been transferred. He soon devoted himself exclusively to teaching and researc.h in geometry, mechanics, thermodynamics, and hydrodynamics. From 1831, Reech was director of the school for thirty-nine years, arranging in 1854 to have it transferred back to Paris, where it had been established in 1765. He also became a professor at the Sorbonne.
Reech published ten memoirs, ranging from a brochure supporting his unsuccessful candidacy for membership in the Académie des Sciences, through lecture notes on mechanics, to tomes on applied thermodynamics. The contribution for which he is still known was the first formulation of the hydraulic- model law of gravitational similitude: the necessary proportionality between the velocity of a ship and the square root of its length (more generally known as Froude’s law of similarity). This is said to have been included in his lectures as early as 1831, but it is first mentioned in his memoir of 1844 and then discussed in detail in his course notes of 1852.
In 1870 Reech retired from active duty and returned to Lorient in Brittany rather than to Alsace because of the German occupation. During the period from 1875 to 1883 he was a member of the Association Francaise pour l’Avancement des Sciences, which possesses the most complete record of his life. At his request he was buried in Soultz-sous-Forêts, close to the village of his birth.
A major work by Reech is Mémoire sur les machines a vapeur et leur application ä la navigation présenté a l’Académie royale des sciences (Paris, 1844). A listing of his works is in Catalogue générale des livres imprimés de la Bibliothèque nationale, CXLVII (1938), cots. 840–841.
A discussion of some of Reech’s work is in H. Rouse and S. Ince, History of Hydraulics (New York, 1963).