‎COLDING, A(UGUST LUDVIG).‎
‎De frie Vandspeilsformer i Ledninger med constant Vandføring. Med 3 lithographerede Tavler. (Extract from: Kgl. Danske Videnskabernes Selskabs Skrifter, 5te Række, naturvidensk. og Matem. Afdeling, 6te. Bind.).‎

‎(Kjöbenhavn, Copenhagen, 1863). 4to. Unbound. Uncut and unopened with a slight miscolouring to top of title-page. Internally nice and clean. 95 pp. + three lithographic plates.‎

Reference : 42726

‎First edition of Colding's contribution to water level in loops with constant water flow.His works with the construction of sewers were the cause of his studies of water movement in closed loops. This led him to the realization of the variation of the coefficient of resistance with flow velocity, a similar result reached by Julius Weisbach. While studying these topics he founded the principles which the later constructed sewage system in Copenhagen was based upon. He expanded the use of these studies to also encompass studies of the free water table forms and currents in the ocean. Ludvig August Colding (1815 - 1888) was a famous Danish engineer and physicist. He was originally educated as a carpenter but graduated as mechanical engineer in 1841. In 1845 he became water-inspector in Copenhagen and in 1847 he was also given the responsibility of the gas- and waterworks. Together with the famous chemist Julius Thomsen, he proved that the cholera spread throughout Copenhagen through the drinking water (1853) - a most significant discovery. After this he was responsible replacing much of the sewer-system of Copenhagen. In 1857 he became state engineer. During this period he overhauled the desperately inadequate water and sanitation system. He articulated the principle of conservation of energy contemporaneously with, and independently of, James Prescott Joule and Julius Robert von Mayer though his contribution was largely overlooked and neglected. ‎