RENWICK

RENWICK 30.05. 1792 Liverpool/UK 12.01. 1863 New York NY/USA James Renwick was brought to New York City in 1794 by his father. A brilliant student, Renwick graduated first in his 1807 class at the Columbia University, where he spent most of his life teaching. His early engineering career included service with the US Topographical Engineers, where his duties included plans of all military positions to obtain intelligence of enemy movements, to keep a journal of the Army, noticing ground, buildings and culture, and to exhibit the positions of the contending armies. He was appointed professor of natural philosophy at Columbia University in 1820, a position he held until 1854. He wrote then widely read biographies on Robert Fulton, among others, and his 1830 Treatise on the steam engine. His textbooks Outlines of natural philosophy, and Outlines of geology were the first works of their kind published in the USA. About this time he also made studies on a canal connecting the Delaware and Hudson Rivers. His suggestion to use inclined planes in lieu of locks was later adopted on the Morris Canal in New Jersey. Note that Robert Fulton (1765-1815) had suggested this system in England about 1794. Renwick, however, patented a stationary steam-enginepowered inclined plane in 1813. Years later, the first application of wire rope for cables on a similarly designed plane in Pennsylvania was proposed by John Roebling (18061869). Other engineering projects that claimed Renwick’s attention were the MaineCanada boundary survey, the Delaware and Hudson Railroad, the proposed Navy Yard at Bergen Point NJ, and the Hudson River Railroad. Early published works include his Outlines of natural philosophy. Renwick’s sons all had distinguished careers in the fields of engineering and architecture. James Jr. was best known for his architectural works including St. Patrick’s Cathedral in New York City, as also the original Smithsonian buildings at Washington DC. Anonymous (1963). Renwick, J. Who was who in America 1607-1896: 438. Marquis: Chicago. Fitzsimons, N. (1966). James Renwick. Civil Engineering 36(8): 78. P Renwick, J. (1822). Outlines of natural philosophy, being the heads of a course of lectures, delivered in Columbia College, New York. Van Winkle: New York. Renwick, J. (1825). Lectures on geology, being the outlines of the science, delivered at the New York Athenaeum. Bliss & White: New York. Renwick, J. (1830). Treatise on the steam engine. Carvill: New York. https://en.wikipedia.org/wiki/James_Renwick_(physicist)

RETTGER 06.04. 1871 Huntington IN/USA 09.10. 1938 Ithaca NY/USA Ernest William Rettger graduated in 1893 with the AB degree from Indiana University, Bloomington IN, receiving the PhD degree from Clark University, Worcester MA, in 1898. He was assistant professor of applied mechanics at Cornell University, Ithaca NY, from 1908 to 1922, continuing there as professor until his retirement in 1936. Rettger took interest in general mathematical and mechanical problems related to engineering. He for instance worked on Lie’s theory of groups and applied it to the theory of least and of virtual work. He also determined the economic penstock diameter, then a problem of vital interest. He became particularly known for the so-called proportional weir, corresponding to a vertical plate-weir normally erected in a rectangular channel, by which the head on the weir is proportional to discharge. The weir shape may be determined by integration of the elementary weir equation, and corresponds essentially to an inverted twin parabola about the channel axis. These weirs have therefore a wide opening close to the channel bottom, reducing toward the channel top. A similar device proposed by Adolphe H. Sutro (1830-1898) had been taken into service in 1908. Whereas the latter has only one curved weir plate and the other being vertical, Sutro’s design further limits the weir width close to the channel bottom. The Sutro and Rettger weirs were model-tested, resulting in a good data fit with the linear discharge-head curve. Both weirs are hardly employed currently, given that electronic devices are applied to control the flow depth in a channel. Anonymous (1927). E.W. Rettger. Engineering News-Record 99(5): 195. P Anonymous (1933). Rettger, E.W. American men of science 5: 924. Science Press: New York. Anonymous (1938). E.W. Rettger. Engineering News-Record 121(Oct.13): 451. Keshava Murthy, K., Rangaraj, C. (1998). Generalized design of single profile weirs. Journal of Hydraulic Research 36(4): 695-706. Mavis, F.T. (1949). There’s no mystery in weir-flow calculations. ENR 142(Jan.6): 76-78. Rettger, E.W. (1914). A proportional-flow weir. Engineering News 71(26): 1409-1410; 72(3): 148-149; 72(9): 462-463; 74(22): 1018-1019. Rettger, E.W. (1915). The inverted weir. Engineering News 73(2): 72-73; 74(6): 277; 74(22): 1018-1019. Stout, O.v.P. (1914). The proportional-flow weir devised in 1896. Engineering News 72(3): 148-149.