WHIPPLE, SQUIRE

born Sept. 16, 1804, Hardwick, Mass., U.S. died March 15, 1888, Albany, N.Y. U.S. civil engineer, inventor, and theoretician who provided the first scientifically based rules for bridge construction. After graduating from Union College, Schenectady, N.Y., in 1830, Whipple conducted surveys for several railroad and canal projects and made surveying instruments. In 1840 he invented a lock for weighing canal boats. In the next years he turned his attention to bridges and invented two new truss designs employing iron as well as timber; in 1853 he completed an iron railroad bridge of 146-foot (44-metre) span near West Troy (now Watervliet), N.Y. In the following year appeared his Work on Bridge Building, the first significant attempt to supply a theoretical means for calculating stresses in place of the rule-of-thumb methods then in general practice. The book, which he expanded and personally printed in 1869 under the title An Elementary and Practical Treatise on Bridge Building, facilitated the rational use of wrought and cast iron and was widely used in railroad engineering for decades.