Abstract
AT a meeting of the Newcomen Society held at the Caxton Hall, Westminster, on March 15, Capt. L. N. Edwards, of the United States Bureau of Roads, read a paper on “The Evolution of Early American Bridges” in which he dealt with the work of the bridge pioneers of America down to the time of the Civil War of 1861–65. All the early settlements, he said, were situated on sheltered bays, tidal inlets or navigable streams and “the water was the first American highway”. When roads came to be con structed, it was natural that the necessary bridges should be simply tree trunks felled at the site. Transportation developments were a challenge to those engaged in bridge building and the art of carpentry became of immense importance. In the eighteenth century, pile and trestle bridges came into use and these were followed by arched and trussed structures, some of great span. The Upper Ferry Bridge over the Schuylkill River built by Louis Wernag in 1812 had a wooden arch of 340 ft. span and the McCalls Ferry Bridge over the Susquehana River built by Theodore Burr in 1814 had a central span of 364 ft. Especially important were the trusses patented by Ithiel Town, 1820, Col. S. H. Long, 1830, William Howe, 1840 and the two Pratts, 1844. A wrought-iron chain suspension bridge was built by James Finley in 1801, while in 1842 Col. Charles Ellet built the first wire suspension bridge in America. Cast iron was successfully used for a bridge in 1836. Sixty-seven patents for bridges were issued by the United States Patent Office between 1797 and 1860. The first books on bridge work were by Herman Haupt, 1842, and Squire Whipple, 1847. Capt. Edwards's paper, which was illustrated with many lantern slides, is a notable addition to the history of the subject of American bridges.
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Early American Bridges. Nature 131, 429 (1933). https://doi.org/10.1038/131429b0
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DOI: https://doi.org/10.1038/131429b0