His earliest venture in the United States was the building of a machine for making
whetstones. Soon afterward he began to build power mills and bridges. While conducting this business he purchased land containing large quantities of
white oak and
pine timber in
New Jersey, from which he got out, about 1809, the
keel for the first U. S.
frigate built at the
Philadelphia Navy Yard. His third wood bridge was built across the
Schuylkill River in 1812-13 at Philadelphia. This structure, known as the "
Colossus of Fairmount," consisted of a single arch, the span of which was 340 feet. In consideration of its length of span — the longest ever erected for a wooden bridge — solidity and strength, "The Colossus" was regarded as one of the wonders of the world. In 1836,
Benjamin Henry Latrobe II designed the first viaduct and bridge over the
Chesapeake and Ohio Canal and
Potomac River at
Harper's Ferry, Virginia, now West Virginia, for the
Baltimore and Ohio Railroad. The bridge, a wooden truss structure, was built by Wernwag in 1836-1837. Over his 27-year career, Wernwag built 29 bridges. These are listed in the
Engineering News of August 15, 1885, p. 99.
Nails and coal In 1813 he moved to
Phoenixville, Pennsylvania, where he took an interest in and charge of the Phoenix Nail Works, and there invented the first machine for cutting and heading spikes from four to seven inches in length. The other machinery was also remodelled and greatly improved by him. He purchased
coal lands near Pottsville, which led to his experimenting toward the use of
anthracite coal. At first he found it almost impossible to ignite it, but he discovered that, by closing the furnace-doors and introducing air from beneath, combustion was possible. He was sanguine of its ultimate use for fuel, and while the Philadelphians drove from the city the person that offered to sell it, believing he offered stone for coal, he invented and used in his own residence a stove for burning it.
Water works The canals of the
Schuylkill Navigation Company, some of the first in the United States, were partially constructed by him, and the
Fairmount Water Works and dam at Philadelphia were erected in accordance with his plans. In 1819 he moved to
Conowingo, Maryland, where he built a bridge and double
saw mill, and prepared the timber for many bridges. Five years later, he moved to Harper's Ferry and purchased the
Isle of Virginius, where he continued his business of preparing timber for bridges. == References ==