A truss of straw contains 36 lb, of old hay 56 lb, of new hay 60 lb.
in the form of boxes with top and bottom plates, side plates, and angles with proper stiffening bars on the side plates, or " I's," or lattice, or other forms of truss work.
The singular Colossus bridge, built in 1812 over the Schuylkill, a kind of flat arched truss, had a span of 340 ft.
20 shows a Fink truss, a characteristic early American type, with cast iron compression and wrought iron tension members.
The Howe truss of 1830 and the Pratt truss of 1844 are examples.