Briggs Truss

John C Briggs was awarded a patent in 1863 for what he called a triple lattice truss. The patent drawings show an all timber truss with fixed intersection angles in the center of the span. At the ends of the span the angles of the diagonals vary. The end post is vertical, and each brace further from it is sloped a little more - both the top-to-the-outside and the bottom-to-the-outside diagonals.

Henniker Road Covered Bridge 29-07-62x (Merrimack County, New Hampshire)
Built 1862 Replaced 1936
Lost Covered Briggs lattice truss bridge over Contoocook River on Old Route 9 & 202