2240 b d³
--------- = W,
L²
[TeX: $\frac{2240 bd^3}{L^2} = W$]
we shall have, in round numbers, the following dimensions:
For the 1st panel, 25 feet long, 8 x 10
" 2d " 37 " " 8 x 10
" 3d " 49 " " 8 x 10
" 4th " 64 " " 8 x 10
" 5th " 78 " " 8 x 10
For the lattice work, a double course on each side of each truss, in
long spans; and a single course, in shorter spans, of 3 x 6, or 2 x 9
plank, bolted at intersections, is sufficient.