One wooden brace and two iron braces are to be put in, as shown upon the
plan hereto annexed. The wooden brace is to be of one piece, or of two
pieces well bolted together, of selected lumber, free from knots and
other imperfections, squared, and measuring 6 by 8 inches in cross
section. The iron braces are to be of 1 inch diameter, best quality
wrought-iron rods. The bearing plates, four to each rod, are to be not
less than 10 inches in diameter, of sufficient strength, and securely
and permanently fastened to the braces.