t 17 )

By means of these formulae and the weight given intables III., Ill (A.), Ill (B.), of a cubic foot of eachwood, the bearing, strength and weight of beams havebeen computed for the lengths of 10, 15, 20 , 25 and30 feet, to the different sections stated in the tablesIV. and V.; the beams in all these cases being sup-posed to be supported at the ends, and loaded in themiddle.