15. If the position of the beam C B (Fig. 1) were changed to that shown by the dotted lines C E, the strain would be greatly increased on both beams. By drawing lines parallel to the beams in this position, expressing the weight by the line C c as before, the pressure on the beam in the position C E will be measured by the line C d instead of C a; while the strain on the beam C A will be nearly doubled, being represented by the line C e.

Hence it appears that enormous strains may be produced by a comparatively small weight, merely by altering the position of the supports. The reader will do well to consider these changes with attention, and to draw figures in different positions, estimating the pressures according to each position, which will render his mind familiar with the subject, and enable him in practice to form accurate notions of the various strains without the labour of calculation.