INTO THE STRENGTH OF WROUGHT-IRON PLATES. 
679 
F F, on which were fixed the cast-iron saddles receiving the cross bar G, from which 
the plates to be experimented upon were suspended. These plates were nearly all of 
the same form as shown at H, and were made narrower in the middle to ensure 
fracture in that part ; the ends, as at b, h, had plates riveted to them on both sides, 
in order to strengthen them at those parts when attached to the bolts and shackle 
under strain. 
The specimens thus prepared were suspended by the cross bolts i, and resting 
upon the standards were torn asunder by weights suspended from the large beam, 
as exhibited in the Plate. 
In addition to the large weight W, a strong scale was attached to the extreme end 
of the lever at I, for the purpose of increasing the weights when required in the 
larger description of experiments, and by the application of a pair of blocks and the 
windlass K, the load was removed, and the changes produced upon the plates were 
by these means carefully determined. 
The following data respecting the weight W, lever, shackle, &c., are taken from 
the actual weights from which the calculations are made : — 
lbs. 
W. The weight with its carriage 2552 
A. The v/eight of the beam 1070 
2 A. The weight of the beam 2140 
3 A. The weight of the beam 3210 
K. Shackle 24 
4 K. Shackle 96 
6 K. Shackle 144 
