3rd Experiment.
Target:—5" thick, and 3' 8" × 4' 7", supported in a horizontal position on a substructure as above, but eight piles of 6" × 6" timber used. Plate bolted to the structure with eights.
Torpedo:—44·4 lbs. of dynamite, enclosed in a wooden case, of same thickness as the Harvey torpedo, and 4" × 13" × 21"; it was placed with surface against the plate, one edge 2" and the other 5-1/2" from the plate; tamping as before.
Effect of explosion:—Plate bulged 3-1/4" in the middle; substructure completely crushed.
4th Experiment.
Target:—5" thick, and 3' 8" × 4' 7"; this was the same plate as used in the previous experiment, laid with bulge uppermost on two beams under the short sides.
Torpedo:—44·4 lbs. of dynamite, enclosed in a cylindrical tin box 7-1/2" × 2'; it was placed on top of plate 11" from one side and with ends 9-1/2" from edge of plate; tamping as before.
Effect of explosion:—A corner of the plate broken off.
5th Experiment.
Target:—Same plate placed vertically in the earth.