1st Experiment.
Target:—1" thick, and 2' × 2', supported in a horizontal position on a substructure consisting of 8" timber resting on two pieces of 6" timber under two sides, and completely supported by earth up to lower edge of substructure.
Torpedo:—33 lbs. of dynamite, enclosed in a square wooden case 2-1/4" high, and 5·5" × 5·5"; it was placed on the middle of the earth with 8" of earth tamping; this tamping representing the resistance of a thin stratum of water.
Effect of explosion:—The plate was broken into four pieces, and substructure crushed.