3rd Experiment.
Countermine:—453 lbs. of dynamite, enclosed in a case, 24-1/2" × 28-1/4" × 1/8". It was moored 9-3/4' below the surface; depth of water as before.
Submarine mines:—As before.
Effect of explosion:—(b) mine, at 49' distance, sunk and not recovered; at 58' distance, very much indented; (c) mine, at 58' distance, case much indented and leaky; (f) mine, at 48-1/2' distance, uninjured.