Effect of explosion:--Effect very great; ship hurled suddenly to starboard. On going on board two minutes after the explosion, the fore compartment was found full, the after compartment became full ten minutes later. Shores and struts were considerably displaced, and there was evidence that the ship had sustained a severe shock. Outer bottom injured over an area 14' × 16', the plates being split in all directions; one piece, 5' square, was torn completely off, and an irregular hole was formed in the outer skin 14' × 12'. In the inner bottom below the wing passage bulkhead a piece 6' × 9' was blown completely out; the wing passage bulkhead was torn from the longitudinal frame and split from top to bottom. The inner skin above the upper longitudinal frame was torn from the latter, and forced in and upwards, but was not otherwise damaged. The vertical bracket frames Nos. 3 and 4, the latter opposite the torpedo, were destroyed, but the solid frame No. 5 was almost uninjured. The outer bottom, where it was not torn off, was forced in 7', or 4' beyond where the _inner_ bottom had been. 8TH EXPERIMENT. Torpedo:--660 lbs. of gunpowder, enclosed in a buoyant cylindrical 1/4" iron case. It was placed 32·3' from No. 4 frame, 29·25" below the surface of the water. Effect of explosion:--The ship and target had been thoroughly repaired, and were in good condition when this experiment was made; the ship was in this case moored in 65 feet of water. No effect was produced on the target by the explosion. 9TH EXPERIMENT. Torpedo:--19 lbs. of dynamite, enclosed in a cylindrical steel case with arched ends. It was placed 10·5' from No. 3 frame, 9·25' below the surface of the water. Effect of explosion:--Effect produced apparently equal to that by No. 3 charge of 112 lbs. of gunpowder at 12'; indentation being from 1/2 to 1-1/4 inches in the outer skin opposite the torpedo. 10TH EXPERIMENT. Torpedo:--19 lbs. of dynamite, enclosed in a case similar to that used in the 9th experiment. It was placed 3·3' from No. 7 frame, 9·25' below the surface of the water. Effect of explosion:--Hole produced in outer skin, 6·5' × 2' to 5'; inner skin only bulged and slightly cracked in two places. Above the longitudinal frame, a bulge was made in the outer skin 8' × 7', with the above-mentioned hole; below the longitudinal frame the indentation was 14' × 5' and 2·1" deep, with two horizontal cracks 10' x 13', and several inches broad. 11TH EXPERIMENT. Torpedo:--112 lbs. of gunpowder, enclosed in a cylindrical case of 3/64" steel, placed in a 3/16" steel case, with 223 lbs. of buoyancy. Ignition effected by a glass igniting bottle. It was placed 5·75' from No. 5 frame, 9·25' below the surface of the water. Effect of explosion:--There was but little upcast of water outside the ship, but a great upcast through the ship. She immediately lurched to starboard, and on boarding her five minutes after, the target was found full of water.