Torpedo:--500 lbs. of gun-cotton, in discs saturated with water, and enclosed in an iron cylindrical case, 34" × 30" × 1/4", with arched ends; the primer consisted of two dry discs, and two detonators. It was placed 101' horizontal from the target, and opposite the condenser on the starboard side; 47' below the surface of the water, on the ground. Effect of explosion:--No damage was done to the hull, or condenser, but light articles, such as bunker plates, gratings, tank lids, &c., were displaced. 2ND EXPERIMENT. Torpedo:--As in first experiment. It was placed on the ground, 80' horizontal and opposite the condenser on the starboard side, 48' below the surface of the water. Effect of explosion:--No damage was done to the hull, of condenser, but the bunker plates, gratings, &c., were displaced to a greater extent than in the previous experiment. 3RD EXPERIMENT. Torpedo:--As before. It was placed on the ground, 60' horizontal, and opposite the condenser on the starboard side; 47' below the surface of the water. Effect of explosion:--No damage was done to the hull. Flanges of the condenser inlet pipe were cracked, and several of the joint bolts were broken. The condenser had been thrown up bodily, and had torn away its holding down bolts; but it was not as well secured as it would have been had it formed part of the machinery of a ship. 4TH EXPERIMENT. Torpedo:--As before. It was placed on the ground, 50' horizontal, and opposite the condenser on the starboard side; 48' below the surface of the water. Effect of explosion:--Outer bottom on starboard indented over a length of about 100', being forced in between the frames; maximum indentation, 3/4". Many bracket frames were disturbed, and outer angle iron of water-tight longitudinal was started for a length of 30', and made to leak slightly. The shell of the condenser was cracked in two places, 3' and 5' in length. Bolts securing condenser, and flanges of pipes and valves, were all more or less damaged. Condenser was rendered unserviceable. 5TH EXPERIMENT. Torpedo:--Same charge as before, but the primer consisted of four dry discs, and two detonators. It was placed 28·5' horizontal, opposite No. 9 frame, on the starboard side, 36' from the stern; 48' below the surface of the water, and 22' from the ground. Effect of explosion:--Bow observed to be lifted several feet. Several angle irons and bracket frames were cracked, and numerous rivets in outer bottom were broken off. The outer bottom on the starboard side was indented between the frames, and brackets were disturbed over a space of 100 feet; inner bottom uninjured. 6TH EXPERIMENT. Torpedo:--As in previous experiment. It was placed on the ground, 28·5' horizontal, opposite No. 36 frame on the starboard side, and 30 feet from the stern; 49·5' below the surface of the water.