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. Torpedo:--44·4 lbs. of dynamite, enclosed in a cylindrical tin box 8·5" × 18"; it was placed on timber, so as to rest against the face and centre of the plate; tamping as usual. Effect of explosion:--Plate broken into four pieces, two of which were large; pieces hurled over parapet, one fell at a distance of 400 feet. _Experiments at Carlscrona, Sweden, in 1874-75._--These experiments were carried out by the Swedish torpedo authorities, to ascertain the effect of different sized charges of dynamite and gunpowder, enclosed in divers cases, and exploded at various distances from a target which represented in all respects, with the exception of the armour, a section of the side of H.M.S. _Hercules_ before the boiler room, she being at that time one of the most powerful vessels afloat. Target:--32' in length, and fitted into the side of an old line of battle ship. Similar in shape to a wing tank, and comprised a double bottom in four water-tight compartments, a wing passage in two water-tight compartments, and two large water-tight compartments in rear of all. It extended from 2' above the water line to within about 5' of the vessel's keel. The thickness of the plates forming the target were:--outer bottom, lower portion 13/16"; part where torpedo took effect, 3/4". Inner bottom, and wing passage bulkhead, 1/2". Vertical and longitudinal frames, both solid and bracket, 7/16". The longitudinal frames were bracket frames, with the exception of the second, which was solid and water-tight, with its outer edge about 8' below the water line. The vertical frames, of which there were seven, were placed 4' apart, the central one being solid and water-tight, the others being bracket frames. The ship was moored in 42 feet of water; the charges were detonated, one fuze being used in all but No. 3 experiment, when five fuzes were employed. 1ST EXPERIMENT. Torpedo:--33 lbs. of dynamite, enclosed in cylindrical steel case, no air space; height 10·75", diameter 10·75", and thickness 1/32". It was placed 25·5' from the target, opposite No. 7 frame, and 9·25' below the surface of the water. Effect of explosion:--Ship appeared to be lifted bodily. A rivet in the midship longitudinal bulkhead of fore compartment was loosened. The torpedo was fired from the ship, and the shock felt was not very great. 2ND EXPERIMENT.