the harpoon would turn foremost, and make a very uncertain shot. F is the harpoon-gun, made strong, and to work on a swivel in a stanchion fixed in the stern-sheets of a boat. My experience with this kind of harpoon and gun, is, that I have harpooned a target of six feet square fifteen or twenty times, at the distance of from thirty to fifty feet, never missing, and always driving the barbed point through three inch boards up to the eye, which practice was so satisfactory, that I did not consider it necessary to repeat it. The object of harpooning a vessel on the larboard and starboard bow, is, to fix one end of the Torpedo-line, then, if the ship be under sail, her action through the water will draw the Torpedo under her; if she be at anchor, the tide will drive it under her, where, at the expiration of the time for which the clockwork was set, the explosion will destroy her. This being the kind of Torpedo and clockwork by which the _Dorothea_ in Walmer roads, and the brig in New-York harbour were blown up, and the harpoon having succeeded to fix the line to the target, these two experiments shall be combined, and the mode of practice, with the prospect of success and risque to the assailants, examined. [Illustration: PLATE IV. _Fig. 1._ _Fig. 2._] PLATE IV, Fig. 1 Represents the stern of a row-boat; a platform about four feet long, three feet wide, is made on her stern on a level with the gunwale, and projecting over the stern fifteen or eighteen inches, so that the Torpedo, in falling into the water, may clear the rudder. On the platform, the Torpedo and its suspending line of cork are to be laid, and the harpoon-line carefully coiled as at F, so that when the harpoon is fired, the line may develope with ease: very pliable well greased, or white line would be best for this purpose. The harpoon and gun are so well engraved as require no explanation. B is the copper case to hold one hundred or one hundred and fifty pounds of powder. C, the box of cork to diminish its tendency to sink and bring it to a specific gravity of only two or three pounds more than sea-water. Its suspending box of cork explained in Plate III is not seen in this figure, lest the drawing should be confused; it can be imagined in its proper place. A, is the brass box with the clockwork lock; D, the pin which prevents the clockwork moving; the line from the pin is tied to a bolt, or otherwise fixed to the boat as at E. Thus fastened, when the Torpedo is pulled into the water, the pin D will remain in the boat, and the clockwork will begin to act. The man who shall be stationed at the gun, and who may be called the harpooner, is to steer the boat and fire when sufficiently near. If he fixes his harpoon in the bow of the enemy, it will then only be necessary to row away; the harpoon and line being fixed to the ship, will pull the Torpedo out of the boat, and at the same instant set the clockwork in motion. This reduces the attack of each boat to