well are hence applicable to Fort Fisher, modified by this increased distance, and diminishing the probability of injuring it or its garrison by the explosion.

I will now give several instances of the explosion of large quantities of gunpowder, and the recorded results of effect produced, in exemplification of the preceding views:

First. Explosion of the magazine at Fort Lyon of the defenses of Washington, on the 9th of June, 1863. The floor of this magazine was nine feet below the parade of the fort. The space for powder was sixty-four by seven by seven [feet] covered on top with logs of fifteen inches square by eighteen feet long, and above them eight feet of earth (in thickness). The amount of powder in the magazine was 17,500 pounds in barrels, besides which there was ammunition prepared for 900 cartridges for 22-pounders, 750 cartridges for 24-pounders, and 500 cartridges for 30-pounder Parrott guns, and about 200 rounds for field pieces. The earth over and on top of the magazine was scattered in every direction, principally upwards. It fell in considerable quantities at a distance of 400 to 500 yards. Other portions of earth were thrown to the right and left, and deposited immediately alongside the outline of the magazine. The logs on top of the powder room were thrown in every direction. Some pieces were thrown to a great distance; in one case 600 yards. The breadth of the cavity in the earth formed by the explosion was about forty-five on top. The explosion did not affect the other earth-work of the fort to any material extent, although it surrounded the magazine on three sides, and not more than eighty feet from the magazine, rising several feet above it. One gun on the rampart was thrown (rolled) into battery and tipped forward, with its muzzle resting on the parapet. The loaded shells in the magazine were thrown to various distances; in one case as far as 2,500 yards. The wooden buildings and tents used as officers' quarters, placed near the magazine, were entirely destroyed. At the time of the explosion most of the garrison were in the bomb-proof, which opens on the front opposite the magazine and about seventy-five feet from it. All the officers and men therein escaped uninjured. At a house 350 yards from the magazine the glass of the windows was blown violently in and the doors out. The walls were started out and toward the magazine-in one its foundation. Several persons were lifted up and thrown to some distance-in one instance about 150 yards-escaping with only slight bruises, while others sustained scarcely a mark on their bodies.

Second. Another example of the explosion of a depot of powder of recent date occurred at City Point, Va. Two barges loaded with ordnance stores exploded, killing and wounding the persons on board and in the immediate neighborhood, but did no substantial injury to the grounds or solid structures or persons on shore, excepting by pieces of timber thrown from the wreck of the barges. This example is of special interest, as the powder was in a vessel afloat, the explosive action of which yielded to the sinking or subsidence of the vessel.

Third. An explosion occurred in July, 1848, on board a schooner moored at the levee opposite New Orleans, loaded with 656 boxes of fixed ammunition, and other boxes of ordnance stores. It took place after 141 boxes of the ordnance stores had been unloaded and reshipped on board a steamer alongside; destroyed the schooner, killed one and wounded another man on board. No injury was done to several other vessels in the immediate neighborhood, or to the buildings on shore.