To these ends the masts and armament of the vessel were removed, and the deck house extended forward to within a few feet of the stem to furnish additional room for stowage of the powder. A sham smokestack in addition to the real one was set up, and the whole vessel painted a neutral tint, nearly approaching to white. In stowing the powder it was determined to place it as much as possible above the water line, and a light deck a few inches below the water line was constructed in the lower hold. Upon this was first placed a tier of barrels full of powder, standing upon end, with the upper heads removed. The remainder of the powder was in canvas bags, holding about sixty pounds each, the whole being stowed as shown on sheet No. 1,* accompanying this report. The total number of tons of powder placed on board was 215.

To communicate fire to this mass of powder in such a manner as to produce a simultaneous ignition of the whole, four separate threads of Gomez fuse were woven through and between the mass just above the main hold, and two ends run down both the forward and after hatches of the main hold. Where three threads crossed each other in the mass of powder, they were "married" or spliced in such a way that the fire, passing along either thread, would communicate itself to the other two. In addition to this, three threads were led from the small room on the starboard side of the engine room, through the forward bulkhead, and into the mass of powder just in front of it. In a small locker or hold, quite aft and under the cabin, pine wood and other combustibles were placed to be fired as the crew left the vessel. To communicate fire to the fuses, the following mechanical appliances were made use of:

The first consisted of the ordinary clock-work movements, and upon the arbor of the minute hand a small cylinder was attached. Upon the surface of this cylinder, at the extremities of two diameters at right angles to each other, four small and smooth steel pins were inserted. A loop at the end of a cat-gut thread was passed over one of these pins, and the cord then wound upon the cylinder in the direction of its motion. The thread was then conducted over a small pulley, and had attached to its extremity a 2-pounder grape-shot. This shot played freely within a vertical copper cylinder, some three feet in length, the bottom of which was closed by a disk with a hole through its center. In this hole, and within the cylinder, a musket cone or nipple was fastened. The ends of the fuses, not inserted in the powder, were fastened so as to be exposed to the flame driven through this cone when a cap was exploded upon it. As the arbor of the minute hand, in revolving, would unwind the thread suspending the grape-shot, a moment would arrive when the loop of the thread would slip off the small pin holding it, when the shot would fall upon the percussion-cap with a force sufficient to explode it, and thus ignite the fuses. Of course the number of turns or parts of a turn of the thread upon the cylinder would determine the time that would elapse before the falling of the shot, and, in this way, the time of the explosion would be regulated.

The second device consisted of a small box, some six inches square. in cross section, and one or two feet long, having five round holes through its cover, and into which pieces of spermaceti candle were inserted. Underneath these holes, and within the box, an end of fuse was fastened, the covering of the composition within it being first removed. The candles were cut to a suitable length, their rate of burning having been first determined, and when consumed the burning wicks, falling upon the fuse, caused it to ignite.

* To appear in the Atlas.

The third device consisted of a box similar to that on which the candles were placed, its two ends, however, having been removed. In this wooden tube, and attached to one of its sides, was a spiral coil of wire, not exactly horizontal, within which a piece of slow match was fastened. To one end of this slow match, one of the fuses was attached. There were three sets of clock-work and percussion arrangements for firing the fuses, one candle box and one slow-match box. The three clocks were placed as follows: One on the starboard side of the vessel, near the waist, and beneath the hurricane deck, communicating fire to two fuses, one of them leading into the forward-hatch, and the other into the after-hatch. The second clock on the port side, in a similar position and communicating fire to two fuses which led in a similar manner. The other clock, and the candle and slow-match boxes, were placed in the small room on the starboard side of the engine room, and each communicated with but one fuse leading through the bulkhead into the mass of powder, just forward. The arrangement of the vessel, storage of the powder, and firing arrangements, are shown on sheet No. 1* accompanying this report.

Fort Fisher, the work against which this powder vessel was conducted, is an earthen fort, of an irregular, quadrilateral trace, with bastions at the four angles. The exterior sides will average about 250 yards. Its northeastern salient approaches the high-water mark within about 100 yards. From this salient, across the beach, a stockade is erected, leading quite down to the water's edge. The land faces of this work exposed to an enfilading fire from the water are very heavily traversed. The tops of these traverses are quite six feet above the general line of the interior crests, and from their size, may have also afforded bomb-proof shelters for the garrison. The exterior and superior slopes of the parapets and the surfaces of the traverses are well sodded. The quarters of the men (wooden shanties) were situated just outside of the work, and to the south of it. One small wooden building stood nearly upon the north glacis, and but a short distance from the northwest bastion. Strewn along, just outside the beach and nearly in front of this fort, are several wrecks of blockade-runners, one in particular, which has three smoke funnels, that at high water extend some distance above its surface. In a southerly direction from the fort, the bar and shallow water extends off from the shore; but in a northeasterly direc tion, deep water, say to three fathoms, can be carried well in toward the northeast salient. This was the direction in which the powder ship was carried toward the fort, or, more correctly, the bearing of the fort from the powder vessel when finally exploded was west southwest by onehalf west. The vessel was taken to its position on the night of December 23 under the command of Commander A. C. Rhind, U. S. Navy, and was placed by him, as he informed me, within 300 yards of the northeast salient of the fort, and that, too, without being discovered by the enemy. A blockade-runner going in just ahead of the vessel acted as a guide in its navigation, and at the same time threw the garrison off its guard. After starting the various appliances for firing the fuses, the time of their running having been fixed at an hour and a half, and also setting fire to the combustibles collected in the after-hold, the crew escaped in a swift steamer held in waiting for them. The explosion took place in one hour and fifty-two minutes from the time of first setting the fire, and at about 2 o'clock on the morning of December 24.

* To appear in the Atlas,

As viewed from the decks of the U. S. steamer Rhode Island at a distance of some twelve miles, the first thing observed was a bright flame, which suddenly leaped into the air a height that would subtend some 6 or 8 degrees of arc. This flame was filled with bright points or coruscations that made its appearance very beautiful. Some ten seconds after the appearance of the flame two sharp and ringing reports, about as loud as those from a 6-pounder brass gun, and following each other in rapid succession, were heard directly over the point of observation. At the same instant the vessel was sensibly jarred and shaken, and upon one of the vessels of the squadron some window glass was broken by the concussion. Immediately following this, a low, rumbling noise like distant thunder was heard in the direction of the explosion, and all was then quiet. The jar and noise of this explosion were apparent at points from 60 to 100 miles removed from it-namely, at Beaufort and New Berne, N. C. Upon an examination of the fort the next morning, no perceptible effects could be seen to have been produced upon the work. The edges and crests of the parapets and traverses remained as sharp and well-defined as ever. The grass covering their surfaces had not been stripped from them. No slides or craters in the parapet could be observed. The stockade from the northeast bastion was intact, and the wooden barracks and other buildings about the fort were still standing. The three smoke-pipes in the wrecked steamer, which was some 900 yards from the exploded vessel, were still standing. It is not believed that any guns were dismounted, and as the fort replied to the fleet for the first hour and a quarter of the fight upon the 24th instant, it is not probable the garrison were so much demoralized as to unfit them for service. The position of the fort, barracks, stockade, &c., are shown on sheet No. 2.* It is very much to be regretted that greater injury to this work did not result from this experiment, but it is believed a glance at the effects produced in a number of recorded cases of explosion, taking especial note of the distances beyond which no destructive action was experienced, will show that this explosion was not an exception to those that have preceded.

In April, 1585, a powder vessel, the Hope, was sent from Antwerp against the bridge erected by Alexander Farnése, prince of Parma, across the Scheldt. The vessel was about eighty tons burden, and contained 7,000 pounds of powder. The arrangement of its stowage was as follows: Along the whole length of the hold was laid down a solid flooring of brick and mortar, one foot thick and five feet wide. Upon this was built a chamber of marble mason work, forty feet long, three and a half feet broad, as many high, and with side walls five feet in thickness. In this the powder was placed, and it was covered with a roof six feet in thickness, formed of blue tombstones placed edge wise. Over this crater rose a hollow cove or pyramid made of heavy marble slabs, and filled with stones, cannon balls, blocks of marble, chain shots, iron hooks, plow coulters, &c. The spaces between the mine and sides of the ship were likewise filled with paving stones, ironbound stakes, harpoons, and other projectiles. The powder was exploded by means of clock-work, and at the instant of explosion the vessel was lying alongside of the bridge. The total length of the bridge was 2,400 feet and a breech but 200 feet long was made in it. It is stated that houses were toppled down miles away, and that some were killed by the concussion of the air, at a distance of 300 yards from the exploded vessel.

*To appear in the Atlas.

In April, 1809, an explosion vessel, devised by Captain Lord Cochrane, of the British Navy, was moved by him against the French fleet then lying in the Basque Roads, under the protection of the batteries of Isle d'Aix. This fleet was still further protected from the approach of this vessel, and other "fire ships" by a heavy boom stretched across the roads in front of the fleet. The boom was constructed of heavy logs and spars chained together, and otherwise secured by anchors and cables. The arrangement of the powder vessel was as follows: The floor was rendered as firm as possible by means of logs placed in close contact into every crevice of which other substances were firmly wedged so as to offer the greatest amount of resistance to the explosion. On this foundation was placed a large number of spirit and water casks, into which 1,500 barrels of powder were emptied. These casks were set on end, and the whole bound round with hempen cables so as to resemble a gigantic mortar, thus causing the explosion to take an upward course. In addition to the powder casks were placed several hundred shells, and over these again nearly 3,000 hand grenades, the whole by means of wedges and sand being compacted as nearly as possible into a solid mass. This vessel was exploded while in direct contact with the boom, which was broken in pieces, not, however, by the direct action of the powder, but by a huge wave caused by the explo sion in the water. When the "explosion vessel" blew up the French frigate Indienne was lying within a half cable's length of it, and was not injured in the least.

The following condensed accounts of other explosions you have been kind enough to allow me to extract from the paper recently addressed by you to the War Department upon the explosion of masses of powder: In June, 1863, a powder magazine in Fort Lyon, defenses of Washington, exploded. It contained about 28,000 pounds of powder. The destructive action was confined principally to the portion of the work immediately above the mine. The parapets of the work, although but some eighty feet distant, were uninjured. The men in the bomb-proofs, not more than seventy-five feet from the explosion, were unharmed. A house 350 yards from the explosion, although considerably shaken, was not destroyed.

An explosion of about 20,000 pounds of powder in a canal-boat moored along side of the pile wharf at City Point, James River, occurred not long since. Some 300 feet of the wharf and the light wooden buildings upon it were destroyed, but the destructive effects of this explosion upon buildings, tents, &c., did not extend beyond 165 yards. In July, 1848, a schooner tied to the levee opposite the city of New Orleans, La., and loaded with 656 boxes of ainmunition and other boxes of ordnance stores, exploded. No injury was done at any considerable distance from the vessel.

At Du Pont's mills for the manufacture of gunpowder and at the various other mills in the country there are repeated and frequent explosions of powder. The injury inflicted does not extend to any great distance.

During the Crimean war, in 1855, a magazine in the Mamelon fort containing about 15,400 pounds of powder exploded. Beyond tearing up the terre-plein just over the magazine no other portion of the work was injured.

In 1769 a square tower of masonry containing 160,000 pounds (French) of powder exploded, but houses were not demolished beyond a radius of 300 toises.

During the siege of Almeida, in Spain, a magazine containing 150,000 pounds (French) of powder exploded, within a radius only of some 250 yards were the buildings destroyed and blown down.

In October, 1864, on the south bank of the Thames, between Eltham and Woolwich, two powder magazines and two barges loaded with powder were exploded. The total quantity of powder set off was some 104,000 pounds. Upon the immediate point of explosion great destruction ensued, but beyond the boundaries of the twenty-acre lot upon which the magazine stood no other damage was inflicted, beyond the breaking of some panes of glass and doors.

In 1807, at Leyden, a vessel loaded with 10,000 pounds of powder exploded and caused the destruction of a number of buildings in one particular quarter of the city and close to the exploded vessel. The. destruction was not, however, widespread.

All these accounts go to show that the distance to which the destructive effects of the exploded gases of powder extend are not very great and that the atmosphere is not put in such violent motion as at any considerable distance to cause a destruction of life and property. I am, general, very respectfully, your obedient servant, THÖS. LINCOLN CASEY,

Brig. Gen. RICHARD DELAFIELD,

Major, Corps of Engineers.

Chief Engineer, U. S. Army, Washington, D. C.

No. 8.

Reports of General Robert E. Lee, C. S. Army, commanding Army of Northern Virginia.

[For Lee's dispatches of December 24, 25, and 27, see p. 856.]

No. 9.

Reports of Maj. Gen. William H. C. Whiting, C. S. Army, commanding Third Military District, Department of North Carolina.

HEADQUARTERS,

Wilmington, December 30, 1864.

COLONEL: This account of the failure for the present of the very formidable combined attack of the enemy by sea and land upon Confederate Point is written for the information of the general commanding and for the War Department, to which I request it may be sent.

The fleet under Admiral Porter, of the sailing of which for Wilmington I received notice on the 18th instant, as communicated also by telegraph to General Lee, made its appearance on the 20th and 21st, and remained in the offing about seven miles from New Inlet during Wednesday and Thursday. The weather was quite heavy and the sea fortunately very rough.

On the 24th it cleared off bright and smooth. Colonel Lamb, commanding Fort Fisher, telegraphed at 12 m. the approach of the fleet to attack. At 12.40 p. m. the Ironsides, as we supposed, leading, opened fire, the other vessels rapidly following as they came into position. Their line of battle was formed apparently in a crescent, the right being opposite Howard's Hill, as near the beach as the depth of the water would allow, the center opposite the bar, and the left extending well on 63 R R-VOL XLII, PT Į