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 Numbers 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.

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* To appear in the Atlas.

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