crops out on the beach between high and low water mark. The island, in fact, is simply an irregular mass of sand, which, by the continued action of wind and sea (particularly the former), has been accumulated upon the bosom of the marsh.

86. The material of which Morris Island is formed, and of which the batteries, trenches, and other siege works were constructed, is a fine and almost white quartz sand, weighing, when dry, 86 pounds to the cubic foot. Twenty-four pounds (about 3 gallons) of water will stature 1 cubic foot of this sand, which is thereby decreased in volume about 5 per cent. Its power of resisting the penetration of shot is also decreased by wetting, while a steady and gradual accumulation of pressure, like the moving of heavy wheels over it, produces a greater effect, by at least three-fold, upon the dry than upon the wet sand.

87. During the first week of our occupation of Morris Island, a succession of heavy ran-storms very materially interfered with the progress of our works. Nearly all the batteries were submerged and much of the powder spoiled, so that the combined attack on fort Wagner, fixed to take place on the 16th of July, was delayed until the 18th, and, finally, instead of commencing at break of day, as had was taken of this unavoidable delay to obtain the range of our mortars. Soon after midday all our batteries opened, and the navy, which had been waiting their completion, closed in opposite the fort, and took a very active and effective part in the engagement.

88. In a short time the fort was entirely silent on the face fronting the land batteries, and practically so on the sea front, from which, at the commencement of the action, a sharp and severe fire had been delivered against the fleet.

ASSAULT ON FORT WAGNER, JULY 18, 1863.

89. Late in afternoon, I sent word to Rear-Admiral Dahlgren that I intended to storm the work about sunset. The time of twilight was selected for the storming party to move to the attack, in order that it might not be distinctly seen from the James and Sullivan's Island batteries and from Fort Sumter. Brigadier General T. Seymour commanded the attacking column.

90. Brigadier-General Strong's brigade led the assault. It was composed of the Fifty-fourth Massachusetts (colored), Colonel Shaw; the Sixth Connecticut, Colonel Chatfield; a battalion of the Seventh Connecticut; the Forty-eighth New York, Colonel Barton; Third New Hampshire, Colonel Jackson; the Ninth Maine, Colonel Emery; the Seventy-sixth Pennsylvania, Colonel Strawbridge; and was supported by Colonel Putnam's brigade, comprising his own regiment, the Seventh New Hampshire, Lieutenant-Colonel Abbott; the One hundredth New York, Colonel Dandy; the Sixty-second Ohio, Colonel Pond, and the Sixty-seventh Ohio, Colonel Voris. The regiment were all small.

As the head of the column debouched from the first parallel, the guns in Wagner, Gregg, Sumter, and also those on James and Sullivan's Islands opened upon it rapidly and simultaneously, and when it approached so near the work that the firing from the navy and that of our own mortars and the gun batteries on the extreme left had to be suspended, a compact and most destructive musketry fire was instantly delivered from the parapet by the garrison, which, up