gren) guns, both afloat and ashore, taking them in enfilade and reserve by their distance curved fire. The barracks were in ruins, nearly all the wood-work burned out, fired by our mortar shells. The light-house nearly in ruins.

I notice the following effects of distant curved fire from the monitors at ranges of 1,800 to 2,000 yards: The amount of curvature on the descending branches of the trajectives seemed remarkable, endangering flanks by direct fires in prolongation of ditches and terre-pleins and casemates by reserve fire. A 15-inch shell passed over the crest of the covered way in front of bastion 5 (see tracing B), passed through the scarp of the flank of bastion Numbers 4, just under key of the casemate arch and burst in the casemate, killing 2 men and wounding 13 others. And 11-inch shell followed nearly the same trajectory, entering the same flank just above one of the embrasures, enlarging it upward about two feet. A few more such shells would have laid open the whole flank. An 11- inch solid shot grazed the crest of curtain 1 (left extremity), struck the parade-wall of curtain 4 (right extremity) at a point only six feet above the parade, penetrating three feet ten inches into the solid brick-work. This shot, therefore, in passing over a horizontal distance of 250 feet descended vertically about twenty- four feet, a declivity of about one-tenth. This indicates the risk run in leaving casemates open at the rear when exposed to these distant fires. The garrison had used sand-bags freely in stopping up some of their casemates to the rear for quarters, and in protecting their principal magazines toward the parade.

The efficiency of the land defense here was very much abridged by the fact that we could approach under perfect cover to within 500 yards of the fort behind the sand-hills along the north shore and the ridge near the south shore, and there establish our batteries without striking a shovel into the ground in the approach.

Very respectfully, your obedient servant,

M. D. McALESTER,

Chief Engineer, Military DIVISION of WEST Mississippi.

[Brigadier General R. DELAFIELD,

Chief Engineer, Washington, D. C.]

Numbers 3. Report of Major Frank W. Marston, Signal Corps, U. S. Army, Chief Signal Officer.

FLAG-SHIP HARTFORD,

Mobile Bay, August 10, 1864.

MAJOR: I have the honor to submit, for the information of the major-general commanding the Military DIVISION of WEST Mississippi, the following report of signal duty performed by the officers of the Signal Corps in the combined land and naval operations against the lower line of defense of Mobile:

My officers were distributed among the principal vessels of the fleet as follows: Captain Denicke, with two flagmen, on the Brooklyn; Lieutenant Dane, with two flagmen, on the Richmond; Lieutenant Adams,