Numbers 5. Reports and Journal of Major Thomas B. Brooks, U. S. Army, Aide-de-Camp, and Assistant Engineer.
ENGINEER'S OFFICE, Morris Island, S. C., August 22, 1863.
GENERAL: I have the honor to state that at 9 o'clock yesterday morning Fort Wagner opened and artillery fire on the head of our sap, distant about 400 yards from the work. Captain J. Walker, in charge at the time, continued the work to 11 o'clock. At least 16 shots were fired. One exploded in the sap-roller, several touched it, and the parapet was much torn. At 11.30 o'clock the work was discontinued on account of this fire and that of the enemy's sharpshooters, who occupied a position in the ruins on the left, which enifladed the trench.
The Eighty-fifth Pennsylvania did the advance guard duty yesterday. Their casualties amounted, I am informed to 25 during the tour of duty.
Yesterday I requested General Terry to have the advanced posts of the guard of the trenches occupy a ridge about 150 yards in advance of the head of the sap (see sketch*) and then by means of the flying sap I hoped to get a lodgment in that, favorable.
The One hundred New York Volunteers, Colonel Dandy in command, made three unsuccessful efforts to hold this ground, but were driven back, losing 5 or 6 men. I witnessed a part of the skirmishing, and believe this ridge could only have been retaken with a much larger force and considerable loss, the enemy being in stronger force than usual.
The advanced line finally settled down the near the position occupied the night before, excepting the left, which was advanced to include the old ruins.
Captain Suess, by means of the flying sap, made a parallel on this picket line entirely across the island. This line is now being strengthened and put in defensible condition.
On Requa piece was last night mounted on the right of this line, enfilading its face and the beach. Another Requa piece is about 50 yards in the rear of this fourth parallel and near the center of the island, and two are in the third parallel. These four defensive pieces comprise all the artillery in position beyond the second parallel.
I think it will be impossible to continue the sap in the daytime under Wagner's artillery fire, but if our picket line continues to advance, which can only be done with considerable loss, we may make some progress with the sap each night. Should the enemy's pickets retire inside his works, which they will soon be forced to do, he will the keep up an artillery fire from his light guns in the fort, which will make it impossible for the sap to progress night or day until this fire be subdued or kept down.
These light guns are run behind the merlons to avoid our shot; hence it is only by destroying this curtain with our heavy guns in the second parallel, thus uncovering them, or by rendering their service impossible by a superior fire from light guns mounted in the fourth parallel, assisted by a strong infantry force.
Our light guns in the second parallel cannot be used effectively
*See p. 263.