known as the Old Barn, and to the right of the covered way leading to the mine; Start's (Third Vermont) and Durell's (D, Independent Pennsylvania) batteries in the heavy work on the left of the same covered way and in the rear of the Taylor house; Roemer's (Thirty-fourth New York) and Mayo's (Third Maine) batteries in the work on the knoll to the left of the Petersburg or Jordan road; Twitchell's (Seventh Maine) battery, one section on the front line to the left of the ice-house bearing upon the ravine in front of the Third Division, one gun to the left of the Taylor house bearing upon the Petersburg road, and one at the right of the house. Two Coehorn mortars were in position at the Old Barn, two confronting the work blown up and two just at the right of the Petersburg road. Eaton's (Twenty-seventh New York), Rhodes' (E, Rhode Island), Wright's (Fourteenth Massachusetts), and Hexamer's (A, New Jersey) batteries were held in reserve at convenient points to be taken down the road to the crest in rear of the enemy's works should our infantry gain that position. Instructions were given battery commanders Friday evening in accordance with instructions received from artillery headquarters, Army of Potomac, and immediately upon the springing of the mine the batteries open upon the designated points, every gun having been previously loaded and pointed, cannoneers at posts, lanyards in hand. Captain Rogers directed his fire mainly upon the work to the right of the work blown up, in which the enemy had a battery that enfiladed our line as it advanced to the assault. Jones' battery also opened upon the same work, but did not pay attention exclusively to it. Captain Rogers used solid shot principally, and his fire was very effective, compelling the enemy to change the position of his guns several times, which he could readily do under cover of the woods and his heavy works. Start's and Durell's batteries directed their fire to the enem's works to the right of the crater; also upon one of the batteries in the edge of the woods far back in rear of the destroyed work, which enfiladed our line, advancing to the crest on the right. Owing to the trees in front, which were directly between these batteries and the enemy's batteries, their fire was not very effective. Roemer's and Mayo's batteries opened fire upon the works of the enemy to the left of the crater. Their fire was as effective as it could possibly be, but there was the same difficulty here, on account of the trees in front, as in Start's and Durell's batteries. The section of Twitchell's battery on the left opened with great effect on the enemy's work in its front, doing most excellent service, injuring the work to such an extent that it was impracticable to fire from the embrasures fronting that portion of the line. The pieces near the Taylor house were excellently served, and did good service, the one on the right throwing shot and shell directly in the embrasures of the enemy's work, rendering it impossible for him to work his guns. The Coehorn mortars, under Captain Smiley (Second Pennsylvania Heavy Artillery), were served with great effect. The fire of the two on the right were directed at the work on the right near the woods, and that of the other four upon the work to the left of the Petersburg road.

The expenditures of ammunition were as follows: 757 rounds solid shot, 2,081 rounds shell, 749 rounds shrapnel; total number of rounds, 3,587. The casualties were very slight, as follows: killed, 1; wounded, 2.

I am, captain, very respectfully, your obedient servant,

J. ALBERT MONROE,

Lieutenant-Colonel and Chief of Artillery.

Captain J. N. CRAIG,

Assistant Adjutant-General.