on which the enemy were retreating, and fire was opened with effect. At 4 o'clock a crossing was made by Barlow's Birney's, and Gibbon's divisions, a section of Ames' battery being taken down to

the river to support the movement. An hour before this a section of Arnold's battery, under Lieutenant Hunt, had an artillery duel with a rebel battery, finally driving it away from its position on the other side of the Po. The troops then rested for the night.

May 10.-The troops were across the river. Brown's battery had a sharp fight on the extreme right of Birney, as did Arnold's. Gibbon's and Birney's divisions moved to the support of the Fifth Corps, leaving Barlow to hold the position south of the Po. A section of Sleeper's battery opened on the enemy's works, as did Brown's battery. The batteries attached to divisions moved with them to the left and were parked. Roder and Sleeper were parked in rear of the line under heavy fire, Captain Sleeper losing some men. At this time the enemy attacked Barlow, who had in his front line of battle one section of Brown's and one of Arnold's batteries. In the retiring of our forces one gun of Arnold's battery was lost. Colonel Tidball was directed to mass his artillery on the north bank of the Po, to protect Barlow's recrossing. Rittenhouse's battery, of the Fifth Corps, was already in position. Edgell was put with Sleeper and Arnold in a second line. The first line was Brown, Roder, and one section of Gilliss; four guns of Gilliss in reserve. Orders were given that when the first line retired it should be by the right flank, so that the second line could open. Brown, Roder, and Beck's section opened on the enemy with solid shot over the heads of our troops with effect. A rebel battery opened a severe enfilading fire, and Rittenhouse attempted to silence it. Edgell was sent to his assistance and drove it away immediately, blowing up one limber; each time that it opened it was silenced by Edgell's fire with great promptness. Our line having recrossed the river, the enemy advanced to take the vacated works. A heavy fire was opened on them with much effect, but they advanced under it and took the works. Word was brought at this time that a heavy force was moving on our flank. Captain Ames' battery was put in position and the foot artillery deployed as skirmishers, there being no infantry at hand. They engaged those of the enemy until relieved by infantry. A new line was now taken up for the night, and two batteries of the Sixth Corps and Ames' were placed in position, supported by Miles' brigade and the heavy artillery. The batteries of the Sixth had been preceded in this position by two of the Fifth, Rittenhouse and Cooper.

May 11.-Moved during the night, conducted by Captain Paine, to the Fifth Corps hospital.

May 12.-By daylight advanced and took position in breast-works of Second Corps. Sleeper reported to Captain Mendell, charge of Second Corps, to take position at the deserted house. Advance of Arnold to first line. Brought up Ames and Brown, placed them to the right and left of Landrum's house. Sent Gilliss to Tompkins (section disabled). Section of Brown and two of Ames' advanced to first line and did good work; brought up Dow and Ricketts to secondl line (Landrum's). Brought up Sleeper and parked in rear of house. Roder relieved Gilliss, who went to the rear to refit. Ames brought off nine guns with his horses, got off Gilliss' guns, and brought heavy artillery in the evening to intrench Roder and support him. Captain Clark reported at night, battery parked in rear of rear house. Edgell all day with Fifth Corps in rear line, parked at night with Clark. Arnold parked in rear of Ricketts.