Afternoon Report.

The Pennsylvania Bucktails Captured.
Meagher's Irishmen Save the first Day.
Jackson's Army in the Fight.
Particulars of the Richmond Fight.
[Tribune's Report.]

About noon the enemy made an attack upon Gen. Stoneman's force in the vicinity of Hanover C. H., probably for the purpose of accomplishing an outflanking movement on the right, to engage our attention in that direction. Shortly after, they commenced a vigorous cannonading from their works on an eminence opposite Mechanicsville, about 1 1/2 miles distant, also from two batteries, one above and the other below. They were responded to by Campbell's Pennsylvania batter on picket duty, one on the Mechanicsville road, and another from behind an earthwork at the right of a grove.

About 2 p.m. the enemy's infantry and squadrons of cavalry crossed the Chickahominy in immense force, a short distance above the Va. Central R. R., making a rapid advance toward Gen. McCall's division, who were entrenched on a high woodland across a swamp. Rapidly, about a mile in the rear of Mechanicsville, the 1st Pa. Bucktail Rifles and Campbell's Pa. battery were on picket duty, all of whom, except one company, had to fall back beyond the breastworks and rifle pits, where the line of battle was drawn up. Co. K of the Bucktails, who were on picket-duty beyond the R. R., were surprised by the enemy, and the last that was heard of them they were trying to cut their way through. It is presumed the greater portion were taken prisoners.

The enemy advanced down at the rear of Mechanicsville, on a low marshy ground to where our forces were drawn up behind rifle pits and earthworks on an eminence on the north side of the ravine, when the conflict began.

The rebels attempted to press forward over the ground, but the grape shot fell among them like hail, mowing them down. This continued till dark, when they withdrew.

The cannonading was kept up on both sides until 9 o'clock, p.m., when the battle ceased.

Our forces were covered by earthworks and suffered but slightly.

Late in the evening the enemy made a charge with cavalry. About 700 of them came rushing down and attempted to cross the ravine, when a squadron of our cavalry seeing their position, made a charge from the bill upon them. The rebels abandoned their horses and fled.

The infantry fight was then renewed, and according to the account of our informant, Surgeon Humphrey's of the Pennsylvania Buck Tail regiment, continued until about 7 o'clock a.m., when a retreat was ordered very much against the will of the Pennsylvania boys, who begged to be allowed to hold their position. The outer forces then began to fall back.

Gen. Porter's corps were some distance below the residence of Dr. Gaines.

Of the next day's battle the correspondent says:

"The cannonading and musketry was terrific. Duryea's regiment of Zouaves were lying upon the ground, while our batteries were shelling the woods over them. Finally, toward night, the enemy attempted to break the center of Dunyea's Zouaves, when the musketry firing became terrific, lasting 20 or 30 minutes. Shortly after, an attempt was made to break through the right, which was repulsed; and, half an hour later, another attempt was made on the left, with the same result. The battle had then been raging for some hours, without any apparent change or advantage on either side. Reinforcements of artillery and infantry then came steadily along the bridge to the field of battle. The enemy then seemed to make their last desperate effort, and came on, forcing our men back into the low ground between the hill and the bridge, where they could have been slaughtered by tens of thousands before they could have crossed that long, narrow bridge. Now guns, army ambluances and men were hurrying toward the bridge, and a panic was almost inevitable, when a guard was placed across the bridge. At the time when the enemy had almost reached the main hospitals, half a mile from the river, Thomas Meagher's Irishmen came over the hill, stripped to the bare arms, and were ordered to ‘go in.‘ They gave a yell, and went to work, and the result was that the enemy fell back to the woods, and thus matters stood up to 11 o'clock yesterday."

Sunday morning at dark, an attack was made along the front of the entire line, and was renewed at two a.m., in front of Generals Hooker, Kearney and Sumner, without material result.

And their correspondent says of Friday's battle: Twice all along the front did the rebels attack our lines, our rifle pits and redouts. Porter with fifty cannons and Sumner's, Hookers and Alger's guns, mowed them with a death harvest. Their loss in killed and wounded was horrible under date of Friday midnight. The Herald correspondent says ten guns was taken form us by a sudden flank attack, covered by the thick smoke which hung around. The Comte de Paris captured a rebel Major who belonged to Jackson's army. He said he had been in the valley of the Shenandoah all winter and came here yesterday with part of Jackson's army. The rest of it arrived this morning. The whole of it was here. He said that in the attack on our right the rebels had from sixty to eighty thousand troops. This will explain the enormous fire under which our men were borne down and swept away, precisely as some of our regiments were swept away at the Seven Pines.

Yesterday the Pa. reserves drove the attacking regiments of Jackson's command. Today they were overpowered by the same troops. Sickles' regulars proved unequal to the task of stopping them, and Slocum's command had to be added to them. The Compte de Paris testifies to the remarkable conduct and order of the regiments that sustained this unequal contest. They gave way indeed, but not one of them ran.

The regular 11th infantry is about annihilated. Nearly every officer in it is killed or wounded. The 14th suffered also severely.

Maj. Rosselle, of the regulars, a kinsman of Gen. McClellan, is killed.

Col. Pratt, of a N. Y. regiment, is also killed, and Lieut. Col. Black.

Our loss in officers is very marked. Indeed the disproportion was so extraordinary, and the obstinacy of our troops so unyielding, that our losses were inevitably large.

The artillery in both Porter's and Smith's divisions piled the rebels in heaps. The fire was terribly effective.