Friday's Great Battle.

[N. Y. Tribune Correspondence.]

WHITE OAK SWAMP, Va. June 28, 1862.

The refusal to give this army ample reinforcements on Friday last came in a hair's breadth of ruining the nation. There was never in a State's history such delicate balance of fortune between life and death as vibrated on the Chickahominy last week. — Our line was north of the river and south of it. From our advanced railroad station, Fair Oaks, to our shipping port, White House Point, was 20 miles. We had erected ten bridges at convenient p laces across the Chickahominy. On Thursday afternoon, the enemy developed his purpose of clearing us out of our positions north and west of the Chickahominy, to cut our railroad connection, and seize White House Point, and destroy us with a destruction compounded of starvation and thrashing.

At three o'clock, an hour too late for re-enforcement from a distance, an assault in great strength upon our troops near Mechanicsville was commenced. The details of the battle must find a history elsewhere. The attack of course was successful. The rebels knew precisely our strength in the position, and pitched on us two to one. We had to abandon the ground at evening after a bloody struggle. The best military minds in the army knew that daylight the next day would bring to us the crisis of the Union campaign in Virginia. It was whispered among them that McClellan had evacuated White House Point and had sent all the Quartermaster's and Commissary stores there, saving a certain number of days' rations, together with the transports, around to James river to City Point.

At early light, the cannonade from Porter's batteries, announced that the shock of the rebel columns had fallen on our extreme right — their plain of present attack being upon an arc curving from the northwest to the southeast. The details of the terrible and honorable battle this corps made against numbers which were unquestionably three to one, must also be left to another place and time. We suffered immensely. We destroyed the rebels indeed horribly — killing and wounding more than we did at Seven Pines. The Romans at Cannae, and the Russians at Borodinox did not show a more martyrdom like courage than the most of our volunteers did in the face of these massed columns of the enemy. They were so close to them that the constant and excellent rebel practice of relieving the regiments under fire with fresh troops, was plainly seen by our weary men, not without sore trial so their resignation and steadfastness. The rebel warfare was similarly vigorous and wise before all the other corps, divisions and brigades, on which it fell on Friday. Superior numbers assailed inferior; the assaults were in the highest degree marked by the confidence which numbers give and by desperate courage and discipline. — Whatever local results favored us on the going down of the sun, it was evident that the army of the Potomac was outnumbered, that it was in certain peril of being surrounded, cut off, crushed, or made prisoners of war. — That I affirm.

Friday night was full of anxiety to all men in the army who had brains. The probability was that the care of their acres of dead and wounded, and the exhausting of two days' fighting would impose quiet on the rebels, and exempt us from attack. In the meantime, the left wing, which had fought the way for the army across the Chickahominy, and at the cost of half its blood had won our victories and maintained our position upon the principal highway to Richmond, was partially in motion to lead the army again so a new line of operations, and to pluck it out of the deep danger that gaped upon us. Keyes was marching at 1 o'clock on Saturday morning for City Point.

Day dawned. Ears ached with the tension with which men listened for the well-known musketry volleys of the rebel assault in mass. Watches were consulted with a strange frequency. Regiments and trains of wagons moved at half past nine to one of the three inlets to the White Oak Swamp, upon which the army was to move in its delicate operations of a change of base. Other regiments move between 10 and 11. At half past eleven while looking in the surgeons' walk at three different legs lying under the operating table, strangely fascinated by their amputated yet suggestive hideousness, a telegraph operator whispered in my ear, "The wires are cut," and passed on. So I knew that the enemy's forces were in possession of the railroad, and that communication with White House Point was lost.

The interest deepened. At twelve it was announced that the rebels were at Dispatch Station, three miles from Savage's. On our front, before the war-worn Hooker, and Kearney, and Sumner, cannonading and musketry volleys had broken out afresh. All this time, whose passage was measured most visibly by thousands, upon their fretted nerves and not the dials of their watches, a terrible stream of wounded had been borne in on the stretchers and ambulances, and paved down, literally touching each other in rows with convenient alleys — paved down in the yards, barns, stables and sheds of the Savage farm, and a large part of his garden.

Three different amputating tables were in full blast of screaming, suffering above and untiring benevolence and labor about — going night and day in the open air — never empty — ever wretchedly vocal despite the benevolent paralysis which chloroform imparts. And if anything on earth is calculated to take the fight out of men, and make them anxious to interpose distance between themselves and ball catridges and shells, it is the sight of the surgery of the desperately wounded after a great battle.

The nervous anxiety at this principal railroad station grew space. A train stood there black with the crowd that filled it and clung to it. They would not believe the announcement made at two o'clock P.M. that the last train the Union employees would run over the road had already gone. At four o'clock Commissary Green told me that he was ordered forthwith to move provisions to Couch's division over the White Oak swamp. I saddled my horse, and while mounted before his tent saw several regiments from Porter's brave command. I rode off cheerful. — I felt sure that Gen. McClellan would change his army's base, and baffle and weaken the enemy while he strengthened his position in Virginia. Yet there were many, very many men in the circle of these headquarters I was riding away from, who at the moment who would have made bets that within two weeks the rebel army would have dictated terms of peace to the United States in the city of Washington — terms part of which would be the recognition of property in slaves and the assumption of sponsorial and conservative coligations in respect to it; the recognition of the independence of the slave States if they should see fit to demand it; the payment of the expenses of the war waged by the rebel States; and the exclusion of all men of anti-slavery opinions from office under the Federal Government.