3

A Mine Fired at Petersburg.

ONE LINE OF REBEL EARTHWORKS BLOWN UP.

Terrible Slaughter of the Enemy.

A REBEL REGIMENT ALMOST ANNIHILATED.

Our Troops Advance and capture the Entrenchments.

Terrific Cannonading and Great Destruction in Petersburg by our shells.

Rebels Reported to have Recrossed the Potomac.

THE REBS RE-OCCUPY THEIR ENTRENCHMENTS.

Loss on both Sides, 4,000 or 5,000.

Gen. Hunter issues an Order for the Expulsion of Rebel Sympathisers.

Great Excitement at Gettysburg.

NEW YORK, Aug. 1. — Times' special before Petersburg, July 30, says as soon after daybreak as was practicable for troops to move in co-operation, an immense mine reaching far away under the enemy's line of earthworks in front of Burnside was fired. The explosion was the signal for the discharge of every piece of artillery we have in position from the Appatamox to our extreme right. The effect was magnificent, as 95 pieces were fired so simultaneously that it seemed as if they might have been discharged by the pull of one lanyard. The firing thus opened was kept up in the same manner with scarcely a perceptible lull for at least one hour and a half, when it slackened to some extent. The result of the explosion of the mine was to almost annihilate one regiment and bury three guns. Under cover of artillery and pushing our advantage gained by the suddenness of the assault the 9th corps advanced, taking possession of the works through the gap made by the explosion and driving the enemy to their second line, which crowns the hill top.

Eastward of the town 19 of the 22d S. C., buried by the explosion, have been dug out alive and badly bruised and scratched, and some of them doubtless mortally hurt.

The attack they pronounce a surprise. The mine was 4,000 feet long, constructed with two galleries diverging from the main passage, with three chambers in which a train of powder 15 inches wide and deep was laid. — The effect of the explosion was very disastrous. The artillery fire for grandeur I have never seen surpassed. The enemy's artillery played but feebly, and but very few minutes elapsed before the rebel lines were entirely shut from view by banks of smoke, and our gunners could only be guided in their work by having obtained a proper range before. — Many of the shells from the front of the 8th corps must have struck far into the streets of [unknown line] black smoke arose soon after the opening of the fire, evidently from the burning buildings.

After the rebel lines were pierced they made a hurried movement to their left and suffered heavily from an enfilading fire.

Gen. Ladlie's division of Burnside's corps led the attack, the 14th New York heavy artillery having the advance.

About 100 prisoners, so far, have been brought into Burnside's headquarters.

Cannonading still hot and the rebels stood their position obstinately. Our infantry have just received orders to advance.

The Herald's special says the mine was to have been sprung at 3 o'clock this morning and the Lieutenant General accompanied by his staff also reached Burnside's headquarters. About that hour, Meade and staff also assembled at the same headquarters.

The appointed hour for the explosion of the mine arrived, but for some reason did not take place. Everything movable in the way had been removed. Troops had been placed in position to move at the first signal. The 2d corps was held in reserve, but up to the hour of writing this dispatch they had not been called into action.

At 4 o'clock a cloud of dust was seen rising from the rebel entrenchments. This was followed by a general upheaving of the earthworks reaching probably 50 feet. The whole mass looked like a huge fountain of earth and dust and formed a most imposing spectacle. Simultaneously with this explosion our batteries along the entire line opened a destructive fire on the rebel breastworks, and our infantry with deafening cheers rushed into the embankments of the enemy.

At six o'clock our valiant troops had captured and occupied the first rebel line of entrenchments, and prisoners were constantly arriving from the front. Several of our wounded are also coming in. They report that the slaughter inflicted upon the enemy by the explosion and accurate range of our shells from guns and mortars as terrible in the extreme. So far victory is ours. The air is thick with flying missiles and we pushing the enemy steadily and surely and occupying his fortifications.

One of the prisoners states that they were busy mining under our works, and that in two days they would have been ready to blow them up. We got the start of them, however, and it is hoped that long ere this reaches you that Petersburg will be in our possession.

Our loss in the charge was severe, as our men had to cross an open field to reach the rebels. The troops engaged were the 9th corps with the 10th supporting them — the 2d and 5th in reserve. The firing is still going on with great fury.

Gens. Grant and Meade, with all the Corps Generals, are at the front watching the progress of affairs.

The army is under arms and in line of battle.

The World's special from Frederick, 31st, says that no rebel infantry had crossed the Potomac.

Three regiments of cavalry, with five pieces of artillery have penetrated Pennsylvania as far as Chambersburg, and perhaps beyond.

Our cavalry under Col. Sowell hold the passes of South Mountain, and also Boonsboro.

It also says that the enemy has recrossed the Potomac, and that no force of rebels are now in Maryland.

The World's special says the movement of the 2d corps across James river was all a feint, as they were brought back during the darkness of Friday night to their old position. Sheridan, with a large force, is operating around the rebels' right wing and important results are anticipated.