From Petersburg.
Petersburg, August 18.
--The enemy's force engaged to-day consisted of three brigades of the Fifth corps, with eighteen pieces of artillery and an unascertained force of cavalry, commanded by General Warton.
The enemy engaged our cavalry, about 2 o'clock, about four miles southwest of the town, driving them in some four miles, when our infantry came into action about two o'clock, driving the enemy back some three-quarters of a miles.
Night closed the engagement, with the enemy the Weldon railroad of a point about three miles below the city.
A force of the enemy's cavalry is reported and behaved, to have gone on a raid in the direction of the Southside railroad.
The enemy slow to-day is Ours is not heavy the wounded are Color Lycil, of Virginia, and Blank, of Mississippi, At out two hundred prisoners were captured.
[Second Dispatch.]
Petersburg, August 19.
--This morning, about 1 o'clock, it being believed that the enemy were massing in our front, our artillery and mortars opened a heavy fire upon them, to which they responded feebly.
The firing was kept up for two hours, breaking up the enemy's intention, if he had any, of charging our breastworks.
Our casualties are few.
This morning, just after day, a heavy wagon train was seen moving to the rear.
The enemy still hold the Weldon road, about two and a half miles south of this place.
Our losses in the fight of yesterday evening are estimated at three hundred and fifty; that of the enemy was much heavier.
[Third Dispatch.]
Petersburg, August 19.
--About 3 o'clock this evening, the arrangements being completed, our forces attacked, in front and rear, Warren's Fifth Yankee corps, which had made a temporary lodgment on the Weldon railroad, two miles below here, driving them backwards upwards of two miles, and capturing over two thousand prisoners, including Brigadier-General Hayes, and a number of stands of colors.
A heavy rain has been falling all day. 