Weldon night before last, the first since the repair of the road. There are now at Petersburg belonging to the Weldon railroad fifteen engines, twenty-one passenger-cars, and thirty box-cars. It was intended that these cars and engines should have been run off last Friday. Mr. Alsop, the yard superintendent, said that General Lee had given an order that it was unsafe yet to run them through, and that notice would be given when it could be done. The engines were all fired up yesterday afternoon, and our informants fearing they would have to go south with them made their way into our lines, coming by the way of the Six-Mile Station. They have not been through on the road since it was cut. They understand that large quantities of supplies have been drawn by wagons from Stoney Creek Station, the larger part of which are taken across the Appomattox on the upper bridge near the canal basin, and from there to the depot of the Richmond and Petersburg Railroad near Dunlop's house, about one mile and a half above Petersburg.

One of these men, while near the provost-marshal's office at Petersburg a few days since, heard portions of a conversation between General Beauregard and the provost-marshal, Major Kerr. General Beauregard remarked that "If I had two lines of battle I would attack them at once, but I have hardly a line and a half." Our shell have done considerable damage in the city, particularly to the Government railroad bridges across the Appomattox River. Three deserters from the Sixty-first Virginia Regiment, Mahone's old brigade, of Mahone's division, came into the lines of the Third Division, Second Army Corps, about 3 o'clock this a.m. They make the following important statement, which we think reliable as previous information goes to corroborate it: That on the return of Mahone's division from their expedition down the Weldon railroad, four or five days since, they relieved Wilcox's division, which was then lying on the extreme right of A. P. Hill's corps and adjoining Longstreet's right; that Wilcox's division went to Chaffin's Bluff on the north side of the James. They all speak positively of this, and think there can be no doubt of it. Heth's division forms the extreme right of the line, not extending to the railroad by a considerable distance. Finegan's brigade is in reserve to the rear of Mahone's division. A division, which they think is Hoke's, is in reserve directly in rear of Longstreet's right, their left. They think the force with Early is as follows: All of Ewell's old corps, Breckinridge's entire division (three brigades, one of which is McCausland's brigade of mounted infantry), Maryland Line, Colonel B. T. Johnson.

NOTE.-Latest estimates of the above force would foot up about 15,000 infantry, 1,000 mounted infantry, 500 cavalry; total, 16,500. The greater portion of Ewell's artillery was left behind at Chaffin's Bluff.

All of which is respectfully submitted by your obedient servant,

J. C. BABCOCK.

[Indorsement.]

HEADQUARTERS ARMY OF THE POTOMAC,
July 10, 1864-11.30 a.m.

Lieutenant-General GRANT:

Above dispatch sent for your information. Pickets and signal officers report the passage this a.m. of several trains, confirming the above statement of the negroes that the enemy is running off his rolling-stock for security. The report of Wilcox's division going to Chaf-