BELLE PLAIN, May 19, 1864. (Received 2 p.m.)

I left the army at 8.30 this morning. Nothing of importance since yesterday morning except that the cavalry under Torbert, who reported for duty yesterday morning, went to Guiney's Station in the afternoon, drove a small rebel force, burned the depot, the post-office, returned to his old bridge, and returned without loss. Wright returned to his old position before dark, and is crowding his lines in upon the rebels and entrenching himself. Burnside occupies this forenoon a position upon Wright's left, and is directed to open roads and intrench himself, crowding as close to the enemy as possible, and especially to get his left as far to the west as he can. Hancock is massed behind the center, ready to move when the time comes. I am taking advantage of this lull in offensive operations to come to Washington for a day to get a few necessary things. When I left I brought with me only a toothbrush, which proves inadequate to the exigencies of prolonged campaign.

C. A. DANA.

Honorable EDWIN M. STANTON,

Secretary of War.

BELLE PLAIN, May 20, 1864-8 p.m. (Received 10 p.m.)

A newspaper correspondent of my acquaintance, who left the front at 4 p.m. to-day, describes the fight of last evening as a very brilliant affair. It was especially valuable because the new heavy artillery troops were engaged in it, and bore themselves with the gallantry of veterans. We took about 700 prisoners. Our losses pretty severe-quite 1,000 killed and wounded, but the enemy, who came out of his entrenchments for the attack, was much more severely punished.

C. A. DANA.

Honorable E. M. STANTON,

Secretary of War.

GUINEY'S STATION, VA., May 21, 1864-5.30 p.m. (Received 11 p.m.)

So far the new movement of the army has been accomplished without interruption. Hancock has not yet been heard from since his arrival at Milford, where he was ordered to halt, but there is no reason to doubt that he has got there and has seized the bridge. Warren is here, across the Mattapony. A body of cavalry opposed passage of the river, but withdrew after a short skirmish. Burnside and Wright were to be at Thornburg to-night, unless the enemy should make too powerful resistance to their advance in that direction, in which case they were to march in this direction, and cross the Ny at ford a mile or more above here. As no sounds of fighting have been heard from that direction it is probable that they have made good the crossing at Thornburg. Trains are all assembled at Villeborough, about 3 1/2 miles from here. Hancock yesterday morning shot one of his stragglers, a private. None of the others have yet been tried.

C. A. DANA.

Honorable EDWIN M. STANTON,

Secretary of War.