HEADQUARTERS FIFTH PROVISIONAL ARMY CORPS, July 8, 1862.

GENERAL: I have the honor to forward an additional flag captured from the rebels at the battle of the Chickahominy June 27, 1862, by the Thirteenth New York Volunteers, commanded by Colonel Marshall, Martindale's brigade, Morell's division, Porter's corps, and supposed to have belonged to the First Tennessee Battalion. Sergt. John Marks, Company D, Thirteenth New York Volunteers, was the captor.

You will please cause this, with the rest of the flags, to be forwarded to the Secretary of War.

I am, general, very respectfully, your obedient servant,
F. J. PORTER,

Brigadier-General, Commanding.

Brigadier General S. WILLIAMS,

Assistant Adjutant-General.

Numbers 94. Report of Colonel John F. Farnsworth,

Eighth Illinois Cavalry, of skirmish near Hanover Court-House, battles of Mechanicsville and Gaines' Mill, and skirmish at Dispatch Station.

HDQRS. EIGHTH REGIMENT ILLINOIS CAVALRY, Camp on James River, July 5, 1862.

SIR: The following is a brief report of the doings of my command from the time of the attack of the enemy on the 26th of June until the 28th, inclusive:

On the morning of the 26th, at about 7 o'clock, the rebels commenced the attack upon my picket some 6 miles north of Mechanicsville, on the Hanover Court-House road. At that time my pickets extended from the farm of the widow Crenshaw, by the way of Atlee's and Shady Grove Church, to the place of attack, a company being stationed at each of those four places, Major Dustin, of my regiment, in charge of the whole line, and Captain R. M. Hooker, with his company (H), on the right. Major Dustin and Captain Hooker had gone up the road toward Hanover a short distance and were returning to the pickets, when they were fired upon by a party of the enemy in ambush. They immediately wheeled into the road (it was thickly wooded) and rode rapidly by a circuitous route to join the company. Captain Hooker being seriously, and I fear mortally, wounded by this fire, gave out and was obliged to dismount, and was taken prisoner by the enemy.

The major joined the company and at once reported the attack and position of matters. Immediately notified all the companies on picket to be on the alert. I also sent two companies to re-enforce Major Dustin, under command of Major Clendenin, and also a company to obstruct the road upon which the rebels were advancing, by felling trees, tearing up bridges, &c., as much as possible. My pickets on the right, being hard pressed by infantry and cavalry, fell back slowly, constantly skirmishing. Soon after Captain Dana, who was on picket at Atlee's, sent me word that the enemy had attacked his pickets at Hughes' Store, and were approaching in force. I directed Captain Dana to fall back slowly in the direction of Shady Grove Church and form a junction with my force there, which he did.