Numbers 11. Report of Captain Thaddeus P. Mott, Third New York Battery.

SEPTEMBER 12, 1861.

SIR: In pursuance to your orders I proceeded to the scene of action yesterday (September 11) near Lewinsville, taking up my position on a wooded hill on the right side of the road, about 1 mile from Lewinsville, controlling that place and the surrounding country. I immediately directed fire towards the smoke from the enemy's battery and in the direction fire towards the smoke form the enemy's battery and in the direction of Captain Griffin's shells. As soon as their battery ceased firing I ordered the shells to be thrown into a clump of woods, believing that I saw the enemy in large numbers therein. The order was well carried out by Lieutenant William Stuart, commanding the section, the shells landing directly in the wood, which immediately caused its evacuation by, I should think, some 700 cavalry, a number of riderless horses, and some infantry.

Receiving orders to change my position, I used the privilege given me by yourself to exercise my discretion in case I could to them any material damage. I therefore kept up the fire on them, after their leaving the wood across a corn field and into another wood, I should think much to heir sorrow. I then moved by your orders to the position before occupied by Captain Griffin, with orders not to unlimber unless for some good object; but seeing a number of them say from 400 to 500, on their retreat to the new-cut road, I could not resist the temptation of having a farewell blow at them. I think the gunners did a great deal of execution, as I could see with my glass great confusion created amongst them, large breaches being made in their ranked, especially by the 32-pounder shrapnel, the paper fuse at the 10-pounder Parrott guns not acting well.

I take pleasure in being able to testify tot he gallant and military bearing of the infantry in my vicinity.

Yours, respectfully, &c.,

THAD'S P. MOTT.

Captain, Artillery, Smith's Brigade.

Brigadier General WILLIAM F. SMITH.

Numbers 12. Report of Captain Charles Griffin, Fifth U. S. Artillery.

BATTERY D, FIFTH ARTILLERY, Camp near Chain Bridge, September 12, 1861.

SIR: Yesterday, after the enemy opened fire on the troops under your command, in accordance with your instructions, two rifles pieces of Battery D, Fifth Artillery, were placed in position some 1,800 yards from the enemy's battery and opened fire, and continued firing until the enemy ceased firing or until Lieutenant Hasbrouck. Some time after Lieutenant Hasbrouck placed his pieces in battery the remaining two pieces of the battery under Lieutenant Hazlett joined and came into battery. The enemy at this time had ceased firing and the cannoneers were resting for