Early in the night the telegraph informed me that Major-General Banks was on his way with his division to re-enforce me, and at about 3 o'clock a. m. the general arrived and assumed command.

A report of my division for the following days will be speedily made out and forwarded.

I cannot conclude this report without bearing testimony to the courage, good discipline, and conduct of all the troops of this division during the day, the events of which have been related in this hurried written report. Those in action behaved like veterans, and those not brought into action showed that alacrity and steadiness in their movements which proved their anxiety to engage the foe in their country's cause.

We mourn the loss of the brave departed dead on the field of honor, if not of success; and we miss the companionship of those of our comrades who have fallen into the hands of our enemies. But all feel that they have earned the title of soldier, and all await with increased confidence another measurement of strength with the foe.

Very respectfully, I am, your most obedient servant,

CHAS. P. STONE,

Brigadier-General, Commanding. .

.

Brigadier General S. WILLIAMS,

Assistant Adjutant-General, Headquarters Army of the Potomac.

HEADQUARTERS CORPS OF OBSERVATION,
Poolesville, October 20, 1861.

Colonel CHARLES DEVENS,

Commanding Fifteenth Regiment Massachusetts Volunteers:

COLONEL: You will please send orders, to the canal to have the two new flat-boats now there opposite the island transferred to the river, and will at 3 o'clock p. m. have the island re-enforced by all of your regiment now on duty on the canal and at the New York battery.

The pickets will be replaced by the companies of the Nineteenth Massachusetts there.

Very respectfully, your obedient servant,

CHAS. P. STONE,

Brigadier-General.

SPECIAL ORDERS,
HEADQUARTERS CORPS OF OBSERVATION,
Numbers -.
Poolesville, October 20, 1861 - 10.30 p. m.

Colonel Devens will land opposite Harrison's Island with five companies of his regiment, and proceed to surprise that camp of the enemy discovered by captain Philbrick in the direction of Leesburg. The landing and march will be effected with silence and rapidity.

Colonel Lee, Twentieth Massachusetts Volunteers, will immediately after Colonel Devens' departure occupy Harrison's Island with four companies of his regiment, and will cause the four-oared boat to be taken across the island to the point of departure of Colonel Devens.

One company will be thrown across to occupy the heights on the Virginia shore after Colonel Devens' departure to cover his return.

two mountain howitzers will be taken silently up the tow-path, and carried to the opposite side of the island under the orders of Colonel Lee.

Colonel Devens will attack the camp of the enemy at daybreak, and, having routed them, will pursue them as far as he deems prudent, and.