At about 10 a. m. the brigade, being under a heavy enfilanding fire from the enemy's batteries, was ordered to fall back in good order. The enemy were in large numbers, coming toward us through the trench, under cover, but below the line of fire of their artillery, and were strongly pressing the most advanced regiments with a galling fire of musketry, throwing them somewhat in disorder. The One hundred and second being within rifle-shot, left the trenches and formed at right angles to it, and poured volleys of musketry into the advancing rebels, which halted them, giving these regiments time to withdraw. After they had passed, rebels came in on both sides, left and right, saying we were surrounded and must surrender, but instead of doing so we disarmed 2 commissioned officers, 1 flag-sergeant, and 20 privates, taking the flag, and bringing our prisoners safe to the rear. The battle-flag and prisoners were from the Twelfth Georgia Volunteers.

Having become detached from the brigade, we formed line (at the order of an officer of General Geary's staff) on the left, and in front of the battery at the burning brick house, in order to pour in a flanking fire upon the rebels should they attempt advancing through the meadow to take the battery. We were driven from this point by the fire of our own artillery, and then, at the instance of Lieutenant-Colonel Dickinson, of General Hooker's staff, we took position directly behind the battery and supported it until it retired, and remained in the same position until another battery replaced the retiring one, which, after firing some rounds of shell and round shot, also retired. After the battery moved, we were the extreme left at that point, as far as we could see, except quite a number of stragglers, who had formed on our right and left, when we again marched under artillery fire to rejoin our brigade,and reached it soon after. In a few minutes thereafter the brigade joined the division; halted and rested for ten minutes. The rebels shelled us, probably seeing the smoke of the fires made by our men for cooking purposes. The command was moved farther to the right, and then countermarched by the right flank and marched to the road, and soon after took position in rifle-pits about 2 miles from the United States Ford. Here we encamped for the night, the One hundred and second New York Volunteers acting as reserve.

At 1 o'clock, May 4, we were marched to the left and rear, and occupied the heights commanding the ford. The One hundred and second then made rifle-pits and trenches the whole length of the regiment, with logs abatis, &c.

At 10 p. m. were moved to the rear on another ridge, and before the morning of the 5th had completed rifle-pits of the length of two regimental fronts, having built during the night three times the length of our own front of rifle-pits and dug the trenches, the men not having slept or rested for upward of thirty-six hours.

May 5.- Rested in our rifle-pits until 10 p. m., when we were called under arms, and the brigade was formed in close column of regiments, and remained under arms until daylight of the morning of may 6, when we marched to the United States Ford, and crossed, after which, by ordinary marches, we again reached Aquia Creek in two days and made camp.

Very respectfully, your obedient servant,

JAS. C. LANE,

Colonel One hundred and second New York State Volunteers.

Captain C. P. HORTON,

Assistant Adjutant-General, Third Brigade.