could be seen, except from the balloon. The following is one of my reports on that day:

BALLOON CAMP,

Near New Bridge, May 29, 1862.

Brigadier General A. A. HUMPHREYS,

Chief of Topographical Engineers:

GENERAL: My last ascent was unable at sundown, which discloses the fact that the enemy have this afternoon established another camp in front of this point in the edge of the woods to the left of the New Bridge road and on a line with the permanent camp about one mile and a half to two miles from the opposite heights. They seem to be strengthening on our left, opposite this place.

Very respectfully, your obedient servant,

T. S. C. LOWE.

P. S.-My last dispatch dated 1.30 o"clock ought to have been 3. My watch had stopped.

LOWE.

On that night or the following morning General McClellan ordered the reserves to be moved up to support General Heintzelman in case of an attack, which took place just as this was accomplished. Had not our forces been concentrated it is very evident that our left, or that portion of our army beyond the Chickahominy, would have been driven back, and in consequence the whole army routed.

I think that I have reason to presume that the cause of this favorable movement of our troops was mainly due to my report that the enemy were moving down and strengthening in front of Fair Oaks.

On the 31st of May, at noon, I ascended at Mechanicsville, and discovered bodies of the enemy and trains of wagons moving from Richmond toward fair Oaks. I remained in the air watching their movements until nearly 2 o"clock, when I saw the enemy form in line of battle, and cannonading immediately commenced. Not having any telegraphic communication here, I dispatched one of my assistants with a verbal message, and, to make the matter doubly sure, I sent the following written dispatch after reaching Doctor Gaines" house forty-five minutes later, and still another at 4.30 p.m.:

DOCTOR GAINES" HOUSE, May 31, 1862.

General McCLELLAN:

I descended at 2 o"clock from near Mechanicsville. The position of the engagement is about four or five miles from New Bridge in a southerly direction.

The enemy on our right seem to remain quiet. Quite a large reserve are in the edge of the woods about one mile and a half from the heights on the road from New Bridge. I will ascend from this point as soon as the wind lulls.

Your very, obedient servant,

T. S. C. LOWE.

MAY 31, 1862-4.30 p.m.

Brigadier-General MARCY,

Chief of Staff:

There are large bodies of troops in the open field beyond the opposite heights on the New Bridge road. White-covered wagons are rapidly moving toward the point of the engagement with artillery in the advance. The firing on our left has ceased.

T. S. C. LOWE,

Chief Aeronaut.

On receipt of the above information General McClellan sent express orders to General Summer to have the bridge across the Chickahominy completed as soon as possible, and to cross with his corps at the