not be able to report the operations of my division on the 21st instant before Bull Run. Believing, besides, that commanders of brigades are directed to report to headquarters, I offer the following for the consideration of the general commanding:

Pursuant to instructions, the brigades of Blenker and Davies, soon after daylight, were in readiness to march and take position, but were prevented from so doing by other division blocking up the road. I discovered, however, that Davies' brigade could be passed to the left and west through fields to Blackburn's Ford. Lieutenant Prime, Engineer officer, conducted the brigade, and as soon as possible it joined Colonel Richardson before the crossing of this ford on Bull Run. Fire was then opened by Hunt's battery, supported by Richardson's brigade on the right. Edwards' 20-pounder rifled guns were posted on the left, about six hundred yards from from Richardson's position, and sustained by a portion of Davies' brigade. Blenker's brigade took position at Centreville, and commenced throwing up entrenchments - one regiment being located at the former work of the enemy, one to the west of the town on the Warrenton road, and two on the heights towards Bull Run. With these last regiments were first placed Tidball's and Greene's batteries, Greene's afterwards being moved to Richardson's position, in consequence of notification being sent by that officer that about 2,000 of the enemy were about to attack him, and that he required more artillery.

I may here remark that some difference existed in the order given Lieutenant Prime and myself in regard to the defensive works to be thrown up, and also as to the quantity of tools he was to receive; my orders being, by the lieutenant's advice, to intrench Centreville; his, from Major Barnard, to throw up works at Blackburn's Ford. No tools came forward but the small amount Lieutenant Prime had of his own. These he took to Richardson's position commenced a battery, and made several hundred yards of abatis. Blenker with his pioneers, improved and extended the works at Centreville left by the enemy.

It was soon reported that the Fourth Pennsylvania Regiment had left at its encampment a battery of field guns. For this Colonel Blenker offered to organize a company of experienced European artillerists, which I accepted. The captain's name, I regret, I have forgotten, as I should recommend his having permanent command of the guns in question. He is an efficient officer.*

So soon as I completed my arrangements with Blenker I visited Colonel Richardson; found him in proper position, and effectively at work, Hunt's and Edwards' batteries being in good position. There was no evidence of the enemy immediately about the ford until after the first opening of the fire, when he fled from barns and houses in the vicinity. I then, after ordering proper supports for the batteries and placing a reserve force in position, returned to Centreville, finding all quiet and the troops at work. Remaining here some time, I returned to Richardson when it was surmised that there was no enemy at that place, and found the ammunition of the batteries rapidly diminishing. I ordered from the brigades a few skirmishers to go forward and examine the ford, determined, if I could cross, to do so, and endeavor to cut the line of travel pursued by retreating and advancing detachments of the enemy. The line of skirmishers had barely entered the woods when a large force of the enemy was discovered cancellated by breast-works.

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*This paragraph refers to the field battery belonging to the Eighth New York State Militia, which was manned by detachments from the Eighth and Twenty-ninth New York Infantry, under Captain Charles Bookwood, of the latter regiment. (See Colonel Blanker's report, p.426.)

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