pened to be absent building a pontoon bridge for Sigel's corps over Potomac Creek, and his answer did not come until last night. Most of our papers relative to the Chickahominy campaign are in Washington in the third story of the house adjacent to my residence. I answer your questions as well as I can, taking them up in order. Major Spaulding, of my brigade, left the White House in charge of about thirty pairs of trestles and four canvas-boats, with accessories complete. On the same day he built two trestle bridges over the Chickahominy at Bottom's Bridge of 80 feet span each. On the night of the same day the remainder of this bridge equipage was taken to Cold Harbor. This was the advance-guard train.

On June 28 I was directed to send away all my bridge teams to the White House. I took the liberty of keeping six of them. Duane turned over the balance of his bridge equipage to me after setting aside enough to build two bridges at New Bridge. The balance numbered but a few pontoons, which were all used at the lower trestle bridge. After the battle of Seven Pines I brought up about twenty-four pontoons, with accessories, but was never able to obtain more than half teams enough to move the equipage all together. I cannot now tell what became of the lower trestle bridge. In the foot bridge, a little below that trestle bridge, three canvas-boats were used, running lengthwise over the stream. I cannot tell what became of them. I think I can find out what became of this and of the lower trestle bridge, and will let you know as soon as I do. Major Spaulding's letter, which I inclose herewith, answers several of your questions. The trestle bridge, the crib bridge, and the two foot bridges over the White Oak Swamp, all at on place, were destroyed by a detachment of the Fifteenth New York, under Lieutenant-Colonel Colgate, assisted by a detachment of the Fifth New Hampshire, under Colonel Cross. Lieutenant Comstock I think has already answered your questions to him. I regret that I did not see you I was last in Washington. Company prevented a call which I had intended to make on the night preceding my return. In your letter of the 4th you request the detail of some officer in the Engineer Brigade as your assistant. I am quite willing that Hargous should be detailed, but I do not even know him by sight. I think Farell would not have recommended him unless he was a person pretty well qualified for the place. You can return him if you do not find him useful. I will ask General Hooker's permission to order him to join you.

Respectfully,

D. P. WOODBURY.

Brigadier-General BARNARD.

[Inclosure Numbers 1]

Report of Captain Wesley Brainerd, Fifteenth New York Engineers.

CAMP NEAR NEW BRIDGE, VA.,

June 2, 1862.

SIR: Agreeably to your instructions I proceeded on Saturday afternoon last (May 31) to make a reconnaissance of the Chickahominy in the direction previously indicated by you, with a view to determine the most favorable position for a bridge. I succeeded in finding a very