HEADQUARTERS CORPS OF OBSERVATION,
Poolesville, November 6, 1861.

GENERAL: I have the honor to inclose herewith memoranda of the river transportation which Brigadier-General and Colonel Baker respectively had at their disposition on the morning of October 21, ultimo.

Very respectfully, I am, general, your obedient servant,

CHAS. P. STONE,

Brigadier-General, Commanding.

[Inclosures.]

River transportation at Edwards' Ferry at the disposition of Brigadier-General Gorman, October 21, 1861.

HEADQUARTERS CORPS OF OBSERVATION,
Poolesville, November 6, 1861.

Three flat-boats, newly constructed, each 25 feet long, 12 feet wide, 2 feet deep; 1 four-oared ship's boat; 1 small flat-boat; new; 2 skiffs.

The easy capacity of the above was as follows:

Each of the there large flat-boats, 40; total, 120; four-oared ship's boat, besides oarsmen, 12; small flat, 12; skiffs, 12; total easy capacity, 156 men; the possible capacity, at lest one-third greater, 52; total capacity, 208. The longest time occupied in crossing by large flatboats in calm day trial, 7 minutes; shortest time, 4 minutes, each containing in trail 35 men. On the morning of October 21 General Gorman added to his transportation a large decked flat-boat, taken from the canal; easy capacity, 66 men.

CHAS. P. STONE,

Brigadier-General, Commanding.

River transportation opposite Harrison's Island, October 21, 1861, at the disposition of Colonel E. D. Baker.

One new flat-boat, 27 feet long, 12 feet wide, 2 feet deep, newly constructed, tested with weight of 65 men, with which it settled but four inches in the water, convenient capacity, say, 45 men; 1 new flat-boat, 25 feet long, 12 feet wide, 2 feet deep, just constructed, convenient capacity, say, 40 men; 1 second-hand ferry-boat, which had been used by the pickets occupying Harrison's Island (had carried 50 men), capacity, say 590 men; 1 metallic life-boat, four-oared, in perfect order which had frequently and safely carried 25 men; 2 skiffs, which had carried 8 each, easy capacity 12 men; total capacity of boats in water and ready for use at 6 a. m., 172 men. To this transportation was added during the morning a new ferry-boat lifted from the canal, 48 feet long, 10 feet wide, easy capacity 100 men; total, 272 men.

Of these boats, two-thirds should have been kept running between the Maryland shore and the island; one-third between the island and Virginia shore. Managed with order and regularity, the trips could have been made with ease once in ten minutes, throwing across 180 men each trip, or 1,080 men every hour; allowing one trip in 15 minutes, 720 men every hour.

CHAS. P. STONE,

Brigadier-General, Commanding.