The cavalry regiment, under Colonel Kellogg, near Aquia, furnishes pickets stationed on aline extending from Stafford Store, on the right, to Potomac Creek, on the left.

The command at Dumfries has a chain of infantry pickets for its own safety about half a mile from the village, cavalry pickets being stationed at prominent points from 2 to 3 miles from the command.

Under the control and supervision of an officer of the day of the corps, who is assisted by the officers of the day of divisions and brigades, the pickets are posted as directed by the general commanding the Grand Reserve Division, with the usual instruction according to the position of our own troops and those of the enemy. Officers of the day of the corps are relieved every five days, and officers of the day of divisions and brigades are relieved daily. The former visit the pickets once a day, and the latter once during the day and once in the night. The chief of staff has the general superintendence over all outpost duty.

The system used in picketing by the Grand Reserve Division is a chain of sentinels,single or double posts according to circumstances, who are relieved by the pickets stationed from 100 to 200 yards in the rear of the chain of sentinels. The relieving pickets, which are, when possible, stationed on the roads, number from 15 to 36 men, and have consequently from 4 to 11 sentinels to be relieved by them, after deducting, in every case, 1 sentinel who is posted near the main picket. Special pickets are stationed on important points, principal roads, fords, and bridges, or for the purpose of connecting the relieving pickets, and to support them in aces of necessity.

In the immediate presence of the enemy, a general reserves of one or two regiments of infantry, wit one or two section of artillery and some cavalry, are posted in a central location, prepared to support the pickets at any moment. This reserve is on duty form sunset to sunrise, and under the direct orders of the corps commanders of the commander of the Grand Division patrols and scouts. Regular patrols are sent from Allcock to the different fords on the Rappahannock River, below Richards' Ford, and below Kellysville, about 6 miles below the crossing of the railroad. The cavalry regiment near Aquia Church, besides patrolling the different roads toward Stafford Springs, Rock Hill Church, and Spottsville, sends a constant patrol over the Telegraph road toward Dumfries. The cavalry at Dumfries send patrols toward Wolf Run Shoals, Independent Hill, Brentsville, and Stafford Springs, and a constant patrol over the Telegraph road toward Stafford Court-House and Occoquan City. The cavalry at Occoquan City patrol toward Wolf run Shoals, Mape Valley, and Greenwood, with constant patrol on the Telegraph road toward Dumfries. The patrols consist of from 5 to 25 men, under the usual instructions. Special patrols are sent out now and then, accompanied by scouts, the former serving as support of the latter.

The number of scouts attached to these headquarters varies from 15 to 25 and 30, according to circumstances. They are sent west and northwest as far as they can go without returning upon the sight of a few rebels, and by passing the rebel patrols and detachments on by roads.

Camp guards are organized as usual; each regiment has its own camp guard and regimental officer of the day. Besides this means of keeping the men within the encampment, outposts are not permitted to pass soldiers without authority from corps headquarters. Provost-marshals of the grand division of corps, divisions, and brigade have their guards