10 a. m. this morning, having left the month of the river yesterday. She reports all quiet along the river, but the officers say that small guerrilla parties are organizing on the Neck between the Rappahannock and Potomac, and that recruiting parties for the Confederate service are at work in the same quarter.

Colonel Morgan, a loyal citizen, who resides 9 miles up the river, in formed me this morning that contrabands, who came in from Culpeper and Gordonsville yesterday or day before, reporter that Ewell was at Gordonsville with a small force, 2,000 or so, and probably in observation. No force of any kind has crossed the river above us for a long time. I am promised early information of any movement of the kind.

I sent a man to the general, who left Richmond Sunday Morning last at 8 o'clock, though he does not seem to have a great deal of information, having been a prisoner there for many weeks.

I should very much like an increase in the cavalry force here. I have barely 300 available for patrol and reconnoitering parties, as well as other duties devolving upon them.

Very respectfully,

RUFUS KING,

Brigadier-General, Commanding.

WASHINGTON, July 4, 1862.

Brigadier-General KING,

Falmouth:

I have submitted you telegraph to the general. He directs me to inform you General Bayard's brigade has been ordered to Warrenton Junction, with directions to send out strong pickets in advance of that place to the Rappahannock, and to keep it under observation between your pickets and the left of General Ricketts', whose division is at Warrenton. General Sigel's corps is ordered to Sperryville, and General Banks' to a point between it and Warrenton.

ED. SCHRIVER,

Colonel and Chief of Staff.

WARRENTON JUNCTION, July 4, 1862.

Colonel E. SCHRIVER,

Chief of Staff:

I had compelled at Warrenton Junction, in compliance with your first instructions, before I received your second. It is 10 miles to the Rappahannock, which makes a pretty long ride, but on account of convenience in getting rations I should prefer to remain here. Shall I move out any farther to-morrow? I have sent a squadron to follow the railroad until they can get where they can see the river; one company on the road to the right and another on the left-hand road. The first two parties will leave each an officer and 25 men on picket about 5 miles from here; the last and officer and 10 men about the same distance. To-morrow I shall send one battalion to the right and one to the left of railroad to explore all the country around down to the Rappahannock.

Where is General Ricketts posted and how far will I have to send scouting party to meet his? How far out does General King send his parties? They have just withdrawn the workmen from the repairs of the railroad and sent them to Manassas.

I have just received your second dispatch. I could do nothing to-day