CHARLESTON, April 28, 1862.

Major-General FREMONT, Wheeling:

Colonel Scammon found works of enemy on other side of New River abandoned. They were quite strong entrenchments; have three tiers of breastworks and rifle pits. These were nearly opposite mouth of Blue Stone. The pickets of Scammon's advance are within 2 miles of top of Flat Top, and we will push forward as soon as roads and transportation will permit. The mud is now in its most tenacious condition, but drying rapidly.

J. D. COX,

Brigadier-General.

HEADQUARTERS,
Wheeling April 28 [1862.]

General COX:

A large number of pack mules will be sent to your district. The quartermaster and commissary both will make every exertion to comply with your desires. Should your men nevertheless not be well provided for a number of days the movement proposed must still be pushed forward. What would be the smallest number of troops necessary to guard your lines of communication, the posts of Gauley Bridge, Gauley Mountain, Chapmanville and Summerville included?

By order of General Fremont:

A. ALBERT,

Chief of Staff.

HDQRS. DEPARTMENT OF THE RAPPAHANNOCK,

Near Aquia Creek Landing, April 29, 1862.

Honorable E. M. STANTON,

Secretary of War:

SIR: I have the honor to acquaint you that General Reynolds' brigade, of McCall's division, has arrived opposite Fredericksburg. Another brigade will be in position by to-morrow.

Information has reached me that the rebels have abandoned the right bank of the Rappahannock, opposite the crossing of Orange and Alexandria Railroad, and fallen back, it is supposed, in the direction of Gordonsville.

Previous reports as to the enemy's force being concentrated on the railroad line between Fredericksburg and Richmond and 12 miles from the latter point are confirmed by contrabands and Union men, who estimate it as high as 12,000 men. The enemy's pickets, however, continue to show themselves on the hills in rear of Fredericksburg, and during the night come into the town and harass the few Union men left there. Five or six od them have been arrested and carried off toward Richmond.

For several nights past the rumbling of wagons leaving town has been heard, and residents say that they are loaded with corn and other supplies.

Urgent appeals for protection against this oppression by the Confederate authorities reach us through loyal men residing on the other side of the river. By means of our boat bridge, which can be easily made available in a few hours, a sufficient force could be thrown across the river to afford this protection, or it could be withdrawn promptly or re-enforced