On Monday evening at 3 o'clock, one hour before the Western World left, the U. S. Florida arrived from the fleet off Charleston, which place she left on Sunday eve, the 23d, bringing the important report that Fort Wagner and Fort Sumter had been reduced, and that our own troops now occupied those forts. This report, Captain Gregory says, has also been received at the fleet off Wilmington from prisoners taken. The report was not contained in the Richmond papers of the 25th, the news from which was telegraphed you, still it may be true, as the rebels are slow to report bad news. The Western Worlds also brings good news from the fleet off Wilmington. On Sunday, the 23d, Admiral Lee ran up the beach to the position where the English steamer Hebe had been driven on shore, and forming in line of battle with the Minnesota, Niphon, Stockton, James Edger, and Western World, attacked a battery supported by the rebels to protect her and the working parties engaged in removing her cargo.

Engagement lasted about two hours, resulting in the dispersion of the rebel force of 300, killing of 8 men, and the wounding of 1; the capture of 2 guns - one an Armstrong and the other a Whitworth - and the total destruction of the Hebe; the captured of army clothes and other things that the rebels had got ashore.

In addition to this, an expedition under Captain Cushing, an hour before this, captured a schooner or 18 men near Old Topsail Inlet. The schooner was lying close in to shore. Captain Cushing ran in with 6 men in a boat, and, by giving orders to an imaginary fleet of boats, deceived the enemy and made them surrender.

J. G. FOSTER,

Major-General.

Major-General HALLECK,

General-in-Chief.

AUGUST 24, 1863.- Skirmish near King George Court-House, Va.

Report of Brigadier General Judson Kilpatrick, commanding Third Division, Cavalry Corps.

HARTWOOD, VA., August 26, 1863.

COLONEL: General Custer has just returned from a reconnaissance in the direction of King George Court-House. He found the enemy 2 miles south of the court-house. Had a skirmish with the Forty-Eighth Alabama Infantry, forced the enemy back to within 2 miles of Port Conway, where he found a brigade of infantry and 4 pieces of artillery under General Law. He returned this morning without the loss of a man.

The enemy lost 2 killed and several wounded. A few prisoners will reach you to-day. With this rebel force on this side the river my lower line is unsafe. Cavalry can cross at Port Conway at the rate of 75 in fifteen minutes. The enemy are obtaining large supplies from the Northern Neck, besides conscripts. With my picket line supported by a small force of infantry at Hartwood Church I could move down the neck with six regiments and a battery, and capture this force and destroy the ferry at Port Conway.

J. KILPATRICK,

Brigadier-General, Commanding.

Lieutenant Colonel C. ROSS SMITH.