A Diary of American Events.

October 17.—This morning a squad of guerrillas made a descent on the Alexandria Railroad at Acotink, Va., and carried off fifteen men belonging to the One Hundred and Twentieth regiment of New-York, who were posted at that point —A party of the Thirteenth New-York cavalry, stationed at Stuart’s, near Chantilly, Va., were surprised and surrounded by Mosby’s guerrillas, and six were captured. — General Buford’s division of cavalry crossed the Rapid Ann River at Germania Ford on Saturday evening, and, following the river to Hunter’s Ford, surprised the enemy in their fortifications, and captured sixty of them. General Buford occupied these works till Sunday morning, when he received orders to return, and recrossed the Rapid Ann, followed by a large force of Stuart’s cavalry and some mounted infantry, whom he gallantly fought, although greatly outnumbered, as he fell back through Stevensburgh to Brandy Station, where he joined Kilpatrick’s forces. The whole cavalry command then slowly retired across the Rappahannock. This action was one of the most gallant and brilliant in the history of the Union cavalry.—The rebel steamer Scottish Chief, and sloop Kate Dale, were destroyed in Hillsborough River, Fla., by the Union gunboats Tahoma and Adela.—(Doc. 200.)