Movements on the Potomac.
--The Alexandria Gazette reports that the steamer Anacostia
, on Wednesday morning, towed to the Arsenal a large three-masted schooner, which she had captured off the mouth of Pamunkey Creek
The steamer soon after went down the river.
About nine o'clock, the steamer Keystone State
passed up. Several carriage guns were on her decks, and a full complement of seamen, but no troops were visible.--The steamer Boston
, accompanied by the propeller Commercial
, loaded with ammunition, also went by. No soldiers could be seen aboard them.
About 10 o'clock, a large propeller steamed down.
At 2 o'clock, the steamer Powhatan
went up. She had been down the river to replace destroyed buoys.