Mr. Thompson to Mr. Gresham.

[Telegram.]

Mr. Thompson reports that the previously neutral fort of Villegaignon has declared for the cause of the revolution and participated in the general but fruitless bombardment on Tuesday last between the revolting vessels and three loyal forts. He announces that Rio de Janeiro will not be fired on. The revolutionists seized an English barge, but no report of interference with United States barges has been heard. A notice was issued by him on September 18 that the legitimate entry and export of merchandise owned by Americans would receive such protection as may be necessary.