Mr. Thompson to Mr. Gresham.

[Telegram.]

Mr. Thompson reports that upon the announcement made by the admiral commanding the revolting war vessels of his intention to bombard Rio de Janeiro, the French, English, Portuguese, Italian, and U. S. ministers held on this day a conference, and advised the commanders of the foreign vessels, who agreed to do so, to take measures to prevent such bombardment in case of necessity. He reports that on the previous day the forts in the harbor were bombarded without result.