The rise in Red river.
--A gentleman who is posted advises the editor of the Macon Telegraph that what is called the "winter rise," in the Western rivers, takes place usually in June, from the thawing of the ice and snows of the mountains.--If that be the case, the Yankee gunboats will probably be floated out of Red river before mid-summer, if they should not be destroyed ad interim. He says they are detained by no "raft," but by a shoal, just above the town of Alexandria, where he felt sure they would be caught when they went above it at this season of the year.