April 15th. This morning, at six o’clock, hove up anchor, and steamed down the river; at ten o’clock, brought ship to anchor five miles above Port Hudson, for the purpose of communicating from masthead, by army signals, with vessels of lower fleet; signalizing from masthead, during the day, with U. S. sloop-of-war Richmond. At six o’clock, Mr. Gabaudan, Admiral’s Secretary, returned on board, in company with some army officers, across the point of land, from lower fleet, after an absence of seven days, upon business of great importance with Major-General Banks at New Orleans. He brought cheering army news. Gen. Augur, with a large force of Banks’s men, was in the rear of Port Hudson, cutting off their possibility of receiving supplies from that quarter, while we had blockaded the mouth of Red River, keeping them from transporting any provisions or stores from Texas out of this stream, and thence down the Mississippi; so the reader must admit that, unless they have a large quantity of beeves and provisions, this rebel stronghold must soon surrender to our arms. Starvation, when it begins, will do the work, which will be better than our being hasty, fighting, and losing thousands of valuable lives.