The naval portion of this expedition sailed from Plymouth on the evening of the 9th instant, in the following order: Wyalusing, Lieutenant Commander Earl English, bearing the broad pennant of Commander W. H. Macomb, commanding the fourth division of the North Atlantic squadron; Valley City, Acting Master J. A. J. Brooks; Otsego, Commander Arnold; Chicopee, Commander Hannell; Bazeley, Acting Ensign Aimes; tug Belle, Acting Master Green; and the picket launch No. 5, Acting Ensign Chapman. The Shamrock was to follow.

A land force commanded by Colonel Frankle had started from Plymouth at daylight the same morning, to co-operate with the fleet.

THE OTSEGO DESTROYED BY A TORPEDO.

Without interruption, the squadron at 9 o'clock the same night arrived at Jamesville, a small town above Plymouth some twelve miles, when the signal to anchor was made from the flag-ship. The night being dark, and the river flowing rapidly in its narrow and tortuous channel, it was thought best to proceed no further until daylight. The Wyalusing had just let go her anchor a few yards above the town, when two loud reports were heard astern, and dense volumes of smoke and steam were seen to envelop the Otsego. That fine vessel had struck two torpedoes, one under the port coal-bunker, the other beneath the keelson, driving a large hole through her bottom, and throwing one of her hundred-pounder rifled Parrotts into the air. She sank in fifteen minutes in three fathoms of water, being a complete wreck. Her officers and men lost all their clothing, except what they had on at the moment of the explosion, but were cared for by their comrades of the other vessels, who hurried to their rescue, and periled their own lives in saving their shipwrecked fellow-sailors. Commander Arnold behaved with great coolness, and his self-possession soon restored order and discipline on board the sunken ship, or rather on her hurricane deck, which alone remained out of water.

DESTRUCTION OF THE BAZELEY.

In the morning orders were given to drag for torpedoes, when it was found that the Otsego had struck upon a perfect nest of them. The boats which had been passing and repassing to and from her during the night, had rowed over numbers of them, happily without touching them. Several were picked up alongside the Otsego, and two were hanging to the torpedo-fender rigged at her bow. The steamer Bazeley during the morning was ordered to run down to Plymouth, to convey orders and dispatches, taking on board for that purpose Paymaster Louis Sands, of the Shamrock, who had been detailed as one of Commander Macomb's aids in this expedition. On her way down, being directed to communicate with the Otsego, Captain Aimes ran towards the sunken vessel, when a torpedo struck the Bazeley under the pilot house, blowing a hole clear through her, killing Wm. C. Rossell, a lad, and John Gerrard, first-class boy, and sinking the ship instantly. The officers and remainder of the crew escaped by swimming, and were picked up by boats. Captain Aimes, upon returning to the flagship, thus laconically reported his loss to Commander Macomb: "Sir, the Bazeley has gone up."

The destruction of two of our vessels so quickly made things look blue, but the grit and metal that headed the expedition were sufficient to overcome such disasters.

A FRESH START.

Preparations were now fully carried out to drag the river by boats for the torpedoes, which were constantly found in the richest and choicest clusters, in some places eight or nine being placed across the river in a line, and having susceptibilities of the most sensitive nature, going off on the slightest provocation. Communication with Plymouth having been obtained, the signal was made to advance, the Valley City taking the lead.

Mr. Chamberlain, a civilian, had volunteered to go with the expedition with a calcium light, which proved to be of great advantage to the fleet in the intense darkness of the nights. The light was placed on the leading vessel, and made our pathway as clear as broad daylight. The fleet proceeded slowly, having six boats constantly employed in dragging and picking up torpedoes, which continued to be found in great profusion. Large numbers were found at Shad Island Bend and other points, and many exploded in the attempt made to get them on shore. Eighty were taken up in a distance of thirty miles.