The Chickasaw, which had so persistently stuck to the ram, now took her in tow and anchored her near the flag-ship. At half-past two of the same afternoon the Chickasaw again got under way and stood down to Fort Powell, engaging it for an hour at a distance of three hundred and fifty yards. The fort had been built to resist an attack from the sound and was not yet ready to meet one coming like this from the rear. That same night it was evacuated and blown up. On the 6th the Chickasaw went down and shelled Fort Gaines, and the following day it was surrendered. Fort Morgan still held out. The army under General Granger was transferred from Dauphin Island to Mobile Point and a siege train, sent from New Orleans, was landed three miles in rear of the fort on the 17th. In the meantime batteries had been constructed; and thirty-four guns had been put in position, with everything ready for opening, on the evening of Saturday the 20th. On Monday the 22d, at daylight, the bombardment began from the batteries, the three monitors, and the ships outside as well as inside the bar. On the 23d the fort surrendered. Mobile as a port for blockade-running was thus sealed by the fleet holding the bay; but the gigantic struggle going on in Virginia, Tennessee, and Georgia hindered for the time any attempt to reduce the city. That would have withdrawn from more important fields a large force for a secondary object, which was put off till the following spring. In the meantime Admiral Farragut went north in December, leaving Commodore Palmer in command of the squadron till the following February, when he was relieved by Acting Rear-Admiral H.K. Thatcher. Palmer, however, stayed by his own wish until the city fell. Several streams having a common origin and communicating with one another enter the head of the bay. Of these the chief and most western is the Mobile River, formed by the junction of the Alabama and Tombigbee. It empties by two principal branches, of which the western keeps the name Mobile, the eastern one being called Spanish River; the city of Mobile is on the west bank of the former. On the east side of the bay the Tensaw[39] enters, also by two mouths, of which the western keeps the name and the eastern is called the Blakely River. The Tensaw and Spanish Rivers have a common mouth about a mile from the city. It is therefore practicable to go from the Mobile to Spanish River, and thence to the Tensaw and Blakely without entering the bay.