e name.
The principal entrance from the Gulf is between Mobile Point--a long,
narrow, sandy beach which projects from the east side of the bay--and
Dauphin Island, one of a chain which runs parallel to the coast of
Mississippi and encloses Mississippi Sound. At the end of Mobile Point
stands Fort Morgan, the principal defense of the bay, for the main ship
channel passes close under its guns. At the eastern end of Dauphin
Island stood a much smaller work, called Fort Gaines. Between this and
Fort Morgan the distance is nearly three miles; but a bank of hard sand
making out from the island prevents vessels of any considerable size
approaching it nearer than two miles. Between Dauphin Island and the
mainland there are some shoal channels, by which vessels of very light
draft can pass from Mississippi Sound into the bay. These were not
practicable for the fighting vessels of Farragut's fleet; but a small
earthwork known as Fort Powell had been thrown up to command the deepest
of them, called Grant's Pass.

The sand bank off Dauphin Island extends south as well as east, reaching
between four and five miles from the entrance. A similar shoal stretches
out to the southward from Mobile Point. Between the two lies the main
ship channel, varying in width from seven hundred and fifty yards, three
miles outside, to two thousand, or about a sea mile, abreast Fort
Morgan. Nearly twenty-one feet can be carried over the bar; and after
passing Fort Morgan the channel spreads, forming a hole or pocket of
irregular contour, about four miles deep by two wide, in which the depth
is from twenty to twenty-four feet. Beyond this hole, on either side
the bay and toward the city, the water shoals gradually but
considerably, and the heavier of Farragut's ships could not act outside
of its limits. The Confederate ironclad Tennessee, on the contrary,
drawing but fourteen feet, had a more extensive field of operations open
to her, and, from the gradual diminution of the soundings, was able to
take her position at a distance where the most formidable of her
opponents could neither follow her nor penetrate her sides with their
shot.

Between the city and the lower bay there were extensive flats, over
which not even the fourteen feet of the Tennessee could be taken; and
these in one part, called Dog River Bar, shoaled to as little as nine
feet. To bring the Tennessee into action for the defense of the entrance
and of the lower bay, it was necessary t