inventor John Ericsson, a Swede by birth, but American by adoption--a
man who combined great original genius with long scientific study and
experience. His invention may be most quickly described as having a
small, very low hull, covered by a much longer and wider flat deck only
a foot or two above the water-line, upon which was placed a revolving
iron turret twenty feet in diameter, nine feet high, and eight inches
thick, on the inside of which were two eleven-inch guns trained side by
side and revolving with the turret. This unique naval structure was
promptly nicknamed "a cheese-box on a raft," and the designation was not
at all inapt. Naval experts at once recognized that her sea-going
qualities were bad; but compensation was thought to exist in the belief
that her iron turret would resist shot and shell, and that the thin edge
of her flat deck would offer only a minimum mark to an enemy's guns: in
other words, that she was no cruiser, but would prove a formidable
floating battery; and this belief she abundantly justified.

The test of her fighting qualities was attended by what almost suggested
a miraculous coincidence. On Saturday, March 8, 1862, about noon, a
strange-looking craft resembling a huge turtle was seen coming into
Hampton Roads out of the mouth of Elizabeth River, and it quickly became
certain that this was the much talked of rebel ironclad _Merrimac_, or,
as the Confederates had renamed her, the _Virginia_. She steamed
rapidly toward Newport News, three miles to the southwest, where the
Union ships _Congress_ and _Cumberland_ lay at anchor. These saw the
uncouth monster coming and prepared for action. The _Minnesota_, the
_St. Lawrence_, and the _Roanoke_, lying at Fortress Monroe also saw her
and gave chase, but, the water being low, they all soon grounded. The
broadsides of the _Congress_, as the _Merrimac_ passed her at three
hundred yards' distance, seemed to produce absolutely no effect upon her
sloping iron roof. Neither did the broadsides of her intended prey, nor
the fire of the shore batteries, for even an instant arrest her speed
as, rushing on, she struck the _Cumberland_, and with her iron prow
broke a hole as large as a hogshead in her side. Then backing away and
hovering over her victim at convenient distance, she raked her decks
with shot and shell until, after three quarters of an hour's combat, the
_Cumberland_ and her heroic defenders, who had maintained the fight with
unyielding st