ints, but not indispensable, provided the vessel has numerous
horizontal and vertical bulkheads to prevent too great a loss of
buoyancy when the vessel is seriously damaged between wind and water.
Harbor-craft may be very low on the water, so that only a little height
of protection is required. But it is generally supposed that sea-going
vessels must be high out of water. Mr. Ericsson's practice, however, is
to the contrary; and it may turn out that a low vessel, over which the
sea makes a clean breach, can be made sufficiently buoyant on his plan,
If high sides are necessary, the plan of Mr. Lungley, of London, may be
adopted,--a streak of protection at the water-line, and another
forming at the top of the battery at the top of the structure, with an
intermediate unprotected space. A shot-proof deck at the water-line, and
the necessary shot-proof passages leading from the parts below water to
the battery, would of course be necessary.

Considering the many expedients for vastly increasing the thickness of
armor, the idea, somewhat widely expressed, especially in England,
that, in view of the exploits of Armstrong, Clay, and Whitworth,
iron-protection must be abandoned, is at least premature. The manner in
which the various principles of construction have thus far been carried
out will be noticed in a brief.

_Description of Prominent Iron-Clad Vessels_. CLASS I. Classified with
reference to the protection, the dimensions of the English Warrior
and Black Prince are, length 380 feet, beam 58 feet, depth 33 feet,
measurement 6,038 tons. Their armor (previously described) extends from
the upper deck down to 5 feet below water, throughout 200 feet of the
length amidships. Vertical shot-proof bulkheads joining the side armor
form a box or casemate in the middle of the vessel, in which the 26
casemate-guns, mostly 68-pounder smooth-bores, are situated and fired
through port-holes in the ordinary manner. Their speed on trial is about
14 knots,--at sea, about 12. The Defence and Resistance, of 275 feet
length and 3,668 tons, and carrying 14 casemate-guns, are similarly
constructed, though their speed is slow. All these vessels are built
entirely of iron.

CLASS II. This differs from the first mentioned in having protection all
around at the water-line. The New Ironsides, (American,) of 3,250 tons,
240 feet length, 58-1/2 feet beam, 28-1/2 feet depth, and 15 feet
draught, and built of wood, has 4-1/2-inch solid armor with 2 fe