Armor

A metal protection against artillery projectiles.

Belted Armor. A plating completely encircling the ship in the vicinity of the water-line, and from ten inches to twenty inches in thickness.

Compound Armor. A combination of iron or steel, or nickel and steel, or other metals. Compound armor is generally considered to refer to a layer of steel facing on iron plate.

Internal Armor. This applies to two denominations of armor: first, as a backing for main or outboard armor; second, for transverse bulkheads, extending from side to side, forward and aft inclosing the battery and protecting the vessel against a raking fire. These bulkheads extend from the water-line to the lower part of the upper deck.

Nickel-steel Armor. A combination of steel and nickel. This is the standard armor for the U.S. Navy. Its advantage is its superior resisting power--the mixing of the two metals makes a very tough substance, and renders it less liable to split upon impact with projectiles.