over the armour belt, the protective deck
is carried all over the ship, but it is not flat, nor is it of equal
thickness, as in a battle-ship. On the top and in the middle it is three
inches thick, but the sides are six inches and they slope abruptly to
below the water-line. Between these sloping sides and the thin armour belt
coal is stored, so that a shell would have to penetrate the outer belt,
six or eight feet of coal, and a sloping belt of steel six inches thick,
the total resistance of which is calculated to be equal to a solid
horizontal armour plate fifteen inches thick.

A cruiser is not supposed to fight with a battle-ship, because it could
not accomplish anything with its 8-inch guns against the 18-inch armour of
its heavier rival, while one well-directed shot from the 12-inch guns of a
battle-ship or monitor would probably sink any armoured cruiser afloat.
For this reason the cruiser must be faster than the battle-ship, so that
she can run away, and the weight that is saved in the armour belt and big
guns is therefore put into the engine-room. The average speed of an
armoured cruiser is about twenty-four miles an hour, and the best types of
this class in the navy are probably the _Brooklyn_ and _New York_.

Some vessels, like the Spaniard _Vizcaya_, are about half way between a
battle-ship and a cruiser, having the heavy guns of the former and the
speed of the latter. The _Vizcaya_, although a cruiser, carried 11-inch
guns with a 12-inch armour belt, and had a speed of twenty-three miles an
hour.

The next step in reducing armament and increasing speed, produced the
protected cruiser, which carries no armour belt, but retains the
protective deck, upon the sloping sides of which is stored the coal. The
turrets disappear altogether, and there is usually only one 8-inch gun,
the battery being principally made up of 4-inch rapid-fire guns and 6, 4,
and 1-pounders. As this class of vessel is not able to cope with the
armoured cruiser, it must be faster, for the general principle holds good
that the weaker the vessel becomes in point of offensive weapons or
defensive armour, the greater the necessity that she should be able to run
away. The best types of the protected cruiser in the navy may be found in
the _Columbia_ and _Minneapolis_, which have a speed of about twenty-seven
miles an hour.

The weakest class of all is composed of the unprotected cruisers, which
have neither armour-belt nor protective deck, a