ce when rifled guns were first introduced. Guns could be
made lighter, and yet be much more powerful than the old patterns of the
same bore, and it was seen that a ship could with advantage be provided
with a "secondary" armament, as it is called of these smaller yet
powerful guns. Armour, too, was being improved, so that it could be
made thinner and yet equally effective; higher speeds were also called
for, and it was evident that warships must be designed on different
lines to meet or take advantage of the new conditions.

The first ship designed on the new lines was the _Collingwood_, a vessel
of 9,500 tons, 16 and a half knots speed, and 7,000 horse-power. She
was the first ship of what was called the "Admiral class,"--several
sister ships named after famous admirals. The four heavy guns of the
_Devastation_ type of turret-ship were retained, mounted fore and aft,
but instead of placing them in turrets, the turret armour was fixed to
the deck, forming what is known as a "barbette," or breastwork, over the
upper edge of which the gun fired. Inside the barbette the gun revolved
on its turn-table; its breech, together with the gunners, was protected
by a hood of armour which revolved with the gun. This arrangement is
probably less liable to be knocked out of action by the enemy's shot
than the turret.

Amidships was the "secondary" armament of six 6-inch breech-loading
guns. All the guns were mounted well above the water, enabling them to
be used even in a heavy sea, which could not be done in the case of
ships lying low in the water like the _Devastation_.

A further impetus was given to the development of the secondary armament
by the introduction of "smokeless" powder--which, however, gives a
_very_ slight smoke,--and the "quick-firing gun." By simplifying the
breech mechanism, using metal cartridge cases for the ammunition instead
of silk bags--which necessitated the sponging out of the piece after
each shot to remove the smouldering fragments--arranging the "sights" of
the gun so that it could be aimed while loading was going on, and other
ingenious arrangements, it was found that 6-inch 100-pounder guns could
be fired many times per minute without any mechanical appliances. About
the same time also, means were found of firing with safety what are
called "high explosives," that is, explosives of far greater destructive
power than the same weight of gunpowder. Similar improvements were
naturally extende