tion: FIG. 31]

[Illustration: FIG. 32]

A battleship is shown in Fig. 30. A battleship should be at least twice
as long as a torpedo-boat destroyer. A view of the battleship as it will
look in the water is shown in Fig. 31. By carefully examining this
drawing the builder will be able to see just the number and shape of
the blocks that enter into the construction of the craft. The battleship
is provided with four main batteries mounted in turrets, one forward and
three aft. A mast is also built, and strings run from it to the top of
the main cabin and to the end of one of the turrets mounted aft. A screw
is placed through the centers of the fore and aft turrets, so they can
be turned to any position. Battleships should be painted gray. It will
be necessary to place rather a heavy keel on the boat just described in
order to bring it down to the proper depth in the water. Otherwise it
will be topheavy and will capsize very easily. A fleet of battleships
and battle-cruisers can easily be made according to the foregoing
instructions, and the builder should not be satisfied with producing
only one.

A pleasure yacht is illustrated in Fig. 32. The hull of this craft is
formed by two boards nailed together. The cabins are very simple, being
formed by a solid block of wood with a piece of cigar-box wood tacked to
the top. The windows and doors are marked in place with a soft
lead-pencil, and the stack is mounted midway between the two cabins. A
wireless antenna should be placed on the boat, with a few guy-wires from
the masts run to various parts of the deck. A lead-in wire also runs
down into one of the cabins. The hull of this boat should be painted
pure white. The deck can be left its natural color, while the stack
should be painted black and the cabins white with green trimmings.

Almost any type of boat can be produced by the use of simple blocks of
wood and other miscellaneous pieces easily brought to shape from
ordinary materials. This method of construction offers a wonderful
opportunity for the boy to exercise his creative faculties.

CHAPTER IV

STEAM AND ELECTRIC PROPULSION

BOATS are propelled by two different systems. Some inland-water boats
still employ side paddle-wheels, while ocean-going vessels use the more
modern propeller or screw.

The paddle-wheel really acts as a continuous oar. Such a wheel is shown
in Fig. 33. As the wheel goes around the paddle dips into the water and
pushes the boat