The power plant of this boat is made up of rubber bands. The power
transmission to the propeller is a little different than the one
previously described. A gear and a pinion are salvaged from the works of
an old alarm-clock, and mounted on a piece of brass, as shown. A little
soldering will be necessary here to make a good job. By using the gear
meshing with the pinion a considerable increase in the speed of the
propeller is obtained, and therefore the speed of the boat is
considerably increased. The method of holding the power plant to the
bottom of the boat is made very clear. In order to bring the boat down
to the proper level in the water, a strip of sheet lead can be tacked to
the bottom. The builder should take care to get a piece of lead just the
correct weight to leave the surface of the deck awash. A coat of gray
paint will also greatly improve the appearance of this craft.

[Illustration: FIG. 22]

[Illustration: FIG. 23]

[Illustration: FIG. 24]

Attention is directed to the construction of boats of different types
made without power plants. Many interesting little crafts can be
produced in this way, and the energetic model-builder can produce a
whole model harbor or dock-yard by constructing a number of boats of
different types according to the following instructions.

The first boat described will be the tug _Mary Ann_ shown in Fig. 22 and
Fig. 23. The blocks necessary to construct this boat are shown in Fig.
24. The hull of the boat is produced by three pieces of wood sawed out
to the same shape with a keyhole saw and glued together. After the glue
is dry the blocks are placed in a vise and the top one or deck block is
planed down as shown. It will be seen that the deck inclines slightly
toward the stern of the boat. When this is done the hull is turned
upside down and the bottom of the stern planed off as illustrated. The
outside of the hull can be finished up with a sharp knife and a
jack-plane.

The little bow piece can also then be tacked in place. After this the
pieces that form the hull can be nailed together from the bottom and
from the top. This is quite necessary, for glue will not hold them in
place after the boat has become thoroughly soaked with water.

The cabin and engine-room are shown very clearly in the illustration and
little need be said about erecting this part of the craft. The two doors
and window on the side of the cabin are made by cutting out small pieces
of cigar-box wood