shovel-handle is cut 22 inches in length. It is pointed at each end, and part of it is planed off to form the upper deck. When this is done, a small flat piece is cut as shown, and nailed or screwed to the flat portion. The conning-tower and periscope are placed on the upper deck, as shown. The rudder on this craft is not made adjustable, so that it always travels in a perfectly straight line. The horizontal rudders however, are made adjustable, and the boat is therefore able to travel upon the surface or submerge, depending upon the position of the rudder.

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.

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 and gluing them to the cabin and engine-room. A good substitute for the wood can be found in tin, but of course this would have to be tacked on. The little skylight on the back of the tug is made by a single block covered by two pieces of cigar-box wood.

In order to stabilize the craft and to bring her down to the proper water-line, a lead keel must be nailed to the bottom. The weight of this keel will have to be adjusted until the boat rests properly in the water. The reader will notice that no dimensions have been given for this boat. This is because most boys will wish to build different sized boats, and therefore it has not been deemed advisable to dimension the boats described in this Chapter. What the author desires to do is to impart the principles of construction, so that every boy may use his own ingenuity in regard to size and proportion of length to beam.

If tugs are constructed according to the design outlined above, the model boat builder will also desire to have something that the tug can haul. A very simple barge for this purpose is outlined in Figs. 25 and 26. This is formed of a single slab with the ends cut at an angle as illustrated. A square flat piece is then tacked to the upper deck, which acts as a cover. Four posts are then put in place in the same way as those on the tug. One is placed in each corner. A boat or a scow like this is generally painted red, and the model described can be made to look much more realistic by painting it this color.