[Illustration:  Fig. 1]

the other piece of wood is an even 1/8 in. all the way around.  Then nail the wheel down firmly, and tack the other piece slightly.

Procure a thin board 1/4 in. thick, and cut it out as shown in Fig. 3; then nail it, with pins or small nails, on the center of one of the square pieces of wood.  Fit this to the two pieces just finished, with the thin wheel down—­but first boring a 3/4-in. hole 1/4 in. deep, in the center of it; and boring a 3/8-in.

[Illustration:  Fig. 3]

hole entirely through at the same place.  Now put mold No.1 (for that is what we shall call this mold) in a vise, and bore six 1/4-in. holes through it.  Be careful to keep these holes well out in the solid part, as shown by the black dots in Fig. 1.  Take the mold apart, and clean all the shavings out of it; then bolt it together, and lay it away to dry.

[Illustration:  Fig. 4]

Now take another of the 12-in. square pieces of wood, and cut it out as shown in Fig. 4, slightly beveled.  After it is finished, place it between two of the 12-in. square pieces of wood, one of which should have a 3/8-in. hole bored through its center.  Then bolt together with six 1/4-in. bolts, as shown by the

[Illustration:  Fig. 5]

black dots in Fig. 4, and lay it away to dry.  This is mold No.2.  Now take mold No.1; see that the bolts are all tight; lay it on a level place, and pour babbitt metal into it, until it is full.  Let it stand for half an hour, then loosen the bolts and remove the casting.

Now cut out one of the 12-in.-square pieces of wood as shown in Fig. 5.  This is the same as Fig. 1, only the one is left-handed, the other right-handed.  Put this together in mold No.1, instead of the right-handed piece; and run in babbitt metal again.  The casting thus made will face together with the casting previously made.

Pour metal into mold No.2.  This will cast a paddle-wheel, which is intended to turn inside of the casting already made.

If there should happen to be any

[Illustration:  Fig. 6]

holes or spots, where the casting did not fill out, fill them by placing a small piece of wood with a hole in it, over the defective part, and pouring metal in to fill it up.

If you cannot obtain the use of a drill press, take an ordinary brace, fasten a 3/8-in. drill in it, and bore a hole through the end of a strip about 2 in. wide and 16 in. long; put the top of the brace through this hole, and fasten the other end of the strip to a bench, as shown in illustration.  Find the center of the paddle-wheel, place it under the drill, true it up with a square; and drill it entirely through.  Find the centers of the insides of the other two castings, and drill them in the same manner.

A piece of mild steel 5 in. long, and 3/8-in. in diameter must now be obtained.  This is for a shaft.  Commencing 1-1/2 in. from the one end, file the shaft off flat for a distance of 1 in.  Then cut a slot in the paddle-wheel, and place the shaft inside of the paddlewheel, with the flat part of the shaft turned to face the slot in the wheel.  Pour metal into the slot to key the wheel on to the shaft.