Bore a ⅛-inch hole through the propeller end, and slip a piece of brass tube 2 inches long which has a bore of inch in it to form a bearing for the propeller shaft. Get a brass rod 1/16 inch in diameter and 2¼ inches long; make an eye on one end and then push the rod through the brass tube in the tail or propeller end of the torpedo, as shown in [Fig. 36], and this is all there is to the propeller shaft. Now cut a propeller out of tin, as shown at E, in [Fig. 37], and solder it to the end of the propeller shaft.
The Steering and Diving Rudders.—The torpedo, like the submarine itself, has two rudders, one for diving and one for steering.
FIG. 37. A, B, C, THE STEERING AND DIVING RUDDERS. D, E, THE COVER AND PROPELLER.
To make the steering rudder, which is the vertical one, cut out a piece of heavy tin 1½ inches wide and 1¾ inches long, as shown at A in [Fig. 37]; cut out one edge ⅜ inch deep as shown by the shaded part, which will leave a tongue sticking out from each corner, and bend these to form little tubes.
Cut off two pieces of wire ⅛ inch thick, have each one 2½ inches long, and bend them as shown at C. Next drill two holes through the tail or propeller end of the torpedo, force the sharp ends of the wires into them and then put the other ends into the tubes of the rudder.
The diving rudder, which is the horizontal one, is made like the steering rudder except that the tongues for the hinge tubes are dropped down a little and a slot ½ inch wide and 1¾ inches long is cut out, as shown by the shaded part at B.
This rudder is 1½ inches wide and 2⅛ inches long; it is fastened by a pair of ⅛ inch wires to the tail end of the torpedo in the same way as the steering rudder. This arrangement leaves enough room for the propeller to turn inside of the wires, as shown at C.