Putting on the Rudder.—And last of all comes the rudder. Cut off two pieces of ⅛-inch brass rod 4 inches long; thread one end of each rod down 1 inch, and sharpen the end a bit; thread the other end of each one down ⅝ inch and screw a nut on it.
YOUR MODEL SUBMARINE IN ACTION
Drill two 3/32-inch holes in the tail block in a vertical line with each other 4⅜ inches apart, and screw in the brass rods as shown in [Fig. 22]. Cut the rudder out of heavy tin—or, better, 1/32-inch-thick sheet brass—the size and shape shown also in [Fig. 22].
Bend the end of each tongue of the rudder to make a knuckle, and slip the knuckles over the pins. Screw a nut on the end of each pin, and by tightening them up you can make the rudder stay at any angle you put it.
Painting Your Craft.—You can buy a good marine paint of almost any color you want at paint stores generally.[14]
Gray is the most appropriate color to paint your model craft with; but whatever color you choose, lay it on the long way of the boat so as not to streak it but make a good smooth job of it. Put on three coats and let each coat dry thoroughly before you apply the next one. And now your submarine is done, and if you have made a good job of it, it will look like the half-tone cut shown here.
How to Work Your Submarine.—Having everything in readiness, take your terrible little U-boat under your arm to the nearest lake or river.
Pump the conning tower full of compressed air and then gently put her in the water. Throw on the switch, and it will do the rest. By this, I mean that the moment you turn on the current the motor will drive the propeller at a goodly clip and the craft will travel over the surface of the water awash—that is, with the water washing over her deck.
At the same time, the ballast tank begins to fill with water, and the added weight makes the boat go deeper and deeper until only the bridge[15] of her conning tower can be seen; and after a few moments more her periscope (or air supply tube) sinks out of sight.