All boys love a toy that "goes"; and so a short account showing how to make
A Steamboat that will actually travel on the water will be very welcome. Our boat, which in reality is not a "steam" boat, inasmuch as no steam is generated, is very simple in its construction and possesses neither wheels nor pistons nor cranks, nor any of the things that one associates with a steamer.
The whole motive power is supplied by one or two candle ends, and a bent piece of strong metal tubing. This last can scarcely be called either "odds" or "ends"; and you will probably have to purchase it at a shop selling model-engine fittings, but a few pence will cover the cost. You must get an eight-inch piece of solid drawn copper or brass tubing, with an inside diameter of 1/8 in. (N.B.—Do not let the man sell you soldered tubing, for it will certainly crack when you bend it.)
The next operation is the most difficult: it is bending the tube to the shape shown in Fig. 89. This must be done very gently, otherwise you will crack or dent it. The loop shown should have a diameter of about 5/8 to 3/4 of an inch.
Fig. 89.
The actual boat itself can be of any shape. If you happen to have an old wooden hull suitable to the purpose, use that; if not, then a flat hull similar to that described on page 70 will do quite well. Fix the bent tubing at the stern of the boat, so that the two open ends project over the edge and dip beneath the surface of the water (Fig. 90). Two pieces of wire bent as in Fig. 90a will hold the tubing in place.
Fig. 90.
All that you need do now is place the candles under the loop of the tube and heat it. (If you have a tiny spirit lamp, that will act more effectively, of course.) The heat from the candles makes the air in the tube very hot. This hot air is expelled from one arm of the tube; and a current of water rushes up one arm of the tube and down the other with considerable force. It is this current that causes the boat to move.