One of the more pleasing novelties which we came across recently, and which will make a fine Christmas present for, as the makers put it, ” boys of all ages,” is the D.C. hot-air engine. At one time full-size hot-air engines had a limited industrial function, and this is a model of such an engine. Worked by means of heat supplied from a small burner, the pumping and displacement pistons are cast as a single unit in a special zinc-alloy, the brass pumping piston working in ⅛ in. by ½ in. cylinder and the aluminium displacement piston in a cylinder with a bore and stroke of ⅛ in. by ½ in. The twin flywheels are precision finished and flanked by brass handrails, there is a pulley (but not much power !) for driving small models, and the engine is mounted on a sturdy cast-aluminium base.
We bought some methylated spirit for ours, which took us back to pondside days in our youth when we played with model–or rather toy–steam launches. Today even reciprocating toy steam engines cost the earth, whereas this little hot-air engine, which is safe and which runs without much noise or smell, costs only 30s, from any good toy shop. It functions sufficiently fast for the piston rods to become a blurr, and 9d. of ” meth ” would appear to be sufficient for at least three hours’ running. This model of a now-historic form of engine should appeal to young and old alike and be immensely popular at Christmas. It has the additional merit of being a British toy. If you have difficulty in obtaining yours, send 31/9d. (which covers postage to the mainland) to Davies Charlton Ltd., Hill’s Meadow, Douglas, I.O.M., mentioning Motor Sport. – W. B.