This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
A tube of tin, or cardboard, having an inside diameter to receive a candle snugly, is hung on an axle in the center
Tallow Dripping from the Ends Alternately Lessens the Weight of the Arms and Causes the Tube to Tip
that turns in bearings made of wood. The construction of the bearings is simple, and they can be made from three pieces of wood as shown. The tube should be well balanced. Pieces of candle are then inserted in the ends, also well balanced. If one is heavier than the other, light it and allow the tallow to run off until it rises; then light the other end. The alternate dripping from the candles Will cause the tube to tip back and forth like a walking beam. It will keep going automatically until the candles are entirely consumed. - Contributed by Geo. Jaques, Chicago.