A Perpetual Whirligig
Camphor is the motive power which drives the device shown in the illustration, and it will cause the whirligig to revolve for several days, or until the camphor is consumed.
Camphor powered whirligig
The whirligig is made of a piece of cork, ¹⁄₂ in. square, with a needle stuck into each of its four sides. Smaller pieces of cork, to which pieces of camphor have been fixed by means of sealing wax, are attached to the ends of the needles. Care should be taken to keep the needles and cork free from oil or grease, as this will retard their movement. As soon as the device is placed in a dish of water it will start whirling and continue to do so as long as motive power is supplied. A small flag or other ornament may be attached to the center cork.