Camphor in Water
If you put very small pieces of camphor on the water, you will see them turn round each other with great velocity. These movements are due to the diminution of the superficial tension of the liquid in the vicinity of the pieces of camphor.
In order to stop them throw a drop of oil in the water, and you will produce a perfect calm. One may utilize the camphor for an amusing recreation.
Construct a small paper or cardboard boat and fasten underneath on the hind part or stern a piece of camphor. Your boat will maneuver on the water. Persons not initiated will be much puzzled, and be long to find out by what contrivance this small craft is propelled.