THE MAGNETIC FISH.
The same sort of a scheme employed in the Magnetic Diver may be used for producing a magnetic fish which will swim around and around a pan of water.
[Illustration: FIG. 191.—The Magnetic Fish.]
It consists of a small wooden fish having a magnetised sewing needle attached to the under side. The fish is placed in a bowl of water on a table having a drawer in which a pair of electro-magnets mounted on a rotating wooden arm may be placed so that they swing around directly underneath. A piece of strong twine wrapped around an empty spool and attached to the centre of the arm makes it possible to rotate the magnets by pulling on the string. When the magnets are connected to a battery they will exert a strong magnetic pull upon the needle fastened to the fish and if slowly rotated will cause the latter to follow slowly around the bowl.