The diver consists of a small glass test tube about two inches long having the figure of a man painted upon it. The lower end is closed by a very small cork through which is pushed a large iron tack with the head on the outside. The test tube contains just enough water to float head up even with the surface of the water. The exact amount of water required to just permit enough buoyancy for the diver to rise again to the surface after he has been to the top will have to be determined by careful experiment. The jar containing the diver should be set on a table having a drawer in which a pair of powerful electromagnets can be placed directly under the jar. The electro-magnets are connected to a strong battery and a switch located under the rug or carpet and so arranged that it may be closed by stepping on it lightly and without attracting attention. If the diver does not have too much bouyancy the attraction between the tack and the electro-magnets when the switch is closed should be sufficient to cause him to descend to the bottom of the jar. When the current is turned off the diver should rise again. [Illustration: FIG. 190.—The Magnetic Diver.] 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. A MAGNETIC CLOWN. Small figures of men or animals cut out of sheet iron will perform many amusing acrobatic feats when under the influence of a magnet. [Illustration: FIG. 192.—The Magnetic Clown.] Such figures are easily cut out of an old tin cracker box with a pair of snips or strong shears. A realistic appearance may be secured with the aid of a little paint. A tin clown having a sharply pointed hat, hands and feet will do all sorts of stunts when hanging from the poles of a horseshoe magnet. If several clowns are made they can be caused to hold hands, stand on each others heads, jump up in the air, etc. AN ELECTRIC BREEZE.