Fig. 29.
An Interesting Experiment of Supporting a Large Bar of Iron within the Helix.
Discovered by Mr. Vail, January, 1844.
It has been shown, many years since, that a magnetic needle would be drawn into and suspended within a helix, conveying a galvanic current, and that in the case of using large bar magnets, the coils or helices might be made to move over them, as in De La Rives’s rings; but in no instance, I believe, has it been recorded, or observed, that a bar of iron weighing a pound or more, could be drawn up into the helix and there sustained in the air, as it were, without support. If the helix, as shown in [figure 30], be connected with from 6 to 12 pairs of Grove’s battery, the bar may be drawn up into its centre and there sustained in a vertical position by the action of the helix, forming an exceedingly interesting and paradoxical experiment.