Magnetostriction

Abstract

IN your issue of March 24, 1904, Mr. Nagaoka gives an account of a lecture experiment on magnetostriction; a few weeks later Prof. W. S. Franklin describes an experiment of the same kind. Both experimenters use a vertical solenoid, along the axis of which is fixed at its upper extremity an iron wire. When a current is sent through wire and solenoid, the wire is twisted. The explanation given is that the wire is magnetised helically, the expansion along the lines of magnetisation resulting in a twist of the free lower extremity.