Physics

The use of a rod or tube of magnetic material (nickel, iron, Nichrome, Monel metal, stainless steel, etc.) to stabilize an oscillating electric circuit, was first proposed by G. W. Pierce, and such rods were employed by him in the production of standards of frequency in the range from 1,000 cycles per second to about 100,000 cycles and in the measurement of the velocity of sound in solids. Other investigators have used such rods for various purposes, but so far as the writer knows there have been no investigations at great amplitudes of vibration. Quartz crystals, actuated by intense electrostatic fields through the pieze-electric effect, have been employed by Langevin, Boyle, Wood and Loomis, Richards and Loomis, Hubbard, and others to produce within liquids very strong, ultrasonic vibrations, some effects of which they have noted. Intense audible sound, however, has never been produced by use of resonant crystals, because crystals thick enough to give audible sound at resonance would require extremely high voltages to make them oscillate strongly; Wood and Loomis found it necessary to use as much as 50,000 volts between opposite faces of quartz crystals a few millimeters thick to produce intense vibrations of frequencies ten to twenty times that of the highest audible sounds. In the present investigation the object has been to increase the power input of magnetostrictive nickel tubes to the limit as set by the mechanical properties of nickel, and then to discover and investigate properties of the intense audible sound produced by the longitudinal vibration. This research in the sonic range has followed somewhat the work done by the above mentioned experimenters in the supersonic range, but has produced some results and effects that so far have never been reported