In February 1917, Langevin started to investigate the piezoelectricityPiezoelectricity of x-cut quartzQuartz as a receiver of ultrasound, initially using a crystal recovered from the Curies’ apparatus. A proposal by Ernest RutherfordRutherford, Ernest to use the quartz piézoélectriqueQuartz piézo-électrique, cut along a different plane, led to later claims of priority. By the summer of 1917, the production of a beam of ultrasound using quartz was demonstrated, exploiting piezoelectric resonanceResonance. Robert BoyleBoyle, Robert visited from England, returning there under Langevin’s guidance to set up the development of asdicasdic using simple quartz transducers. Langevin designed his resonant quartz sandwich transducer, resulting in successful sea trials in the summer of 1918. He shared his knowledge at the Interallied Conference on SupersonicsInterallied Conference on Supersonics in Paris in October 1918.