Discovery of Ultrasound Technology

Pierre Curie and his brother, Jacques Curie, discovered the piezoelectric effect in certain crystals in Paris, France, leading to the evolution of high frequency echo-sounding techniques.

J. Curie and P. Curie: Bulletin de la Société Minéralogique de France 3 (1880) 90. and also published in Comp. Rend. 91 (1880) 294 and 383.