Vibration helmet according to Prof. Jean-Martin Charcot, Fig. 1-3, p. 265, 1892, Scientific American. Ser. 2, Jg. 67. New York: Scientific American, 1892.
Vibration helmet according to Prof. Jean-Martin Charcot, Fig. 1-3, p. 265, 1892, Scientific American. Ser. 2, Jg. 67. New York: Scientific American, 1892