Demonstrating 'Chichester Bell's Singing Water-jet', 1912.

Plate taken from 'Soap Bubbles' (1912) by Charles Vernon Boys, demonstrating that a jet of water is 'a machine for magnifying sound'. The 'Water telephone' was one of a great number of experiments devised by Chichester Bell, cousin of telephony pioneer Alexander Graham Bell. Charles Vernon Boys (1855-1944), English physicist, designed a calorimeter for determining the calorific value of coal gas. He was President of the Physical Society in the period 1916-1918.