Breguet and Roosevelt Breguet and Roosevelts method of handing telephones. Suspending fork, F, is a key switch which puts the bell into the circuit. and Magnetism, London, 1891. Editorial Stock Photo - Afloimages
Breguet and Roosevelt's method of handing telephones. Suspending fork, F, is a key switch which puts the bell into the circuit. and Magnetism, London, 1891.