CURIOSIDADES DO ARQUIVO EPHEMERA – MÁQUINA ELECTROMAGNÉTICA DE DAVIS E KIDDER
NATIONAL MUSEUM OF AMERICAN HISTORY Davis & Kidder medical magneto machine. Wooden box with brass corners and ivory handle. A vertically-mounted horseshoe magnet with two electromagnet coils set next to the magnet ends. A geared mechanism connected to the coils is actuated by a crank that extends through the […]