Magneto-electric machines like this were common in the second half of the 19th century.
These easy-to-use machines were sold to doctors and the general public as a cure for pain and many other ailments. They produce periodic pulses of alternating current (AC), which are applied to the body.
Early telephones used similar devices, which provided electric current to make them ring.
Made in Philadelphia
Made of wood, steel, brass, and wires