"Gaiffe Induction Coil"
Signed "A[dolphe] G[aiffe]", 19th century, wood and brass, wire spool. Portable induction device with a moving coil on an arch-shaped slide allowing the desired voltage to be adjusted. Used in conjunction with a battery, it was used for electrotherapy.
Bears on its base the intertwined initials "AG" for Ladislas Adolphe Gaiffe ((1830-1903) and the number 143316.
Nice demonstration model for a physics cabinet.