Zamboni’s “Perpetual electromotor” and its parts

The “perpetual electromotor” or Zamboni’s battery is made up of a series of superimposed discs, each with a diameter of 20-30 millimetres. The discs are made from a sheet of paper soaked in a zinc sulphate solution, left to dry and then coated on one side with very fine tinfoil and on the other with manganese dioxide mixed with honey to maintain a minimum level of humidity. The discs, connected to each other with wire, are inserted in sequence into a glass cylinder. The space between the discs and the glass is filled with melted wax and turpentine. The outside of the cylinder is coated with bituminous material to avoid losses of current. Two brass electrodes complete the battery, which is capable of attaining high voltages.
The inventories of the Museo Galileo (n. 390) indicate that this particular battery, now broken, was one of the two main components of a Zamboni’s machine, incorrectly referred to as an “electromotor.” In fact, the description reads: “Zamboni’s electromotor composed of two galvanic batteries inside glass tubes provided with glued ferrules. These batteries run along the base in a brass culisse [sic]. The needle is missing and a tube is smashed.”