Franklin’s board, invented by the American scientist Benjamin Franklin (1706-1790), consists of a framed glass plate in the centre of which a thin sheet of tin foil is glued on each side.

One of the two foil plates is connected to the ground, and then the insulated side is placed in contact with one of the terminals of an electrostatic machine, resulting in the accumulation of charge on the foil.

After the panel has been disconnected from the electrical machine, the side connected to ground is touched with one of the contacts of the discharger 55ME; when the other pole of this is brought near to the isolated side of the panel, it is discharged with production of a spark.

Device on display.