SCHALL & SONS MEDICAL COIL WITH GLASS TOOLS, 1920's

A1201 Schall & Sons Medical Coil with Glass Tools 1920's

Also known as 'Ultra Violet' machines due to the Violet glow of the electrodes. These were used for skin complaints , similar to the modern 'Tens' machine.
The principal of Magnetic induction was first discovered by Michael Faraday (1791-1867) in 1831. This was later used in machines like this for medical complaints such as skin disorders, and to power X ray machines. Marconi used a large induction coil for his transmitter system at Poldhu in Cornwall for the first transatlantic transmission

They work by two coils, one with a smaller number of turns but of greater size of wire, surrounded by another of much greater turns but of smaller diameter wire, inside the centre winding is a core of iron at the end of which is a piece of metal, attached to a make and break contact which interrupts the supply to the centre winding, exactly as in an electric bell. The result is an transfer of power from the centre winding to the outer, with a proportional change in voltage to the number of turns, i.e from a small voltage you can create a very high voltage, but at much lower current.

Bruce Hammond Collection

A1201