[Milsurplus] How does it work?

[J. Forster]

I picked up a 'Magnetic Rectifier' at a ham flea market today, made in about the
1930s by the French Company in Cleveland.

It is NOT:   http://geoffegel.tripod.com/rect.htm

It has a transformer wound on a core of iron wires with a 110 VAC primary and a
6 VAC secondary with a center tap. There is also a horse shoe magnet, vibrating
reed and two contacts with carbon brushes.

Anyone wanna guess how it works?

-John