Unusual instrument

Joe, for your list in eqtemp.htm:

"1876: Koenig's Tonametric was invented. This instrument divided four
octaves into 670 equal parts - this was an early instrument that made
use of microtuning." From http://www.elektronik.co.uk/hist-elek.htm

The 335th root of 4 has very good approximations to 3/2, 5/4, 7/4 and
11/8. Does anyone know how the Tonametric worked?

Manuel