The watchmakers document by Haefliger is a microscope for watchmakers. Herman Haefliger invented this horology microscope around 1920. The C-shaped base has small fittings to support the watch being repaired Haefliger obtained the microscope’s patent in May 1918.
Of interest is that before its invention, the instruments used to support the watch were separate from the microscope. This required adjusting the holding instruments and the microscope independently. Now, with this invention there was no longer any need for moving instruments around.
Horologists could use this as a way of supporting the watch and working on it all with the same instrument.