The Universal Shunt is a precision resistance bridge used with a galvanometer to monitor the insulation of early Telephone Lines and  Telegraph lines. This one was purchased in Lyon, France, similar units are documented in the USA, UK and Australia in the early 1900’s. 

It is nearly identical to the Model B in the 1907 Carpentier Catalogue with comparision resistance measured at 100.3k ohms and the Reduction Resistance as 10.04K Ohms across the galvanometer (individual resistances 9,040, 901, 90.5, 9.4 and 1.1 ohms measured with non- precision multimeter). The only slight difference is the earth (terre) leg not being marked on the line connection terminals. 

The photos also include french info from the 1907 catalogue and an english description of a Universal bridge . They are somewhat rare, but there are example in museums. A lovely scientific collectable.

I can ship internationally, though shipping to the USA seems much interrrupted by customs at the moment. 

The resistances are all intact and the switches work - albeit a bit stiffy. Looks great in timber, brass and some insulation material - perhaps bakelite. It is likely bigger than you think- Base measures 15.5cm square, height is about 15cm and weight is just over 1.6kg 

Message me if you want more information. 

Jules Carpentier was a student at the French École polytechnique. He bought the Ruhmkorff workshops in Paris when Heinrich Daniel Ruhmkorff died and made it a successful business for building electrical and magnetical devices. From 1890, he started to build photographic and cinematographic cameras. He is the designer of the submarine periscope, and worked at the adjustment of trichromic process of colour photography.He patented the "Cinématographe", which serves as a film projector and developer in the late 1890s, and built devices from the Lumière Brothers.