Category: Sphygmograph
Estimated Date: 1910
Name: Sphygmograph
Manufacturer: Maw son and son

Description: 3.5” x 1.5” x 1.75” black paper covered box containing 2.5” x 3/4” x 3/4” metal sphymograph, which completely collapes into the box. The stylus can be activated by lifting a metal holder and pulling out a rod on the bottom. It is wound by turning a knob on the top and turned on with a lever.

Reference 1: 37

Sphygmograph, Dudgeons
Mackenzie polygraph
MacKenzie-Lewis Polygraph
Jacquet Sphygmograph