Category: Pulse
Estimated Date: 1905
Name: Mackenzie polygraph
Manufacturer: Mr. S. Shaw

Description: 10×6×3.5 leather covered case with blue velvet lining contains complete polygraph including, motor-timer, 2 venous pulse, 1 arterial pulse, two pen mounts, extra paper with tracings, ink, extra pen mount. The motor measures 3.5“x3“x2 “and the pen mount on an arm 4.5” with 4.5” pens. Pens are activated pneumatically on ruber diaphragms. Tubing to connect pens to detectors is missing.

Reference 1: 129