Estimated Date: 1914
Name: Sphygmomanometer, Nicholson"Princo”
Manufacturer: Precision Thermometer and Instrument Co.
Description: Oak box, 7× 2.25× 1.5” which lifts lid to reveal manometer folded in half. Extends with metal scale to 260 mm Hg. The reservoir is at the side about 2 x .75. When the tube folds down a valve closes to prevent the loss of mercury. The base contains directions on a metal plate. A card in the box is signed by Percival Nicholson and is numbered 1578, Nicholsons new pocket sphymomanometer.
Reference 1: 401