Sphygmomanometer The rectangular wooden box contains a sphygmomanometer, a device used to measure blood pressure. The box opens by turning a metal button and unfolds to a 90-degree angle. Inside the lid, there is a white and black scale secured in a metal frame. The scale has two ranges: one from 0 to 260 and the other from 10 to 250. Between these scales is a glass tube with a red-ink mercury column that shows the blood pressure reading. The glass tube is connected to a metal and black plastic chamber, which links to a length of black India rubber tubing. This tubing connects to a black cotton fabric cuff, which is wrapped around the arm. There is also a pumping mechanism, likely a rubber bulb, that inflates the cuff. On the lid of the box, a metal plaque reads: "The Britometer Sphygmomanometer. Standard for Blood Pressure. Made in England." This device is a mercury sphygmomanometer, a reliable tool for measuring blood pressure, often used in the early to mid-20th century 1900-1975