Sphygmometer made in France, around 1900 by Collin, a well known French instrument maker. Sphygmometers such as this one were used to demonstrate arterial blood pressure using an aneroid manometer which was placed vertically over the patient's wrist (at the radial pulse). It is made from nickel with a rubber end. This design is known as the Cruise sphygmometer having been invented by Sir Francis Richard Cruise (1834-1912), a pioneering Irish surgeon who also invented the endoscope.