French, c.1910, signed on case 'G. Boulitte Ingr. Constructeur 15.21 R.Bobillot. Paris 13', in nickel plated brass,, case 12.5cm across.

Note: The earliest and simplest version of Jaquet’s Sphygmograph. A dial adjusts the tension in a spring connected to the manometer which allows the user to vary the pressure on the radial artery. In addition to the main needle recording the pulse there is a second needle used to calibrate time. The clockwork mechanism is wound by the front dial and can be engaged and disengaged from the paper roller by a switch at the side.