Dudgeon sphygmograph by Mayer and Meltzer, in case, English Dudgeon sphygmograph by Mayer and Meltzer
Pachon sphygmomanometer by G. Boulitte, 15-21 rue Bobillot, Paris, France. Pachon sphygmomanometer by G. Boulitte
Dudgeon sphygmograph by Krohne and Sesemann, in case, English Dudgeon sphygmograph by Krohne and Sesemann 1870-1900
Early type of Richardson sphygmograph, in case, c.1883, English Early type of Richardson sphygmograph circa 1883