Richardson sphygmograph (modified Dudgeon) c.1906, in case Richardson sphygmograph (modified Dudgeon) c.1906 1901-1910
Early type of Richardson sphygmograph, in case, c.1883, English Early type of Richardson sphygmograph circa 1883
Part of a Sphygmograph(?) gilt brass and nickel plated brass with rubber drum, French, 1880-1920 Part of a Sphygmograph(?) gilt brass and nickel pl 1880-1920
Dudgeon sphygmograph by Krohne and Sesemann, in case, English Dudgeon sphygmograph by Krohne and Sesemann 1870-1900
Dudgeon sphygmograph by Mayer and Meltzer, in case, English Dudgeon sphygmograph by Mayer and Meltzer