00232_5_Fig-4

Measurement of blood pressure by Stephen Hales. On the left: The original figure produced by Statham Medical Instruments, Inc. illustrating Experiment III of Stephen Hales measuring the blood pressure in the carotid artery of a 10-12 years old mare. On the right: The actual first Experiment in which Stephen Hales measured the blood pressure in the femoral artery of a 14 years old mare.