Bloch sphygmometer in its case dating from 1880. It was made in France by Charles Verdin. This was a compression device used for blood pressure measurement. The physician would place his finger over the patient's pulse and with his other hand, the metal sphygmometer would be held at 45 degrees with the receiver end (a cork cushion) placed on his fingernail. Force would be applied down the length of the instrument onto the fingernail until the pulse could no longer be felt. A spring dial would register the level of pressure required to stop the pulse on a numbered scale. This number would indicate the patient's blood pressure. The Bloch sphygmometer was soon replaced by more accurate instruments.