City Readers Digital Historic Collections at the New York Society Library

Stephen Hales (17 September 1677 – 4 January 1761) was an English clergyman who made major contributions to a range of scientific fields including botany, pneumatic chemistry and physiology. He was the first person to measure blood pressure. He also invented several devices, including a ventilator, a pneumatic trough and a surgical forceps for the removal of bladder stones. In addition to these achievements, he was a philanthropist and wrote a popular tract on alcoholic intemperance.