Large sliding compass (grand compass a glissiere) for the measurement of the foot, the middle and little finger and the elbow in Bertillon's anthropometrical criminal identification system, perhaps Bertillon's own, from the Identification Bureau of the Paris Prefecture of Police, c. 1883

The Bertillon system for criminal identification used this large sliding compass to measure the foot, the middle and little finger, and the elbow. French criminologist Alphonse Bertillon (1853–1914) developed an identification system called anthropometrics. It recorded detailed physical measurements to identify individuals. Bertillon used the compass and other tools to measure height, head circumference, arm length, leg length, and even finger lengths. His system was used to identify suspects in criminal cases. The system was extremely popular in France, leading to many convictions. It was superseded by more accurate and less labour-intensive fingerprinting. Bertillon pioneered many modern forensics techniques such as the ‘mug shot’, which is the standardised photography of criminals.