Life indicator for coffins patent, 1882. Artwork of a device designed by John Krichbaum to save a person accidentally buried alive. The person would rotate a set of handles connected to a periscope like device while a dial visible above the surface revealed the movement. A more forceful upwards push allowed air to enter the coffin. Such 'safety coffins' were a common invention at the time owing to a fear of unintentional live burial. There are no known reports of such devices actually saving an accidentally buried person.