Soufléto used his own version of the English “grasshopper” action, invented by John Geib. The jack is attached to the key by a rocker. Since the back check is following the arc of the key (moving toward the front of the key), the catcher needs to be inverted from the modern design, where the check is attached to the wippen.Escapement is effected by the movement of the jack regulating button against a slanted surface. A variant of this principle (with the regulation button extending toward an angled face on the jack from the hammer rail) was used for many years, before being replaced by the current style of jack in the shape of an “L,” with the tender hitting against an adjustable escapement button. Note the adjustable flange for the hammer butt, which allows for tightening or loosening the action center. It also allows the butt to be removed with the flange remaining in place.
