1. A new form of piston recorder and some of the changes of the volume of the finger which it records Author(s): Lombard, Warren P. (Warren Plimpton), 1855-1939, authorPillsbury, W. B. (Walter Bowers), 1872-1960, author Publication: [Bethesda, MD] : [publisher not identified], [1899] Subject(s): Plethysmography -- instrumentationBlood Pressure MonitorsBlood Pressure -- physiologyHeart Rate -- physiologyMonitoring, Physiologic -- methodsEquipment and Supplies