From Wilmore JH, Davis JA, Norton AC. An automated system for assessing metabolic and respiratory function during exercise. J Appl Physiol 1976; 40(6): 619-624.
Wood cabinet with drawer in front to hold accessories. Top right side has compartment to hold oxygen tank. Control panel is metal. Has two breathing tubes ending in mouthpiece. Clear covered carbon dioxide exhalation chamber for bucket of “metabolime.” Readout recorder with original paper. Dials, light, and switches.
Described in text as a 30 liter recording spirometer. From: Boothby WM. The determination of the circulation rate in man at rest and in work. Amer J Physiol, 1915, v37, p383.