Closed circuit respiration apparatus for measuring BMR, 1909. F.G. Benedict.
Taken from: The Development of Methods for Determining Basal Metabolism of Mankind Carpenter, Thorne M. The Ohio Journal of Science. v33 n5 (September, 1933), 297-314
A Godart Metabolic Testing System, circa 1980’s. Image from Mr. Kevin Hogben International. Sales and Product Specialist Manager for Medisoft