Found on the Francis A. Countway Library of Medicine website. Warren Anatomical Museum Catalog Number: 21643.  This wedge Krogh spirometer was manufactured by the Doelcam Corporation between 1950 and 1980 and was used in conjunction with experimental whole plethysmograph (WAM 21595) for respiration research in the Department of Physiology at the Harvard School of Public Health. It was donated to the Warren Anatomical Museum by Dr. Stephen H. Loring in December 2015.  53 W x 56 D x 22 H cm.