The iron lung. The following legends accompanied the original figures: (A) Mechanical respirator, showing tank with pump mechanism connected by flexible tube at foot end. The collar and head rest are in place and the patient is ready to be pushed into the tank. (B) A patient in the respirator. Note the position of the portholes. Attendant has his hands on the dial of the thermostat which controls the temperature and humidity of the air in the tank. Reprinted from ref. 51.