Type 'B' articifical respirators are now shown. The patient is only partially enclosed. The next model is a Paul-Bragg pulsator; the chest is rhythmically subjected to positive pressure; the patient is not enclosed, instead he lies in an upright position. There are clear shots of the patient s chest rising and falling as well as the operation of the machine. Next a Burstall respirator is shown; the chest is rhythmically subjected to negative pressure. An unconscious and possibly paralysed youth is shown being fitted with what looks like a cross between medieval armour and something from Flash Gordon. Operation is by means of a foot pump.