Physical description

Black and white photograph of a drawing of a portable drawover apparatus. There are two vaporisers with metal valves, one made of glass, connected to the ends of two corrugated tubes which are connected to a face mask at the other ends. A small rebreathing bag is connected to the underside of one of the vaporisers.

Inscriptions & markings

Handwritten in black ink on surface of photograph the letters A - H, J, labelling each part of the apparatus.