Black and white negative of a Pall and Co. machine. Negative missing.

Black and white negative for Shell Oil. Negative missing.

Black and white negative close-up of an Industrial Staff member. Negative missing.

Black and white negative close-up of an Industrial Staff member. Negative missing.

Black and white negative close-up of an Industrial Staff member. Negative missing.

Black and white negative close-up of an Industrial Staff member. Negative missing.

Black and white negative close-up of an Industrial Staff member. Negative missing.

Black and white negative close-up of an Industrial Staff member. Negative missing.