A Vincent Mechanical Models Test, including a test diagram booklet, in a black wooden box, by the National Institute of Industrial Pyschology, London, 1920-1950. A Vincent Mechanical Models Test 1920-1950
A machine tool operator's test with writing implement missing. No maker marked. 1920-1939. Also an envelope of forms labelled 'Rheinisches Provinxial Institut für Arbeitsund Berufsfurshung, Düsseldorf'. A machine tool operator's test with writing implement missing 1920-1939
An Osram machine feeder's test, a 'ball dropper' with red cotton bag of marbles of two different diameters, and a pencilled sketch, probably made at NIIP, 1920-1940. (Possibly BPS Inv. No. 0081a.) An Osram machine feeder's test 1920-1940