The “Master Wheel”
Accession Number: 2010.lej.23
A 11.5 cm slide rule; it is essentially a white envelope in which there is a circular sheet that can rotate, with the centre being the geometrical centre of the envelope. This slide rule is made of cardboard coated with plastic and has tiny screws for enclosing the circular scale within the envelope. The instructions for use and the special considerations to be given for different construction materials are all printed on the slide rule.
Primary Materials: Cardboard
Old Inventory Number = 23.
There is unintelligible writing on the top surface of the slide rude.
Height = 0.1, Width = 7.3, Length = 11.4
Function: For facilitating calculations.
Condition: Item is in very good condition.
The Master Builders Company, Cleveland, Buffalo, Toronto.
Date of Manufacture: c. 1930-1970