The “Master Wheel”

L. E. Jones

Accession Number: 2010.lej.23


A 11.5 cm slide rule; Essentially a white envelope in which a circular sheet of 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. Markings: There is unintelligible writing on the top surface of the slide rude.

Alternative Name:

Primary Materials: Cardboard

Markings: Old Inventory Number = 23.

Dimensions (cm):

Length = 11.4 cm, Width = 7.3 cm, Height = 0.1

Function: Facilitating calculations.

Condition: Item is in very good condition.

Associated Instruments:


The Master Builders Company, Cleveland, Buffalo, Toronto.

Date of Manufacture: c. 1930-1970


Donated to UTSIC: No

Historical Notes: