This object is part of a collection relating to the history and development of calculating devices assembled by Assoc Professor Allan Bromley of Sydney University, comprising mathematical instruments, slide-rules, mechanical and electronic calculators, electronic analogue computers, computer components, kit computers, education computers, and associated ephemera.

Allan Bromley was a lecturer and researcher at the University of Sydney Basser Department of Computer Science from 1978 until his untimely death in August 2002. He specialised in Computer Architecture, Computer Logic and in particular the History of Computing. He was regarded as the world authority on Charles Babbage's Calculating Engines (instigating the building of the Difference Engine No.2 at the Science Museum London) and the Ankithera Mechanism and had extensive knowledge of calculators, analogue computers, logic, stereopsis, totalisators, clocks and time keeping and mechanical engineering.

Part of the Bromley collection

Proportional dividers with case and instruction sheet, metal / paper / leatherette, made by Staedtler, Germany, 1950-1970

Staedtler proportional dividers are a pair of metal sliding pointers with decimal scaling joined by a knurled knob scale-slide clamp which locks the angle and the proportional scale between the pointers. Each pointer has a compass point at either end. In blue velvet (corduroy) lined leatherette case, with instruction sheet.

They are used to transfer dimensions from one scale to another in drawing charts and plans.

Made: 1950 - 1970

Staedtler brand on leatherette case, scales on each pointer.

2010/1/166

1950 - 1970