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, stereoscopy, totalisators, clocks and time keeping and mechanical engineering.

Circular slide rule watch with packaging, Boucher type, metal / glass / cardboard box, Research Institute for Control Equipment, Moscow, USSR, 1960-1970.

Circular sliderule. Soviet KL-1, Russian manufacture : MATSKM ?

Boucher's style, double sided circular sliderule, with scale in radians on front and long (spiral) scale on reverse. In yellow card box. This is a pocket watch sized, double-sided circular slide rule with a glass face. On the front side there are the two log scales of a standard slide rule. On the reverse side there is a spiral inner tangent scale, a sine scale and an outer log scale. The "sliding" disks are rotated around the fixed disks by a knurled knob and there is another knob to wind the cursors.

Made: 1960 - 1970

Scales and signature style name: MATSKM

2010/1/200

1960 - 1970

50 mm