Whythe-Fuller complex-number slide rule
Object No. 2020/7/1-1
The slide rule is a type of mechanical analogue computer which represents an important era in the development of technology before the advent of pocket calculators and digital computers. Slide rules enabled the simple computation of numerous difficult mathematical problems, including trigonometry and logarithms, but were primarily used for computation of large multiplication and division equations. Slide rules were common tools for surveyors, engineers and architects up until the 1970s when pocket calculators began to dominate. This is a complex-number slide rule, designed for multiplication and division of numbers of the complex-number plane. There were different models of complex slide rules, however, this model was a special Fuller (cylindrical-helical) slide rule designed by D.J. Whythe in 1960. This slide rule is believed to be the last Fuller-style model manufactured by W.F. Stanley. It retailed at £21 in a 1962 W. F. Stanley catalogue, which was a considerable amount at the time. It unknown exactly how many were manufactured and sold, but its time and success on the market was short-lived as more powerful and accurate electronic calculators became increasingly available. Thus, this complex-number slide rule remains a rare model, in excellent condition, of the latest technology that preceded the introduction of next-generation computing devices. This specific instrument was imported and sold by Esdaile & Sons, one of the oldest Australian scientific instrument manufacturers and retailers, and used at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) to assist industry professionals with complex computations, before its eventual replacement by more sophisticated computing technology. As well as demonstrating the development of technology, it therefore helps to document the way in which science was carried out in Australia in the mid-twentieth century. Erica Balilo, Curatorial Intern Supervised by Sarah Reeves, Assistant Curator, 2018 References: Harry Henderson, Encyclopedia of Computer Science and Technology (revised edition), Facts On File, Inc., 2009, pp 13-14. Aristotle Tympas, Calculation and Computation in the Pre-electronic Era: The Mechanical and Electrical Ages, Springer-Verlag- London Ltd, 2017, pp 68.
Loading...
Summary
Object Statement
Complex-number slide rule, metal / paper / plastic, made by W F Stanley & Limited, New Eltham, England, retailed by Esdaile & Sons Pty Ltd, Glebe, New South Wales, Australia, c. 1960
Physical Description
A complex slide rule, made by W.F. Stanley & Company Limited, contained in a mahogany box with a holding bracket. The complex-number-slide rule is made of three cylinders. An inner cylinder can be extended out and rotated from within a larger fixed cylinder and wrapped around the fixed cylinder is a smaller moveable 6-inch cylinder on which complex-numbers are engraved. The surface area of the cylinder is divided into four equal regions which represent the four quadrants of the Argand complex-number plane. To aid the user, the corresponding quadrant of the complex-number Argand diagram is shaded above each region. Attached to bottom of the fixed cylinder and top of the inner cylinder are two transparent cursors. The top inner cylinder cursor can be rotated around for mechanical computation. There is also an angled metal holding bracket in the box. It functions as an adaptor which can be inserted into the end of the box and the slide rule handle, thus enabling the box to be used as a stand to facilitate calculations.
PRODUCTION
Notes
The Whythe-Fuller complex slide rule was designed by D.J. Whythe based on the cylindrical models created by American civil engineering professor George Fuller. The slide rule was later marketed and manufactured by British company W.F. Stanley & Co Ltd. in London from 1961. The general design of the slide rule was to facilitate the rapid computation of multiplication and division of numbers of the complex-number plane. The complex-numbers are plotted on a plane and engraved onto the cylinder. One transparent plastic cursor is attached to the inner tube which can be extended and rotated about the fixed cylinder to which the handle and other cursor remain attached. The complex-numbers for multiplication or division are plotted on the movable cylinder and can be used to multiply and divide complex-numbers. Computations using the complex-number slide rule could be completed with the same level of ease and accuracy as the calculation with a conventional slide rule of real numbers. As with conventional slide rules, the position of the decimal point must be estimated upon inspection. This slide rule was retailed in Sydney, Australia by renowned opticians and instrument manufacturer and retailer, Esdaile & Sons Pty. Ltd., a subsidiary of Esdaile (Holdings) Ltd formed in 1953. Although many of the scientific instruments were imported from Europe, America and Asia, the Esdaile company was involved in special purpose manufacture, particularly important to Australia during the Second World War. The firm was originally located at 42 Hunter Street, Sydney but moved operations to Glebe in 1962. Esdaile (Holdings) was then subject to a takeover by Watson Victor Holdings Limited in 1971. Consequently, this particular complex slide rule was likely distributed and sold between 1961-1971. References: Edwin Chamberlain, 'Slide Rule Decimal Point Location Methods', The Journal of the Oughtred Society, 7(1), 1998, pp 38-52. Marie Fielder, 'Fielder Instrument Co. The final chapter: A short history of surveying instrument companies in NSW', Azimuth: The NSW Surveyor's Monthly Magazine, 51(4), 2012, pp 279-311. Robert J. MacG. Dawson, 'What is it?', The Mathematical Intelligencer, 31(2), 2009, pp 57-58. D.J. Whythe, 'The Whythe Complex Slide Rule in Fuller Style', The Journal of the Oughtred Society, 8(1), 1999, pp 15-17.
HISTORY
Notes
Slide rule instruments were produced between the late 17th and mid-20th centuries to perform mathematical computations. The early slide rule was a circular and first developed in 1630 by William Oughtred after the publication of John Napier's work on logarithms. Although slide rules were being used in the mid-17th century, they were not widely used until they took a more modern form in the late 1950s and became widely used in Europe by those in the growing science and engineering professions. With the emergence of more expensive special slide rules in the early to mid-1900s, many people did not completely abandon the use of the conventional slide rules but instead made conversions and adjustments for complex equations. Created in 1960, this slide rule model soon became obsolete with the introduction of electronic calculators in the 1970s. Therefore, despite the centuries-long history of slide rule calculation, the manufacture and use of Whythe-Fuller style slide rules spanned less than two decades. This complex slide rule was previously used by individuals working at the CSIRO and was donated by former employee, Dr David Hollway, after the organisation discontinued use of the complex-number slide rule in its research in favour of newer technologies. References: Robert J. MacG. Dawson, 'What is it?', The Mathematical Intelligencer, 31(2), 2009, pp 57-58. The Editors of Encyclopaedia Britannica, 'Slide Rule', Encyclopedia Britannica, britannical.com/science. Accessed July 20 2018.
SOURCE
Acquisition Date
17 January 2020
Copyright for the above image is held by the Powerhouse and may be subject to third-party copyright restrictions. Please submit an Image Licensing Enquiry for information regarding reproduction, copyright and fees. Text is released under Attribution-Non Commercial-No Derivative licence.
Image Licensing Enquiry
Object Enquiry