The Cambridge Scientific Instrument Company has its origins in a workshop set up in 1878 by James Stuart (1843-1913), the first Professor of Mechanism and Applied Mechanics at Cambridge. The workshop made equipment for his research and instruments for colleagues in other departments. Stuart’s chief mechanic was Robert Fulcher (1845-1916) but within a year, he left to set up his own instrument-making business in partnership with Albert George Dew-Smith (1848-1903), a physiologist and lens maker, in a workshop on Panton Street. Some of the instruments Fulcher made were designed by engineer Horace Darwin (1851-1928). When Fulcher left the business at the end of 1880, Darwin went into partnership with Dew-Smith to form the Cambridge Scientific Instrument Company on 1 January 1881.

Darwin and Dew-Smith divided the work whilst the Company was becoming established; Dew-Smith corresponding with the customers and Darwin taking charge of the design and manufacture of the instruments. Most of the early instruments made by the Company were for physiological or biological research as this was where the demand lay. By early 1882 the Company had outgrown its premises on Panton Street and on 25 March 1882 moved to a new workshop in St. Tibb’s Row.

Dew-Smith was a man of independent wealth and he financed the founding of The Journal of Physiology in 1878. Before long, in order to provide the journal with adequate illustrations, the Scientific Instrument Company, under Dew-Smith's direction, undertook lithographic and other similar work. In 1890 the partnership between Dew-Smith and Darwin was dissolved; Dew-Smith, however, retained the lithography and photography side of the business.

Darwin was a skilled designer and developed many instruments for the Company. One of his early outstanding products was a rocking microtome, which cut biological materials into thin slices for examination under a microscope. Darwin’s design in 1885 was not the first microtome, but it improved earlier models due to its simplicity, accuracy, and robustness. Its simplicity meant it could be produced for a fraction of the price and its excellent design ensured that it remained relatively unchanged until the 1970s. Darwin also worked closely with scientists, who designed new instruments for the Company to make. Research into new instruments increased in the 1890s, so the business once again outgrew its premises and in 1895 moved into a purpose-built workshop on the corner of Carlyle Road and Chesterton Road.

Robert Stewart Whipple (1871-1953) joined the Company in 1898, becoming Company Secretary. As well as designing instruments (he became an authority on temperature-measuring equipment), he helped introduce new ways of working: setting profit targets, broadening the product range to include instruments for use in industry, and encouraging larger-scale production. Whipple became a Director in 1905 and Joint Managing Director in 1909.

Following the start of the First World War, the Company was made a ‘controlled factory’ in July 1915, meaning it could only do government-approved work. It designed and made instruments for the military and munitions factories for the remainder of the war. In order to keep up with increased production, the Company built new workshops and hired women to replace serving men, many of whom remained with the Company following the end of the war.

In 1919 the Company took over R. W. Paul Instrument Company and its London factory in Muswell Hill and changed its name to Cambridge and Paul Instrument Company, before shortening it to Cambridge Instrument Company in 1924. The Company also opened a Head Office at 45 Grosvenor Place, London in 1919.  

In 1922 an associated American Company was formed, trading as The Cambridge Instrument Company, Inc. 

During the Second World War, the Company once again made equipment for the war effort before returning to the manufacture of industrial equipment and development of new instruments for peacetime industries at home and abroad. To meet increased demand, the Company expanded its workshops and bought a factory in Finchley, London which became the production centre for mechanical thermometers and pressure gauges.

In 1959 the Company built a new research block on Chesterton Road and was making over 2000 different instruments at this time. However, the Company lacked sufficient resources to research and develop new products. To overcome this deficit, the new Managing Director Harold Pritchard (appointed in 1958) encouraged the Company to buy the rights to make innovative products that had been invented outside of the Company rather than solely relying on developing instruments in-house. In particular, Pritchard wanted something large that used new technology to reinvigorate the Company and modernise its image.

A collaboration between the University of Cambridge Cavendish Laboratory and Tube Investments Research Laboratories produced the Microscan in 1960, an instrument capable of analysing the structure and composition of materials on a microscopic scale. It was an immediate success and partly responsible for the Company’s record export turnover in 1960, which was 47% higher than the previous year. Customers included atomic energy authorities, steel companies, and research laboratories. The Microscan was replaced in 1964 by the Geoscan which had wider use and was used to examine the first moon rocks brought back by Apollo 11. In December 1965 the Stereoscan was officially launched. It produced stereoscopic or 3D images and was the first commercial scanning electron microscope in the world. The Company won a Queen’s Award for Industry ‘for technological innovation in a scanning electron microscope’ in 1967. The Company expanded in the 1960s by taking over other scientific instrument makers but in 1968 the firm merged with leading instrument maker George Kent Ltd. The merger signalled the end of the Company in its original form.

At the time of the merger, the Cambridge Instrument Company was organised into four divisions:
- Cambridge Industrial Instruments Limited (instruments for industrial applications)
- Cambridge Scientific Instruments Limited (scientific and medical instruments)
- Electronic Instruments Limited (analytical instruments)
- H. W. Sullivan Limited (instruments for precise electrical measurement)
Following the merger with George Kent, these divisions were subject to further mergers and buyouts and by 1985 all had been sold or wound up.