When Cambridge University established the Science Tripos in there were no facilities for making apparatus in Cambridge. To meet their requirements for apparatus, the research and teaching staff had to manage as best they could by making their own. The workshop attached to the Department of Mechanism began to make apparatus in 1878 and soon after the Cavendish Laboratory of Physics established its own facilities. It was from this workshop that a mechanic named Robert Fulcher left to set up his own scientific instrument making business, taking advantage of the increasing demand by the University for apparatus. However his design abilities were somewhat limited and Horace Darwin, the youngest surviving son of Charles Darwin the botanist began to take an interest in the firm. Eventually in 1881 Darwin purchased the business in partnership with his friend Dew-Smith so founding the Cambridge Scientific Instrument Company.
An example of an instrument from this period is the 1884/85 rocking microtome seen at the museum, together with a later version of the instrument of the 1950s. It was one of Darwin's successful designs that continued to be manufactured until the 1970s.

Very few scientific instruments were used in industry at that time and Darwin saw this as an area in which to expand. His first successful instrument for industrial use, which he acquired sole manufacturing rights was the Callendar resistance thermometer, soon to be followed by the Callendar recorder in 1898.

In 1958 the company embarked on a completely new product the electron probe microanalyser, the highly successful Microscan. It was totally different to anything that had been made previously and many new skills had to be learned. One from the first batch made dating from 1961 is on display in the corner of the Electric Room. The purpose of this instrument was for the non-destructive determination of the elements within a very small area of a specimen. Although originally designed for metallurgical and mineralogical specimens it was later to be used by chemists and biologists.
This was soon followed by another electron probe instrument, the scanning electron microscope, originally developed by Professor Oakley with his team at Cambridge University Engineering Department, further developed into the worlds first commercial instrument by Cambridge Instruments. The first of a very successful range of instruments known as the Stereoscan was completed in 1964 followed by exports all over the world and inevitably to be copied. The transmission electron microscope was well established but suffered from the limitation that the specimen had to be very thin. The advantage of the scanning electron probe microscope was that solid specimens could be examined.

In 1968 the company was sold to George Kent and since the merger it was organised into four divisions, each being eventually separately sold off. Many ex-company employees either founded other well-known companies or gained important positions in them. William T. Pye, who had joined as foreman in 1880 left in 1898 to form the W.G. Pye Instrument Company with his son, ultimately to branch out into Pye Radio. Charles Foster, a chief draughtsman formed the Foster Instrument Company, E. I. Everett joined with Edgecombe to form Everett Edgecome Ltd, George Whipple who worked at Muswell Hill became Managing Director of E. R. Watts & Son and S.W.J.Stubbens, a foreman formed Unicam Instruments Ltd to name a few examples.