The Brown Instrument Company developed, manufactured, and sold industrial controls and measuring instruments, such as thermometers, pressure gauges, voltmeters, and pyrometers. The company was founded in 1857 by an English engineer and inventor, Edward Brown (1834-1905).

In the late 1850's Brown immigrated to Philadelphia, bringing with him his knowledge of kilns, foundries, and the high temperatures involved in both. Edward Brown invented the first pyrometer (carbon-rod pyrometer) in 1869, based on differential expansion of iron and graphite rods. Until that time there had been no accurate way to measure the high temperatures in kilns and foundries. The pyrometer made it possible to measure these high temperatures that ordinary thermometers could not measure. This was important because it made it possible to set accurately the optimal temperatures for forging quality iron and steel, thereby reducing the amount of flawed iron and steel produced.

The business that would evolve into the Brown Instrument Company began in the mid-nineteenth century. According to the Philadelphia Directory, Edward Brown was listed as an engineer and patent agent in 1867. In 1873, he was listed as a solicitor of patents and his business was established in 1860. His 1880 listing had him with the United States & Foreign Patent Office, along with an advertisement that he sold pyrometers, scotch glass tubes, and steam gauges. By 1889, Edward Brown was no longer listed as a patent agent, and was advertising his instruments exclusively.

Edward Brown's son, Richard P. Brown (1884-1976), took over the business after his father's death in 1905. The Philadelphia Directory for 1906 lists the business as Edward Brown & Son. The Brown Instrument Company was established on April 19, 1910, with Richard Brown as president (for one year, 1918, the company was listed as Brown Instrument Co. & Keystone Electrical Instrument Co., but by 1919 it was listed again as only Brown Instrument Company). The purpose of the company was to manufacture electrical measuring instruments. The company became one of America's largest producers of industrial thermometers and thermostats, providing large steel companies with the means of regulating the high temperatures of their blast furnaces. By 1934, the company held a large number of instrument patents, was a producer of about five-hundred instrument products, employed five-hundred workers, and brought in annual revenues of about two million dollars. The company's success as a worldwide leader in industrial controls and indicators made it an attractive possible acquisition for other companies.

Willard L. Huff (1889-1968), treasurer of Minneapolis-Honeywell Regulator Company, happened by chance to be seated next to Richard Brown on a train to New York after a National Recovery Act meeting in Washington DC During the course of casual conversation they began to discuss the similarities between their respective companies. Brown was the maker of the best recording, indicating, and controlling instruments but did not make the valves and accessories needed for complete instrumentation. Minneapolis-Honeywell did make these valves and accessories. Brown and Huff realized that their companies were a natural fit and soon after entered into negotiations. In 1934 Minneapolis-Honeywell bought Brown Instrument's assets for $2.3 million, becoming one of several acquisitions Minneapolis-Honeywell made in the area of industrial process controls.

Minneapolis-Honeywell was also interested in Brown Instrument Company because they provided another opportunity for expansion into the global market. In 1930 Minneapolis-Honeywell established a subsidiary in Toronto, Canada where, since 1915, small inroads had been made with distributors for Minneapolis Heat Regulator Company thermostats. In the same year that they bought Brown Instrument Company, Minneapolis-Honeywell had opened its first European subsidiary in Amsterdam, and in 1936 they established one in England as well. Brown Instrument Company gave Minneapolis-Honeywell an opportunity to enter the Pacific Rim.

Brown had a close relationship with Yamatake Corporation of Tokyo, Japan. This Japanese company was distributing Brown products by 1920, and after the merger with Minneapolis-Honeywell, the relationship was expanded to include that companies commercial and residential heating controls. Yamatake-Honeywell was a 50-50 venture, but was pared down to 20% for Honeywell by the 1990's, and both companies would continue to benefit from technical cooperation.

World War II disrupted this new global expansion. In the Netherlands, their employee numbers were reduced to five, three of which were in hiding and could not hold jobs. Communications with Yamatake were severed. The owner, Takehiko Yamaguchi, continued with production, keeping track of royalties owed to Honeywell. At the end of the War Yamaguchi sent his son to Honeywell to give an accounting of the business during the war years. With much of the factory destroyed, Yamatake would have trouble paying the debt. Honeywell helped them reorganize, rebuild, and establish a presence in the Orient. The post war rebuilding was a boom for Honeywell's international business as factories were built throughout Europe and Asia. In this time of industrial growth, technologies centered on industrial controls would become important.

After their merger with Minneapolis-Honeywell Regulator Company, Brown Instrument began to develop control systems capable of measuring and adjusting the temperature, pressure, and flow rates of various liquids and gases. These developments were particularly important to the oil and chemical industries. Just prior to World War II, Brown developed electromechanical devices, which contributed to the automation of factories.

After World War II, Brown began to experiment with remote control devices similar to those developed at M.I.T.'s Servomechanisms Laboratory. According to reports from M.I.T.'s Lincoln Laboratory, during the 1950s, Brown began to use modern concepts of control engineering originally developed through research on guided missiles. With the 1950's came the rise of computers, and Brown began to use analog computers to develop control systems more powerful than the previous electromechanical systems. These systems could perform all calculations automatically and aided continuous process industries, such as oil and chemical, by automatically controlling liquids and gasses as they flowed through pipes and membranes.

In the late 1940s and early 1950s, Brown Instrument Company worked closely with IBM, who was also promoting industrial automation through its Industrial Computation Seminar, to develop automated systems for companies such as Sun Oil, DuPont, and Texaco. By the mid-fifties, Brown was working with Procter and Gamble, Sun, Standard Oil, Seagram, General Electric, Shell, and the Atomic Energy Commission to install systems capable of supervising an entire factory by analog computer.

In a 1988 pamphlet, Honeywell asserted that the legacy of Brown Instrument lived on with the 1975 development of TDC 2000, a digital process management system incorporating microprocessors. In 1983, TDC 3000 integrated all aspects of plant function, linking process equipment, control subsystems, and computers to a high-speed communications network. In summary, Brown Instrument Company had a major impact on the development of modern industrial production. From invention of the pyrometer to the advent of sophisticated measurement and control systems, Brown Instrument was instrumental in the creation of modern industrial automation.

The Brown Instrument name survived until 1949, at which point it became Philadelphia Division. On many of the engineering reports in the collection, the company is referred to as the Brown Instrument Division. Later it became the Process Control Division of Honeywell, Inc., located in Fort Washington, Pennsylvania. (Honeywell, Inc. became the official name in 1963, replacing Minneapolis-Honeywell Regulator Company). Today it is the Industrial Automation & Control Division (IAC) located in Phoenix, Arizona.