Mark Barr

James Mark McGinnis Barr (May 18, 1871, Pennsylvania – December 15, 1950, The Bronx) was an electrical engineer, physicist, inventor, and polymath known for proposing the standard notation for the golden ratio. Born in America, but with English citizenship, Barr lived in both London and New York City at different times of his life.

Though remembered primarily for his contributions to abstract mathematics, Barr put much of his efforts over the years into the design of machines, and especially calculating machines. He won a gold medal at the 1900 Paris Exposition Universelle for an extremely accurate engraving machine.

Barr was the son of Charles B. Barr and Ann M'Ginnis. He was educated in London, then worked for the Westinghouse Electric Company in Pittsburgh from 1887 to 1890 as a "draughtsman, laboratory assistant and erection engineer". From 1890 to 1892 he worked in New York City at the journal Electrical World as an assistant editor, at the same time studying chemistry at the New York City College of Technology. Possibly it was during this time, and certainly before 1900, that he worked with both Nikola Tesla and Mihajlo Pupin in New York; he was notorious among acquaintances for his low opinion of Thomas Edison. Returning to London in 1892, he studied physics and electrical engineering at the City and Guilds of London Technical College until 1895, and later became a Fellow of the City and Guilds Institute (F.C.G.I.)

From 1896 to 1900 he worked for Linotype in England, and from 1900 to 1904 he worked as a technical advisor to Trevor Williams in London. Beginning in 1902, he was elected to the Small Screw Gauge Committee of the British Association for the Advancement of Science. The committee was set up to put into practice the system of British Association screw threads, which had been settled on but not implemented in 1884. More broadly, it considered "standardisation of engineering materials, tools, and machinery".

...
Wikipedia