# Mark Barr

James Mark McGinnis Barr (May 18, 1871 – December 15, 1950) 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, including calculating machines.