 Whitehead, in subsequent letters to his son North in 1924 and 1925, writes of Barr's struggles to sell the design for one of his calculating machines to an unnamed large American company.In the 1925 letter, Whitehead writes that Barr's son Stephen was staying with him while Barr and his wife Mabel visited Elyria, Ohio to oversee a test build of the device.However, by 1927 Barr and Whitehead had fallen out, Whitehead writing to North (amid much complaint about Barr's character) that he was "very doubtful whether he will keep his post at the business school here";
Barr was a "research assistant in finance" at Harvard Business School around this time.