Assistant secretary to the then newly formed Royal Society of Arts in London from January 1756. In 1757 he was made secretary, and it has been written of him that "he was a most efficient and competent official. He served the Society faithfully for twenty-five years, and such records of him as appear from time to time in the minutes show that he was entirely trustworthy and possessed the regard and confidence of the members."1 He served the society in various positions until he retired from failing health in 1779.2
Boswell called on Mr. Box in London on November 28, 1762, to get out of having to pay for his membership of the Society of Arts. He successfully argued that, as he had been in Scotland since his admittance to the society in 1760, he might as well never have been a member, and therefore should not pay anything. He described Box as "a very civil man". He also thought that Mr. Box, being the collector of the society, was "admirably named".