Letts's Diary No 1, 1847 diary documents accounts of Margary working at the office in his house in Dawlish, meetings with ‘Mr. Brunel’ at his office in Duke Street, they note dealings with other engineers of the South Devon Railway including Messrs Hammond, Harrison, Glennie. They include accounts of travelling on the atmospheric railway and on mail trains, accounts of frequent visits to atmospheric engine houses including Starcross and Torquay, details of meetings with men from Boulton and Watt to set up engines in Atmospheric engine houses.