File of correspondence and papers relating to track recording and curve measuring apparatus designed by the French engineer Emile Hallade. The file contains correspondence between the Great Northern Railway (GNR) and the Chemins de Fer de Paris a Lyon et a la Mediterranee in 1922 about the use and introduction of the machines, and there is also a letter from W. Silversteen & Co., engineers, of London, giving the details and price of the curve-measuring apparatus. The LNER carried on the correspondence in 1923, including a report on the GNR's experiences of the Hallade apparatus submitted to "Modern Transport" in February 1923. The file also includes various printed papers and offprints of articles by Hallade from journals, from 1909, 1910 and 1921.