Mendes Cohen (1831-1915) worked for the Baltimore & Ohio Railroad Company, chiefly in the Motive Power Department, from 1851 to 1855, where he adaptated wood-burning locomotives to coal-burning and devised the method for handling traffic on the 10% temporary grade over the Kingwood Tunnel. The report covers a series of tests and improvements conducted in 1853 and 1854 with the aim of reducing flue wear and tear and fuel consumption in the large coal-burning engines