"An open hearth furnace has a large bed (E) lined with fire-brick and sand (H) on which the charge is placed. Gas is used as fuel and is heated before entering the furnace by pass-heated gas is passed into the furnace through a pipe (a), while through another flue (b) aur enters which has been similarly heated...hot, gaseous product escapes through checkerworks (C,D)..." -Brownlee 1907
Brownlee, Raymond B., Fuller, Robert W., Hancock, William J., Sohon, Michael D., Whitsit, Jesee E. First Principles of Chemistry (Boston: Allyn and Bacon, 1907) 335
