U. S. NATIONAL MUSEUM 



BULLETIN 173 PLATE 10 



Early steam Engines. 



^ 1. Heron's turbine, c. 150 A. D. (model; U.S.X.M. no. 308462). See p. 26. 

 2. Watt pumping engine, "Old Bess," 1777 (model; I'.S.X.M. no. .i08469). See p. 31. 



