GREAT LAKES 71 



717. U. S. Engineer department. Rivers and harbors board. 



1936-1937. Transportation lines on the Great Lakes, 1935. Washington, 

 D. C., 1936. X, 83 p. plates, maps. (Transportation series 

 no. 3.) Rev. ed. 1937. 



718. U. S. Hydrographic office. 



1921. Great Lakes pilot. Vol. I-II. 2d ed. (Discontinued; with- 



drawn from issue.) 



719. *U. S. Weather bureau. 



1933-1944. Summary of ice conditions for the Great Lakes. Issued weekly 

 during the ice season. Each year numbered separately. 



