PLATE 12 



MACKINAW 



79 .80 



\ 



579.90 



8Q 



JULY S5.I9M JULY 20 



JUL 



25 



JUD 



30 



AUG 



4 6 



AUG 6 



AU3 II 



AU( 



16 



AUG 



21 



AUG 



26 28 



579.90 



MACJKINAfr 



HARBOR EACH 



579.90 



579.90 





".BO 1 



MILWAUKEE 



579.90 



Observed 



Corrected for barometric and wind effects 



Rainfall + inflow outflow 



Elevations of water surface, Lake Michigan-Huron, July 15- August 28, 1911. 



