724 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



amount to several feet, and such fluctuations are liable to have been still 

 greater in the glacial lakeiL , though there are at present no recognized means 

 of computing them. The present lakes show also a marked fluctuation or 

 disturbance of level through the action of wind. Strong winds from the 

 west have been known to drive the water from the western into the eastern 

 end of Lake Erie, until the level at Buffalo became several feet higher than 

 at Toledo. No doubt disturbances of this sort affected the glacial lakes, 

 there being some evidence that the wind was from the same quarter. It is 

 probable that the combined influence of the rainfall and the wind would 

 give Lake Erie a variation of 12 feet and possibly 15 feet in level, and a 

 beach is liable to be foi'med at the highest as well as the lowest level. The 

 writer found the level of a well-defined storm beach at Westfield, N. Y., to 

 be 12 feet above the ordinary low- water level of Lake Erie, and this may 

 not rejDresent the maximum height attained by storm beaches in other parts 

 of the shore. 



Li addition to these factors of disturbance, the glacial lakes seem likely 

 to have responded to the attraction of the ice sheet and to have stood appre- 

 ciably higher near the ice margin than at points more remote. Woodward's 

 computations ^ indicate that the deformation of the lake surface may have 

 amounted to several inches per mile in the vicinity of the ice margin. It is 

 therefore a matter of some importance to determine how much of the north- 

 eastward rise is due to ice attraction. 



Turning now to the Maumee beaches, it is found that the upper beach 

 stands about 775 to 780 feet above tide in the vicinity of the Fort Wayne 

 outlet. Near the State line of Ohio and Michigan, 50 to 75 miles from the 

 head of the outlet, several observations unite in giving the beach an altitude 

 about 20 feet higher. The Fairfield (Mich.) geodetic station is 799 feet, 

 while the railway stations at Fayette and West Unity, Ohio, which stand 

 very near the level of the beach at those points, are 798 and 800 feet, 

 respectively; but upon continuing northeastward from Fairfield, Mich., the 

 altitude for the next 30 miles seems to become lower rather than higher. 

 The aneroid determinations from several railway stations sustain this view, 

 and an inspection of the profile of the Toledo and Ann Arbor Railway con- 

 firms it. This railway profile shows the altitude to be but 790 feet where it 

 crosses the beach, 4 miles north of Milan. The altitude of the sand bar on 



' See Bull. U. S. Geol. Survey No. 28. 



