184 Ohio State Academy of Science 



near the other Great Lakes indicate that the whole region has 

 undergone tilting. 



Gilbert's Researches. 



Whether this tilting is still going on or ceased long ago does 

 not appear from an examination of these old beaches. In 1895 

 Mr. G. K. Gilbert found evidence that it was still continuing. 

 By comparing the heights above the normal lake level of a 

 bench-mark in Cleveland and one at the head of the Welland 

 Canal with the heights of the same as carefully determined in 

 1858, it appeared that the land near the northeast end of the lake 

 had risen as compared with Cleveland. In hke manner he found 

 that tilting was still going on in the region of Lake Ontario and 

 Lake Huron and Michigan. 



Deepening of the Water. 



Inasmuch as the tilting produces a rise of the land toward 

 the northeast as compared with that toward the southwest it is 

 elevating the point of outlet of Lake Erie as compared with the 

 rest of the lake. As the lake is continually receiving water 

 through the Detroit River and other sources the elevation of the 

 point of outflow raises the level of the water throughout the 

 entire basin. 



In 1860, H. A. Winters now living in Sandusky, had occasion 

 to visit Eagle Island many times. In a pond too deep for hip 

 boots, but which he crossed with his boat, was a walnut stump 

 whose sapwood had rotted away. The heartwood about four- 

 feet in diameter was still well preserved and showed that it had 

 been neatly chopped off. Alvin Fox told him that he had 

 helped to chop the tree in 1828, when the land about it was all 

 dry. Through the summer of 1860 the stump stood in about 

 two feet of water. 



According to J. W. Lockwood, who lives on the north side 

 of Sandusky Bay near the Plaster Beds, a man named Craighill 

 cut an oak supposed to be two hundred or three hundred years 

 old about 1823 or 182-1 on what was then a dry prairie but where 

 there has been a marsh ever since. This marsh borders what is 

 known as West Harbor in the peninsula north of Sandusky Bay. 



These observations and many others made it clear that the 

 water had deepened but in view of the fluctuations produced by 

 rainfall and the lack of early records of rainfall they did not 

 afford a means of calculating with any degree of accuracy how 

 fast the deepening would progress if the rainfall remained 

 uniform. Not until the fall of 1904 was any means discovered 

 of making such a calculation. It came from studying the parallel 

 ridges which traverse the terminal portion of the Cedar Point 



