756 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



altitude being 731 feet and the highest 742 feet above tide. A part of this 

 difference may be due to discrepancies between railway surveys and a part 

 to the difference in the height to which the beach was built above mean 

 lake level. These elements of error and of variation being eliminated, it 

 is doubtful if enough difference will remain to require any crust warping. 

 Eastward from Ashtabula, the beach is found by levels on the Grirard 

 topographic sheet to reach 746 feet at the Ohio-Pennsylvania line, 748 feet 

 near East Springfield, Pa., and 752 feSt 4 miles farther east, while levels 

 run by Taylor show it to be 765 feet at Swanville. This gives the beach 

 a rise of 19 feet in a distance of about 19 miles. At Erie, 10 miles farther , 

 east, the city levels show the altitude to reach 772 feet, and at Northeast, 

 15 miles farther, levels run by Gilbert show the beach to be 788 feet above 

 tide. Near the Pennsylvania-New York line, about 5 miles from North- 

 east, the profile of the Lake Shore and Michigan Southern Railway shows 

 the altitude to be only 785 feet, but in the next 10 miles to Chautauqua 

 Creek, south of Westfield, the beach, as shown by the Westfield topo- 

 o-raphic sheet, rises above the 800-foot contour. About 20 miles farther, 

 near Fredonia, as shown by the Dunkirk topographic sheet, the beach rises 

 above the 820-foot contour. Near Sheridan, 6 miles farther, Gilbert found 

 the altitude by Locke level to be 834 feet. Six miles farther, near Han- 

 over Center, the beach reaches the 840-foot contour. From Hanover 

 Center to Cattaraugus Creek the course of the beach is south of east, or 

 nearly at a right angle to the direction of uplift, and it holds a very uniform 

 level at about 840 feet. It is very nearly 840 feet on the east side of 

 Cattaraugus Creek, near the Indian Council House, as determined by spirit 

 level by Fairchild from Lawton station. Four miles north, opposite North 

 Collins, as determined by Locke level from North Collins station, it reaches 

 850 feet, being 20 feet above the railway station. Beyond this point 

 measurements were made only with the aneroid, but these show a strong- 

 increase, the altitude southeast of Hamburg being 875 feet and near Elma 

 station 890 feet. At the supposed terminus in Marilla the aneroid indicates 

 an altitude of nearly 900 feet. 



The rise of about 150 feet between the Ohio-Pennsylvania line and 

 Marilla, N.. Y., is made in a distance by direct line of not more than 125 

 miles, and contrasts strikingly with the variation of less than 15 feet in the 

 200 miles west from the Ohio-Pennsylvania line. 



