THE CONNECTIONS 67 



and number 7156 had been divided in two. The correspondence 

 among the three curves is excellent. 



Agreement Among Curves from Widely Separated 

 Localities 



The agreement between calculated normal curves from differ- 

 ent parts of the same lake, or from widely separated valleys, 

 can be studied on the plates. For details regarding these curves 

 reference may be made to the description on pages 49-63. 

 Curves 3 to 5 (PI. I) show the striking agreement between 

 normal curves based on two groups of measurements in the same 

 lake, one group lying 20 miles (32 km.) closer to the ice edge than 

 the other. Curves 11, 12, and 13 (Pis. II and III) are constructed 

 from profiles in a corresponding situation to the ice border as 

 those just mentioned. The latter part of graph 13 represents 

 measurements in the Hudson and Connecticut Valleys, and curve 



14 (PI. Ill) records profiles in the Hudson, Connecticut, and 

 Merrimac Valleys. The distance between the Hudson and 

 Connecticut Valleys is 60 miles (95 km.), between the Connecti- 

 cut and Merrimac Valleys 50 (80 km.), and between the Hudson 

 and Merrimac consequently no miles (175 km.). The cor- 

 respondences between the curves are on the whole good, and in 

 some horizons excellent, considering the great distances between 

 these lakes and the differences in their drainage areas. The 

 series from the Hudson Valley is put in to fill a gap in the Con- 

 necticut curve, but only so much is reproduced as is necessary 

 to show connections. As a matter of fact, the total series extends 

 200 varves downward and 100 varves upward, making in all 

 600 layers. The whole series shows good agreement with the 

 Connecticut and Merrimac curves. 



Curves 15, 16, and 17 (Pis. Ill and IV) are based on measure- 

 ments in the Connecticut and Merrimac Valleys, and curve 



15 also on one in the glacial lake at Keene, N. H. Except for 

 drainage varves the agreement is very satisfactory. Curves 19 

 and 20 (PI. V), finally, are compiled from two groups of measure- 



