370 WILLIAM HERBERT HOBBS 



Mr. Brown has measured the direction of a total of 1,004 joints, 

 most of which are in the vicinity of Ithaca, N. Y. Some of the 

 localities examined are Six Mile, Cascadilla, Fall, and Buttermilk 

 Creeks; the Bates, Sheehey, Driscoll, and Veder quarries; Coy's, 

 Shugar's, and Estey Glens ; and other localities in and about Lansing, 

 Taughannock, Portage, Genesee, and Hamilton. Another set of 

 observations is taken from the Cayuga Creek gorge, Havana and 



Fig. 6. — Diagram to show the orientation of joints in the Cayuga Lake basin 

 of western New York (Brown). 



Watkins Glens, the west shore of Seneca Lake, and localities about 

 Norwich. The results of this investigation are not published, but 

 through the courtesy of Mr. Brown I am permitted to make use of 

 his results in this article. After a careful enumeration of the joint 

 directions observed, Mr. Brown says in his thesis: 



The correlation presented in Fig. 4 seems to indicate that these joints con- 

 stitute two orthogonal systems. Those whose direction trend N. and N. 45' 

 degrees W., and' N. 70 degrees E. and E., constituting the major system; while 

 those whose direction trend between N. and N. 20 degrees E., and N. 70 degrees 

 W. and W., constitute the minor system. It will also be seen that the major 

 system contains 551 of the 572 joints correlated, 1 or 96 per cent, of the whole 

 number; while 374, or 67 per cent., of those constituting the major system lie 

 between N. and N. 45 degrees W. 



Mr. Brown's results covering this area I have brought together 

 below in a single table, in order to show their orientation as respects 

 the entire area: 



1 This does not include the later work. 



