SECTION OF PETROGRAPHY 573 



The Society adjourned for the noon recess. On reassembling at 2.10 

 o'clock, Vice-President H. S. Williams in the chair, it was announced 

 that the papers in petrography would be presented in a separate section, 

 to meet in room 104 of the same building. The general program was 

 continued in room 116 and the first paper was 



EFFECT OF CLIFF EROSION ON FORM OF CONTACT SURFACES 

 BY N. M. FENNKMAN 



The paper is printed as pages 205-214 of this volume. 

 The second paper was 



DRAINAGE FEATURES OF CENTRAL NEW YORK 

 BY RALPH S. TARR 



Remarks on the subject of the paper were made by G. K. Gilbert, 

 W. M. Davis, and the author. The paper is printed as pages 229-242 of 

 this volume. 



The third paper was 



HANGING VALLEYS 

 BY ISRAEL C. RUSSELL 



This paper is printed as pages 75-90 of this volume. 

 The fourth and last paper of the day was the following : 



ICE EROSION THEORY A FALLACY 

 BY H. L. FAIRCHILD 



The paper was discussed by J. W. Spencer, A. C. Lane, A. P. Coleman, 

 I. C. Russell, G. K. Gilbert, W. M. Davis, and the author. The paper is 

 printed as pages 13-74 of this volume. 



The Society adjourned. No evening session was held. 



Section of Petrography 



During Friday afternoon, while the papers described above were pre- 

 sented in the general session the papers classified on the printed program 

 as petrographic were presented in room 104. The temporary section 

 was called to order by J. P. Iddings, and by viva voce vote B. K. Em- 

 erson was made Chairman and E. O. Hovey Secretary. 



