632 FRANK D. ADAMS AND J. AUSTEN BANCROFT 



60,000, and 65,000 pounds, respectively. It will be noted that the 

 same effect, though on a smaller scale, was produced as that just 

 described as the result of impact. An abnormal increase of load 



Fig. 11. — Photograph of a specimen of Trenton limestone which has been cut by 

 a narrow dyke of camptonite. The whole has then been distorted by pressure exerted 

 by the intrusion of the igneous mass constituting Mount Royal. The harder camp- 

 tonite has been broken into fragments which have been carried apart in the flowing 

 mass of more plastic limestone (Canadian Northern Railway Tunnel through Mount 

 Royal, Montreal, Canada). 



