104 REVIEWS 



pot-holes cutting into one another. Near Rock Point the abandoned 

 bed of the old stream, 150 feet above the present stream, is also in the 

 Homewood Sandstone. A number of pot-holes have been seen here, 

 and views show that the steep side is on the southern side, and the 

 eroded, rounded side on the northern side of the hole, thus clearly 

 indicating that the former stream flowed northward. 



The fragments of the bed of this old north-flowing Beaver are 

 practically level from Pittsburg to Rock Point, a distance of about 

 forty miles. The next fragments found a few miles north of these 

 pot-holes are, however, some 80-100 feet lower than at the pot-holes. 

 Observation shows that pot-holes are formed only where the stream is 

 very rapid, and these pot-holes, therefore, indicate that the old north- 

 flowing stream had a greatly increased fall northward for several miles, 

 and a series of rapids here occurred, or perhaps a fall. The pot-holes, 

 therefore, bring the fragments farther north (810 feet) into har- 

 mony with the level at the pot-holes (900 feet), and harmonize the 

 almost horizontal fragments southward to Pittsburg, with the 80-100 

 feet of fall found immediately northward. 



Ames K?iob, North Haven, Mai?ie ; A Seaside Note'. By Bailey 

 Willis, Washington, D. C. (Abstract of Paper to Appear 

 with Illustrations in Bull. G. S. A.^ 

 Ames Knob is a mass of andesitic volcanic rock rising 160 feet 

 above the sea, on the neck of land between the Fox Island thorough- 

 fare and South Harbor, North Haven Island, in Penobscot Bay. Its 

 petrographic character and geologic relations have been described by 

 G. O. Smith, in his essay on the geology of the Fox Islands, Me. It is 

 bounded on the north by a low plain cut in shales and limestones, of 

 Niagara age, and its northern slope is a cliff resulting from the rela- 

 tively great hardness of the igneous rock. The other slopes of the 

 knob are of practically uniformly resistant rock, and variations in profile 

 are attributable to conditions of attack, rather than of resistance. At 

 an altitude of approximately 80 feet above the sea, on the southeastern 

 and southern sides facing the Atlantic ocean, is a well-marked bench 

 from which a steep facet rises 40 to 60 feet to the summit of the knob. 

 This bench, which has an average width of about 200 yards, is attrib- 

 uted to the action of waves cutting at rock level. The rocks in place 

 exposed upon this bench and about its margin exhibit rounded 

 glaciated profiles, but no longer bear striae, so far as observed. Hence 



