No. 4.] SPENCER — SURFACE GEOLOGY. 221 



streams, mostly dry in summer, have worn back the limestone 

 escarpment, over which they flow, to distances varying from a 

 few yards to a few hundred, making glens at whose head in 

 spring time some picturesque cascades can be seen. iVt Mount 

 Albion, six miles east of Hamilton, there are two of these larger 

 gorges, whose waters, after passing over picturesque falls, 70 feet 

 high, and through glens several hundred yards in length, empty 

 into the triangular valley noticed before. On the northern side of 

 the Dun das valley, besides small gorges with their streams com- 

 parable to those on the south side, there are several of much 

 larger dimensions; for example that at Waterdown, six miles 

 north of Hamilton. Still larger is Glen Spencer which has & canon 

 half a mile long, 300 feet deep and between 200 and 300 yards 

 wide at its mouth. At the head of this is Spencer falls, 135 

 feet high, and joining it laterally there is another carton, with a 

 considerable stream flowing from Webster's falls, which, how- 

 ever, is of less height than the other. The waters feeding these 

 streams come from northward of the escarpment, and belong to a 

 system of drainage different from those streams which flow down 

 through the drift of the Dundas valley, and are of much greater 

 length. At the foot of Spencer falls, the waters strike the upper 

 portion of the Clinton shaly beds. The Falls are two feet deeper 

 than twenty years ago. Yet the stream is small, and makes a 

 pond below in the soft shales. But this diflPerence in height does 

 not represent the rate of wearing or recession of the precipice, but 

 only the removal of a little dehrls at the base. That the stream 

 is much smaller than formerly is plainly to be seen, for at present 

 it has cut a narrow channel, from ten to fifteen yards in width, 

 above the falls, and from four to six feet deep on one side of the 

 more ancient valley, which is about 50 ynrds wide and 30 feet 

 deep, excavated in the Niagara dolomites. 



The surface of the escarpment on both sides of Glens Spencer 

 and Webster presents a peculiar aspect. That on the north- 

 eastern side has a maximum height of 520 feet above the lake. 

 On the same side, a section, made longitudinally, shows several 

 broad shallow glens nearly a hundred feet deep crossing it and 

 entering Glen Spencer. The surface of the rocks is glaciated, 

 but not parallel with the direction of the channels. On the 

 south-western side of the same canon, we find that a portion of 

 the thin beds of Upper Niagara limestone have been removed. 

 This absence is not general, for it soon regains its average heioht 

 of about 500 feet. 



