134 SPENCEE ON THE lEOQUOIS BEACH. 



region the country is occupied by barren Laurentiau ridges, woods and lakes, but at 

 various places, beaches, probably belonging to the Iroquois system, may be seen, as 

 as well as a little beyond the Ottawa E-iver. From Hamilton, at the western end of the 

 lake, the beach is along the foot of the Niagara escarpment, and parallel to the modern 

 lake shore. At Lewiston, it is 385 feet above the sea ; at Rochester, 436 feet, and at 

 Sodus, 458. But eastward of this place it bends round, passes under Cayuga Lake 

 (G-ilbert), encloses an archipelago and Oneida Lake valley, and then skirts the foot 

 of the Cambro-Siluriau escarpment northward to Cape Rutland (near Black River). 

 At Canastota, the elevation it 411 feet ; at Cleveland, 484; at Constantia, 489 ; at Adam's 

 Centre, 657 : at CapeRutlaud, 700 feet (barometric). Eastward of this region, the beach 

 rests against drift ridges or rocky ledges, crosses the Black River, above G-reat Bend (at 

 678 feet, barometric), rests upon the broad Pine Plains, a sort of terrace of construction, 

 and thence it may be followed among the Laurentian ridges or islands (at 667 feet, 

 barometric) to near Stirling Bush, in front of which there is a kind of cutterrace in flat 

 Palœozoic rocks. As the work was discontinued, it has not been followed beyond this 

 point, and it still remains to be seen how far it can be explored. The Iroquois Beach, 

 at the eastern end of the lake, is composed of three ridges, with an extreme difference 

 of height of from twenty-two to twenty-five feet, and this diiFerence is still seen amongst 

 the Laurentian ridges to the eastward. 



The above elevations from Lewiston to Adam's Centre are from Mr. Gilbert's observa- 

 tions, and the remainder, where not otherwise stated, have been obtained, by the writer, 

 from levels run to adjacent known points upon the railways. The list is far from com- 

 plete, but the work promises a rich harvest in return for future labor. The barometric 

 determination should be corrected by instrumental measurements. 



