REPORT OP COMMITTEE ON PHOTOGRAPHS 471 



Size, 4.} by 65 inches. Tliirtx-seven photographed by G. K. Gilbert 



1743. Sliore of lake Ontario, Niagara county. New York. Illustrates mode of 



origin of beach shingle by showing rock in place and angular rocks re- 

 cently detached. Gilbert, 1898. 



1744. Beach of fiat shingle. Shore of lake Ontario at Golden Hill creek, New 



York. Gilbert, 1898. 



1745. Beach of well rounded shingle. Shore of lake Ontario at Golden Hill creek. 



New York. Gilbert, 1898. 



1746. Cemented shingle in spit of glacial lake Iroquois at Lewiston, New York. 



Gilbert, 1898. 



1747. Section of spit of glacial lake Iroquois at Lewiston, New York. The dip is 



landward, indicating growth on the inside of the spit. Gilbert, 1898. 



1748. Section of spit of glacial lake Iroquois at Lewiston, New York. The dip is 



landward, indicating growth on the inside of the spit. Gilbert, 1898. 



1749. Cut terrace of the Iroquois shore line, 2 miles west of Dickersonville, New 



York. Lacustrine plain, bed of lake Iroquois, near Jeddo, New York. 

 The water edge was at base of cliflF. The cliff is carved from Medina shale. 

 Gilbert, 1898. 



1750. Till plain, i mile south of Jeddo, Niagara county. New York. Gilbert, 



1898. 



1751. Cross-bedding and unconformity in sand kame, 3 miles east of Lockport, 



New York. Gilbert, 1898. 



1752. Till. Shore of lake Ontario, Wilson, New York. Gilbert, 1898. 



1753. Deposit by torrent of Brian water on the withdrawal of the ice-sheet from the 



escarpment at Lewiston, New York. Unassorted and unworn alluvium. 

 Gilbert, 1898. 



1754. Section of talus, Niagara gorge. Gilbert, 1898. 



1755. Angular gravel in kame, south of Royalton, Niagara county, New York. 



Gilbert, 1898. 



1756. Solitary gravel kame, 3 miles south of Middleport, New York. Gilbert, 



1898. 



1757. Escarpment of the Niagara limestone, looking west from a point on the talus 



near Lewiston, New York. Gilbert, 1898. 



1758. Niagara escarpment capped by Niagara limestone, looking east from a point 



5 miles west of Lockport, New York. Gilbert, 1898. 



1759. Niagara escarpment without capping of Niagara limestone ; looking west 



from a point near Middleport, New York. Gilbert, 1898. 



1760. Drowned valley of Twelve-mile creek, near Wilson, Niagara county, New 



York. Water lilies grow on submerged alluvial plain. Gilbert, 1898. 



1761. Head of estuary of Twelve-mile creek, Niagara county, New York. Sub- 



merged alluvial plain supports rushes. Gilbert, 1898. 



1762. Estuary of Eighteen-mile creek, near Olcott, Niagara county. New York. 



Channel deep, current slow. Submerged alluvial plain supports rushes. 

 Gilbert, 1898. 



1763. Valley of Eighteen-mile creek, Niagara county, New York, above head of 



estuary. Channel shallow, current rapid ; alluvial plain dry except during 

 flood. Gilbert, 1898. 



