43 



20 to 25 feet (6-1 to 7-6 m.) in depth. Twenty years 

 or more ago the angle at the apex of the fall was sharper 

 and more acute. The principal change in the outline 

 in recent years has been a falling away of the crest along 

 the line to the right of the apex as seen from this point. 



The water pouring into the angle near the apex some- 

 times produces a remarkable effect, like an explosion in 

 the depths below. It makes a perceptible booming sound 

 and throws up jets of spray to heights considerably above 

 the top of the falls. This effect is best seen from here 

 and was formerly more marked than now. 



The Horseshoe Fall, looking south from bluff at southwest corner of Goat Island. 

 Goat island shelf in the foreground. 



The Sister Islands and the First Cascade. — Here 



is a picturesque spot where small branches of the rapids 

 pass between small rocky islands. The beds of Lockport 

 limestone here are thick and massive, leaving an abrupt 

 descent of five or six feet where they part along their 

 joint planes. One of these beds runs from the shore of 

 Goat island just above the Sister islands directly south 

 across the river. It extends in a nearly straight line and 

 the water falls over it in what is known as the First cascade. 



