WHIRLPOOL BASIN AND COVE SECTION. 65 
side whirl in the basin next above, nor for the use of the names “ Eddy 
basin”? and Whirlpool basin” for these two parts of the gorge. 
In passing from the Eddy basin to the Whirlpool there is a slight con- 
traction of the gorge, the top width narrowing from about 1,200 to 1,000 
feet, while the width at the water line narrows from about 850 to 550 
feet. At the place of greatest contraction there is a ledge of rocks pro- 
jecting from the east bank directly out into the swift current 50 feet or 
more and covered by only a few feet of water.* In low seasons and 
when the water is clear it is plainly visible. Besides this visible ledge, 
the behavior of the water indicates a shoal spanning the river in the con- 
tracted part. 
WHIRLPOOL BASIN 
Next below the shoal ledge is the Whirlpool. So far as the post- 
glacial or modern river is concerned, the history of this part of the gorge © 
is very simple. The Whirlpool basin is part of the old Saint Davids 
gorge, which extends northwestward to the village of Saint Davids, where 
it opens out with a wide mouth at the line of the escarpment. ‘This old 
gorge is now filled with drift, and the modern river had only to wash out 
the part now occupied by the Whirlpool when it had cut back this far. 
Where the western wall of the old gorge is exposed, in Bowmans ravine 
north of the Whirlpool, it is found to be smoothed and scored by glacial 
action, and bears strie even as far down as the Clinton limestone. These 
circumstances prove beyond a doubt that this section is of preglacial or 
interglacial age. It also appears to have great depth. Considering the 
kind of action that goes on in the Whirlpool, itseems hard to think of it 
as being much less than 200 feet deep. 
COVE SECTION 
At the lower side of the Whirlpool, where the water passes out, there 
is a much sharper contraction than that noted above. The top width 
for a few rods is only about 900 feet, the narrowest point anywhere out- 
side of the gorge of the Whirlpool rapids, and the width at the water line 
is about 450 feet. The river is shallow at this place, and the sharp 
descent of the short rapids seems to show that it falls over a shoal ledge 
spanning the river from side to side. Below this the gorge widens and 
deepens. For most of this section, which for convenience we may call 
the Cove section, the top width is nearly 1,300 feet, but just above 
Wintergreen flat it broadens to 1,600 feet.— After passing the shoal at 
* This ledge was pointed out to the writer by Mr Gilbert in August, 1896. 
{By a glance at the map, figure 1, page 62, it will be seen that there is a small cove running 
northward from the northeast end of the wide, deep section which lies between the Whirlpool and 
Wintergreen flat. This is probably the most quiet piece of water to be found on the river between 
the falls and Lewiston, and it seems to furnish an appropriate name for this section. 
