Lakes have been more numerous, &c. 17 
Ihave now enumerated the various caufes that 
contribute to the transformation of Lakes, by the 
gradual enlargement of their outlets, and have 
pointed out thofe circumftances, which in procefs 
of time unavoidably hinder future alterations of 
the kind. It will therefore be proper, in confor- 
mity to the plan of the effay, to confirm the truth 
of the theory by the following remarks, which I 
truft will not be found contradictory to the expe- 
rience of any one, who has had an opportunity to 
make fimilar obfervations. 
_ There are many vallies in the north of England, 
which, if we may judge from their appearance, 
have formerly been filled with water. ‘The coves 
which feem fcooped out of the fides of feveral hills 
are perhaps the moft fingular objects of the kind. 
The entrance into one of thefe places always lies 
through a narrow pafs, between two fteep banks. 
A rivulet moft commonly flows through this open- 
' ing, which, in fome cafes, conveys away the 
fuperfluous water of a bafon lying in the centre 
of the natural amphitheatre. If the courfe of this 
ftream be traced to fome part where its declivity 
is interrupted by a plane, the obferver may have 
an opportunity of difcovering what has once been 
iis employment. For he will frequently find it 
flowing along a channel confiderably elevated by a 
_ broad bed of pebbles. ‘The fragments conftituting 
this ridge are in all probability the remains of.a 
C rock, 
