80 
Mr. AiKin on the Vallies and Watercourses 
From the above mentioned facts it may be concluded that the 
navigation of a river is very precarious, and liable to long and fre- 
quent interruptions, even in a rainy climate, when the descent of the 
water exceeds 3 feet per mile; and that the highest floods run off 
in a few hours, even when the descent amounts to but 2 feet 5 inches 
in the same space. 
The highest flat land in the county is Corndon marsh, elevated 
between 900 and 1000 feet above the sea. From this marsh arises 
a large brook, which after a southward course of five or six miles, 
arrives at the village of Moor 730 feet above the sea, and situated 
in the valley in which Montgomery and Bishopscastie are built, and 
which forms an oblique connexion between the great Montgomery- 
shire valley in which the Severn flows, and the valley of the Teme. 
From Moor the ground slopes so equally both east and west that the 
very uncommon circumstance here occurs of the stream dividing 
itself: that portion which goes off to the west, being soon joined by 
other streams forms the river Camlet, which after an indirect and 
circuitous course of about seventeen miles, falls into the Severn, above 
Welsh pool, having descended in this space nearly 300 feet, being at 
the rate of feet per mile. The eastern branch after the junction 
of a few brooks, forms the Onny river and falls into the Teme at 
BromfieJd three miles above Ludlow, having run a course of nearly 
equal length and fall with the Camlet. 
The length of the Teme from its junction with the Onny to its 
termination in the Severn, about three miles below Worcester, is 
nearly forty-two miles, in which space it falls 367 feet, being at the 
rate of about 8 feet 9 inches, per mile: nearly the whole of its 
course is directly opposite to the rise of the strata over which it 
flows, which, added to the rapidity of its desqent, is obviously the 
