63 
the aggregate flow of which at the minimum is approximately 
50 cu. ft. per minute, or 4,687 gallons per minute; this, 
according to the Thames standard, would require a basin of 
624 sq. miles, whilst we have one of but 23 sq. miles, but little 
over a third of that area, clearly showing the inapplicability of 
that standard in the case of the Frome, which river intersects 
‘no permeable strata in descending, after its development at 
Chalford, and progressively increases in volume from tributaries 
in its north-western course, contrary to the conditions that 
prevail in the valleys of the rivers Churn and Coln, both 
trending to the south-east. 
_ Where does all the water come from ? 
It has been suggested that some of it may come from the 
waters lost from’ the Churn valley, or from portions of the 
districts shown on the map marked the ‘“ Upper Thames and 
the Avon Basins,” in both cases by means of known extensive 
faults. This is possible, and to some extent probable. Then it 
is a popular notion at Chalford that the springs have some 
connection with Cherrington lake, which is supposed to feed 
them; which idea is of course erroneous, for Cherrington lake 
is in the Fuller’s Earth, and the level of the springs issuing 
from the hill side that feed the lake is 410.00 ft. on Ordnance 
datum, whilst the Fuller’s Earth springs at the Hyde, above 
_Chalford, is, as shown on the Ordnance Survey, 530.00 ft., 
- difference 120.00 ft., showing a dip of 120 ft. in 23 miles 
seweesiyCherrington, or 1 in 104. : 
_ The origin of these. copious and beautiful springs at 
Chalford is not, I think, difficult to find. They are the outflow 
_ from a very extensive natural subterranean equalizing reservoir 
“situated in the valley above them, which stores the floods of 
_ winter and the storms of summer, to give out the waters with 
increased uniformity to the river below. This extensive reser- 
yoir has a sound impervious floor or base throughout in the 
thick clays of the Upper Lias, which preclude the downward 
escape of any waters. 
_ “Why then,” it may be asked, “do not similar conditions 
prevail in the Churn valley, where it has been shown that 
2,403,000 gallons per diem have been lost in traversing the 
a 
