274 PROCEEDINGS OF THE GEOLOGICAL SOCIETY.  [ Mar. 8, 
Vernon Tipping of Lawton, Mr. John Latham of Congleton, Mr. 
Thomas Williamson of Stonetrough Colhery, and Mr. Hodgkinson 
of Booth Lane Head. 
For particulars of the brine at Middlewich I am indebted to Mr. R. 
Llewellyn Vawdrey, Mr. Brereton, and Mr. Peter Hoole of that place. 
Rock-salt has not been found at Middlewich. The strata through 
which all the pits are sunk are composed of alternate beds of red and 
blue indurated clay with gypsum. 
In the pits at Northwich and Winsford, and also it is presumed at 
Malkins Bank, the brine lies on the rock-salt or “ rock-head ;”? such 
also is doubtless the case at Lawton. At Middlewich it is found in 
two different positions, which are worthy of attention as probably 
explaining the reasons of the appearance of brine-springs in other 
parts of the country apparently remote from salt-rock. 
In seven brine-pits at Middlewich, the brine, to use the local term, 
is a ‘‘seek ;” that is, it wells out from a layer of black gravel, about 
nine inches in thickness, between two horizontal beds of indurated 
clay or rock. In most of these pits there is but one seek, at about 
78 feet from the surface. To this depth the majority of the pits 
were originally sunk. Two other seeks, however, are met with at the 
depths of 126 and 144 feet. It does not appear that any advantage 
has been gained by deepening the pits to these depths. These pits, 
including the borings, vary in depth from 78 to 309 feet. The level 
of the brine is 18 feet from the surface. The amount of salt yielded is 
from 2 lbs. 6 oz. to 2 Ibs. 10 oz. to the gallon. 
The remaining, pit differs from those just described. It is situated 
to the east of the town and of the pits just mentioned: it is 177 feet 
deep. This pit was originally only 135 feet deep, but was extended 
below this depth by “‘auger-holes”’ kept open by iron rods. About 
eight years since, there being a deficiency of brine, a by-shaft or level 
of about 10 feet was cut, and then a perpendicular one of 42 feet. 
Since this time the supply has been constant and never failed. It is 
avery old pit; the date of sinking is not known. The brine here 
rises so near the surface as to be within reach of the hand. The 
brine never fails: it yields 2 lbs. 12 oz. to the gallon. 
This last pit may probably afford a key to the peculiar position in 
which the Middlewich brine is found. This pit, very probably, jud- 
ging from the quantity of water and the level to which it rises, is sunk 
on or near to a fault, up which, as a conduit, the brine, though ap- 
parently here coming also from a seek, rises from the strata where it 
has become impregnated, forming originally a natural, but now an 
enlarged Artesian sprmg. From this fault the brine would percolate 
through the “black gravel’? between the horizontal gypseous beds, 
forming the seeks found in the other pits. 
The level of the rivers Dane and Wheelock at Middlewich is about 
85 feet above the sea. The level of the Weever at Winsford Lock is 
59 feet 6 inches. The level to which the last-mentioned brine-spring 
rises is higher than the brook, which runs about 300 feet to the north 
of the same and falls into the Dane, and is about 120 or 130 feet 
above the sea. 
