The Salt Industry in Cheshire. 163 
only brine to be obtained is that produced by rainfall from year to 
year ; and after a very dry season, there is a perceptible diminu- 
tion in the supply, so that in a way we are living from hand to 
mouth with regard to natural brine. It rarely rises nowadays 
many yards above the rock-salt stratum. 
Much of the brine now obtained (nearly a// of that in the old 
salt region of Northwich) is of a semiartificial nature. It is 
pumped from the o/d mines, and is probably formed almost 
entirely by the surface water getting down old shafts and the 
many vast holes and cracks now made in that region. In this way 
even the small pillars of those mines have been melted and the 
salt immediately under the town and valley is being dissolved. In 
the Winsford region, which makes two-thirds of the whole salt 
made, the brine is all gzz¢e natural. 
No one is known to have ever traced a brine stream under- 
ground ; it is only to be seen running in at the bottom of the 
shafts. In one place a large natural cave had formed where the 
stream was running in, and someone once tried to walk along, but 
the soil and stones were too loose to be traversed with safety for 
more than a very short distance. 
The theory about it is that the brine is forced up by the action 
of gravity, as in the case of artesian wells, though there is no 
direct proof of this. It certainly seems to be the most probable 
explanation when we come to look into the facts. Cheshire is 
known, from various circumstances (such as the borings for water, 
etc.), to be geologically in the form of a large basin. On the west 
are the Edisbury hills, and on the east and south-east the hills of 
Alderly Edge and Macclesfield. On the north side is a part with 
no hills, but a kind of cut, which may be represented as a lip of 
the basin, and outside this runs the river Mersey. From south to 
north, running right across the middle of the basin, is the valley 
of the river Weaver. As the layer of flagstone does not extend 
right over the hills, which consist chiefly of the new red sandstone 
that absorbs water like a sponge, the rain that falls in those parts 
soaks down below the surface, and then, flowing in the direction 
of the lower part of the basin, gets in under the flagstone. 
Besides this, some rain will always run through the stone itself, 
wherever there may be cracks or holes, so that altogether a good 
deal of water manages to get down to the top rock-salt stratum. As 
it flows towards the lower part of the basin, it gradually becomes 
converted into brine, by dissolving the salt over which it is running. 
It seems that this dissolving takes place in the higher parts of 
Cheshire only, for by the time it reaches the lower parts it has 
become an almost saturated solution. In fact, it is then so dense 
that any rain-water from the soil above, coming in direct contact 
with it, through gaps in the flagstone, will not, on account of the 
