[March, 
1 1-8 Salt Industry of England. 
the form of a small quadrangular though irregular pyramid. 
For common salt the temperature is i6o° to 170°. The salt 
thus formed is close in texture and clustered together in 
larger or smaller pyramids according to the heat applied. 
For large-grained flakey salt the temperature is 130° to 140°. 
For large grained fishing salt the temperature is 100° to no 0 , 
the slowness of the evaporation allowing the salt to form in 
large cubical crystals, although it appears they are not 
perfect cubes. To produce these kinds, foreign matter sup- 
posed to be of a harmless kind, such as the white of eggs, 
calves and cows feet, ale, flour, resin, butter, alum, &c., have 
long been added to the brine for clarifying and to promote 
crystallisation. 
The earthy matter contained in the brine is got rid of in 
the manufacture by its adhering to the pans in the form of 
scale, called pan-scale, or pan -scratch. There is also the 
chloride of magnesium, called bittern, which remains in 
solution after the chloride of sodium, or common salt, is 
formed. This is often purposely allowed to flow away by 
having the floor, called the hurdles, on to which the salt is 
lifted from the pans, lower than the top of the pan. The 
pans are of various sizes, the only limitation being that they 
must not be too wide for a man to draw out the salt with a 
ladle. They are commonly made of wrought iron, three 
eighths of an inch in thickness, and about 50 or 60 feet 
in length by 24 or 25 feet in breadth, and 2 feet in depth ; 
but some of the new pans are 140 feet by 30 feet by 2 feet. 
In the early manufacture of salt, it appears that evapora- 
tion was by the heat of the sun, and the operation of the 
air. The brine or sea water was run into shallow pits or 
reservoirs, where it evaporated to a certain degree, and was 
afterwards completed by pouring it upon twigs, and some- 
times, it is said, by pouring it upon burning wood, and 
collecting the salt deposited upon the ashes. Until long 
after historic times wood was the only fuel used, and the 
large consumption for this purpose seems to have been early 
complained of. It was not until the year 1656 that the 
substitution of coal at Nantwich is mentioned as a novelty. 
The brine springs, which flowed naturally into the valleys, 
would probably be used first, and when they began to fail, 
or become insufficient for the increasing wants, it appears 
they were followed down with buckets and with pumps 
worked by hand, water-wheel, and windmill, until now, 
when the only method used for pumping is the steam 
engine. 
