Technology & Change in the Early Modern Period
By about the 1620′s the cost of wood for firing the pans had become unsustainable and the Cheshire salt makers were forced to change to cheaper coal, now readily obtainable from mines in Lancashire, East Cheshire and North Staffordshire.
They were to find however that using coal with their traditional method of salt making in lead pans frequently melted the lead. When the Earl of Huntington visited Nantwich in 1635 he noted that some salt makers were repairing pan leakages almost daily. The result was a gradual change from lead pans to iron pans.
There are medieval records of coastal salt making in lead pans with sea coal fires and this was no doubt quite practical with a slow fire at the salt crystallisation stage. But the Cheshire Rules of Walling limited the times of salt making and the aim was to evaporate the brine as fast as possible in the time available.
Visitors to Cheshire salt towns in the 16th century observed that brine was distributed to each salt house along a system of overhead wooden channels and it is natural to assume that there must have been a method of metering this flow of brine. For obvious practical reasons the number of channels would be limited with one crossing the river and flowing to a communal storage cistern. In the 1624 survey of walling lands we do indeed find that there was a “common cistern ” between the Great and Little Wood Streets and extending for their full length.
The surviving documents which record that the fires under the pans were only allowed to burn for set periods of time refer to this as “walling in kale” and this was in effect the system of metering the brine since there was a limit to the amount of salt that could be made in each pan in a given time. All pans were of a standard size which a Ruler of Walling would check with his “gauge”.
There would have been an incentive to boil the pan as rapidly as possible to make as much salt as possible without melting the lead. In the Nantwich Manor Court Rolls we find that named wallers were fined for burning “kidds” -ie faggots – and it seems likely that, like coal, these burned too hot for a lead pan which was the property of the owner. Wallers were also fined for “walling out of kale”
The change from lead to iron was not without its disadvantage. Lead pans did not corrode and were easy to make and moreover the old pans were readily recycled into new pans. Riveted wrought iron pans on the other hand were expensive to fabricate, corroded by the brine and rust could discolour the salt. They were also not recyclable like the lead pans.
Since Roman times, there had been a standard convenient size for lead pans and a 17th century Nantwich record quotes three-feet by two-feet for the “ancient lead”. At first the Nantwich Ruler of Walling required the iron replacements to be the same size as the lead pans but soon four iron pans four-foot square were allowed to replace the six lead pans. All Nantwich pans had been converted to iron by 1650 but the break down of the ancient controls on salt making was slow at Nantwich whilst elsewhere change was rapid. As early as the 1620′s salt works had been established by the Booth family in the Bollin valley on their Dunham Massey estate south of Manchester and by the Smyth, Needham and Delves families on their land alongside the Weaver above Nantwich. These salthouses had single large iron pans and coal fires and similar conversions were made at Middlewich and Northwich.
The 17th century was to see the widespread adoption of the brine pump worked either by hand, waterwheel or horse gin. Such pumps are illustrated in Agricola’s De Re Metallica of ca 1550.
At Northwich in 1669, Earl Rivers established a saltworks with three large iron pans on Leftwich Eye just beyond the town boundary. Surviving accounts show that the pans were worked continuously and according to the demand for salt and availability of coal. Salt was stockpiled in the loft above the hothouses and coal was stockpiled for the winter months. There is no reference to Rules of Walling. Eggs, blood and ale are still used to clarify the brine and this pattern of inland salt making would be typical for the next century but with growing size of pan.
In spite of the developments of a “free trade” at the other salt towns, Nantwich was still endeavouring to work to its Rules of Walling in 1695 when Samuel Acton, who was himself an Occupier, dug a new brine pit on his walling land and began to make salt continuously, and regardless of any rules. The Town brought a High Court action which Acton won on appeal and was awarded costs which bankrupted the town. Acton remained in business as a salt maker and took over the town pit. But this was essentially the end of Nantwich as a significant salt town.
Rock Salt Refining
Earl Rivers was obtaining his coal by packhorse and the occasional wagon. Much came from Lancashire and some came part of the way by boat up the Weaver to its tidal reach at Pickerings. While seeking a nearer supply of coal, rock salt was discovered near Northwich in 1670. Its discovery was recorded in a letter from Adam Martindale to the Royal Society which appeared in the December 12th 1670 issue of the ‘Philosophical Transactions’:-
“A gentleman of good account and reputation assures me that in our County there is lately found out a great rarity, viz. a Rock Salt from which issues a vigorous sharp brine, beyond any of the brine springs made use of in our salt works. ………. I have just returned from visiting the salt work and find things according to my Friend’s Relation: ….The first discoverer of it was one John Jackson of Halton about lady day last, as he was searching for coals on the behalf of the Lord of the Soil, William Marbury Esquire.”
By the 1690s, there were several rock pits in the area and the brown rocksalt was refined to white salt by re-crystallisation from water. Liverpool merchants were quick to realise that re-crystallisation from sea water would give a ten per cent saving and refineries were established on the Mersey estuary at Liverpool, Dungeon and Frodsham. Another was established on Hilbre in the Dee Estuary.
Coastal salt-making flourished in the 17th century, especially where there was a coastal coalfield such as Cumberland, Ayr, Tyneside and Fife where there the Crown continued to encourage innovation. A revealing account of one example of this innovation is to be found in Sir William Brereton’s “Travels” of 1635 (Chetham Society Volume I, 1844) in which he likens a new salt works at Shields to the salt works of his brother[in-law] William Booth of Dunham Massey.
At the traditional salt ports of Southern England trade continued and salt making was expanded by the import and re-crystallisation of the grey Bay Salt by the “salt on salt” process. The discovery of Cheshire rock salt presented a new opportunity and numerous refineries were established to the alarm of the Cheshire white salt makers. Further growth of coastal refineries outside Cheshire was prevented by the 1702 Act.
G D Twigg – February 2003
Making salt required vast quantities of timber to heat the salt pans and evaporate the water from the brine. This resulted in extensive reduction of the Cheshire forests. Lancashire and Staffordshire coal started to arrive at the Cheshire wiches as a replacement fuel for the salt pans. The same pack-horse trains which brought the coal, took salt to growing markets in South Lancashire and the Potteries.
The destruction of Cheshire timber and the need to obtain fuel allowed Liverpool merchants a foothold in the highly conservative salt trade. They raised Northwich from a sleepy, dirty town, “full of smoak” riddled with restrictive practices, to a centre of British salt production.