Across the North Sea by ecosal atlantis

What are the challenges facing archaeologists looking at the remains of the last 500 years? What are the issues for archaeology itself in today’s rapidly-changing economic and political circumstances? How can we develop a uniquely European historical archaeology? The result of a conference in 2009, Across the North Sea contains 24 papers from 28 leading archaeologists, historians, curators and heritage managers from Britain and Denmark, and explores a wide range of issues – including the development of the discipline and current practice in both countries, together with a range of case studies, and discussion of future directions. This fascinating book provides an essential guide for anyone wanting to understand the evolving discipline of historical archaeology in Britain, Denmark and the North Sea region.

Across the North Sea

What is historical archaeology?

Across the North Sea

Later Historical Archaeology in Britain and Denmark, c. 1500-2000 AD edited by Henrik Harnow, David Cranstone, Paul Belford and Lene Høst-Madsen

Across the North Sea:

Later Historical Archaeology in Britain and Denmark, c. 1500-2000 AD edited by Henrik Harnow, David Cranstone, Paul Belford and Lene Høst Madsen A joint publication of the Society for Post-Medieval Archaeology, Odense City Museums and the Museum of Copenhagen

Later Historical Archaeology in Britain and Denmark, c. 1500-2000 AD

Society for Post-Medieval Archaeology

University Press of Southern Denmark

David Cranstone

The panhouse as cradle of industry: coastal saltmaking and the ‘long Industrial Revolution’ Note This paper is the product of three projects undertaken by the present author on coastal saltmaking; the Solway Salt Project (Cranstone 2006) and the Anglo-Scottish Salt Project (interim report Cranstone 2008), both focussing on northern England and southern Scotland, and the ECOSAL project in which the author is working with Bournemouth University and French, Spanish, and Portuguese partners, focussing on the Atlantic coasts from the Straits of Gibraltar to northern Scotland (http://www.bournemouth.ac.uk/applied-sciences/ research/ecosal-atlantis/index.html , http://ecosal-atlantis.ua.pt/; formal reports in preparation). The latter two projects are ongoing at the time of writing.

The background – ways of making salt The development of saltmaking around the North Sea has received surprisingly little study, and the understanding that does exist has been distorted by incomplete understandings of the range of processes that have been used, and by differences in interpretation between national research traditions that have not communicated fully with each other. It therefore forms a very suitable subject for discussion at an Anglo-Danish conference. The development of the panhouse process in particular, centred on the 15th century and depending (I will argue) on a synergy between English/Scottish and Danish/Swedish technical advances, has much to tell us about links between Britain and Scandinavia, about the processes of innovation and technology transfer across the North Sea, and about the Medieval-Post Medieval transition. In this context, it must be remembered that England and Scotland were totally separate and normally hostile nation-states until 1603 (and united only at Crown level until 1707), whereas Denmark and Sweden (along with Norway) were united in the Kalmar Union until 1523, and Halland and Scania remained part of Denmark until 1658. Salt occurs naturally in three main forms – as rock-salt, as brines normally derived from rock-salt, and as seawater. Rock-salt is normally fairly pure chemically, but contains varying amounts of physical impurities such as marl and grit. Although rock-salt has been mined since antiquity in parts of central and southern Europe, none of these early-mined deposits lay within easy pre-industrial transport distance from the North Sea or Baltic; the first British deposits were not discovered until 1670 in Cheshire (other deposits have been discovered

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and exploited more recently), and the Danish rock-salt reserves were not discovered and exploited until the 20th century. Brines of geological origin (or at least those brine-springs which have been exploited on a large scale) were normally close to saturation (26% sodium chloride at 0°C, 28% at 100°C); they therefore required little boiling-down before salt crystallisation started. Strong brines are normally fairly pure chemically, with varying levels of mud and other physical and organic impurities. The main natural brine source within the North Sea region was at Luneberg in northern Germany, which was a major source of salt for northern Europe from the early Middle Ages onwards; the salt being exported primarily from Lubeck. English brine springs at Droitwich in Worcestershire and Nantwich, Middlewich and Northwich in Cheshire were important domestic salt suppliers from the Iron Age onwards (see for example Woodiwiss (ed) 1992, Hurst (ed) 1997 for Droitwich; the Cheshire evidence is broadly similar), though they did not produce enough to support a substantial export trade until after the discovery of rock-salt and the development of brine pumping in the 18th century. An unusual occurrence of seawater-derived brine on the Danish island of Læsø, in the Kattegat east of Aalborg, also formed an important source of salt for the North Sea and Baltic regions (Vellev 2000; Christensen 2005). On Læsø, winter storm surges soaked into a layer of sand in the subsoil just above normal sea level; summer drying then naturally concentrated the seawater to a brine containing c 14% salt, which could easily be raised from shallow wells and boiled (using wood, imported when the island’s woodland was depleted) with far lower fuel consumption than saltmaking from seawater. Seawater of course was, and is, available on all the coasts of the North Sea and the Atlantic (Baltic seawater is of far lower salinity). It normally contains c 3.5% salt, though it can be diluted by freshwater (especially in estuaries in winter) or concentrated by evaporation (especially in lagoons and inlets in summer). Unlike most rock-salt and geological brines, it contains appreciable amounts of other minerals; in practice calcium sulphate (‘panscratch’) precipitates out before the salt, whereas magnesium sulphate, sodium sulphate and potassium chloride, being highly soluble, remain in solution as ‘bittern’ until almost all the salt has crystallised out. It is traces of these (especially magnesium sulphate) that give modern sea-salt its distinctive taste, but larger amounts make the salt liable to attract moisture and liquate, and also affect its suitability for some purposes, notably for curing fish. Making salt from seawater therefore takes about nine times as much energy as saltmaking from a saturated brine. In principle, the processes divide into three types:  Solar - evaporation from seawater through to salt with no separate concentration and no artificial heating  Direct boiling - boiling from seawater through to salt with no prior concentration  Pre-concentration - removal of water or addition of salt to convert seawater to a concentrated brine before boiling. In practice, at least eight (or eleven, depending whether the variants of sleeching are lumped or split) methods are known to have been used on the British, North Sea and Atlantic coasts (Petanidou 1977, 69-181 and Vellev 2000, 81-96 for European overviews, the former concentrating on southern and central Europe and the latter on northern Europe; Collins 1682 and Brownrigg 1748 for contemporary British descriptions, except where otherwise referenced). 160

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Fig. 1. Solar saltworks at the Ecomusée du Marais Vendéen, Daviaud, on the Bay of Bourgneuf (France). Seawater is supplied by gravity from the tidal creek in the foreground to the array of concentrating and crystallising ponds in the background; the small windmill is to pump out winter freshwater. Small saltstore to right (David Cranstone phot.).

These were:  Total solar (often referred to simply as ‘solar’) – evaporation from seawater through to salt by sun and wind, in a series of very shallow interconnected ponds (often referred to as ‘pans’ in the literature, but the present author prefers to confine this term to boiling vessels, in order to minimise confusion) (Fig. 1)  Partial solar – seawater was concentrated by evaporation, but then boiled in pans to crystallise-out the salt (Fig. 2)  A range of processes referred to as ‘sand-washing’ in 17th-18th century sources, or sleeching in most of the modern literature. The salt-encrusted surface of saltmarsh silts (not actually sands) was scraped off, the salt content leached out, and the resulting strong brine filtered and then boiled in a ‘saltcote’ (a small building normally containing lead pans fuelled with peat or wood). Since the bittern normally remained in the underlying silt rather than the salt-rich crust, sleeching produced a high-quality ‘white salt’, especially when leached with fresh water rather than seawater (Sturman 1984, 52); the same was probably true of selnering. The sleeching processes can be subdivided into:

• Foreshore sleeching – the leaching and filtering stages were undertaken on the open foreshore, using mobile or temporary equipment

• Mound sleeching – the salt/silt mixture was carted to a processing area on dry land, where the leaching, filtering, and boiling stages were conducted, and the waste silt dumped to form huge mounds The panhouse as cradle of industry

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Fig. 2. Seventeenth century boiling and salt storage houses at Lymington, Hampshire, now converted to other uses. The channel in foreground is a canal, to bring in coal fuel and take out the salt (David Cranstone phot.).

• Enclosed-bed sleeching – instead of scraping up ‘sleech’ on the open foreshore, seawater was run onto a prepared (harrowed or ploughed) area behind a seawall, presumably close to the leaching and boiling area

• Sand-pit sleeching – seawater was led into shallow ponds filled with sand (in this case probably coarse sand in the modern sense, rather than silt), which acted like a blotting medium to soak it up and promote evaporation. The sand was then shovelled out, leached, and re-used, while the brine was filtered and boiled in the normal way

 Selnering – peat exposed near high-tide level and impregnated with salt was cut, airdried, and burnt, and the salt was leached from the ashes to form a strong brine for boiling. In practice the peat was burnt close to its outcrop, but the ashes were taken to nearby towns for leaching and boiling (Leenders 1989, 2004; van Geel and Borger 2002, 2005). ‘Peat-salt’ had a very high reputation for quality, perhaps because of a low bittern content (Bridbury 1955, 12-14)  Zostera saltmaking – Zostera (eel-grass) is a grass which has adapted to growing in shallow marine environments by secreting salt into internal cells; its ashes therefore contain a high salt-content and could be burnt, and the ashes leached and boiled in a similar way to peat-ash in the selnering process (van Geel and Borger 2002, 2005; van der Meer 2009). 162

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Fig. 3. Section and elevation of a developed 18th century panhouse. Seawater is pumped (in this case by hand) into the cistern and settling tank at left. The panhouse itself contains two pans (‘d’) over a coal fire stoked from a shared central forehearth area; the air supply entered the ashpits from the forehearth, rising through the firegrate and venting via flues under the pan to chimneys at each end of the building. The smoke and steam pollution is clearly shown on the elevation drawing (Brownrigg 1748, Plate II).

 Graduation – seawater or weak geological brines were raised to a trough in the top of a timber structure (a ‘graduation tower’ or ‘graduation wall’, depending on height and shape), and trickled down through a hedge-like mass of brushwood or thorns to be concentrated by evaporation (Vellev 2000, 83-87). A projecting roof provided shelter from rain, and evaporation was largely by wind rather than sun. The concentrated brine was then boiled in a boiling house, as with the other processes just described  Direct boiling. Unlike the pre-concentration processes described above (all of which, except Zostera, relied to some degree on evaporation under dry summer conditions), direct boiling depended entirely on fuel and unconcentrated seawater (strictly speaking, the process did not always involve boiling, as opposed to simmering at a temperature below boiling point). Direct boiling processes could therefore be undertaken regardless of climatic or environmental constraints, provided that some source of fuel was available. However their fuel consumption was extremely high, and in practice they do not seem to have been widely used until the Late Medieval development of the ‘panhouse process’. This relied on the combination of coal fuel, appropriate air-flow and ash-disposal structures, and very large iron pans, built into a specially designed structure – the panhouse (Fig. 3). The development of the panhouse process is the main focus of this paper.  Salt refining – an impure salt (initially French ‘Bay’ salt, later rock-salt) was dissolved in seawater to form a concentrated brine, the physical impurities settled out, and the brine boiled to recover clean ‘white’ salt. In practice, major British salt refining was an offshoot of the panhouse process; Dutch refining (important from the 15th century) may have differed. The panhouse as cradle of industry

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All of these processes had their own requirements, constraints, and implications, both environmental and social. Environmentally, the solar methods required warm dry summer weather with wind as well as sun, as to a lesser extent did sleeching, selnering and graduation; both solar and sleeching methods required low-lying coastlines with exposed saltmarsh silt for foreshore and mound sleeching and land close to high tide level but protected from tidal flooding (or slightly higher with the seawater being artificially raised) for solar and enclosed-bed and sand-pit sleeching; selnering required peat deposits exposed to occasional marine inundation; Zostera saltmaking required access to eel-grass beds in shallow sheltered waters; and by contrast direct boiling seems to have actively preferred rocky coasts (perhaps due to cleaner seawater). Refining required facilities for importing and unloading the impure salt (normally by boat). As regards fuel, all the pre-concentration methods required substantial supplies (normally wood or peat); direct boiling required very abundant and cheap fuel supplies (in practice normally coal for the panhouse process); and refining also required relatively-cheap fuel (again normally coal, at least in Britain). As well as physical availability, all these facilities needed to be socially accessible to the saltworkers, involving for example tenurial rights in a feudal economy. The saltworks were also inextricably linked into their local economies, both in terms of supply and demand (sometimes, as in fish-curing, for specific types of salt), and also for the ‘pre-industrial’ methods into the rural seasonal cycle; all of these processes were at least partially seasonal (even if their boiling stages were conducted year-round or over the winter) and conducted by part-time operatives who were often also tenant farmers or peasants (see Duncan 1812 for a description of how this functioned in a very late Scottish context). By contrast, the panhouse process and the related large-scale refining were year-round and 24-hour processes requiring a full-time industrial workforce as well as substantial investment by a landowner or entrepreneur (Whatley 1987, 15-20, 61-76). In Scotland, this led to a notorious form of industrial serfdom (Whatley 1987, 98-125).

The Medieval picture The distribution of these processes in the High Middle Ages was complex, and there are considerable uncertainties and contradictions between national research traditions. Internationally (Bridbury 1955), the Loire estuary and southern Brittany lay at the northern limit for large-scale and economically-successful solar saltmaking; ‘Bay’ salt from the Bay of Bourgneuf just south of the Loire was traded on a very large scale into northern Europe, as was solar salt from Spain and Portugal (which was considered to be of higher quality). Luneberg salt, a mainstay of the Hanseatic League, was also very widely traded, though its focus was more to Scandinavia and the Baltic. The extent and direction of salt trade varied considerably during the later Middle Ages, due to technological, climatic, economic, and political changes. As regards production within the North Sea region, Dutch white salt (initially from selnering, perhaps later from refining) was important, and English east coast salt (assumed by Bridbury to be from selnering, but in fact almost certainly largely from sleeching) was also important. The output from Læsø, though intensive within its small production area, appears to have been relatively minor within a broader North Sea context (it may have gone east or north rather than west). The extent and methods of saltmaking on the German North Sea coast (if any) is unclear. In terms of production methods, selnering was important in the Netherlands but does not appear to be positively documented elsewhere; 164

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sleeching was clearly dominant in eastern England (see below) and was also used in northern France (Sturman 1984, quoting Guettard 1768 and Gidon 1953), but does not appear to be clearly documented on the continental coasts of the North Sea; Zostera is documented in both the Netherlands and Jutland; and refining (though perhaps not by the later English method) became important in the Netherlands by the end of the period. Solar, partial-solar, graduation, and direct boiling do not appear to be positively documented (historically or archaeologically) on the Continental North Sea littorals during the later Medieval period, at least in the Anglophone literature. However this picture may well be distorted by problems of non-recognition and different interpretations within different national research traditions, as well as by the present author’s lack of linguistic skills. In Britain (Cranstone 2006, 2008; ongoing ECOSAL research by David Cranstone and Michael Fradley), the historical evidence from both England and Scotland comes largely from 12th-13th century monastic charters – it is therefore drastically biassed towards monastic saltmaking. On close reading, the cartulary entries are normally grants of preexisting saltworks to the monasteries, and often these seem to have been clusters of salinae on favourable stretches of estuarine or saltmarsh coastline being divided up between the monastic houses. The charters sometimes include a source of either wood or peat fuel (peat tending to replace wood, at least in Scotland; Oram 2012), but beyond that, and with rare exceptions, they give few clues to the process – a salina is the generic term for a saltworks, though generally not a panhouse (at least in Scotland), and a ‘saltcote’ may be specifically the boiling hut for the sleeching process, but the term may also have been applied to the boiling huts from other pre-concentration processes if these were in use. On the East Coast, there is good archaeological evidence for a massive mound sleeching industry along the Fenland and Lincolnshire coasts (Grady 1998, Healey 1999, McAvoy 1994), with vast areas of flat-topped ‘platform’ mounds of waste silt. Further north, the documented monastic salinae cluster strongly on areas of estuarine saltmarsh - notably the Tees, Blyth, and Coquet in England, and the upper Forth in Scotland (Cranstone 2006, 2008), with a smaller concentration on the Montrose basin and documented place-name evidence for the Moray saltmarshes near Elgin (Oram 2012); the last of these may reflect David I’s plantation of a southern Scottish/Anglo-Norman aristocracy and economy into Moray in the mid-12th century (Oram 2011, esp 82-84, 318-319). However a documented site at Altens near Aberdeen lies on a rocky coast more suitable for direct boiling. Sleeching mounds are now known as far north as north Northumberland (fieldwork on the east coast Scottish locations has not yet been undertaken). To the south, large sleeching mounds appear to occur intermittently on suitable estuaries and other saltmarshes in East Anglia, Essex, Kent, and Sussex, extending their distribution to the eastern part of the Channel coast. However the picture is rather different in western Britain. For southwest England, the rather limited documentary evidence suggests a strong focus on Lymington (on the Solent in Hampshire), the later centre of partial-solar production. However the historical evidence (Hughes 1934, 84) strongly suggests a switch in 1625 from mound sleeching (‘sand mounds’, which were prohibited) to the partial solar process (‘floor pans’ – the phrases ‘floor pans’ and ‘salt floors’ are widely used in 17th century documents in contexts where it is clear that they refer to solar ponds), and fieldwork has identified features which may well be sleeching mounds modified by later activity. Further west (from Dorset round to north Devon), very limited documentary evidence is supplemented by ‘saltern’ (not ‘saltcote’) placenames; the precise significance of ‘saltern’ is uncertain, but on 17th century charts it does seem to be The panhouse as cradle of industry

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used for (partial) solar works. However locations such as Bideford on the exposed west coast of Devon do seem unlikely for successful long-term partial-solar production. Very little archaeological field evidence has yet been found within the region. It is possible that production in this area fluctuated between the two processes in tune with climatic fluctuation, and also that local production was less than might be expected due to the easy availability of imported ‘Bay’ salt and/or of Droitwich white salt. From north Devon via the Bristol Channel and Wales to southern Lancashire there is very little evidence, historical or archaeological, for any Medieval coastal saltmaking; the most likely explanation is competition from the inland Droitwich and Cheshire sources. From the Ribble estuary in Lancashire northwards to the Solway (including its Scottish side), both cartulary references and ‘saltcote’ placenames are again common, and there are clear post-Medieval descriptions of sleeching from Lancashire (Collins 1682, 27-28, including both mound (or possibly foreshore) and enclosed-bed variants), Ulverston in south Cumbria (Brownrigg 1748, 135), and Ruthwell in Dumfriesshire (Duncan 1812). However fieldwork throughout this region has consistently failed to identify substantial ‘East Coast type’ sleeching mounds; the few sleeching mounds which have been located are tiny in comparison, and the field evidence when it can be located at all is dominated by slight earthworks of tanks, pits and channels whose interpretation in terms of process is unclear. It is possible therefore that this area was dominated by enclosed-bed or foreshore sleeching, or by one of the non-sleeching processes. A grant in the 1190s (Todd 1997, 87) to Wetheral Priory of ‘duas salinariis cum ariis’ (‘two saltworks with floors’) and rights to a supply of peat on Burgh Marsh (on the English side of the Solway, just west of Carlisle) almost certainly indicates a partial-solar works, but could be either the clue to the main process in the area or an unusual and perhaps short-lived exception; the modern climate of the Cumbrian coast suggests the latter. The very limited evidence from the Ayrshire coast, further north again, is discussed below since it may bear on the evolution of the panhouse process.

The development of panhouse saltmaking As already noted, the panhouse process was a form of the more generic direct boiling process which in its developed form combined the use of coal fuel (specifically small coal rather than the large lump coal needed for domestic consumption), appropriate ash-removal, air supply and heat-distribution facilities (ashpit, firegrate, under-pan flue system, and chimney), and very large iron pans which could withstand the heat (including the inevitable ‘hotspots’ on a large underside exposed to the fire) and sulphurous fumes of the coal, and offer a wide surface area for efficient evaporation (Fig 3). The latter two elements were ‘house-built’ (to borrow a term from steam engine-house terminology) into a single purpose-designed ‘panhouse’ structure. The huge pan was presumably the most remarkable feature of the works to contemporaries (at least in its early days when terminology was developed and then fossilised), since it was this that entered the language (English and Scots) in forms such as Prestonpans; ‘pan’ names appear to be diagnostic indicators of panhouse works, and in Latin documents patella appears to have had, or at least developed, a similar connotation (at least in Scottish Latin – salina continued to be used in English Latin documents for what were clearly panhouse works). The pans were normally fabricated from plates of wrought iron, though cast iron pans were occasionally used, at least in the 17th century (Collins 1682, 49); by the 1750s (when pan sizes had probably increased consider166

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ably from the 15th-16th centuries) a single pan at South Shields used 125 plates weighing 6-7 tons in total, and lasted 12 to 15 years with regular maintenance and repair (Berg and Berg 2001, 243). The pans required good quality wrought iron: the plates in the partial-solar panhouses at Portsea were made from non-phosphoric Forest of Dean iron rather than the local Wealden iron (Collins 1682, 50). As an economically-successful technology, panhouse saltmaking therefore required a well-developed coal mining industry able to supply large quantities at low prices; this had developed in several areas of both England and Scotland by the 15th century (Hatcher 1993), most notably on Tyneside which supplied the domestic fuel needs of London and much of eastern England via a well-developed coastal shipping trade. However there was a synergy – the domestic market required large lump coal, whereas the panhouse with its efficient combustion system could use small coal which was otherwise often literally a waste product. This in turn had an implication for the future - the ashpit/firegate/flue system probably originally developed in panhouse saltmaking eventually rendered developments such as the steam-engine boiler and the reverberatory furnace possible. The panhouse also required large quantities of good-quality plate iron, again at affordable prices. In England, despite considerable research on bloomery ironmaking there is surprisingly little information on semi-finished products such as plate, or on the relative importance of domestic production and imports. Childs (1981) implies that in the 15th century imports may well have outweighed home production; for England as a whole these imports were overwhelmingly from Spain, but for east coast ports Baltic (including Swedish and any Danish contribution), central European, and Low Countries imports were also significant. The physical form is rarely specified, the only identifiable import of plates seemingly being from Flanders. Threlfall-Holmes (1999), looking specifically at the iron supplies to Durham Priory between 1464 and 1520, finds that ‘Spanish’ (the term is probably literal, rather than generic for imported iron) iron strongly outweighed local until 1485, when the proportions abruptly reversed; plates are not mentioned. No equivalent analysis has been performed for Scotland; Richard Oram (pers.com.) suggests that Scottish domestic production before the 16th century was minor. In analysing the historical evidence for the transition to panhouse saltmaking, it is necessary to be cautious in using secondary sources; unfortunately many recent historians, from the 19th century onwards, have used ‘pan’; or ‘saltpan’ indiscriminately to refer to any saltworks, including those referred to as salina in the contemporary primary documentation. The following analysis is therefore restricted to cases where the original wording is quoted, or where the author has been able to check with a primary document or published transcript (a work in progress). The earliest references to patellae so far located come from the west coast of Scotland in the late 12th century; in or soon after 1174 the Cistercian abbey of Melrose was granted a patella in the township of Preston (at the mouth of the Nith south of Dumfries, not the Preston on the Forth which later became Prestonpans), and in the 1190s the same abbey was granted a salina and a patella at Greenan near Ayr on the outer Firth of Clyde (Fawcett and Oram 2004, 243-244; Oram 2012; Richard Oram pers. comm.). Both grants included woodland for fuel, though they are in locations where outcropping coal should also have been available. The Preston grant may simply have been a chance usage of patella rather than salina, but the Greenan grant clearly distinguishes between the two and is also unusual in that only ten years later it was replaced by two saltworks at Turnberry (further The panhouse as cradle of industry

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south on the Ayrshire coast) because the woods at Greenan had been ‘completely burned and destroyed’. One possible interpretation is that the Greenan site was a then-unusual direct-boiling works, with the patella being a very large concentrating pan (whether of lead or iron) and the salina a more normal crystallising pan, and the grant of woodland adequate only for the far lower demands of a sleeching works. Fieldwork indicates that much of the Greenan coastline is rocky and suitable for direct boiling though saltmarsh may possibly have been available on the nearby Doon estuary. At Turnberry the name ‘Pan Knowe’ (northeast of Turnberry castle) is probably a later coinage but may well indicate the location of one or both of the Medieval works; if so both the name and the coastline indicate direct boiling. The earliest recorded use of coal in saltmaking comes from Whitehaven in Cumbria (England), where in the mid-13th century the monks of St. Bees Priory were granted (or confirmed) the right to take coal from their mine in the cliffs to their nearby salina; details in the document point to one of two alternative locations, both on exposed coasts more suitable for direct boiling than for sleeching (Cranstone 2006, 95; Cranstone 2007, 28-29, 139-141). The earliest known English/Scots usage of ‘pan’ as a site or placename also comes from England, in this case from the north east: Wearmouth Priory had saltpans (the word does appear to be used in the original documents) at Sunderland from at least 1437 and since Sunderland also had a coal staithe by this date it can be assumed that the pans were coal-fuelled (Meikle and Newman 2007, 89-91; Cookson 2010, 6). However this did not mark the take-off of a major salt industry in north-east England; the Wearmouth pans probably remained in use until the Dissolution, but the industry had not expanded and had to be re-established later in the 16th century on a new site where it did indeed become important (Meikle and Newman 2007, 96-102). The crucial step-change occurred at the end of the 15th century with the establishment of the South Shields industry in a town with no known earlier saltmaking. In 1489 a Lionel Bell leased land from Durham Priory on which by 1499 he had constructed two iron salt-pans (the first specific mention of iron pans in England, on present knowledge), and in 1490 John Raker or Raket also leased land with permission to erect ‘pannys’ with seawater storage pits and conduits. The industry rapidly expanded, becoming the centre of English coastal salt production from the 16th century until eclipse by ‘inland’ Cheshire salt in the 18th century. By the 1530s the cathedral-priory of Durham (a major landowner throughout the county and also a consumer of salt, whose Medieval records largely survive) had switched its main source of supply to South Shields from its consistent earlier reliance on its Tessside sleeching works (Hodgson 1903/1996, 61, 64; Page 1905, 293-295). This rapid and successful expansion, with no evidence of experimentation or ‘learning-curve’ failures, looks like the adoption of an already-developed new technology rather the processes of technological innovation and development. However it is not clear whether the impetus came from Durham Priory as landlords or from Bell and Raker/Raket (and perhaps other lessees at around the same time), whether Bell and Raker/Raket were entrepreneurial manufacturers or merely investors, or where they (or the expertise of their employees) came from – the names are English rather than Scottish or indeed Continental. In this context, it is unfortunate that virtually no documentary evidence for 15th century saltmaking in Northumberland is known to survive. Tynemouth Priory had earlier-Medieval salinae (presumably sleeching works utilising the limited areas of suitable terrain on the north bank of the Tyne) which in general terms evolved into the important North Shields 168

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panhouse industry documented from the Dissolution onwards (Craster 1907, 17-19, 56, 114, 297-301), and Newminster Abbey (along with other monastic houses) had 12th century salinae at Blyth which by 1534 had evolved into seven ‘salt-pannes’ (Page 1909, 318, 350352). North Shields or other precocious Northumberland panhouses may well have been the immediate source of the technology introduced to South Shields from 1489 onwards, but on present evidence there is absolutely no indication of any major take-off in either production sites or outbound salt trade before the 16th century. In Scotland however the picture is very different (Oram 2012). As already noted, there are hints that direct boiling (in its generic sense) was occasionally used throughout the Middle Ages, though sleeching appears to have been the main process of salt production. Oram also argues for a major switch from wood to peat fuel during the 12th century, reflecting competing pressures on the limited woodland resources; the switch from renewable to semi-fossil fuel may have eased the subsequent transition to coal (certainly in terms of access rights to below-ground rather than growing resources, and the linkages to the broader agrarian economy and workforce). Although peat reserves as such did not come under widespread pressure within the period, the climatic deterioration of the 14th century may have seriously affected the viability of sleeching (perhaps much more so in Scotland than much of England, with the former’s cooler and more marginal climate). Oram draws attention to the problems potentially caused by cool wet summers for large-scale peat-cutting and drying, and the present author would add the similar effect on sleech ‘harvesting’; at Ruthwell on the Solway there were often only 12-14 days of suitable conditions per year in the early 19th century (Duncan 1812, 528-529). Whatever the reasons, a switch to coal fuel was already underway by c 1400. Newbattle Abbey had held saltworks at ‘Preston’ (the modern Prestonpans, east of Edinburgh) from the 12th century, though there is no evidence that they were using coal at that time. The abbey was certainly developing coal mines on its Preston grange lands from the 13th century, and by the beginning of the 15th century the burgh of Preston had ten saltworks producing 800-900 bushels per week (http://en.wikipedia.org/wiki/Prestonpans accessed 3/05/2012; the remainder of this paragraph derives from Oram 2012), the number of works and scale of production strongly suggesting that they were coal-fuelled. By 1438 the provost of nearby Tranent coalworks was delivering substantial quantities of white salt to the Scottish Crown. In 1460, a number of Scottish abbeys re-allocated their saltmaking interests around the Firth of Forth, with Newbattle and to a lesser extent Melrose consolidating onto Prestonpans; Melrose held three patellae seemingly on rocky outcrops and with a storehouse between them. From the same date, references to major saltworks, many specifically referred to as pans or patellae and/or as being coal-fuelled, become common throughout the coalfield coasts of the Forth, as opposed to the non-coalfield saltmarsh areas. A new and rapidly-growing Scottish export trade also developed; as early as 1456 substantial quantities of Scottish salt were being imported into Hull (confirming that the Scottish industry was in advance of the English), and from the 1460s onwards rapidly-increasing quantities were exported both from Edinburgh and Prestonpans on the south side of the Forth and from Dysart and Ravenscraig on the north. Most of these exports went to the Baltic and Scandinavia; although they formed only a small proportion of the Baltic salt supply (compared to Luneberg, ‘Bay ‘ salt, and Spain and Portugal), they were substantial in terms of their contribution to the Scottish economy - a picture which continued through the 16th and 17th centuries, with considerable fluctuations due to political factors, and led to the imposition of The panhouse as cradle of industry

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serfdom on salters and colliers due to the essential nature of their linked occupations to the Scottish economy (Whatley 1987, 7-8, 98-125). The missing element in the preceding discussion has been the nature of the actual pans. The first explicit mention is not until 1488, when an iron lacus is recorded at Prestonpans (Oram 2012 and pers. comm.). The use of lacus may indicate that patella had come to mean specifically ‘panhouse’, the structure of which the massive pan was an integral part, whereas the English/Scots word ‘pan’ could have either meaning according to context. However given the practical difficulties of using lead pans with coal fuel, especially with production on the scale documented, there seems little reasonable doubt that iron was used from well before 1488 (and there is equally no evidence for the use of lead pans, or for the massive demand for lead which that would imply). The evidence indicates that a substantial coalfuelled salt industry was in existence by c. 1400, with perhaps a step-change in scale from c. 1460. The ‘technological package’ of coal fuel, efficient furnace and flue-system, and massive iron pans fabricated from plate iron presumably developed over a period of time, and it is possible (and probably correct) to envisage a number of intermediate steps such as lead pans over coal, inefficient coal-burning under either metal, and small single-piece iron pans; the evidence does suggest that the use of coal was an early element of the package, but otherwise it would be unwise to make assumptions. If the large multiplate iron pan was indeed the final element that made panhouse saltmaking an internationally-competitive technology, its adoption should date from no later than c 1460. The source of the iron, and specifically of plate iron in large quantities and at affordable prices (as well as of the expertise in rivetting and sealing the joints), and of the substantial quantities of other ironwork that went into a panhouse installation, is unknown; it is assumed that (as in later centuries) the pans were fabricated on-site, from plates bought-in from elsewhere. As noted above, it is unlikely that Scottish domestic iron production was equal to the task, and the admittedly-limited evidence from England gives no indication that plate iron was being produced in such quantities let alone exported to Scotland (especially when the English salt industry was conspicuously not showing the early take-off of the Scottish). Of the possible Continental sources, the geographical locus of the Scottish breakthrough, coupled with the evidence of salt exports to the Baltic, immediately suggests Sweden and/or Danish Halland and Scania as the most likely source; this latter area had a substantial bloomery iron industry throughout the Middle Ages, including early water-powered forges, and Ălvsborg (near Gothenburg, on the then Swedish/Danish border) was certainly exporting iron to Scotland by the 16th century (Geijerstam and Nisser (eds) 2011, 32-35, 38-39, 49-50) Intriguingly, Halland did indeed have connections to saltmaking as well as to iron (Vellev 2004, 37-66; I am very grateful to Katia Hueso Kortekaas for translating the important passages for me). The estate of Tvååker in Halland was granted in 1197 to the Cistercian monastery of Sorø on Zeeland; at this time Tvååker produced both iron and salt, though it is not clear whether the two were closely linked, or how the salt was produced except that it involved wood-fuelled boiling. The area continued to produce iron throughout the Middle Ages. From 1515 to 1518, two residents of Sybbarp (an adjacent parish to Tvååker) were involved in a legal dispute over their share in a ‘saltkettle’ (the connotation seems to be similar to that of patella/pan) on Læsø, which was clearly of iron; the grandfather (Bjørn Smed Bjørn Smith) of one of them had constructed this pan and taken it to Læsø. Assuming a generation-length of twenty years, and that the grandfather was of similar age to the 1515 deponents (who were probably young, since they were trying to establish their title), this 170

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would give a construction date for the pan in the 1470s; if the generation-length was longer, or the grandfather much older than his grandsons, the date could go into the earlier 15th century. Since the pan was still in use (though presumably much repaired) it had presumably been successful – whether its construction had been an innovation or merely a routine event that had happened to become subject to a legal dispute, and whether iron pans were the norm on Læsø, is not clear. The later history of panhouse saltmaking can only be very briefly summarised. In Scotland (Whatley 1987), it remained totally dominant until the final eclipse of British coastal saltmaking in the 19th century (see below), and formed a very important element in the Scottish economy from the later 16th to the 18th centuries. In England, the picture is more complex, and the main existing synthesis (Hughes 1934) is now very dated, does not distinguish clearly between the technologies, and is as riveting a read as its title (Studies in Administration and Finance 1558-1825) suggests. Despite Hughes’ (1934, 31-66) emphasis on patents, monopolies, and the doings of Elizabethan courtiers and the mainly-German experts (with or without inverted commas) that they introduced, the present author’s impression is that these had limited impact on the reality of English (and Welsh) saltmaking, in which the panhouse industry centred on Tyneside gradually rose to dominance and began to displace sleeching. This process continued through the 17th century, with the addition of the Lymington/Portsea partial-solar process in the limited south coast areas which were climatically suitable. By the end of the century, however, coastal saltmaking began to decline in the face of rapidly-expanding Cheshire production, triggered by the discovery of rock-salt in 1670, the abolition of Medieval restrictions on saltmaking at the traditional ‘wiches’ in the 1690s, and construction of a river navigation (and later of canals) which greatly eased the transport both of coal fuel to the salt towns and of rock-salt and white salt from them to the port of Liverpool. This process continued through the 18th century, tempered somewhat by a floruit of salt refining using Cheshire rock-salt and affecting Scotland later and more gradually than England, and by the early 19th century coastal panhouse saltmaking was of negligible importance, though the last traditional coal-fuelled works, at Prestonpans, did not close until 1959.

Conclusions Panhouse saltmaking formed probably the first coal-fuelled industry anywhere in the West, in the sense of a process actively designed round the use of coal fuel rather than getting away with coal use in processes that primarily used wood or other fuels (such as smithing and limeburning). It was here that the practical problems of using coal (especially small coal) as an industrial fuel were first resolved, laying the foundation for much of the Industrial Revolution. Panhouse saltmaking also pioneered the switch from renewable to fossil fuels, and the problems of massive air pollution from its smoke (regularly commented on by observers from the early 17th century onwards). It also played an important role in the development of capitalist industry and of an industrial working class. It was therefore a development of considerable importance – arguably the beginning of the ‘long Industrial Revolution’. The evidence presented in this paper indicates that the development of the panhouse process took place from the 12th to the 15th centuries, initially across a wide area of northern England and southern Scotland but coming to fruition in central Scotland in the 15th century; this fruition probably arose from cross-fertilisation between English and Scottish expertise in coal mining with Swedish and Danish expertise in ironworking. The panhouse as cradle of industry

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Fig. 4. The 16th-17th century saltworks at Port Eynon, Wales. Seawater storage and pumping area in foreground; the actual pans were within the building at a higher level behind, but the detailed arrangement did not survive (David Cranstone phot.).

However many questions remain, some of which are more likely to be solved by archaeological work than by historical research; it will have been noted that this paper has in fact relied almost entirely on historical rather than archaeological evidence. This is because virtually no archaeological work has been done on saltmaking in the crucial areas and periods; the earliest excavated panhouses are at Port Eynon (south Wales) (Fig. 4) where the actual pans appear to have been placed on an upper level and did not survive (Wilkinson et al 1998), and Brora (northern Scotland) (Fig. 5) where only the back wall of a 1598 panhouse survived although the associated salt storehouse was well preserved as were remains of a separate 18th century works (Dawson and Hambly 2011). Our understanding is therefore very much conditioned by the excavated 18th century sites of Preston Island (Ewart et al 1996) and St Monans (Yeoman (ed) 1999), both in Fife, Scotland, which may have been very different from their 15th-16th century predecessors. At a technological level, excavation, archaeological science, and historical research are desperately needed on sites which may illustrate the transition to the panhouse process â&#x20AC;&#x201C; the model presented in this paper needs testing and fleshing out. How does the archaeological evidence, when we acquire it, relate to the often imprecise historical evidence, and what was (perhaps) going on on the ground that is not mentioned in the surviving historical record, or may even actively contradict it? And can the development of a saltmaking proletariat and their material culture be investigated? At a broader level, is the apparent connection between early panhouse saltmaking and monastic houses, especially Cistercian houses and even specifically Newbattle and Melrose Abbeys, an artifact of the patchily-surviving his172

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Fig. 5. Brora, Highland Region, Scotland. Salt store (‘girnel’ in Scots) of the 1598 panhouse works during excavation. The actual panhouse lay behind to the left, but had been largely destroyed by erosion (David Cranstone phot.).

torical evidence or genuinely significant? Can the connections across the North Sea between Scottish saltmaking and Scandinavian ironmaking be demonstrated, or refuted? Combining the last questions, did the Cistercian Grand Chapter play an important role as a venue for technology transfer that helped to shape the transition from the Medieval to the modern and capitalist world? Or were the connections more broad-based, merchantilist, and to an extent bottom up, with the demands of Scottish saltmakers influencing the development of Swedish/Danish ironmaking in way that prefigured the broader web of connections between Swedish ironmaking, British ironworking, and (by then) the Atlantic world (Evans and Rydén 2007)? This paper has, I hope, raised far more questions than it has answered.

Acknowledgements As well as previous work, this paper is based on two current projects: the ECOSAL Project funded by the EU INTERREG programme, on which I am working for Bournemouth University, and the Anglo-Scottish Salt project funded by English Heritage and Historic Scotland. I am grateful to these funding bodies, and to Professor Mark Brisbane and Dr Michael Fradley of Bournemouth University, Gildas Buron, Jesús Carrasco, Belén Escobar, Andrew and Annelise Fielding, Katia Hueso Kortekaas, Loic Menanteau, Renato Neves, Benoit Poitevin, and other partners in the ECOSAL project for their friendly co-operation. The panhouse as cradle of industry

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My thanks also to Professor Jens Vellev (Aarhus University) for generous help and copies of his publications, to Professor Richard Oram (Stirling University) for many useful email discussions and a pre-publication draft of his 2012 paper on Scottish saltmaking, to the participants at the Mariager/Laesoe salt conference in 2008, to Henrik Harnow and other participants at the â&#x20AC;&#x2DC;Across the North Seaâ&#x20AC;&#x2122; conference, and to the many other colleagues from whom I have learned so much about salt over the last few years.

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Across the North Sea

What is historical archaeology?

Across the North Sea

Later Historical Archaeology in Britain and Denmark, c. 1500-2000 AD edited by Henrik Harnow, David Cranstone, Paul Belford and Lene Høst-Madsen

Across the North Sea:

Later Historical Archaeology in Britain and Denmark, c. 1500-2000 AD

Society for Post-Medieval Archaeology

University Press of Southern Denmark