Belfry Bulletin

Search Our Site

Article Index

Mendip Mining

Large areas of gruffy ground containing old mineshafts are a feature of Mendip; and this article is intended to give a resume of the history and development of these landmarks, with which we are so familiar at the Belfry.

Lead mining on Mendip was almost certainly commenced by Early Iron Age people, perhaps two hundred years BC.  Evidence of this was the discovery of lead net sinlers at Mere and at the later lake village at Glastonbury. This early form of smelting probably consisted of roasting lumps of galena (lead sulphide) in an open fire, and then allowing the molten lead to run over the stone fire base into rough clay moulds.

It took the Roman brain to organise the Mendip mines into a large concern, and these were under imperial control within a few years of the Claudian invasion of 43AD.  Large pigs of lead have been found at Charterhouse; Wookey Hole; Bristol and other places, all bearing Roman inscriptions and clearly having been mined on Mendip.  A pig of lead found near Green Ore bore the inscriptions EX.ARG.VERB. which could be translated as either ‘from the silver mines’ or ‘desilverised lead’. Whether the practice of extracting silver was a common or widespread one in Roman times is not yet known; much of the smelting having been carried out in villas and other small sites where few remains exist on which to base tests for desilverisation.  In a field south west of Fair Lady Well, the plough has turned up many fragments of Samian ware, and several lumps of a heavy, pink, crystalline material, together with a few weathered pieces of lead and galena. X-ray diffraction has shown that this pink substance is crystalline litharge (lead monoxide).

Crystalline Litharge can only be found by the cooling of a litharge melt – its melting point is 879 degrees centigrade – and this temperature is considerably greater that is usually associated with galena.  Further examination showed that silver was conspicuous by its complete absence and that the material contained no sulphite or sulphide.  Thus, the material could have not been normal slag from the process of smelting galena.  In any case, it would have been a very inefficient process to leave a third of the slag behind as lead.  This, plus a comparison of the silver content with normal galena found near the Belfry site, proved that the desilverisation was actually carried on at the site of the Roman villa behind the Belfry.

The method the Romans used for extracting the sliver is known as cupellation.  It is mentioned by Pliny – a Roman historian.  After roman times, the process is lost, and was rediscovered by Patterson in 1833.

The early method of desilverisation lead was to allow the molten metal which contained all the silver from the ore, to cool slowly.  The first crystals to appear were pure lead and these were removed, usually with a perforated iron ladle.  This process was repeated until about seven-eighths of the lead had been removed. The remaining alloy, rich in silver, was then melted on a flat ‘cupel’ or hearth, usually made of limestone clay or a barites/clay mixture, in a blast of air.  As the temperature obtained was greater than 900 degrees centigrade, the litharge formed; flowed away, and took with it some of the calcium, manganese, aluminium and other metals present as impurities.  On cooling, it crystallised into the pink crystalline litharge which was found near the Belfry site.  The rest of the litharge was absorbed in the porous cupel, leaving a shining globule of metallic silver about 99.95% pure.

Just when this sophisticated process was introduced by the Romans on Mendip is not known.  Caesar, in De Bello Gallico’ makes no comment of silver when referring to the economic value of Britain Cicero, when writing to a friend, says, ‘it is well known that there is not a pennyweight of silver in the whole island’. Nevertheless, according to Strabo, silver was one of the main exports of Britain by the time of Augustus, and we can be reasonably certain that some of this came from Mendip lead – refined on the spot, one of those spots being behind the Belfry.

Excavation carried out by the Rev. Skinner and indirectly by the Mendip Mining Company in the last century revealed Charterhouse as the hub of Roman mining activity.  The Town Field and Raynes Batch Field contained a number of square and circular mounds around which were found pottery; coins; smelting refuse and the remains of furnaces.  A small amphitheatre was also found, the remains of which are still conspicuous today.

A fairly large Romano-British community must have lived, mined and smelted in the area from AD49 to the end of the Roman occupation in AD410.  Mines were probably open trenches following the ore veins.  The amphitheatre was used for sports like bear-baiting; cock-fighting and wrestling.  The provision of food for this community must have been a problem but the excavation of a Romano-British farm in the Chew Valley by Ratz and Greenfield has given rise to a theory that this valley may have supplied the miners with farm produce.

Several postulates have been made about the route used by the Romans for transporting Mendip lead. Certainly, there is a Roman road from Tyning’s Farm down to Cheddar which, unlike the usual Roman road, is not straight but was designed to drop off Mendip at an almost uniform gradient all the way.  This would have been a very convenient arrangement for a road used for the transport of heavy loads.  Hoare, who surveyed a Roman road from Old Sarum to Uphill, considered that the ingots travelled to the continent by boat from Uphill.  An alternative, and more likely route, was the overland route to the south coast, and then by sea to Gaul, possible from Axmouth.  Uphill may have been a point for shipments to South Wales and, since some pigs were found in Bristol, the port of Sea Mills (Portus Abone) may also have been used for lead cargoes.

No records exist of the Romans mining metals other than lead on Mendip, although iron furnaces were unearthed at Camerton and at Chew Park Farm.  The intense mining operations of the Middle Ages must have obliterated many of the earlier traces.

Towards the end of the Roman occupation, mining activity on Mendip declined, and during the seven hundred years immediately following, there is no evidence of British or Saxon mining.  Gough suggests that lead was still worked to some extent to provide roof for churches. However, very few remains of this period have been revealed.  Possibly the Derbyshire Peak was a more important centre for the lead. It would be interesting to hear from anybody who knows of any Saxon or early English finds in the Mendip district.

Collinson, in his ‘History of Somerset’, quotes some Domesday Book records of the sizes and wealth of MANORS, which later became important mining centres, but these Norman records give no hint of any lead mining industry.

During the twelfth and thirteenth centuries, mining and mineral rights charters were granted to the Bishop of Bath and Wells, and to the Prior of Witham to enable them to work lead on Mendip.  From this time onwards, numerous records of the lead industry are known.

The mining areas, during the period from 1300 to 1700, were governed by four ‘Lords Royal’.  These were the Lords of Chewton; the Bishop of Bath and Wells; the Lord of Harptree and a fourth Lord, who was always the current owner of ‘HYDON’ or Charterhouse-on-Mendip. These lords were guided in their rulings by a code of ten laws.  Two of the most interesting of these are quoted: -

When a workman hath landed oare he may carry it to cleansing and blowing to what mineries he do please for ye speedy making of same so that he do truly pay the tenth thereof to the Lord of the soyle.

If any man do pick and steal ye lead to ye value of 13½d, the Lord may arrest his lead with all his works and keepe them as a forfeit and shall take ye person and bring where his house, and his tools belonging to his occupation be and put him in his house and sett fire about him and banish him from that occupation for ever.

Lead mining reached maximum productivity during the period 1600 to 1670, but another branch of mining was established by then.  Brass was first introduced to Britain by the Germans during Elizabeth’s reign, and in 1560 zinc was being mined on Worle Hill.  The zinc mining industry soon became established in the dolomitic conglomerate of Western Mendip and in later years took precedence over lead mining.

Methods of raising and smelting ore are of interest.  Shafts or ‘gruffs’ were dug everywhere and, although not usually vertical, they could attain a depth of one hundred and eighty feet.  Single ropes and wooden ladders were used for descent and for the sides or bottom of the shafts, timbered ‘leers’ followed the ore veins. Ventilation was sometimes obtained by running a subsidiary shaft into the main shaft some ten feet below the surface. This caused a flow of air through the working.  People were often digging in such close proximity to each other that they broke into one another’s workings, causing complex legal arguments about ownerships.

On being raised, the ore was taken for one of the four mineries for cleaning (buddling) and smelting in a rotatable hearth furnace.  These were turned to catch the wind form any quarter and bellows were used to increase the draught from the wind.  After smelting, the miner had to give one tenth of his lead to the lord of the manor in which it was raised.  This toll was known as ‘lead lot’.

The seventeenth century produced a lot of the old slag in the Belfry area.  It was also the time during which most of the pits and hollows were made.  The present forestry land north of Stock Hill was extensively worked for lead about 1690.

At the onset of the eighteenth century, the production of the Mendip mines was decreasing.  The Lead Reeve’s book for Chewton Minery, during the period form 1700 to 1708 showed and average return of three tons of lead lot per year.  This compares unfavourable with production in the period 1660 to 1666 which averaged fourteen and a half ton per year.  Apart from this peak of prosperity and it became completely extinct in 1908.

The reasons for the start of this deterioration were mainly the competition from the superior quality peak lead of Derbyshire, and the exhaustion of ore veins near the surface on Mendip.  Working the deeper lodes required drainage and hauling equipment which were both expensive items and the miners were not prepared to finance this equipment because they feared that Derbyshire and foreign lead industries would eventually overwhelm that of Mendip.  The water drainage problem must have been serious, as some of the richest of the mines, at Rowpits to the north of Stock Hill, had to be abandoned because of flooding. This suggested that many of the eighteenth century pits must have been two or three hundred feet deep in spite of the poor equipment used.  Some shafts well over a hundred feet deep and still open, show no signs of extensive flooding.

As the lead mines declined, so the calamine industry at Shipham, Rowberrow and East Harptree prospered and, in 1778, an agreement was made to apply the mineral code for lead to all other minerals – zinc, iron and manganese – mined on the hill.

Large quantities of zinc were sold to a Bristol brass company and Collinson, writing in 1793, described Shipham as having ‘up to one hundred mines working in the streets, the yards and some in the very houses.’  However, soon after this, even the calamine industry was to die out.

Through the eighteenth century, some lead was still being mined, but another crippling blow was struck when the import duty on foreign lead was reduced in 1825.  The mining privileges and customs died with the enclosing of the land in the early nineteenth century, and the position of the Lead Reeves was abolished; first at Chewton and finally at Harptree in 1834. In connection with the enclosing of land at this time, it is of interest to correct a misconception which seems to be widespread, that the dry stone walls which are such a prominent feature of Mendip to-day are of great antiquity.  In fact, two hundred years ago, hardly any of them existed.

At this time also, a Dr. Somers made a few attempts to find lead and ochre and was responsible for digging Dolbury Adit (now sealed).  Also, a Mr. Webster attempted to drive a tunnel through Sandford Hill while somebody else put forward a plan to drive an adit from Compton Martin to Wookey in an attempt to drain the mines.  This project was not even started.  (What a pity! – Ed.  If it had been carried out, we could have a through trip right through Mendip!).

With the mining industry virtually dead, Dr. Somers turned his attention to smelting the Roman and Medieval slags at Charterhouse.  Some of these contained up to 25% lead, and from 1824 to 1848, Dr. Somers made the re-smelting pay.  In the 1840’s, he also worked the slag at Priddy.  After Dr. Somer’s death in 1848, a Cornishman, Nicholas Ennor, started smelting at Priddy.  Ennor introduced mechanical buddling and reverbatory furnaces and was responsible for building the horizontal flues – the remains of which can still be seen. The main flue for collecting lead is eight hundred yards long.  In 1863, Hodginsons of Wookey Hole Paper Mill brought a successful lawsuit against Ennor, restraining him from putting buddling water into the swallets ( Plantation and St. Cuthbert’s) and soon after this, the works were taken over and further mechanised by Horatio Hornblower. Hornblower used blast furnaces to smelt the slag, erected a number of buildings and built a railway from the old workings north of Stock Hill to St. Cuthbert’s.  By smelting the old slags, he produced up to one hundred and thirty tons of lead in six months.  Lead was then priced at about thirty shillings a ton.  (Sorry, thirty POUNDS a ton – Ed.)

At the same time, another Cornishman was operating a works at Charterhouse, where a Pattinson plant for silver recovery had been installed which often produced a thousand ounces of silver in a year.

In 1869, St. Cuthbert’s Lead works closed, through falls in the price of lead, but in 1879 work re-started and continued under various ownerships until 1902.  A new firm, the New Chaffers Extended Mining Company, was then formed to produce metal and sand dressed ore for smelting in Bristol.  Production of dressed ore increased to over nine hundred tons in 1906 but then declined, and the works finally closed in 1908.  This was the last smelting activity to finish on Mendip, the Charterhouse and East Harptree works having closed in the 1870’s.  The black slag now to be seen was re-smelted between 1980 and 1908 and now contains less than 1% of lead.

On three occasions since, lead smelting and mining almost came back to Mendip.  Bert Russell used to tell how a company was formed in 1923 or 4 to re-open the smelting and mining activities at Priddy.  It appears that they even got as far as holding a celebratory dinner in Wells to mark the re-birth of the industry.  Money was, however, not forthcoming, and the project never got started.

During the Second World War of 1939 to 1945, some interest was aroused in the subject of home produced lead from Mendip, and the subject was examined yet again.  It was decided that, even at wartime, the idea would not have been sound, and the project was dropped.

Aroused by the success of German chemists who successfully re-smelted the tin slag from Kitty Wheal in Cornwall in the 1950’s, a suggestion was put forward by a London chemist to re-smelt the slag for the recovery of a number of elements on a branch-top scale using electricity.  This might have paid on a one to one basis for a number of years.  The chemist concerned subsequently took a job in Africa, and the scheme remained a paperwork project.

Thus, the activity from which Mendip is generally thought to have got its very name (mine Deep) and which inspired Blake to write the well know poem ‘ Jerusalem’ is no more and is very unlikely indeed to ever be revived.  Mendip mining is now part of history, and likely to remain so.

Editor’s Note     This article is mainly that as written by Mervyn Hannam, with parts of G.A. Faulkner’s articles on Desilverisation added where appropriate.  Some further additions have been supplied by the editor.

*****************************************

Roger Stenner would like to thank all those who helped in the collection of water samples in Cuthbert’s and G.B.  Without this help, he would not have been able to have successfully completed his M.Sc. Degree.

*****************************************

Are you fed up by the continual appeals for money for the Hut Fund and for running the club? Before you answer, make sure you are in a position to grumble!  IF YOU HAVE NOT YET PAID YOUR SUB FOR 1970, NO WONDER WE ARE STILL SHORT OF MONEY! Take the hint now!