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Alum
Historical and geographical information
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Alum
The Jurassic shales and sandstone of
Cliff Ridge and Gribdale contain bands of ironstone,
jet and alum, as well as whinstone.
The oldest of these industries was alum.
This mineral had been used since ancient times for many purposes including
medicinal (as cure for haemorrhages, nits and dandruff, and other ailments).
Its main uses since the middle gages were to increase the suppleness and
durability of leather and in the textile industry as a mordant to make
vegetable dyes fast.
Prior to the middle of the fifteenth
century the supply of alum came from Turkey and a flourishing trade was done
between Asia Minor and Italy. The Italians required the alum for their dyeing
establishments, and after the capture of Constantinople by the Turks in 1453
they objected to buying it from Islam and sought other sources of supply. John
di Castro, who had been a dyer of cloth in Constantinople and had watched the
manufacture of alum, was driven back to Italy. There, at Tolfa, he discovered
an alum rock and was duly rewarded by the Pope, who thereupon began the great
papal monopoly in alum; an industry thus began at Tolfa which still exists, and is the source of the commercial Roman alum.
Although German miners had settled in
England long before the reign of Queen Elizabeth, the queen did much to
encourage home industries and in order to escape the
payment of tribute to the Pope she invited to Britain "certain foreign chymistes and mineral masters." Among them was Cornelius
Devoz, to whom was granted the privilege of "mining
and digging in our realm of England for allom and
copperas." After that there is a gap in our knowledge of the alum
industry, but the Belham Bank works near Guisborough are supposed to have been
opened in 1595. According to A. Anderson the first alum works in England were
erected at Guisborough in 1608. The person responsible was either Sir Thomas
Chaloner, who according to T. Pennant suspected the presence of alum because
the trees in the district were of a weak colour, and according to G. Young
because of the taste of the water issuing from the shales; or Sir J. Bouchier,
who is said to have improved upon the method of manufacture. At any rate,
Chaloner apparently induced Italians to leave the papal works at Tolfa and come
to Yorkshire, for which he was excommunicated and heavily cursed by the Roman
Church.
Alum Shale is found in beds immediately
beneath the sandstone of the North York Moors.
Alum mining has been a North Yorkshire
industry since alum was first discovered in the hills around Guisborough by Sir
Thomas Chaloner the younger in the 1590s. At the end of the 16th century Thomas
Chaloner visited alum works in the Papal States where he observed that the rock
being processed was similar to that under his
Guisborough estate. At that time alum was important for medicinal uses, in
curing leather and for fixing dyed cloths and the Papal States and Spain
maintained monopolies on its production and sale. Chaloner secretly brought
workmen to develop the industry in Yorkshire, and alum was produced near
Sandsend Ness 5 km from Whitby in the reign of James I. Once the industry was
established, imports were banned and although the methods in its production
were laborious, England became self-sufficient. Whitby grew significantly as a
port as a result of the alum trade and by importing
coal from the Durham coalfield to process it.
In 1610 James I made Alum production a
monopoly of the Crown.
In 1616 Alum production began at Selby
Hagg, near Hagg Farm, Skelton around this date. It is said that ships anchored
off Saltburn to transport the finished product. They brought with them casks of
urine, which was mixed with the liquid that had been obtained from the calcined
shale. It is not presently known where this process was carried out initially,
as later in the century it was done in an Alum House sited near Cat Nab in
Saltburn. The shale liquid ran from Selby Hagg by gravity down a trough
that followed the course of Millholme Beck.
From the early seventeenth century until
the 1860s it was extensively mined at Guisborough and along the East Cleveland
coast. The actual extraction of alum from shale was a long and expensive
process and it took an average of 50 tons of shale to produce one ton of alum.
In the 16th-century alum was essential in the textile industry
as a fixative for dyes. Initially imported from Italy where there was a Papal
monopoly on the industry, the supply to Great Britain was cut off during the
Reformation. In response to this need Thomas Challoner set up Britains first
Alum works in Guisborough. He recognised that the fossils found around the
Yorkshire coast were similar to those found in the Alum quarries in Europe. As
the industry grew, sites along the coast were favoured as access to the shales
and subsequent transportation was much easier.
Alum mine, Cleveland
In
the mid eighteenth century the price of alum was particularly high and reached
a peak of £24 per ton in 1765. It therefore became commercially viable to mine
in places where this had not been the case previously. Several new mines were
therefore opened including one east of Ayton at Ayton Bank, just north of
Hunter’s Scar.
Cockshaw
Alum Works at Gribdale quarried and processed the
shale to produce alum crystals in the eighteenth century.
At the peak of alum production the industry required 200
tonnes of urine every year, equivalent to the produce of 1,000 people. The
demand was such that it was imported from London and Newcastle, buckets were
left on street corners for collection and reportedly public toilets were built
in Hull in order to supply the alum works. This unsavoury liquor was left until
the alum crystals settled out, ready to be removed. An intriguing method was
employed to judge when the optimum amount of alum had been extracted from the
liquor when it was ready an egg could be floated in the solution.
The last Alum works on the Yorkshire Coast closed in 1871. This was due to the
invention of manufacturing synthetic alum in 1855, then subsequently the
creation of aniline dyes which contained their own fixative.
There are many sites
along the Yorkshire Coast which bear evidence of the alum industry. These
include Loftus Alum Quarries where the cliff profile
is drastically changed by extraction and huge shale tips remain. Further South
are the Ravenscar Alum Works, which are well preserved and enable visitors to
visualise the processes which took place
Alum and Skelton
In the Skelton
area Alum production began from about 1603. The first profitable site in
Yorkshire was opened in 1603 at Spring Bank, Slapewath,
which was then part of Skelton. This was the project of John Atherton, joint
owner by marriage of a third part of the Skelton Estate.
Britain at this time was an Agricultural
nation and Wool was its chief export.
Alum was used in the dyeing process as
the setting agent and was also needed in the tanning of hides. It was therefore
a highly valued product, which up to this time had been imported. Rich rewards
seemed to beckon those who could create a home industry. The process was
complex. The alum bearing rock was quarried, broken up and ‘calcined’ or built
into large clamps with alternating layers of wood and these piles would be
ignited and a controlled burning would last for weeks. It needed many tons of
shale to produce 1 ton of alum. The
burnt, ‘calcined’, shale was then steeped in water-filled stone troughs until a
certain specific gravity had been reached (tested for, the story goes, by
floating an egg in the liquid). The liquid was then run off and boiled in large
pans heated by coal for 24 hours and mixed with an alkali, obtained from urine
or seaweed.
Thomas Chaloner of Guisborough is
reputed to have sold his personal urine for one penny a Firkin, which was about
8 gallons. How often he earned or spent a penny or earned one is not recorded.
History shows that we have had many odd
names for imperial measures, pecks and gills etc. A ‘Firkin a Fortnight’ for
pee.
Next the mixture was transferred to
small coolers to crystallize, the resulting crystals of alum being further
boiled and condensed to get rid of impurities. Many legends survive, but it is
not known how this long and involved chemical process was discovered in these
times, when people believed in alchemy and the modern science of Chemistry was
a mystery.
It is reported that the workers suffered
terrible conditions – the heaps of shale gave off poisonous sulphurous fumes
and at times their wages of 6 pence a day were often withheld or ‘given in half
rotten meat and corn.’
The alum workers were described at one
point as: ‘poor snakes, tattered and naked, ready to starve for want of food
and clothes.’
Other Alum mines were eventually opened
by the Skelton Estate, notably at Coombe Bank, Boosbeck
and Selby Hagg between Skelton and Brotton and were worked on and off during
the next two centuries. The Selby Hagg works were located to the east of Hagg
Farm, near Skelton-in-Cleveland, and would seem to have had three distinct
periods of operation.
During the first of these, from about
1617 to 1643, the Alum house may have been located within the quarry.
The second phase ran from 1670 to 1685,
and the third from 1765 to 1775. The alum houses for these latter two phases
were located at Saltburn.
Most successful were the ones on the
coast which did not have the cost of transporting fuel and the finished product
for shipment.
The Alum workings at Hummersea,
Loftus were worked well into the 19th Century.
Major Robert Bell Turton
of Kildale Hall, N Yorks The Alum Farm, 1937: "There was a house at Spring
Bank, near Mygrave [now Margrove
Park] erected, but not completed for the manufacture of Alum. On the 15th
November 1603 an agreement was made between John Atherton and Katherine his
wife of the one part and Mr Leycolt of the other,
under which the Athertons were, at their own cost, to
complete the house and furnish it with the necessary appliances, namely, four
Furnaces and four pans of lead and iron for boiling Alum, Coolers of lead for
congealing , and convenient Cisterns of lead for keeping and saving the
"mothers" or strong liquors of alum and Copperas [green vitriol or
Iron Sulphate]. They were also to set up a lead-finer with furnace, a balnium for trial of the earth for alum and copperas, pits,
pipes, vessels for draining the earth and making liquors and all other
necessary implements."