Potash pit
   HOME

TheInfoList



OR:

Potash pits were kiln sites which were dug and lined with drystone walling for the production of
potash Potash () includes various mined and manufactured salts that contain potassium in water-soluble form.
prior to the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
. The scouring or degreasing of the natural
lanolin Lanolin (from Latin 'wool', and 'oil'), also called wool yolk, wool wax, or wool grease, is a wax secreted by the sebaceous glands of wool-bearing animals. Lanolin used by humans comes from domestic sheep breeds that are raised specifically fo ...
from wool requires the application of soft soap produced using fat and an alkaline potash solutionthat contains water-soluble
potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...
salts such as potassium carbonate and potassium hydroxide.Potash
USGS 2008 Minerals Yearbook


Purpose

The potash pit was a basic stone lined
ashery An ashery is a factory that converts hardwood ashes into lye, potash, or pearlash. Asheries were common in newly settled areas of North America during the late 18th century and much of the 19th century, when excess wood was available as settler ...
in which hardwoods such as
birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...
wood or
bracken Bracken (''Pteridium'') is a genus of large, coarse ferns in the family Dennstaedtiaceae. Ferns (Pteridophyta) are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells (eggs ...
were burned to produce ashes which were then placed in a copper cauldron manufactured from strips of copper and boiled together with water and
quicklime Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. The broadly used term "''lime''" connotes calcium-containing inorganic ma ...
. The
alkaline In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as ...
solution produced by the ashes and added quicklime could be filtered to remove particles and once the required alkalinity was reached fats were added to produce a soft soap for the scouring or degreasing of the wool as a vital step in the production of wool for spinning into yarn.


Location

Many potash pits were built in or near areas of suitable
deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...
woodlands and as such they are an important landscape features indicating both the processing of wool and the presence of a suitable hardwood
woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...
present at the site or nearby at the time that potash pits were in use.Muir, Pages 91 - 92.


Construction

The often circular pits were built often into earthen banks and were lined with drystone walling. A tunnel fireplace was required to draw in the air for the burning conversion of the birch, bracken, etc. into ashes, used for heating the cauldron as well as the source of the potash.Hawksley, Page 46


Geographical location

The pits are a feature found in sheep farming districts with extensive woodlands such as the
Lake District The Lake District, also known as the Lakes or Lakeland, is a mountainous region in North West England. A popular holiday destination, it is famous for its lakes, forests, and mountains (or ''fells''), and its associations with William Wordswor ...
in England. One example is located in the Lickle Valley,The Lickle Valley
Retrieved : 2013-07-28
Broughton in Furness Broughton in Furness is a market town in the civil parish of Broughton West in the South Lakeland district of Cumbria, England. It had a population of 529 at the 2011 Census. It is located on the south western boundary of England's Lake Distr ...
.


Industrial archaeology

As a landscape feature, the remains of potash pits are superficially similar in appearance and location to
Q-pit Q-pits are kiln sites which were dug for the production of white coal prior to the Industrial Revolution when white coal was largely superseded by the use of coke. Purpose The white coal produced in Q-pits was largely used in the smelting of le ...
s that were constructed to make
white coal White coal is a form of fuel produced by drying chopped wood over a fire. It differs from charcoal which is carbonised wood. White coal was used in England to melt lead ore from the mid-sixteenth to the late seventeenth centuries. It produces more ...
for use in smelting lead.
Saw pit A saw pit or sawpit is a pit over which timber is positioned to be sawed with a long two-handled saw, usually a whipsaw, by two people, one standing above the timber and the other below. It was used for producing sawn planks from tree trunks, whi ...
s were constructed in areas of woodland also, however they were rectangular in shape and are easily distinguished from the aforementioned.


References

;Notes ;Sources # Hawksley, L., Jenks, D., et al. ''The Magic & Mystery of the Lake District''. Bristol : Dempsey park. . # Muir, Richard (2008). ''Woods, Hedgerows and Leafy Lanes.'' Stroud : Tempus. . {{Portal, England Buildings and structures in Cumbria Buildings and structures in England Archaeological sites in England History of forestry Forestry in the United Kingdom Potash