Monument record MDR9600 - Cowhay (later Lea) Lead Works (site of), Lea

North of Lea Mills, between the road and Lea Brook, lies a large whitish heap of calcium sulphate, the principal remains of what was once the largest lead smelting site in Derbyshire. The Lea Lead Works closed down within living memory but its origins lie at least as far back as the 1630s. The first reference is in a release dated June 2 1634 which refers to a tenement and close called the Cowhay in Lea and a 'lead mylne or smelting house' in Lea and Ashover with dams, watercourses etc. It is probable, based on later documents, that the 1634 lead mill is the same as that later known by the name Cowhay and which developed into the 19th century Lea Lead Works. A document of 1679 refers to four "Smiltinge" houses called by the several names of the Cow hay Mills and the Hollin Mills - the latter probably lay to the south of the Cowhay property. Accounts for 1757-9 make constant reference to a 'cupyloe', a slag mill and an ore mill, but unfortunately without naming them or saying where they were. It is probable, however, that all were at Cowhay. The final mention of the Cowhay site by that name is in 1800; in the 1820s Glover's Directory notes: "The Messrs. Alsop, of Lea Wood, are the greatest smelters of lead ore in the county; they frequently smelt thirty tons per week". A plan attached to a lease of the works in 1856 shows a rolling mill, stable, slag mill with chimney and dam, ore house, three cupolas, blacksmith's shop, office, Nether Cupola, red lead mill, lime kiln and foreman's house and garden. A later plan, part of a lease of 1912, shows that there were four Scotch hearths by this time, but that three out of the five cupolas were disused. The works closed in 1934 and the buildings were finally taken down in 1948. (1) In 1739 Cowhay had two smelting mills, one of the new Cupola furnaces, a slag mill and an ore mill. In 1763 there was also a rolling mill and another cupola in 1776. There were five cupolas at one stage, but these were replaced by Scotch Hearths in 1886. Lead vapours were intercepted in structures where they were condensed. In 1825 Joseph Wass introduced an elaborate 70 foot high expansion tower to deal with the gases. This was superseded by 900 yards of flues and horizontal chimneys, and in 1880 by an enormous brick box (a 'haystack condenser') the size of a large house, the roof of which collapsed in 1929. (2) This is a possible 17th century site for lead smelting, possibly originally owned by the Nightingales. By 1900 virtually all Derbyshire lead was smelted here. It continued to work up to the 1939-45 War, the buildings being demolished after the war. A row of stone houses dated 1947 were built from stone recovered from the site after demolition was carried out. According to an elderly local resident, the old office block was used as a dwelling house until it was burnt out to a ruin. In the 1970s the remains of underground workings and vents were still visible on part of the levelled site. Some of the site was occupied by dwelling houses, the remains of the old office block and spent slagheaps. The slag heaps used to be covered with lime. This formed a crust which prevented the dust from blowing about and poisoning the surroundings. The site was described in July 1973 as being very rich in Lepidoptera. There was some birch scrub and plentiful birdsfoot trefoil with large numbers of Common Blue and other species. (3) Cowhay lead works, later called Lea Lead Works, is referred to in the mid 17th century. From the 1630s the Spateman family operated the works at Cowhay. At the beginning of the 18th century, the Nightingale family became increasingly involved. Their involvement continued until 1934 when the works were bought by Millclose Mines Ltd at Darley Dale. The works were dismantled in 1948. (4) The key to the 17th century history of the Cowhay mills is the involvement of the Spateman family. They worked the smelting mill in the 1630s and bought the property in 1682 from John Wigley. Thomas Nightingale was tenant or partner in the mills by 1709 and passed them to his son Peter who added a cupola in the 1740s. The mills were still smelting in 1758. The site was subsequently used for the Lea Wood cupola and slag mill. The head-race was probably fed from the Pear Tree Farm mill tail race as well as from the stream, and ran along the east side of the valley, being visible close to the former eastern edge of the reservoir subsequently created to enhance the supply to the textile mill at Lea Bridge. The race appears to have been filled in when the dam for the reservoir was built, although the spillway at the eastern end of this dam was built on the line of the earlier channel. This can be followed south to the ruins and earthworks of the Lea Wood lead works, which are assumed to have been built on the smelting mill site. (5) Lea Brook is a stream which saw the building of Peter Nightingale's cotton mill in 1783, and which already powered a lead smelting mill and a rolling mill both in Nightingale's possession, but was capable of further development. During 1784 and 1785 the stream's capacity was enhanced by the creation of two dams higher up the valley from the cotton mill, and there was a further substantial investment in 1792 with the creation of a third dam for the cotton mill. It was as a result of this development that the existing corn mill ceased to operate and Nightingale created a new one higher up the valley on a site that is now known as Pear Tree Farm. Much physical evidence of these developments remains. The dams and watercourses are discernable on the ground and the lead smelting site is visible in the form of slag heaps even though all the buildings have gone, so have the mills below the cotton mill, of which the hat factory was the largest. Structures present at some time during the 19th century included a rolling mill, red lead mill, smoke condenser, cottages, stable, blacksmith's shop and store, ore shed cupola, reverberatory furnaces, four Scotch hearths, boiler house, slag mill dam and a limekiln. After the smelting mill's closure in 1934 it was acquired by Millclose Mines Ltd of Darley Dale. Then it was briefly an iron foundry before this was moved to Whatstandwell in 1948 and the site was dismantled. The last obvious remains of Cowhay Lead Works are being levelled only now at the start of the 21st century. Above the site some dams can be traced but on the actual site little remains except some stone troughs and the foundations of the office. Slag can be found and the poisonous effects of lead remain, stunting or preventing vegetation. (6)