Lead ore (galena) is found deposited in vertical mineral veins in Swaledale, Arkengarthdale, and Wensleydale in the north of the Dales and between Nidderdale and Wharfedale in the south, alongside other minerals such as fluorspar, calcite and barites. These veins are cracks or faults in the rock that have been filled with a mineral rich solution that has crystallised out to form the vein. Lead ore is not continuous in the vein, but often found in pockets, which is one reason why lead mining could be a very speculative activity.
Mining from an early date relied on shafts. The course of out-cropping veins is often marked by lines of closely spaced mounds, which in the past have been incorrectly called bell pits. From at least the Medieval period miners worked a system where they leased small blocks of ground along veins. These blocks were known as meers. This system is often referred to as customary mining law and lines of closely spaced shaft mounds are usually an indication of this style of mining because miners were expected to work or prove the vein along the length of the meers. Good examples of this type of mining can be seen on Grassington Moor and on Craven Moor either side of the Grassington to Greenhow Hill road near Stump Cross Caverns.
Customary mining was abandoned by the end of the 18th century and then mining companies leased large blocks of ground from the owners of the mineral rights. Deeper shafts were sunk that often worked several veins. The large mounds of these shafts can have the remains of horse powered winding engines called ‘whims’ or ‘gins’, or occasionally steam engines, although steam engines were rare in the Yorkshire Dales. The site of a horse whim can be seen at Yarnbury.
In many parts of the Yorkshire Dales the mineral field, the area where mineral veins can be found, is cut by deep valleys. From beginning in the late 18th century onwards, a number of long cross cut levels were driven into the valley sides. These were usually intended to provide drainage and haulage for a number of veins but they were also a useful means of prospecting the ground. Levels are most prominent in the northern part of the Yorkshire Dales around Swaledale and Arkengarthdale where they are often referred to as horse levels as they were large enough to allow horses to pull waggons full of ore.
Another form of mining found in the Yorkshire Dales is hushing. This term is used for a form of opencast working using water. This involved building a small turf dam at the top of a hill above the area to be worked. When it was full the water was released and rushed down the hillside scouring the soil and any loose rock away. Once the vein was uncovered, crowbars, chisels and hammers were used to loosen the rock and extract ore. In this process, which was repeated over and over again, broken rock accumulated on the floor of the hush and was eventually washed away. Most hushes date from the late 18th and early 19th centuries. Examples of hushes can be seen in Gunnerside Gill, Swaledale, for example Bunton hush, and from the road between Low Row in Swaledale and Langthwaite in Arkengarthdale.
Once mined the mixture of ore, mineral and rock brought to the surface, known as bouse, needed to be processed before smelting to clean it and separate the lead ore from the waste. This was known as dressing. Dressing usually involved crushing and then washing. The earlier methods of dressing occurred near to the shafts and involved manual processing and left few visible remains other than small mounds of gravel-like rock, often vegetation free because of the heavy metal content of the waste material. Later, large centralised dressing floors were built. These mechanised dressing floors were equipped with water-powered ore crushers, and hotching tubs where heavy ore was separated from lighter waste by plunging a basket containing bouse up and down in a tub of water. Also used were buddles where fine particles of lead were recovered using flowing water, much like gold panning. When you introduce bouse into a stream of water the light waste is washed away leaving the heavier ore behind. As much of the ore dressing machinery was made of wood, which rots, or was sold to other mines, or scrapped when the mines closed, it has left little trace, however, detailed archaeological survey can help to reconstruct the activities that happened on sites. There are also often buildings housing offices and smithies found on dressing floors. These were very important to the day to day running of the mines. Blacksmiths made and repaired equipment for the mines, but most of their time would be spent sharpening the drills that the miners used to drill holes, by hand, to allow the rock underground to be blasted. Miners also needed accommodation. In sparsely populated Arkengarthdale, C B Yard was built both as miners’ housing and for workshops. Good examples of dressing floors can be seen near the Old Gang Smelt Mill, in Hard Level Gill, Swaledale, and in Hebden Gill, near Grassington and at Bolton Park. Two other late examples are Red Scar mine and West Stonesdale mine.
Once the ore is dressed it needs to be heated to convert it into metallic lead, a process known as smelting. The Yorkshire Dales contain a wide range of smelting sites ranging from the Medieval ‘Bales’, which were simple wind blown furnaces, similar to a bonfire, to the large smelting complexes of the 18th and 19th centuries. Grassington’s Cupola Mill was one of the largest smelting sites in the area and was opened in 1792 when it replaced several smaller mills. The mill gets its name from the reverberatory or cupola furnaces installed here which were unusual in Yorkshire. The remains of smaller smelt mills can be seen at Surrender in Swaledale and Braithwaite in Walden.
Many smelt mills were built with short horizontal flues linked to a chimney, but during the 19th century these were extended and some ended up several miles long. These long flues allow the smoke to cool and the lead to condense onto the flue sides and also reduced pollution. The flues could be swept out from special access points and the metal recovered. As well as at Grassington good examples of smelt mills with long flues can be found in Swaledale, at Grinton for example. Most smelt mills in the areas used a mixture of peat and local ‘moor coal’. Good examples of open-sided peat stores survive at Blakethwaite; Surrender Mill, and Old Gang on the north side of Swaledale, and at Grinton on the south side.
Please note that the underground remains of lead mining should not be explored unless you are properly experienced and equipped.
Contributor: Martin Roe. Revised December 2015.
Clough, Robert T (1962) Lead Smelting Mills of the Yorkshire Dales: Their Architectural Character, Construction and Place in the European Tradition Leeds: The Author
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Roe, M (2003) ‘Lead Mining Archaeology in the Yorkshire Dales’ Landscapes Vol 4:1 pp65-78
White, Robert (2002) The Yorkshire Dales. A Landscape Through Time Ilkley: Great Northern Books