Lead Mining

Lead ore (galena) is found deposited in vertical mineral veins in Swaledale, Arkengarthdale, and Wensleydale, 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 the Moulds Tops between Surrender and Arkengarthdale.

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, the Mineral Lords. 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, but these were rare in the Yorkshire Dales but examples can also be seen on Moulds Tops and steam was used at Hurst.

In many parts of the Yorkshire Dales the mineral field, the area where mineral veins can be found, is cut by deep valleys and beginning in the late 18th century a number of long cross cut levels were driven. 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 wagons 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 to some extent released and rushed down the hillside scouring the soil and any loose rock away. But 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. Revealing the mineral was more of a manual process than an hydraulic one. Most hushes date from the late 18th and early 19th centuries. Examples of hushes can be seen in Gunnerside Gill, and in Arkengarthdale. between Langthwaite and Great Pinseat.

Dressing Lead Ore

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 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. 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. Good examples of dressing floors can be seen near the Old Gang Smelt Mill and at Moulds.

Dressing Lead Ore in 1811

Once the lead ore was found it was brought to the surface, broken up, sorted and washed. John Farey noted how it was done in 1811.

“The Ore and Spar from Lead Mines is drawn to the surface in small barrels or Kibbles by Men, or in larger geer Barrels by Horse-Gins, which are attended by a Gin-driver, who stops his Horse or Horses, when the Barrel is arrived at top of the Shaft, and the Striker then lands, unhooks, and empties the contents, on to the Striking-floor, and having again hooked on the empty geer-barrel, he proceeds to sort the Stuff or Bowse into three parts, viz. Knockings, Ridlings or Picking-stones, and Fell, the latter being what passes through an inch iron wire Sieve or Riddle, in which the Ridlings or Picking-stones remain. The Knockings, which are large pieces of Spar or Stone, most of them with Ore intermixed or adhering, are put into a barrow, and wheeled to the Bank, the Ridlings are emptied into the swiller and picker Women’s Whiskets, or wooden Hoppets, brought and set near to the Striking-floor for that purpose, and the Fell he removes to the Fell-heap near, by which means the Striking-floor is again clear, and ready for the next geer-barrel.

The Women (or Men) called Swillers, have a large tub, which they call the Swilling Tub, nearly filled with water, and a Riddle or iron wire Sieve with inch openings, having handles projecting above the sides or rim of the Riddle; into which Riddle she puts a quantity of Ridlings from the Striking-floor, and having sunk the sieve into the Swilling Tub, she gives a twisting and brisk motion to it, as she holds it by the handles, by which operation the dirt is washed off the Ridlings, and sinks in the Swilling Tub; but sometimes the washing is performed in a square wooden trough, called a Standing-buddle, in which the Ridlings or Fell are stirred by a spade. The washed Ridlings are then turned over on to the Picking-board, which is usually an old Door supported on Trussels like a Table, and Women, called Pickers, there sort over the Ridlings, and pick out the clean pieces of Ore, and put them into the Ore-whisket.”

Taken from J. Farey, A General View of the Agriculture and Minerals of Derbyshire. Volume 1. 1811

Smelting Lead Ore

Early methods of separating the lead from the waste products were primitive. Smelting took place on hilltops facing into the prevailing westerly winds which provided the draught for the fire. It involved building what was essentially a large bonfire on top of the hill, using alternating layers of wood and ore. It worked because lead has a relatively low melting point but it was very inefficient and used large quantities of wood. The dales were fully forested in Norse times. Cutting down timber for fuel was largely responsible for the dales deforestation.

Smelting usually took place in the spring when several days of strong wind could be relied upon. Ore and fuel was stockpiled and the process would last until the wind died down or the supplies of timber and ore were exhausted. As the lead melted, it was collected at the base of the fire and channelled into moulds called pigs.

These early primitive hearths were called Bales. There are many such sites throughout the dales.

The ore hearth was a later development and similar to a blacksmith’s forge, but here the draught was provided by bellows powered by a waterwheel. The smelting sites therefore transferred from the hilltops to the river valleys. These hearths were much more efficient. (They were about 55% efficient.) In fact it became economic to reprocess the slag which had been produced by the boles, and recover more lead as well as smelting new ore. This was done at the Copperthwaite Bales above Marrick.

Hearths still relied on wood as fuel, but it was now specially prepared for the purpose and was known as white coal. The timber was chopped up into small chips and dried over a fire before use. White coal was produced in woodlands which were specially managed for the purpose.

This method of smelting required the mixture to be constantly stirred by the smelters, who consequently worked in an atmosphere of poisonous fumes. A man employed as a lead smelter usually had a relatively short life.

The final technological development was the cupola or reverberatory furnace. This used coal and cinders (coke) as fuel and was completely enclosed. The fire and the ore were separated by a low wall and the flames and heat were ‘reverberated’ on to the ore from the domed roof. The reverberatory furnace was built just to the west of the Marrick High and Low Smelt Mills, and was called the Cupola. The furnace used a tall chimney to provide the draught for the fire. These smelters were often situated on the barren moorland where there was less chance of farm animals being poisoned by the fumes. They were much more efficient than the ore hearth, about 65%.