Sargill ore hearth lead smelt mill, on North Rigg, 340m south east of Sargill Lead Mine


Heritage Category:
Scheduled Monument
List Entry Number:
Date first listed:


Ordnance survey map of Sargill ore hearth lead smelt mill, on North Rigg, 340m south east of Sargill Lead Mine
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The building or site itself may lie within the boundary of more than one authority.

North Yorkshire
Richmondshire (District Authority)
High Abbotside
National Park:
National Grid Reference:
SD 89754 92627

Reasons for Designation

Approximately 10,000 lead industry sites are estimated to survive in England, spanning nearly three millennia of mining history from the later Bronze Age (c.1000 BC) until the present day, though before the Roman period it is likely to have been on a small scale. Two hundred and fifty one lead industry sites, representing approximately 2.5% of the estimated national archaeological resource for the industry, have been identified as being of national importance. This selection of nationally important monuments, compiled and assessed through a comprehensive survey of the lead industry, is designed to represent the industry's chronological depth, technological breadth and regional diversity. Ore hearth smelt mills were introduced in the 16th century and continued to develop until the late 19th century. They were the normal type of lead smelter until the 18th century, when they were partially replaced by the reverberatory smelt mill. The ore hearth itself consisted of a low open hearth, in which lead ore was mixed with fuel (initially dried wood, later a mixture of peat and coal). An air blast was supplied by bellows, normally operated by a waterwheel; more sophisticated arrangements were used at some 19th century sites. The slags from the ore hearth still contained some lead. This was extracted by resmelting the slags at a higher temperature using charcoal or (later) coke fuel, normally in a separate slag hearth. This was typically within the ore hearth smelt mill, though separate slag mills are known. Early sites were typically small and simple buildings with one or two hearths, whereas late 18th and 19th century smelt mills were often large complexes containing several ore and slag hearths, roasting furnaces for preparing the ore, refining furnaces for extracting silver from the lead by a process known as cupellation, and reducing furnaces for recovering lead from the residue or litharge produced by cupellation, together with sometimes complex systems of flues, condensers and chimneys for recovering lead from the fumes given off by the various hearths and furnaces. The ore hearth smelt mill site will also contain fuel stores and other ancillary buildings. Ore hearth smelt mills have existed in and near all the lead mining fields of England, though late 18th and 19th century examples were virtually confined to the Pennines from Yorkshire northwards (and surviving evidence is strongly concentrated in North Yorkshire). It is believed that several hundred examples existed nationally. The sample identified as meriting protection includes: all sites with surviving evidence of hearths; sites with intact slag tips of importance for understanding the development of smelting technology; all 16th- 17th century sites with appreciable standing structural remains; 16th-17th century sites with well preserved earthwork remains; and a more selective sample of 18th and 19th century sites to include the best surviving evidence for smelt mill structures, and flue/condenser/chimney systems.

Sargill ore hearth smelt mill survives well and significant remains of the technical processes are preserved. The surviving remains of shaft-type ore and slag hearths are of particular importance as they, are on present knowledge, the best-preserved in England. This type of slag hearth is unusual for the area. Also present are the remains of the unfinished zig-zag flue system, another an unusual feature in the Dales. These features form important survivals of 19th century developments in lead smelting technology.


The monument includes the well preserved standing remains of the Sargill ore hearth lead smelt mill and associated structures. The monument is situated on a modified terrace on the north bank of Sargill Beck on Staggs Fell about 2km north east of Sedbusk. The smelt mill is believed to have been built in the 1840s, located 340m to the south east of the mine which produced the lead ore. The lead from the mine was originally taken to a mill at Summerlodge in Swaledale but, owing to the transportation costs, a mill was built closer to the mine. The mine and mill both ceased production in 1870. The smelt mill building is a rectangular structure 17m by 9m, partly built into the slope. Although ruined, the front walls stand to a maximum height of 3.95m. Internally the mill was divided into two main areas: the western end which held a waterwheel and a bellows system and the eastern part in which the ore hearths were located. The waterwheel stood in a wheel pit and was powered by water flowing through a channel taken from Sargill Beck approximately 220m upstream. Only the final 12m of this channel is included in the scheduling. In the eastern part of the mill were two ore hearths located against the rear wall. As well as smelting ore, it appears that the easternmost of the two hearths was also used for re-smelting slag. This was produced from the primary smelt which could contain appreciable amounts of lead. Although the remains of the hearths are obscured by rubble, it is clear that both the hearths were of a shaft-furnace form, rather than the low hearth type traditional to the area. Such furnaces were introduced in the 1850s as a development from the Spanish Slag Hearth, although they were not used exclusively for smelting slag. Immediately to the rear of the hearths is a narrow chamber which held a condenser, used to extract lead from the exhaust fumes. To the rear of the mill are the remains of a stone built flue extending up the hillside for 19m. This comprised a stone lined vertical sided trench 0.8m wide which is now open, the original roof covering having collapsed. At the end of the flue is the remains of a rectangular chimney stack which survives up to 2.4m high. Immediately north of the chimney is a substantial `V' shaped zig-zig ditch extending northward for 73m. There are shallow banks formed from spoil alongside the ditch. This feature is an uncompleted extension to the flue. The zig-zag shape would create turbulence within the exhaust fumes from the mill which would allow lead in the fume to be deposited in the flue to be recovered for re-processing. Attached to the west wall of the mill was a rectangular room 6.7m by 5.25m, containing a roasting furnace which heated the ore prior to smelting. To the east of the mill building are two level platforms which represent processing or storage and loading areas. To the north of these are two natural gullies, the southern ends of which have been modified in order to control water supply into the mill complex. Access to the mill from the mine was provided by a track extending north west from the mill which still survives.

MAP EXTRACT The site of the monument is shown on the attached map extract.


The contents of this record have been generated from a legacy data system.

Legacy System number:
Legacy System:


Books and journals
Clough, R T , The Lead Smelting Mills of the Yorkshire Dales, (1962), 101-102
Raistrick, A, The Lead Industry of Swaledale and Wensleydale: The Mines, (1975), 95-98
Willies, L, 'Bulletin of the Peak District Mines Historical Society' in Derbyshire Lead Smelting in the 18th and 19th centuries, , Vol. VOL 11, (1990), 10-12
Rep No. 1997-8(020)/7682, Wild, C and Cranstone, D, Sargill Lead Smelting Site North Yorkshire, (1997)


This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

End of official listing

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