Details

The monument includes St Thomas' Work, a late 16th/early 17th century
Elizabethan opencut copper mine, together with an adjacent associated ore
dressing area. It is located at the foot of crags on the eastern side of the
Newlands Valley 320m north west of Grey Buttress.
An opencut is a process of mineral extraction whereby the ore is worked
directly from the surface resulting in a linear opening along the mineral
vein. Such extraction processes typically survive as a gully or ravine. At
St Thomas' Work two exceptionally fine slit-like opencuts were driven into a
rock outcrop and survive as when abandoned in the late 16th/early 17th
century.
Immediately to the north is a dressing area consisting of a number of small
ledges, some exhibiting dressing waste. This indicates where the ore was
reduced and sorted by hand into grades suitable for further processing. One of
these dressing areas has a stone revetment wall on its downslope side.
St Thomas' Work is considered to be one of many mines in the Keswick area
which were worked by the Mines Royal Company who, during the 16th and 17th
centuries, were leaders in European mining technology.

MAP EXTRACT
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.

Source: Historic England

Reasons for Scheduling

Copper was extracted in Britain intermittently from the Early Bronze Age
(about 2000 BC) until the early 20th century, after when the industry was
confined to by-product production and small scale reworkings of mines and
dumps. There is very limited evidence for copper mining before the 15th and
16th centuries, and most known sites are of later date, principally of the
industry's 18th and 19th century peak after it had been revitalised by
developments in smelting technology. In the 18th and 19th centuries, as
perhaps it had also been in prehistory, British production was important on a
European scale.
Nucleated copper mines are a prominent type of field monument produced by
copper mining. They consist of a range of features grouped around the adits
and/or shafts of a mine. The simplest examples contain merely a shaft or adit
with associated spoil tip, but more complex and, in general, later examples
may include remains of engine houses for pumping and/or winding from shafts,
housing, lodging shops and offices and power transmission features such as
wheel pits and leats. The majority of nucleated copper mines are of 18th to
20th century date, earlier mining being normally by rakes, opencuts and open
levels, and including scattered ore dressing features.
An essential part of a copper mining site is the ore works, where the mixture
of ore and waste rock extracted from the ground was separated (dressed) to
form a smeltable concentrate. The range of processes can be summarised as:
picking out clean lumps of ore and waste; hammering (breaking down lumps to a
smaller size by manual hammering or by mechanical crushing); jigging
(separation of gravel-sized material by shaking on a sieve in a tub of water;
and buddling (separation of finer material by washing away the lighter waste
in a current of water). Field remains of ore works include crushing devices,
separating structures and tanks and tips of distinctive waste from the various
processes, together with associated water supplies. Simple ore dressing
devices had been developed by the 16th century, but the large majority date
from the 18th to 20th centuries, when technology evolved rapidly.
During English Heritage's national evaluation of the copper industry, 130
sites were assessed. This is a highly select sample of the numbers of sites
that historically existed in England; although there are no national
estimates, for the south west alone an estimate has been made of over 10,000
sites. It is considered that protection by scheduling is appropriate for less
than 50, with alternative means of protection or management being considered
more appropriate for the other nationally important sites.

St Thomas' Work Elizabethan copper mine, 320m north west of Grey Buttress, and
the associated dressing area have remained unworked since abandonment and are
thus a rare example of a late 16th/early 17th century copper mine. As one of
the mines owned by the Mines Royal Company it is of major importance for the
study of post-medieval mining in Britain, and in particular for the degree or
otherwise of German influence on British mining technology.

Source: Historic England

Sources

Books and journals
Adams, J, Mines of the Lake District Fells, (1988), 67

Source: Historic England