At 12:34 09/09/04 +0100, David Hardwick wrote:
>...... Do you know what is meant by the 'cakeing' properties of coal?
>This is referred to both in the analyses sent to me by John Cornwell, and
>in a traveller's report dated 1698, both referring to Kingswood coal.>
David,
I suspect, given the date, that this is not referring to the strength of
the coal for coke making but its ability to consolidate for smithing
purposes. If your correspondent refers to Great Britain: National Coal
Board, The Coalfields of Great Britain: variation in the rank of coal,
(London, 1960) and determines the ranking of the coal in the Kingswood
area, he should get some idea. Best coking coal is in the old NCB ranking
301a and 301b whereas the 'caking' coal is in the rankings 400 to 800 with
its ability to cake diminishing towards 800.
Coals with the ability to cake, ie. ring coals, were in demand for smithing
purposes throughout the medieval and early modern periods and such coals
were shipped, even overland, to sites well away from the coalfields. Its
properties as a quality fuel for smithing iron tools were well known by the
late medieval period. Its advantage lay in the physical properties - its
ability to provide a sustained and concentrated heat source capable of
withstanding the rigours of the smith's hearth. Particular grades of coal
in south-west Wales are noted by 16/17th century writers as being preferred
by smiths for their ability to combine and consolidate in the hearth.
Hatcher (Towards the Age of Coal, pp. 418-25) lists many instances of the
preference for coal and also comments on the problem of charcoal being
displaced by the blast from the smith's bellows.
Peter
______________________________________________
Dr Peter Claughton,
Blaenpant Morfil, nr. Rosebush, Clynderwen, Pembrokeshire, Wales SA66 7RE.
Tel. +44 (0)1437 532578; Fax. +44 (0)1437 532921; Mobile +44 (0)7831 427599
Hon. University Fellow
School of Historical, Political and Sociological Studies (Centre for South
Western Historical Studies)
University of Exeter
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