Coal is so intimately connected with all that is essentially modern—machinery, steam, and the black pall that overhangs our great towns and manufacturing districts—that it comes almost as a surprise to find it in use in Britain at the beginning of the Christian era. Yet excavation has proved beyond all doubt that coal was used by the Romans, ashes and stores of the unburnt mineral being found all along the Wall, at Lanchester and Ebchester in Durham,[1] at Wroxeter[2] in Shropshire and elsewhere. For the most part it appears to have been used for working iron, but it was possibly also used for heating hypocausts, and there seems good reason to believe that it formed the fuel of the sacred fire in the temple of Minerva at Bath, as Solinus, writing about the end of the third century, comments on the 'stony balls' which were left as ashes by this sacred fire.[3] That such coal as was used by the Romans was obtained from outcrops, where the seams came to the surface, is more than probable. There appears to be no certain evidence of any regular mining at this period. With the departure of the Romans from Britain coal went out of use, and no trace of its employment can be found prior to the Norman Conquest, or indeed for more than a century after that date. It was not until quite the end of the twelfth century that coal was rediscovered, and the history of its use in England may be said for all practical purposes to begin with the reign of Henry III. (1216). In the 'Boldon Book'[4] survey of the see of Durham, compiled in 1183, there are several references to smiths who were bound to make ploughshares and to 'find the coal' therefor, but unfortunately the Latin word _invenire_ bears the same double meaning as its English equivalent 'to find,' and may imply either discovery or simple provision. In view of the fact that the word used for coal (_carbonem_) in this passage is unqualified, and that _carbo_, as also the English 'cole,' practically always implies charcoal, it would be unsafe to conclude that mineral coal is here referred to. The latter is almost invariably given a distinguishing adjective, appearing as earth coal, subterranean coal, stone coal, quarry coal, etc., but far most frequently as 'sea coal.' The origin of this term may perhaps be indicated by a passage in a sixteenth-century account of the salt works in the county of Durham:[5] 'As the tide comes in it bringeth a small wash sea coal which is employed to the making of salt and the fuel of the poor fisher towns adjoining.' It is most probable that the first coal used was that thus washed up by the sea and such as could be quarried from the face of the cliffs where the seams were exposed by the action of the waves. The term was next applied, for convenience, to similar coal obtained inland, and as an export trade grew up it acquired the secondary significance of sea-borne coal.