William Smith: The maps supporting his published maps

William Smith's great A Delineation of the Strata of England and Wales with part of Scotland, 1815, is an iconic map recognised beyond the geological world, but how did he arrive at the finished product? Two aspects to this question are considered: the large scale mapping available to Smith for his field work and John Cary's fundamental contribution. Smith wrote that he realised very early on that it was vital to record his observations on a large scale in order to draw accurately on a smaller scale map of the whole country. Smith worked before the advent of the accurate maps of the Ordnance Survey; yet, over 90% of England had one inch to the mile scale county mapping of variable quality produced by several independent surveyors and publishers. This paper looks at Smith's options for field mapping and how available maps influenced his specification for his 1815 map. In 1812, John Cary offered to assist Smith in the realisation of his ambition to publish a map of the geology of the England and Wales. Smith's early mapping experience, the early connections between John Cary and William Smith, Cary's role in creating the 1815 map, and his continuing support with Smith's subsequent county geological maps and the 1820 map are explored.