Sheet 20, Old Series 1". Covering Bristol Channel, N.Devon, S.Wales coast, no date Base map 1809, railways unnoted, but updated…
Sheet 20, Old Series 1". Covering Bristol Channel, N.Devon, S.Wales coast, no date Base map 1809, railways unnoted, but updated to 1862 (Watchett branch) No date for geological mapping, indicates first edition. Hand-coloured engraving, 68 x 100cm (26.75 x 39.5”), dissected and mounted on linen folding between marbled soft card covers. Age-toned but colours bright. In good to very good condition. Clear plate mark. Fits into original sleeve, red cloth covered card with Stanford label, worn on all edges with short tears at corners but intact and rigid; fair to good condition.
About the England & Wales One Inch Old Series
The Geological Survey of England and Wales used the Old Series of the Ordnance Survey topographic map at a scale of one inch to the mile as its basemap, initially. These engraved basemaps were published and revised between 1805 and 1885; the sheet sizes varied and the layout and numbering system were eccentric. The Old Series geological maps were hand-coloured and without geological sections, which were published separately. The GS of E&W published the Old Series from 1850 to 1900, when it switched to the colour printing and the New Series one inch maps. However, old stock of the Old Series continued to be issued, hand-coloured, until the 1930s.