Sheet 20, Old Series 1". Somerset, Bristol Channel, Quantocks, Glamorgan, c1850.

Sheet  20, Old Series 1". Somerset, Bristol Channel, Quantocks, Glamorgan, c1850. 40% sea. Portlock on west edge, Bridgewater on east Barry on north shore. No geol date or revision dates, therefore first edition. The earliest geological maps omitted to record the survey and publishing dates. Hand-coloured engraving, 68 x100 cm, cut and mounted on linen and folded to 17 x 13cm between marbled covers with original Stanford’s red cloth-covered sleeve, which is 115worn and faded corner but intact. In good to very 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.

See also: Index Map for England & Wales One Inch Old Series.