Sheet 76N & S, Old Series 1". Early 1850s. Caernarvonshire: Lleyn / Llŷn Peninsula, Bardsey Island. Hand-coloured
Sheet 76N & S, Old Series 1". Early 1850s. Caernarvonshire: Lleyn / Llŷn Peninsula, Bardsey Island. Hand-coloured engraving, 71 x 49.5cm, two quarter sheets dissected, mounted on linen, and folded to 24 x 16.5cm with index map pasted on top outside fold. Topographic date1840 for SE quadrants. No geological date. Issue date for NE quadrant is 1854.Some dates lost in the joining of the two quarters. For notional sheet 77, the NW and NE quadrants were never published being entirely at sea; therefore, these sheets have always been officially referenced as 76 north and 76south. Legend in sea area in south. Sides trimmed close to map border, faint geological survey blind stamp. 90% sea. Clean, bright colours. In fine condition. North half is rare as few printed.
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.