Sheet 39, Old Series 1". c1850. 1st edition. Pembrokeshire: St.Davids, Skomer Island. Hand-coloured
Sheet 39, Old Series 1". c1850. 1st edition. Pembrokeshire: St.Davids, Skomer Island. Hand-coloured engraving, 68 x 99.5cm, dissected, mounted on linen, and folded to 24 x 16.5cm. Outline 1820, issued 1853. No key, typical of earliest S.Wales sheets. Clear plate mark. Slightly age-toned, but still bright colours. Only sheet in Old Series that overlaps with adjacent sheet 40, otherwise it would have been 99% sea. Other unusual aspects of this sheet are that there is no title of Geological Map and the scale bar is at the top of the sheet. Geologically, only offshore islets, not covered by adjacent sheet 40, are coloured. Topographically, there is no hachuring, In fine condition. Rare.
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.