| Name: | Great Britain. Ordnance Survey. |
| Title: | Diagram shewing the Principal Triangulation for the Ordnance Survey of Great Britain and Ireland. |
| Imprint: | [Southampton : Ordnance Survey], ca. 1852? |
| Pagination: | 1 map; 82 x 57 cm, on sheet 102 x 68 cm. |
| Shelfmark: | Map.Area.C16(144) |
| Notes: | This diagram reflects the work of William Yolland, and differs significantly from later Principal Triangulation diagrams that reflect the simplifications made by Alexander Ross Clarke. Read further information in our OS six-inch Scotland 1st edition maps - background essay. |
| Zoom Into Map: | Click on the map to view in greater detail. |
