These maps are based on Britain's first national mapping project, Ordnance Survey's One-Inch (‘Old Series’) maps which were first published between 1805 and 1874. They have all been carefully scanned, digitally re-projected and enlarged to match the present-day Ordnance Survey Landranger® series. Each Cassini Old Series map is directly comparable with the corresponding Ordnance Survey Landranger® and uses the same sheet number and grid references, so enabling the past and the present to be compared with ease and accuracy. All the Old Series maps of England & Wales (123 in all) have now been published.