ELAN VALLEY and BUILTH WELLS, including Devil's Bridge, Llangurig, Llandrindod Wells, Llanwrtyd Wells and Rhayader. (Cassini Popular Edition Historical Map POP 147 1919-1923). Matching ORDNANCE SURVEY LANDRANGER No. 147. 1:50,000.

(1923) 2007 1st edition thus. Folding map in blue card covers. This map includes the Elan Valley, Builth Wells, Devil's Bridge, Llangurig, Llandrindod Wells, Llanwrtyd Wells and Rhayader.

The Cassini Popular Edition series provides a fascinating snapshot of the human geography of Britain in the period between the two world wars. These maps are taken from the Ordnance Survey One-Inch 'Popular Edition' sheets, surveyed between 1919 and 1923. The original series of maps were 1" to the mile, and surveyed on a grid different from that employed today. In this new series, however, the 1" maps have been reprojected onto the OS National Grid so that all the edges match up. This makes the whole country into one single sheet from which positions can be read off in National Grid Numbers. This single sheet has been redivided, creating new sheets each corresponding precisely to a current Landranger map. The scale is now larger, at 1:50,000. This new series is uniquely useful for exploring the land and accurately pin-pointing where things are, or used to be. Uniquely useful for comparisons with current maps on the kitchen table too. Much to be recommended.