ELAN VALLEY and BUILTH WELLS, including Devil's Bridge, Llangurig, Llandrindod Wells, Llanwrtyd Wells and Rhayader. (Cassini Revised New Series Historical Map RNC 147 1900-1903). Matching ORDNANCE SURVEY LANDRANGER No. 147. 1:50,000.

(1903) 2007 1st edition thus. Folding map in green-blue card covers. This map includes the Elan Valley, Builth Wells, Devil's Bridge, Llangurig, Llandrindod Wells, Llanwrtyd Wells and Rhayader.

The Cassini Revised New Series provides a fascinating snapshot of the human geography of Britain at the turn of the twentieth century. These maps are taken from the Ordnance Survey One-Inch 'Revised New Series'sheets, surveyed between 1900 and 1903. 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. Equally useful for comparisons with current maps on the kitchen table. Much to be recommended.