Ordnance Survey - Quarter Inch to the Mile Maps of Scotland - 1921-1923<
These maps at quarter inch to the mile (1:253,440) were reduced from larger-scale mapping at the half-inch and one-inch to the mile scales, primarily dating from the third national revision of 1912-1923. With some minor variations, each sheet covers 72 x 108 miles, with all of Scotland covered in ten sheets. The attractive and distinctive layer colouring is especially good for indicating relief, and there were several later 'aeronautical issues' of the series in the 1920s and 1930s. This series was also published as an atlas in 1924. For the first time for the Quarter-Inch series of Scotland, it was constructed on Cassini's Projection with a point of origin at Delamere Forest - as also for the One-Inch Popular edition of Scotland, which began publication at the same time.