The Ordnance Survey of Great Britain is now in its 167th year. Founded in 1791, it has provided a map coverage of this country which is unexcelled in its completeness and in the range of its scales. All the most important towns are now being mapped on a 1/1250 (50-in,) scale in a new survey, over 60 per cent of which have now been completed. Only a few mountainous and uninhabited regions are excluded from the 1/2500 (25-in.) scale which otherwise covers the whole country. Consequential from this scale is a further series of maps at scales of 1/10,560 (6-in.), 1/25,000 (2½-in.), 1/63,360 (1-in.), 1/126,720 (½-in.), and 1/253,440(¼-in.). Except for the north-west of Scotland the 1/25/000 (2½-in.) scale map covers the whole of the country, but the 1/126,720 (½-in.) scale has only recently been started and will take some years to complete.
An unusual feature of the whole of these map series when compared with other national surveys is the attention it pays to the mapping of antiquities. This is not confined to the delineation of those ancient features which have size and bulk which make it impossible to omit them from any map. A big range of antiquities is shown. The current list shows 107 different types ranging in date from the earliest times down to the 18th century. Some, like burial mounds, are small; others, like major hill-forts or Roman town sites, cover many acres, while others of linear type like Hadrian’s Wall or Offa’s Dyke approach or exceed 100 miles in length. Apart from this kind of antiquity which can still be recognized on the ground, there are many places indicated where important finds of portable objects have been made, and the sites of battles and other historic events are shown.