Map scale – an explanation of its significance

Map scale, County maps and the Yorkshire survey

From the 1840s onwards the Ordnance Survey undertook the monumental task of surveying and producing maps of all Great Britain.   These maps were initially in the 6 inches to one mile scale (1:10560) and were undertaken on a county by county basis.  These became known as the “County Maps Series”.   Yorkshire at this time was organised into three divisions or Ridings which had been derived from the Danish word ‘thridding’ meaning a third.   For the survey the OS further subdivided the North, West and East Ridings of Yorkshire  into a total of 301 areas.  From 1854 it was decided that the Ordnance Survey would also produce a more detailed 25 inch to the mile (1:2500) survey in addition to the existing six inch version.

The links below show each of the 301 areas and land that falls within each.  This is an excellent resource from the “Vision of Britain” website and gives a very detailed overview of the Ridings.

North Riding

East Riding

West Riding – North

West Riding – South

Issues of scale

The scale of a map determines the degree of detail a map can show and the amount of area it can cover.  In a comparison between the 1:2500 scale and the 1:10560, the 1:2500 can show a greater degree of detail because it uses 25 inches to represent a mile as opposed to six. However it can’t cover the same amount of area as the 1:10560 can.  It is in effect a trade off between the ability to show detail and the ability to show a larger geographic area.

The matrix above is of the 186 section of Yorkshire. If this section was shown in the 1:10560 scale it would be shown in 4 separate maps being NW, NE, SE and SW.  If this area was to be drawn to the 1:2500 scale it would take 16 separate maps (1 to 16) to cover the same area.

The two excerpts below show how much greater detail a 1:2500 map can portray in comparison with its 1:10560 scale counterpart.

A section of Otley centre in 1:10560 scale
The same section in a 1:2500 scale

As can be seen the 1:2500 shows much greater detail but covers a smaller area.  We hope that you have found the above explanation informative and  helpful.