Question: How do I find out what ‘Publish Year Start’ and ‘Publish Year End’ dates means for the maps in Historic Digimap?
Answer: The publishing date range of a map in the Map Details tab from the Main Map View in Historic Digimap. This is achieved by using the View Map Details tool (an i symbol) and clicking on the historic map at the point of interest.
The maps shown on the screen are created from the National Grid “cookie cut” files – images which have been rectified and clipped to create a national grid based “tiled” dataset akin to those available for the contemporary Ordnance Survey data. However, the National Grid does not match up with the County Series maps, because the County Series were created on a per County, rather than a national, basis. It is therefore likely that one “cookie cut” National Grid tile comprises parts of more than one County Series map sheet, each of which could have a different publishing date.
The metadata for the National Grid “cookie cuts” often does not contain one publishing date but the range (from, to) of publishing dates of the Orginal mapsheets which make up that national grid cookie cut tile. It is this range which is reported under the Map Details tab.
Unfortunately, EDINA does not have any survey dates for the maps in the Historic Digimap. Landmark Information Group who provided the maps did not capture the survey dates when the maps were digitised (scanned). This is because the maps were originally digitsed for a specific purpose which did not require the information held in the marginalia of each map sheet. During the digitisation process the marginalia was trimmed from the resultant files, meaning that it was never captured in digital form.
A solution to this is to visit a library which holds historic maps; many university libraries have historic map collections with specialised cartographers and support staff. The map details taken from Historic Digimap can be used to search for and locate the map(s) corresponding to your area of interest. Once found, it is in a map’s marginalia where you can find the recorded survey dates.
More detailed information about historic maps and Historic Digimap can be found in the Help pages.
