OpenHistoricalMap/Projects/London

This page intends to detail the efforts to map London, England, and outline some of the resources available to mappers.

Mapping

A few different mappers have mapped various parts of London in OpenHistoricalMap. We'd love to see more people get involved in mapping London's history! Information on getting started with mapping in OpenHistoricalMap can be found on the main Wiki page here and the OHM Basics page.

There are a number of different features which can be mapped, here are some suggestions:

• Roads - it would be good to have a comprehensive map of the road network throughout London and beyond, showing how it has changed over time. The 1893-6 1:1056 and 1947-63 1:1056 OS maps are good base maps to use for tracing many of the roads and then you can use older maps to identify whether the road existed at that earlier date.
• Buildings - buildings make the map much more interesting, especially adding the key buildings in an area.
  • Public buildings. Opening dates for major public buildings are generally easy to find.
  • Churches and other places of worship - these are key features of the historic townscape, and many have a long history though they have often been rebuilt over the years. Where they have been rebuilt it may be easier to add a node for the amenity=place_of_worship and name tag including the earlier start date, and a separate way for the building if this is more recent.
  • Pubs - many have long histories, though again they have often been rebuilt. There were far more pubs in the past so it might be a bit of a challenge to map them all! London also has had lots of breweries in its history - a book 'London Brewed' details all of these.
  • Factories/industrial buildings.
  • Schools, colleges and universities
  • Theatres
• Parks/gardens - much has been done already, it would be good to add all the parks!
• Railways - there has been much work done on this already, it would be great to have a full map of the changing railway network in and around London. The dates when stations and railway lines opened can generally be found on Wikipedia (it is advisable to check sources), and in railway history books.

It is easiest to map in London using the old Ordnance Survey maps provided by the National Library of Scotland as a background. Most mapping is aligned with the OS 1:1250 or 1:2500 post-Second World War maps which cover the whole of Greater London and beyond. These can be added to iD (the web browser editor) by pressing B for background settings, select 'Custom', copying and pasting in the following link: https://mapseries-tilesets.s3.amazonaws.com/london_1940s/{z}/{x}/{y}.png. There are also various other maps that can be used in the editors such as the OS 1862-64 1:1250 map, see the bibliography for details.

Tagging

These are just a few suggestions for tagging the features you're mapping in London in OpenHistoricalMap. Please also refer to the tagging guidance elsewhere in the OHM pages on the Wiki. Please add any further suggestions you have!

• Please always try to ensure there is a start_date tag on everything you add, so that we don't have for example motorways and railway lines appearing on the map in Roman times! Also please always try and add an end_date if the feature no longer exists.
• Currently the renderer only recognizes dates in the format yyyy or yyyy-mm-dd so these must be used in start_date and end_date. Often however you will only know an approximate date and it is important to record this uncertainty using a start_date:edtf or end_date:edtf tag.
• When exact dates are not known it's probably best to take a cautious approach to setting the start and end dates - use what seems to be the latest possible date for start_date and and earliest possible date for end_date.
• Names of streets etc have often changed in London over the years, and the map should try to represent these changes.
  • A couple of different options have been proposed for mapping such changes. A simple option is to use an overlapping way with the older name tag set on one way, with the end_date set as when it changed to the new name. For the new name create a new way using the same nodes with the start_date set as when the road changed to the new name. Another method is to use a relation.
  • It can be difficult to determine exactly when that name has changed - one possible idea as a temporary workaround until the date of the change is identified is to put both names in the name tag separated by a semicolon.
  • Before the 19th century however spellings of road names and other features were often not standardized in the way they are today so different sources of a similar date may have different spellings. It may be best to tag these variations in spelling with an alt_name tag instead.

Resources available

There are lots of resources for mapping the history of London. Here are just a few. See bibliography for a fuller list detailing specific resources which are available.

• The National Library of Scotland has made available a number of maps to OpenStreetMap and OpenHistoricalMap mappers. These are available as tiles for tracing in the editors. The 1:1056 Ordnance Survey 'town plan' dated 1893-6 and 1947-63 maps are particularly useful, as detailed and accurate maps.
• Ordnance Survey maps become out-of-copyright after 50 years. Though if you are using an old Ordnance Survey map published on a website you need to ensure the website's terms of use allow the use of those maps.
• Wikipedia and Wikimedia Commons have a number of useful resources including old maps and articles referring to the history of buildings and streets. The 1746 John Rocque map [1] for example is quite useful as a detailed early map of central London.
• Layers of London [2] provides many different resources including maps, photos and articles. It appears this is mostly under a Creative Commons Attribution (CC-BY) licence, so it should be possible to use this as long as attribution is provided.
• The Internet Archive has a huge number of books relating to the history of London, though it can take a bit of effort to find the most useful content amongst all the material on the site. Try these subject searches London - history, Survey of London, London - architecture, London - description and travel. Note that some material (including all/most of the 'lending library' material) is subject to copyright, and can only be used to help research simple facts like start and end dates, but any copying of maps, descriptions etc must not be done as this will likely be a breach of copyright law. Many of the earlier histories and contemporary descriptions from the time give much detail and so can be very useful.
• London's archives, libraries and museums have more resources on the history of London than any other source (much more than the internet!). In general you'd need to visit in person, though some provide access to a limited selection of material online.
• There are many different local history organizations across London, many of which produce journals and other publications which may be of use (though be careful not to breach copyright law). London-wide examples include the London Topographical Society and London and Middlesex Archaeological Society, but there are many others covering specific areas of London.

Issues to fix

There are a number of issues which need to be fixed on the map in the London area which you can help with including the following key issues.

• Adding missing start dates. There are a number of objects that have been added to the map without a start date. This is a big problem as it means they will appear on the map throughout the whole of time! If you don't know the date you can check old maps and if the feature is present on that map use the date when that map was surveyed or published as the start date. Then add an start_date:edtf showing that the feature existed at least by that date and perhaps a note tag explaining this. A start date that is later than the actual date the feature first existed is much better than having no start date at all! However it is OK at present for natural features such as rivers to not include a start date.
• Completing the road network. Even in areas which are quite well mapped there are often various gaps in the road network which need to be filled in.
• Mapping changes to road names. As noted above under tagging, as a temporary measure some have been mapped with multiple names separated by semi-colons, but these should really be separated into different ways or relations, one with the older name and one with the later name. To alter these it will be necessary to find out when the name changed so the appropriate start and end dates can be tagged. A useful source is the 'List of the streets and places' published by London County Council and later the Greater London Council, including dates of when streets were ordered to be renamed. Various editions were published. Copies of this are available to consult at the London Archives and various libraries.
• Adding place nodes (points) for London's suburbs etc. To do this research will be needed to find out when that place name first existed. There may be multiple nodes for one place covering different dates - for example a place may be a village to start with and a suburb or town later on.