Maps and views blog

Cartographic perspectives from our Map Librarians

25 June 2020

Flickr Maps on the Georeferencer Finished!

Way back in 2014,  the British Library released over 50000 images of maps onto the Georeferencer that had been extracted from the millions of Flickr images from books with the help of volunteers. Ever since then the volunteers have been hard at work adding coordinate data and I am delighted to announce that the collection is now very close to or very probably completed. Many thanks to Sarah Shepherd, Singout for getting in touch about this. The upgraded Georeferencer and the time we have all had to spend indoors over the last months appear to have provided the project with a new impetus, well done to all!

The methods used to extract maps from the corpus of Flickr images meant that there were always going to be some images on the platform that were difficult to georeference such as celestial maps, cross-sections through geographical features like glaciers and fictional maps. Therefore, although the progress bar [] still shows over 3000 maps left it may be difficult or impossible to attach coordinates to those that remain.

Progress Bar 06-2020
The Georeferencer progress bar

To learn more about the Flickr maps collection and their addition to the Georeferencer platform back in 2014 take a look at this blog post ( Those of you who have been on the platform recently will probably have found it difficult if not impossible to get hold of a map to georeference.  We are not 100% sure that the maps are completely finished and if volunteers are interested in seeking out those possible last remaining images these links might make finding the images easier. Those tagged as 'togeoref' on Flickr:

or on James Heald's brilliant wikimedia tool which, sadly, is not being updated due to breaking changes caused by the upgraded Georeferencer:

Do get in contact with your experiences at [email protected] Thanks to Maurice Nicholson for his comments on the present situation and indeed all his help over the years.

The work of Georeferencer volunteers has been invaluable to the Library; the addition of coordinate data from the Flickr collection to the British Library's catalogue has offered a new metadata perspective for our collections. The British Library's Goad fire insurance maps have also recently been made available on the Layers of London platform.

It would not be possible to view the digitised maps on the Layers of London web map interface without the addition of thousands of control points by our georeferencers. We are currently working to add new images to the Georeferencer although bringing this to fruition is not made easier by the current circumstances and the difficulties they cause in accessing data on-site.

In the meantime I would like to highlight an issue with our OS drawings and Civil war maps. When the Georeferencer was upgraded we resupplied thousands of images. Unfortunately, we made an error with several hundred that were added with an erroneous 'colour bar'. Please see this example.


Ordnance Surveyor Drawing of part of Nottingham (Maps OSD 290) with the colour bar

The additional colour bar means that the new image does not match up with the original control points. Please accept my apologies for this error. We have been trying to track down the original files and book time and funds to replace them on the system. In the meantime, if you would like to correct these images please do so, your work would be helpful, but otherwise we will replace the images when we can which will align the original georeferencing. We know that Civil War and OS Drawings collections suffer from this problem but if you find other images or you would like to provide any other feedback please get in contact at [email protected]

Colton's map of the Pacific States, 1862 (Maps 71495.(60.)) with colour bar

Finally, if you are missing georeferencing and looking for a different challenge, there are other opportunities to volunteer for British Library projects. The first point of call is to sign up for our LibCrowds newsletter [`] It's a great way to find out about BL ongoing crowd-sourcing projects including Playbills [] or Siberian Photographs []. Please do stay involved!

Gethin Rees