Maps and views blog

24 posts categorized "Georeferencer"

20 November 2013

2,700 new maps online for georeferencing

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Those with an interest in the history of industrial Britain and the urban landscape will be pleased to hear: Goad fire insurance plans are now online and available for georeferencing. These maps are a mine of information about the towns and cities of late 19th-century and early 20th-century Britian and Ireland, capturing practical elements such as individual addresses and building footprints, as well as the overall character of a place in terms of class, space and the built environment.

Georeferencer-link-smallThese Goad plans were selected for scanning and inclusion in the latest release of BL Georeferencer because of the huge demand for them at the Library. We're asking the public to help "place" them, ie identify their locations by assigning points using modern mapping. It can be a challenge, but it is an opportunity to discover familiar areas as they existed around 100 years ago.

Goad Manchester Clowes St maps_145_b_17_(3)_f042r

This detail of Sheet 42 of the City of Manchester illustrates the richness of information on the maps. These densely partitioned street is home to warehousing and a variety of industrial activity, cheek-by-jowl with small tenement housing units. Detail about the individual buildings: their materials, the number of floors, windows, and building use, is outstanding. See the map legend, online exhibition and curator's notes, and guide on the Library's holdings for further information about this collection. 

The first edition Goad maps of all British and Irish towns, 1886-1930, are now online. Georeferencing opens today; you can be assigned a Goad map at random, or start by selecting a place.

10 May 2013

Ordnance Surveyors’ Drawings opened for reuse

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The Library’s unique collection of Ordnance Surveyors’ Drawings is now available under new terms, making the maps freely accessible and usable in digital tools.

The Ordnance Surveyors’ Drawings (OSDs), compiled between 1789 and c.1840, represent the first continuous topographic mapping of England and Wales and are the most detailed record of the landscape preceding full-scale industrialisation in the mid-19th century. These original manuscript maps, drawn primarily at scales of ca. 1:21,120 and 1:31,680, with coastal areas of military significance at ca. 1:10,560, depict the whole of Wales and England south of an east-west Preston-Hull line.


Detail of OSD 267(pt.2). Ordnance Surveyors’ Drawings. Boyce, draughtsman. 1814

Though these ink-on-paper drawings formed the cartographic basis for the first published Ordnance Survey one-inch mapping, they contain topographic details not captured in the smaller-scale, printed series. The detail above of the 1814 OSD 267(pt.2) was drawn at a scale of two-inches-to-the-mile and indicates field boundaries, land cover, water courses, relief, roads and footpaths, and built features, including the presence of stone walls, drawn here in red.


Detail of Sheet 64. Ordnance Survey,  Old series,  First ed.  1:63,360. 1824

In contrast, the published sheet above in the First Ed (Old Series), printed in 1824 and based on the OSD, was by necessity generalised, due to the smaller scale (one-inch-to-the-mile) and limitation to black-and-white. 

The OSDs were georeferenced in 2012, and partly as a result of the immense success of that public crowdsourcing effort – BL Georeferencer - scanned images of the maps have been “opened up” for reuse under an Open Government Licence. A small sample of four OSD images have been posted to Wikimedia Commons here. The remaining 400 or so will follow; if you wish to be notified when it is complete, contact

Another exciting development with these maps is their inclusion in British Library Labs, a new project supporting research and development with BL digital data that offers direct curatorial and financial support, including an expenses-paid residency at the British Library. We are hoping that researchers and developers with an interest in cartographic history and geospatial data will participate, and we'll see these maps put to new and dynamic uses online!

01 February 2013

BL Georeferencer - maps go like hotcakes

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This is more a news update than anything else, to say that some amazing stuff has gone on this week with BL Georeferencer, our online crowdsourcing project for placing historic maps at
In less than *three* days from the lauch (four from the "soft" launch of social media leaks!), all of the 781 historic maps we put online for georeferencing were completed using the BL Georeferencer tool. Participants captured spatial metadata about the maps so that they may now be seached and viewed using popular geographic web tools, eg Google Earth and Old Maps Online, and data (OSM, OS OpenData). 
So before I head off to a training session, I wanted to say "thank you" to the volunteers who gave their time to sort out where all these maps belonged. I know from my familiarity with this collection that finding the places depicted often required plenty of patience, online research and a spatial sense!


02 November 2012

Annoucing BL Georeferencer champions

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All the maps in this latest round of BL Georeferencer were completed yesterday, 1 Nov, thus producing second lot of of the Library's historic maps that know where they belong. A related result was the amicable conclusion of the weeklong point leapfrogging between the two top participants, Sue White and Maurice Nicholson.

A heartfelt "thank you" to Sue and Maurice for their dedicated work! In what must have been mutual design or compromise, each contributed precisely 3,300 points over the course of the six days. This impressive number is evident in the high quality of the georeferencing they produced, and will be enjoyed by users overlaying the maps in future. 

This Christopher Saxton map of Kent, Sussex, Middlesex and Surrey was assigned a mind-boggling 398 points, more than any other map!

A quarter of the maps were georeferenced with 3-5 points, with more than half of the maps sporting between 6 and 30 points. Less - ~18% - have between 30 and 100 points at present, such as this 1928 OS map of the south west coast of Wales (38 points).


Thanks to all the volunteers that assisted in the BL Georeferencer effort. We will see their work added to Old Maps Online in future, where maps from numerous collections can be searched geographically and by time. Before that, however, we have some error-checking that I'll be looking for help with... stay tuned! 


30 October 2012

Difficult maps

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Sometimes the map that's leftover, that no else wants to decipher, is the most valuable to georeference.

In my periodic checks on BL Georeferencer, I've noticed that the more opaque, difficult to discern maps are avoided - and this is entirely understandable! Associating the places that appear on historic maps with their current geographic location on the ground can be straightforward, but not always. Here are a few of those more demanding:

Banbury castle4
This 16th c. drawing required reading the title and description to get any idea of where or what it was - there is no text on the map!

This ca 1600 map of Shopshire is nicely labelled, but requires some interpretation.  Shewsbury is labelled "Salop", an historical name for the city, and scale varies over the map: the loop of the river on which the city is located is of an inordinately large scale, but this emphasises its prime geographic feature making it firmly recognisable.

Thanks to Steven Feldman for taking on these two.

Below are a couple I am less certain will make it...

Numerous maps from the Kensington Turnpike Trust are available, and all seem to be difficult to move. This, sheet 6, has even less information than most!

Estate map
No one has dared attempt this estate map of "the manors of Mincingbury, Abbotsbury and Hoares, in Barley, Hertfordshire." If anyone can figure where this might be located, please help!

What makes the difficult maps especially valuable to georeference is their very obscurity; because most folks will not know what they represent, they are made less useful. Once their location is known, they are able to be found and used as maps. 

My thanks and admiration go out those participants in the BL Georeferncer project that accept the challenging maps!

26 October 2012

Chance to georeference maps online!

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It was only this morning that a new set of 700 maps was opened to the public for georeferencing, but this afternoon I am overwhelmed at the interest we've received. Participating individuals examined the scanned maps closely - many of which were not easy to decipher, being of an earlier and more "characterful" sort - and, using an online gazetteer and map, found and assigned their locations. Amazing.

There is plenty left to do. Please give it a try!

Screenshot for instructions
Once a map has been georeferenced with this tool, it may be viewed overlaid on the landscape, and each participant is credited for the number of points they submit.  

But it is not all about immediate gratification and competition! Georeferencing these maps extends their usability and findability, and allows visualisation in new ways using popular geospatial tools. The British Library has tremendous collections of historic maps that, without georeferencing, lack visibility via digital technologies, so we decided to crowd-source the activity. All the data created from this effort will be used for enhanced searching; the results of our initial pilot (thanks to those volunteers) have already been applied in Old Maps Online ( and we have plans for our own uses.

27 February 2012

Success in "placing" historic maps

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The crowdsourcing effort described in my last post was, I am happy to say, complete in less than one week. Many thanks to all that participated! Maurice Nicholson of Bedford submitted the most maps, and he will be in for a visit to the British Library in a couple of weeks.

Below is a visualisation of the maps completed (before any error-checking!)


All of the maps in the project are still open for editing. Adding more points - spread across the entire map - will improve the accuracy of the data. From here, simply click on the red marker representing the map you wish to edit to enter the Georeferencer tool. If you have local knowledge of an area, we'd appreciate you reviewing what's there to ensure the best fit and minimise errors.   

Because of the quick work, the newly-georeferenced maps were integrated into the JISC-funded Old Maps Online, in which The British Library is partnering, in time for its launch. More on that soon...

Get in touch via if you wish to be contacted when the next batch of maps is ready for georeferencing.

14 February 2012

Georeferencing maps online - will it work?

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We're asking the online public to undertake a task beyond our own means: to georeference some of our treasures of British mapping.

The maps included represent a very small sample, to be sure. But the the Ordnance Survey Drawings are some of the most enquired-after maps we have, being unique manuscript documents that portray the lanscape of England and Wales before the onslaught of industrialisation made its mark.

  GE - Exeter4
This is a detail of OSD 40, pt. 3. In 1801, Exeter was a small and compact town!

The other collection we've included in this effort is a selection of the Crace Collection of Maps of London. I've found these maps to be more difficult to georeference, and am eager to see how others fare with them.

The project web page is - there is a short video there and detailed instructions. Access is also available from within the map pages in the Online Gallery. Please try this new tool out, as it will be a great help towards improving access to and visibility of these collections!