Now, grid north is an artifact of a map projection’s grid lines. On a map grid there’s always some difference between true north and grid north except along the central meridian, which in Ordnance Survey maps is two degrees west of Greenwich. The further away from that central meridian, the greater the difference.

What the Ordnance Survey is hyping is that magnetic north, which is constantly shifting, has moved to a point where magnetic declination (the difference between true north and magnetic north) is zero along that central meridian. Kind of neat—if you’re using an Ordnance Survey map. Because this particular triple alignment only exists for Ordnance Survey maps. It’s all a bit anglocentric, really (especially the bit in the video that describes true north as “the line which runs through Britain to the North Pole”).

The removal of military installations from OS maps was at its height in the 19th century and the World Wars, but throughout the Cold War and beyond, many sensitive sites were left off the maps entirely. It took the public availability of high-resolution satellite imagery at the turn of the 21st century to render this type of censorship largely ineffective, although labels are still omitted in some cases.

The Ordnance Survey did survey and map sensitive sites, but those maps were military-only. The differences between these military maps and the public maps make for a number of interesting comparisons: see the post for examples.

To commemorate the 50th anniversary of the first crewed landing on the Moon, the Ordnance Survey has released a map of the Apollo 11 landing site. The map is based on a 60-metre digital elevation model and covers a roughly 1,350×1,000 km swath of the near side at a scale of 1:1,470,000. Details from the map are available at this Flickr album. Paul Naylor describes the creation of the map here. The Ordnance Survey is selling a paper version of the map (100×89 cm, in rolled and folded versions) for £16. I kind of want one for my wall.

The Ordnance Survey produced a map of Mars in 2016.

To mark the 70th anniversary of the legislation creating the United Kingdom’s national parks, the Ordnance Survey has released the above poster showing each of Britain’s 15 national parks in relief. The 84 × 119 cm poster can be had for £15 via the Ordnance Survey’s shop.

The first map produced by the Ordnance Survey, their blog reminds us, was this map of Kent. Published in 1801 at the scale of two inches to one mile (1:31,680), it took three years to complete; the OS started in Kent over fears of a French invasion. As such, the map “focused on communication routes and included hill shading to ensure men at arms could interpret the landscape with precision. Over time, this map design became less focused on these elements and was developed to appeal to a much wider audience.”

The definitive history of the early years of the Ordnance Survey is Rachel Hewitt’s Map of a Nation, which I reviewed in 2012.

If the purpose here is to point to the route less travelled, well and good, but I suspect the effect will be rather like what happens when a travel guide raves about an out-of-the-way, hidden gem of a restaurant.

At the Edinburgh Fringe Festival? You may want to check out The OS Map Fan Club, an hour-long solo performance about Ordnance Survey maps that sounds relevant to our interests. Written and performed by Helen Wood, The OS Map Fan Club has been making the fringe and festival circuit this year and has been getting good reviews (see here, here and here). At the Edinburgh Fringe until 18 August; details and tickets here. [Map of the Week]

Previously: Cartography: ‘A Gently Interactive Show’ at the Halifax Fringe Festival.

Now seems an odd time to be launching a line of standalone, single-purpose GPS devices, but the Ordnance Survey has gone and done so: they’ve announced a total of four devices, ranging in size from the cycling-friendly Velo to the robust Aventura and in price from £370 to £500. The OS has been offering third-party devices from the likes of Garmin and Satmap through its online store; it’ll be interesting to see how people see these as measuring up against those devices—or against an app on the smartphone they may already own. More at Road.cc.

The Ordnance Survey isn’t above an April Fool’s prank, it seems. For the April 2018 issue of Country Walking magazine, they created a fictional island in the Atlantic Ocean that “had been lost to the sea centuries ago, only for it to have now mysteriously risen out of the waves in need of mapping.” (Its name, “Hy-Breasal,” might have been a tip-off.) In a post on the Ordnance Survey’s blog, cartographer Mark Wolstenholme explains how he used existing OS mapping to create a made-up island in a very short time frame.

After an aborted attempt at cutting up Lundy, I chose the Outer Hebrides’ isle of Pabbay for the main part of our new island. To disguise its origin, I flipped and rotated the island. To achieve that, all the names, symbols and vegetation had to stripped off, and because OS Explorer mapping is a raster image, that meant a lot of pixel selecting in Photoshop. Another restriction with the raster, meant I could only rotate the island by 90 or 180 degrees. Any other angle would re-interpolate the pixels and the print quality would be lost.

To further disguise the island, I looked for a smaller island to add, this time taken from the Orkney Islands. This was joined by the addition of an area of sand and reworked low water line. To finish the shaping, I added a handful of rocky outcrops around the coast as well as some mud, sand and a redrawn high-water line through the dunes. A bigger loch was hand drawn and is unique to this island.

Adding new features and Easter eggs in Illustrator and Photoshop came next. Read the post for the details.

The Ordnance Survey’s OS Maps mobile app now has a new augmented reality mode. “Using the phone or tablet’s camera view, hills, mountains, coastal features, lakes, settlements, transport hubs and woodland in the vicinity are identified and labelled. If a label is pressed and there is a data connection, a page of useful information about that location is displayed, including nearby walks, photos and places to stay.” AR is very neat but battery-intensive; nevertheless this strikes me as a very useful application of the technology. [iOS App Store, Google Play]

As part of National Map Reading Week, the British Library’s map blog points to at least one example of how map reading used to be taught.

One of the most celebrated 20th century children’s map reading guides is showcased in our forthcoming exhibition Maps and the 20th Century: Drawing the Line. Published in 1948, Ronald Lampitt and James Deverson’s The Map that Came to Life follows the story of John and Joanna who use an Ordnance Survey map to walk to town. As they pass over fields, past houses and along footpaths, their surroundings are compared with map adjacent on the same page. The fields turn into contoured blank spaces, houses become black cubes, footpaths dashed lines. Map literacy is acquired by the reader as they accompany the children on their virtual journey, matching map with reality.

In The Map that Came to Life the map is portrayed as an objective, precise and above all truthful mirror of nature. And this inherent trustworthiness enabled maps to become important features of the lives of successive generations of people.

The idea that maps are objective and truthful is not something that would fly today, I think, but in the context of entry-level map education, which in Britain always seems to be specifically in terms of how to read an Ordnance Survey map, rather than maps in general, it seems harmless enough.

A complete scan of the book is available on this website. Back in 2008, Philip Wilkinson talked about the book on the English Buildings blog.

Maps of War: Mapping Conflict Through the Centuries by Jeremy Black (Conway, 11 October). “There is little documented mapping of conflict prior to the Renaissance period, but, from the 17th century onward, military commanders and strategists began to document the wars in which they were involved and, later, to use mapping to actually plan the progress of a conflict. Using contemporary maps, this sumptuous new volume covers the history of the mapping of land wars, and shows the way in which maps provide a guide to the history of war.”

War Map: Pictorial Conflict Maps, 1900-1950 by Philip Curtis and Jakob Sondergard Pedersen (The Map House, 6 October). This is a companion book to the Map House’s exhibition of pictorial conflict maps, which I told you about last week.

Scotland: Mapping the Islands by Christopher Fleet, Charles W.J. Withers and Margaret Wilkes (Birlinn, 20 October). A follow-up to Scotland: Mapping the Nation (Birlinn, 2012), this book explores the Scottish islands through maps from the National Library of Scotland’s collection.

Art and Optics in the Hereford Map: An English Mappa Mundi, c. 1300 by Marcia Kupfer (Yale University Press, 25 October). Reinterpretation of the Hereford Mappa Mundi from an art history perspective. “Features of the colored and gilded map that baffle modern expectations are typically dismissed as the product of careless execution. Kupfer argues that they should rightly be seen as part of the map’s encoded commentary on the nature of vision itself.”

I told you about the Ordnance Survey’s Great British Colouring Map (Laurence King, 10 October) last July; it’s available this week. “Based on the accurate maps of Ordnance Survey, the colouring pages explore the coasts, towns, forests and countryside of England, Scotland and Wales. Includes detailed maps of cities and other places of interest such as Britain’s most recognizable tourist and historical locations, plus a stunning gatefold of London.”

Britain’s Tudor Maps: County by County (Batsford, 13 October) reproduces  the maps from John Speed’s 1611 Theatre of the Empire of Great Britaine. These apparently include the first individual county maps of Great Britain, so this is a work of some historical significance.

People were asked to plot various locations, from cities to National Parks on an outline map of Britain and we were pretty surprised at the results. Some 40% of people struggled to pinpoint London and only 14% could accurately plot Edinburgh’s location. […]

Even more worrying to us, just 40% of those surveyed felt they could confidently read a map with 10% never having used a paper map.

Now, map literacy and geographical knowledge aren’t the same thing: you can know how to read a map without being any good at placing something on a blank map (at least in theory). Either way, the Ordnance Survey will be producing guides and hosting workshops during the week in question. (In the meantime, they point to these map reading guides.)

As a major publisher of maps, it’s in their interest to do this sort of thing—a map-reading public is a map-buying public, after all—but increasing map literacy is an unquestionably good thing.

This unlikely assembly came about because the survey was instructed to make a map at a scale of six inches to one mile. The scale might seem unexceptional to anyone who grew up using the survey’s maps, but at the time it was nothing short of revolutionary—it called for enormous maps of frequently sparsely inhabited areas, and at a level of detail never before seen across such a vast expanse of land. How was the survey to gather the information to fill in such detailed maps? The answer was to task not only the engineers of the army, but also a crew of civilian workers under Petrie’s supervision, to both map the physical features of the landscape and also record every possible aspect of the landscape from its placenames (the initial justification for employing Irish language scholars) and archeology to its productive economy.

[WMS]

Previously: A-Z Maps Colouring Book; Albion’s Glorious Ile: A 400-Year-Old Map Colouring Book; City Maps: An Adult Colouring Book.

The Ordnance Survey has created a series of data visualizations showing the most popular walking and cycling routes, based on OS Maps usage. “The 500,000 plus routes were illustrated in a series of beautiful data visualisations by [cartographic designer] Charley [Glynn], who found it amazing that the people who created routes for their outdoors adventures had logged almost every bit of British coastline. It neatly frames the rest of the data and gives the illusion you are looking at a map of Great Britain. The darker, thicker areas illustrate the higher concentration of routes and reveal popularity.” Flickr gallery. [Mountain Bike Rider]

• Concomitant with the Survey’s map of Mars was a competition to design a map symbol to represent landing sites. The winner has been announced: the OS will use Paul Marsh’s symbol, which incorporates the Mars symbol with landing gear, on its Mars maps in the future.

The Ordnance Survey are marking the 80th anniversary of the Retriangulation of Great Britain, which began on this day in 1936. More from BBC News. Events include the Trig Pillar Trail Challenge, which invites people to post pictures to social media of one of 25 selected trig (triangulation) pillars (the #TrigPillar80 hashtag is very busy this morning). There are Flickr galleries of various trig pillars from Flickr user Andrew (who took the one above in 2013) and (of course) the Ordnance Survey.

The Ordnance Survey has created a map of Mars. “The one-off Ordnance Survey Mars map, created using NASA open data and made to a 1:4,000,000 scale, is made to see if our style of mapping has potential for future Mars missions.” It looks very much like a topographic map of Mars might; the reduced version is a bit more screen-friendly.

Inasmuch as a history of field surveying and copper-plate engraving can be made anything other than dull, Hewitt has managed to produce a narrative that fairly crackles with interest. She starts at the bloody Battle of Culloden, not only as a way of setting the stage for the Military Survey of Scotland, a predecessor to the OS, but also as a rationale for mapping the whole of Britain’s territory in the first place. From there we’re led through the Scottish Highlands, joint French-British observations to measure the distance between their observatories, the triangulation of Britain and the survey of Ireland. The narrative closes with the publication of the last maps of the First Series and the expansion of the OS’s works into city maps. Along the way we get glimpses into the equipment used in the survey, such as the theodolite, and the mapmaking process; there’s a lovely section on how the OS dealt with Irish placenames, and digressions into art and poetry.

It does read a bit traditionally, in the sense that it is an institutional history seen through the lens of those in charge. It’s a history of those making the maps; the impact of those maps is less thoroughly covered. And if you ask me, it ends too soon—just as the OS is getting started. A lot more could still be written, I think.

Previously: Forthcoming History of the Ordnance Survey; Map of a Nation: Hewitt’s History of the Ordnance Survey Is Now Available.

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