The Ordnance Survey is making a small deal over a so-called “triple alignment” of true north, magnetic north and grid north early this month: “the historic triple alignment will make landfall at the little village of Langton Matravers just west of Swanage in early November and will stay converged on Great Britain for three and a half years as it slowly travels up the country.”
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.
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.”
Today is the publication date for The Ordnance Survey Puzzle Book (Trapeze), a collection of map quizzes and puzzles—a “mix of navigational tests, word games, code-crackers, anagrams and mathematical conundrums” contrived by Gareth Moore—based on some 40 Ordnance Survey maps dating as far back as 1801. It’s out in the U.K. only; North Americans will have to try third-party sellers on Amazon (or elsewhere) or order directly from British vendors.
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]
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.
Two things about CityGuide’s beginner’s guide to map collecting. One, it’s not so much for beginners as written by a beginner; the author, Chris Sharp, is recounting his own journey into map collecting. Which brings me to the other thing: what kind of map collecting he’s talking about, which is to say, the “collecting all the OS Landranger maps” kind of map collecting, not the “paying exorbitant sums for a rare and ancient map that might be a forgery or sliced out of a volume from a library’s rare books collection” kind of map collecting. I don’t want to invoke Dunning-Kruger here, but I’m not sure he knows how much more there is out there. I suspect that he’s going to find out. Not being British myself, I don’t know to what extent Ordnance Survey maps are the gateway drug to a serious map collecting jones, but I have my suspicions. [WMS]
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]
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.
October is a busy month: I’m aware of six new map books coming out. Two deal with the mapping of war, three with the rich cartographical history of Great Britain, while the sixth is a colouring book.
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.”
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.”