By SANDRA RENDGEN
In these days of restricted travel, maps bring us some comfort – we can trace coastlines, measure journeys we plan to undertake. But when is a map not a map?
Cartography – an age-old discipline combining science and art – has created a unique way of looking at our planet, of flying over continuous landscapes and endless oceans. The 19th century was a golden age of atlases. Beautiful pieces for the educated household were printed in the world over. Many featured one very special type of map: the comparative tableau showing the longest rivers and highest mountains of the world.
This type of map makes possible the mind-blowing experience of looking at the whole world at once. Instead of depicting a given landscape according to the conventions of accurate cartography, we are shown the world’s biggest mountains and the longest rivers in one fictional space. Many different variations of this type of map were created during the 19th century, and it is fascinating to see a format that integrates diagram, map and panoramic view in one visual.
Mapmakers pulled out all the stops to arrange the geographic elements in innovative, ornate layouts – sometimes in a circle, sometimes in a diagonal design, sometimes in a diagram. This alluring example, printed in London in 1836, perfectly exemplifies what I love about these incredible precursor to the infographic: they look like a map, but they are not. They defy our expectations that we are looking at a unified representation of geographical space, presenting us instead with an impossible accumulation of rivers and mountains.
Look at the neatly ordered rivers! Their arrangement forms a beautiful halo around the centrepiece of this map: a virtual mountain, which absorbs in its enormous belly the highest individual peaks of the world. The rivers meander gently from source to estuary, flowing into a non-descript universal sea at the top; it is but one of the map’s curiosities that the rivers flow upwards. Another is that when you order rivers by their length instead of their geographical position you create new neighbours. The Mississippi and the Yangtze bring New Orleans and Nanjing to within a stone’s throw of each other.
For centuries now, maps have been based on the conventional grid of longitude and latitude. This coordinate system for representing terrestrial space is deeply engrained in our brains and is invoked whenever we look at a map (and this is also why cartograms – which represent a statistical variable by blowing up or shrinking the respective map space are so difficult to wrap your head around). Comparative tableaux dissolve this cartographic space to enable comparison.
What I particularly like are the fictions that arise from this logic of arrangement. Defying scientific standards, these fictions are readily embraced and beautifully executed. For instance, our monolithic mountain rises from a non-descript ocean, in order to provide a sea level reference for all comparative heights. Along the “shore”, we find several places that genuinely lie at or near sea level, such as London and Rome (on the right) as well as the pyramids and the Niagara falls (on the left). Not only are these locations placed randomly along the bottom of the mountain, but their properties are also sometimes affected. It is fun to see how Niagara falls burst out conveniently into the sea and how the pyramids (whose surrounding sea of sand is very much part of their image) have their silhouette reflected in the water.
Mountain peaks are depicted rather creatively too – looking more like jelly bag caps than mountain peaks. Our virtual mountain is topped by the Dhaulagiri, a peak in Nepal considered at the time to be the highest mountain in the world. Note the lovely narrative details such as the little volcanos, the air balloon to the right or the condor to the left – all instances of compared heights.
This 19th century cartographic specialty – once called “the comparative machine” – integrates two conventions: the map and the diagram. It never ceases to amaze me that the marriage of two scientific schemes creates a rather unlikely virtual world. I guess that is what people call science fiction – fiction arising from science.
Images via David Rumsey Cartography Associates. I recommend the excellent book “Le monde sur une feuille” (Jean-Christophe Bailly, Jean-Marc Besse, Gilles Palsky, 2014), which focusses only on this particular type of maps and presents many many beautiful examples. The quote of the “comparative machine” is taken from Jean-Christophe Bailly’s preface (p. 4).
Sandra Rendgen is the author of two bestselling books on data visualisation and infographics, both published by Taschen. Currently she is getting lost in the history of data visualisation.