Wednesday, 27 November 2019

Tranchot and the mapping of the Rhineland

Monument to cartographer Jean-Joseph Tranchot on the Lousberg in Aachen

Anyone wishing to win over the affections of their valentine could do worse than to chaperone them to the summit of the Lousberg in Aachen. Admittedly, it doesn't have the same romantic ring about it as the Spanish Steps or Montmartre, but the view from the top of this humpbacked hill just outside the city centre is as enchanting as any in these whereabouts.
Indeed, the unbroken views offered from this lofty vantage point were not lost on early cartographers either, as the prominent obelisk on its summit bears witness.

The story of the obelisk dates back over 200 years, at a time when military aggression was good for mapmaking. After Napoleon invaded and then occupied the Rhineland at the turn of the 19th century, he demanded that detailed maps be made of his newly acquired possessions. The man chosen for the job was Jean Joseph Tranchot (1752–1815), a French army officer who had already carved out a distinguished career as a cartographer.

France and the birth of modern cartography 
Of all the nations in Europe during this period, France had taken the lead in systematised mapping. This was largely due to the Cassinis, a dynasty of accomplished astronomers and cartographers who, over the course of four generations from 1671 to 1793, occupied the position of Directeur général de l'Observatoire in Paris. Between 1750 and 1793, under the aegis of César-François Cassini (known as Cassini III), the first nationwide map of the country was produced in a total of 182 sheets at a scale of 1:86,400. It was achieved using the most advanced scientific principles of the day, namely astronomy and triangulation.

It was against this background that Jean Joseph Tranchot launched his career. His first surveying commission took him to Corsica where he was to help with the triangulation of the island of which France had taken control from the Republic of Genoa in 1768. After two decades serving on this project, Tranchot - who had singled himself for the great accuracy of his work - received a commendation from the French Academy of Sciences. Later he worked as a chief surveyor in the Méchain/Delambre measurement of the meridian arc between Dunkirk and Barcelona (1792-1798), which had the aim of establishing the exact size of the earth on which the new metric system would ultimately be based. 

The triangulation of the Rhineland 
So it was that Tranchot was tasked with mapping the newly conquered Rhineland in 1801. He set up his surveying operations in Aachen, the prefecture of the newly formed Département de la Roër, one of the four Départements réunis de la rive gauche du Rhin (on the left bank of the Rhine) stretching from Kleve (Cleves) in the north to Saarbrücken in the south. His first mission was to establish the exact geodetic coordinates of the highest point of the Lousberg, a prominent hilltop overlooking the town. From here the whole of the surrounding country could be triangulated and mapped. To do this he took meticulous astronomical observations from the summit over a period of 3 and a half weeks in the summer of 1803. The purposes of this was so that the Lousberg (264m) could be connected up to existing triangulation networks in France and the Netherlands and subsequently function as the starting point for the new Rhineland network.

From here, Tranchot created a system of 55 triangulation stations throughout the Rhineland. In the lower-lying areas, measurements would have been taken from church steeples. Those in Sittard and Erkelenz, which were in direct sight of the Lousberg, were amongst the first to be triangulated and they measured a distance of 28.12 and 36.59 kilometres respectively. However in other parts of the countryside, where higher points were covered in dense forest, such as in the Eifel, wooden beacons had to be constructed.

The French instrument of choice to triangulate was Borda’s repeating circle, a contemporary alternative to the theodolite. The instrument consisted of two telescopes mounted on a shared axis which could be rotated through 360 degrees. Using calibrated scales, the angle between the two – fixed on any distant object - could be measured. The telescopes could be swivelled and adjusted many times over so that multiple measurements could be made, so increasing the accuracy of the readings. 

The cartographic work 
Once primary triangulation in the Rhineland had been completed, topographic surveys could commence to map out the countryside in greater. This was done using plane tables, another piece of surveying equipment, consisting of a drawing board mounted on adjustable legs and used in the field for plotting measurements directly. The results of these measurements were recorded in ‘field maps’ (first at a scale of 1:10,000 and later at 1:20,000). Draughtsmen would depict variations in relief (i.e. slopes) by the use of hachuring where steeper slopes were represented by thicker, shorter ‘hatching’, while gentler slopes were represented by strokes which were thinner, longer and further apart. A very gentle slope or a flat area, like the top of a hill, was usually left blank.

For the Rhineland maps, cartographers were instructed to draw these hachures using the relatively new ‘oblique illumination’ technique, which introduced the principle of hill shading to cartography. In this way the terrain could be depicted in a more realistic fashion by showing how the three-dimensional surface might be illuminated from a point light source, for example, in the top left corner of a map. However, the cartographers of the day were not always properly acquainted with the technique. Others who had to work in haste did not always heed the requirements and there is said to be a lack of uniformity between the Tranchot maps.

The maps also included a cadastral element, so, for example, land was designated by its use: ‘B’ (Bois) indicated woodland; ‘T’ (Terres labourables) arable land; ‘P’(Prés) meadowland;  and so on.

After Napoleon’s abdication and subsequent exile to Elba in 1814, the French withdrew from the Rhineland. The topographic survey of the region continued under Prussian rule supervised by General Karl von Müffling from 1816 to 1828. The cartographic series dating from the whole of this period is therefore known as the Tranchot/von Müffling series. 

In all, 264 maps – each covering an area of 10 x 10 kilometres - were produced at a scale of 1:20,000 (later reduced to 1:25.000).

Part of the Tranchot/v. Müffling map of the Rhineland, sheet 76: Herzogenrath 

Snapshots of a bygone age 
The Tranchot maps paint a picture of the social and economic conditions of the pre-industrialised era in perhaps a more expressive way than any history book. Agricultural reform was still in its infancy, individual settlements had not yet expanded and new roads between major towns and cities had not been built. Through a comparison with modern-day maps it’s possible to understand the far-reaching changes that the landscape has undergone. On the other hand, in some remoter rural areas, it is surprising to see how much time has seemingly stood still for the last 200 years.

As for the Lousberg, the obelisk on the top of the hill tells its own story, one which captures the romance of cartography for map lovers like myself.

The triangulation point on the Lousberg was originally marked by a wooden signal. However, in 1807 a stone pyramid was erected on the spot and inscribed with various commemorative texts, not least proclaiming the accuracy of Tranchot’s geodetic calculations. The square base stood 3.6 metres high and the pyramid which rose above it reached a height of 8.7 metres. Later that year a lead casket was placed in the base containing 55 gold and silver coins and 13 bronze medallions celebrating key moments in the life of the Emperor Napoleon.
On 2 April 1814, after French troops had withdrawn from the Rhineland, the obelisk was torn down by Prussian soldiers hell-bent on looting the valuables contained in the lead casket. In the process, several stones were damaged, some toppling down the steep slope at the top of the hill.
Following this act of vandalism, in an act of generosity towards a fellow surveyor, Major-general von Müffling, the chief of general staff for the Prussian army in Niederrhein, immediately ordered the pyramid to be reconstructed, faithfully reproducing the texts that had been inscribed on the original pyramid, barring a eulogy in praise of the recently deposed Napoleon.

Happily, the monument still stands today to serve as a tangible record of the remarkable feats of cartographers of a bygone age. And if, while taking in the sweeping view from the top of the Lousberg, you were wanting to hold your heart-throb completely spellbound, what better way to do this than by telling them the captivating tale of Tranchot and his maps?

Further reading (in German):
Schmidt, R (1973) Die Kartenaufname der Rheinlande durch Tranchot und v. Müffling 1801 – 1828, Gesellschaft für Rheinische Geschichtskunde XII
Geilen Quirin (1991), Entstehung der Tranchot-Müfflingschen Kartenaufname und des rheinischen Kadasters in ‘Mit Wasser und Dampf’, Fehl, Kaspari-Küffen and Meyer, Meyer & Meyer 

This article was written as part of the Mapping the Mountains exhibition, organised under the auspices of the Dutch Mountain Film Festival #9, which takes place in Heerlen (NL) from 31 October 2019 to 29 February 2020.

For more information:

Tuesday, 15 October 2019

Mountaineers turned cartographers

The Heart of the Grand Canyon Map, published in 1978 (National Geographic Maps)

When the sport of mountaineering arrived in the Alps in the mid-1800s, cartography was still essentially an undertaking that was reserved for the military. Once they had organised themselves into alpine clubs, practitioners of the sport came to the conclusion that existing maps were either not fit for purpose or they were simply not available to the public. A number of these alpine clubs thereupon assumed the mantle of cartographer – indeed, to this day, the Deutsche and Österreichische Alpenvereine still produce their own detailed maps of the Alps and regions beyond. Later, other individuals, acting alone or with others, would take it upon themselves to create their own maps, either to fill in the blanks, or simply to add to our knowledge of the mountains, so leaving their own idiosyncratic mark on the cartographic and mountaineering landscape.

Two individuals that very much fit into this mould are the American mountaineer, Bradford Washburn (1910-2007) and English fellwalker, Alfred Wainwright (1907-1991). In terms of personality, they were highly disparate and it is hardly likely they were even aware of each other’s existence. Washburn was a brash American who later became curator of the Boston Science Museum, whilst Wainwright was a social introvert whose day job was working as municipal treasurer for a sleepy town in the north of England. Yet both of them had an abiding love of the outdoors and contributed enormously to our love and appreciation of the hills.

Bradford Washburn

Bradford Washburn (1910-2007) came to prominence as a mountaineering talent during his time at Harvard University. His playground of choice was the remote mountain country of Alaska and the Yukon where he made several first ascents, often opening up supply routes in inaccessible areas by plane, a complete novelty in the 1930s.

His skills were soon recognised by the National Geographic which commissioned him, at the age of 25, to write an article for the magazine describing the first ascent of Mount Crillon (3847m) in Alaska. After this, he established a lifelong relationship with the magazine and also became an avid contributor to the American Alpine Journal.

In 1938 he was appointed director of the Boston Museum of Natural History (later the Boston Science Museum), where he worked until retirement in 1980. From here he was able to strike out on another career path as museum curator, but he combined this role with a long list of other activities, which included mountaineering, photography, and - not least - cartography.

Having given up serious mountaineering in the early 1950s, he applied his skills to survey work. With his unrivalled knowledge of Alaska he entered into a collaboration with the Swiss Eidgenössische Landestopographie (now Swisstopo) to produce the first detailed map of the Mount McKinley range (now Denali) in 1960. Incorporating many familiar Swiss cartographic features, it was the first time that the topographic service had ever printed a map outside Switzerland.

In 1970, Washburn teamed up again with the National Geographic for his Heart of the Grand Canyon Map project (see main image). Determined to create a unique two-dimensional representation of this natural wonder, Washburn, working with his wife Barbara, spent seven years working on the map. To gather the data, they hauled cumbersome equipment, such as theodolites and odometers, over hundreds of miles of trails. Many of the points they surveyed were so inaccessible that they had to be dropped in by helicopter. After the fieldwork came the job of committing the data to paper and to do this he once again called in the support of the Swiss topographic services.

In the early 1980s, Washburn coordinated an ambitious plan to map Everest. Multinational in nature, it involved the Boston Museum of Science, National Geographic, the Swiss topographic services and had the blessing of the Chinese and Nepalese governments who had hitherto blocked efforts to have the mountain surveyed. Using vast amounts of photogrammetric material that Wasburn himself had recorded, often in treacherous conditions, his aim was to produce a 1:50,000 map that was very much in keeping with Swiss topographic traditions. He clearly succeeded.

Alfred Wainwright

Description of Bowfell (2960 ft): from Alfred Wainwright’s ‘The Southern Fells’

The name of Alfred Wainwright (1907-1991) will forever be associated with the Lake District in the north-west of England. Ever since his 7-volume hand-drawn and hand-written Pictorial Guides to the Lakeland Fells were published between 1952 and 1965, they have been inspiring ramblers with great enthusiasm for the outdoors.

Born into a working class family in the Lancashire mill town of Blackburn, he took up work as a clerk with his local council. He was 23 years old when, on a walking trip to Lake District, he became smitten with the fells. Later, as his accountancy career progressed he was appointed as borough treasurer in the town of Kendal, on the edge of the Lake District and much closer to his beloved hills. Trapped in an unhappy marriage, Wainwright spent all his spare time exploring the Lake District alone, travelling by public transport.

An accomplished illustrator, Wainwright hatched a plan to produce a pictorial guide to the Fells, initially without any intention to publish. At weekends he would roam the hills with a camera and notebook, meticulously sketching scenes and noting every feature of the landscape. On long winter evenings he would pore over Ordnance Survey maps and commit ink to paper, by way of illustrations, diagrams, maps, route descriptions and accompanying text.

It was an exercise in methodical planning. He divided the Lakeland into 7 areas, which would then provide material for the 7 different volumes. He included 214 fells (now affectionately known as the Wainwrights), the highest being Scafell Pike (3210 feet/978m) and the lowest Castle Crag (985 feet/300m). For each of these hills, he produced pen-and-ink drawings showing the main features, maps, bird’s eye views, summit routes, 360-degree panorama plans and wheels.

At the time, they were the most informative and detailed guidebooks ever written about the Lakeland and they have more than stood the test of time. His works have become British icons. In the words of his biographer Hunter Davies, they are "not merely guidebooks, but philosophical strolls, personal outpourings of feelings and observations, written and drawn by a craftsman, conceived and created as a total work of art". Wainwright himself described the first in the series as "a love letter".

Wainwright was something of a recluse and he shunned the limelight. He preferred animals to people and liked solitude best of all. He would have been horrified by the present-day commercialisation of the hills, which ironically he helped bring about with the guides. A million copies of his guides were sold within his lifetime and he died a rich man, leaving all his money to an animal refuge. His ashes were scattered across his cherished fells. 

This article was written as part of the Mapping the Mountains exhibition, organised under the auspices of the Dutch Mountain Film Festival #9, which takes place in Heerlen (NL) from 31 October 2019 to
29 February 2020.
For more information: