Chain of Custody

The earliest map visited on my travels is of a navigation channel for the Spaarne by Pieter Bruins, Bruinsz or Bruinszoon in 1584. The dotted line marked ‘7 voet’ probably denotes water ‘deeper than’ and as such I consider it neither contour nor isobath (though the map is very lovely indeed). It’s unlikely that my personal shining star Pierre Ancelin knew of it when he invented isobaths over 100 years later. Information on him is hard to come by, there’s every chance he was a Huguenot, an article I have says he was ‘trained in France’ before going to work as ‘Town Surveyor’ in Rotterdam. Picked for his knowledge of water systems and the use of dams and other methods to reposition water flows, his contract was to create a series of scientific maps so the town elders could take effective measures to avoid the sanding up of channels. His employers were happy with the results, because his temporary contract was made permanent in 1698.How do I know this much? For each pocket of knowledge – as with ideas and inventions – there appears to me to be a ‘chain of custody’: David Fairbairn (Newcastle University) recommended visiting Peter van der Krogt (Amsterdam University), who in turn gave me an article about Ancelin written by Bertus Woude… in Dutch. I looked at the pictures and recognised dates, places and the odd word. Then whilst on mini-residency at VARC I happened to mention the article to friend and local resident Jan Ashdown who put me in touch with sheep farmer Peter Samsom who, being Dutch and shortly to embark on a long train journey, was happy to be given some diverting reading matter. A week later I met him in the Rocky Road Café where he managed a very elegant synopsis of Woude’s 19 pages over a pot of tea. There are probably easier ways of doing research, I like this way.

Certain books on cartography from the 1980’s suggest it was the Italian Luigi Marsigli  who invented Isobaths, and indeed he did! (Around 10 years after Ancelin). So Ancelin and Marsigli both – independently – invented Isobaths; Nicolaus (Kruik or) Cruquius did not, although he claims to have done: it is clear he had seen Ancelin’s beautiful manuscript maps and also met with Marsigli on his visit to Holland. Cruquius ‘popularised’ isobaths, he was the first to promote the idea of them, and he wrote extensively on ‘his’ invention, but that actual ‘light-bulb’ moment was not his to claim.

I’m not even sure how important it is to be ‘first’ to think something; perhaps Cruquius is just as important as the disseminator of an idea: how to convey height or depth with a line.

Then there’s that giant step, or leap, out of the water; how to survey for and accurately position a line of equal altitude on dry land… or mountainside.

Did our Charles Hutton ‘invent’ Contour Lines without prior knowledge of Isobaths? It’s possible Henry Cavendish (who most certainly knew of them) tipped him the nod, I’d love to know. So Tuesday I’m away to Cambridge University Library to have a dig about in the Royal Greenwich Observatory’s archives, perhaps there’s a notebook, librarian or indeed a sheep farmer who can throw some light on my quest.

With kind acknowledgements to the Hoogheemraadschap van Rijnland, Rotterdam Stadsarchief and Leiden University for access to their archives and permission to use the photographs here.

Illuminated Contours

In lieu of the publication – which is still not ready – I created an exhibition ‘Companion’ which I’ve seen quite a few library visitors reading (by the way, the Library is closed this Saturday so the last opportunity to visit the exhibition is Friday). Within the ‘Companion’ is a short piece by David Fairbairn from the School of Civil Engineering and Geosciences at Newcastle University. For those unable to visit I have added it here:

As is evident from Karen Rann’s Great Lines project, a pattern of contour lines can be used to quantitatively model a rigorous framework for terrain, but can also be applied more impressionistically to convey a sense of the shape and variations of the earth’s surface.

Mapmakers have no control over the location of the contour lines which represent reality, but their graphical appearance can be modified to give particular effects.  For example, the colour of a contour line on a standard topographic map can be used to reflect the nature of the surface: blue contour lines over ice, black contour lines over rock, brown contour lines over soil:Other characteristics of lines, such as form (dashed lines, continuous lines) and thickness, can be used to modify the appearance of the contour pattern.  An effective combination, varying colour/shade and thickness, is that proposed by Japanese cartographer Kitiro Tanaka in the 1950s.  Sometimes called ‘illuminated contours’, this method of rendering the contour lines shows them lighter if they are on a terrain slope facing towards the north-west, and darker on slopes facing south-east.  In addition, the lines are made slightly thicker if they face directly north-west or south-east, and thinner otherwise.  The example here shows this method applied to the contours of Schiehallion: the result is a pseudo-three-dimensional portrayal of the terrain surface, helping with the interpretation of the contour pattern.I particularly wanted to include his piece as this image ties in so nicely with my models which are also examples of ‘illuminated contours’.

Maps & Words, Lost & Found

Is there a correlation? A month before the exhibition opening my mum finally lost the map of her house, even when stood in the kitchen surrounded by ‘white goods’ there is nothing there she recognises. I say “by the sink mum” she looks around and turns toward the door, lost. As with the map so with words, lost and found, out for a walk she turns to me and says “I’ve put Mr Toad in my pocket to keep my hands warm”. Two minutes before we’d passed and commented on a boat called “Mr Toad” and in that moment when she reached into her mind for the word ‘hands’, ‘Mr Toad’ popped out instead. It happens a lot and I try not to laugh knowing how frustrating it is for her that – song lines and times-tables apart – she’s losing her grip on vocabulary.

And as her facility with words slips, I grasp a tighter hold on mine; never have I written so much for a project, taking solace in shaping a sentence first this way, now that, changing tenses because I can. Mum lives in the moment out of necessity, there’s so little past or future to take her bearings from.So I cling to maps, grasp for more, plan journeys to: Phoenix House in Ireland, Cambridge Uni Archives, to Paris, back to Rotterdam City Archives and fool myself it’s all in the name of research, nothing to do with sensing and repelling the thought another 10, 20 years and it’ll be me.

Modelling

I imagined handing over 2 sets of ‘data’ to a university department who would use some modern process (thermo-form blah) to create 2 models: one of Hutton’s contour lines of Schiehallion and another – same mountain – but current contours. The models would be neat, precise, scientific. But with Exhibition looming and no takers, I decided to have a crack myself. There were advantages:

• I could build on Perspex and – using the same scale as the map – would be able to sit the models atop it, also – at the Lit and Phil – illuminate from beneath.
• I like making stuff

I like handling materials, thinking with my hands. There were many lovely studio days spent deciding on materials (a heavy, cotton-rich paper), and processes: emphasising the vertical lines on Hutton’s and horizontal planes for the modern; slowly figuring which lines should appear: every 200ft for Hutton, 100m intervals for the OS.On the 4ft map every 100 feet is marked (and 50 in places), it is remarkable how much data those surveyors collected between 1774 and 76. However much the French were ahead of the British in theorising on contour lines they had no equivalent data set to match Hutton’s and thus did not possess the capability to make a map accurate enough to equal his. (I may be speaking too soon – I haven’t seen any of the French maps yet.)

Even the British Ordnance Survey of Schiehallion in 1862 (90 years later!) did not survey with the same thoroughness, the pole bearers marked only three ascents, from the northern flank spot heights appear sporadically at: 1850, 2229, 3109 and the summit, 3547ft. Slightly more numbers adorn a western ascent. While their equipment certainly had improved since Hutton’s day, they would have had neither the time-scale nor workforce for covering just one peak. There’s a lovely snippet in Nan Shepherd’s Living Mountain regarding those early OS men: “on Ben MacDhui… [are] the remains of the hut where the men who made the Ordnance Survey of the eighteen-sixties lived for the whole season – an old man has told me how down in the valley they used to watch a light glow now from one summit, now another, as the measurements were made and checked”.

What they made up for in accuracy was lost in detail; their first 6” map depicts the whole southern flank of Schiehallion as one vast swathe of apparent nothing.Image use courtesy of the National Library of Scotland Map Library

Talk about Hutton

Without Professor Robin Johnson there would be no ‘centre piece’ map in the exhibition, Robin was able to enlighten and elucidate on the maths Charles Hutton used in inventing lines of equal altitude. As Nevil Maskelyne – the Astronomer Royal – needed Hutton, so I have needed the Professor to help me re-create Hutton’s missing map (and 3d model).

Last night to a packed hall, Robin gave a talk: Charles Hutton: scientist, mathematician and the density of the Earth (a copy of it is available through this link: Charles Hutton)

Hutton would not have recognised the title “British inventor of contour lines“. Mathematician, scientist even natural philosopher are descriptions he would have understood. Robin talked us through his humble origins in the mining community of Newcastle, through the ‘accident’ that led to his schooling, his mentors, and the range of mathematical conundrums he was involved in. It was both fascinating and remarkable how much material Robin uncovered that I had missed.

One of the many joys of this project has been encountering professionals both curious enough and generous with their time; they have enhanced the research and opened new avenues in both breadth and depth. And it was great to see so many of them at the Opening.

Next up is a ‘fantasy maps’ free drop-in at the Lit and Phil this Saturday 10 till noon, if you have young children interested in creative thinking and making things do call by.

The Exhibition

The Exhibition opens tomorrow with Preview & meet the artist: 5.30 to 6.30pm (FYI Library closes at 7). The Lit & Phil, Newcastle, NE1 1SE

Alongside 4ft map, models and drawings will be material held by the Lit & Phil pertaining to Charles Hutton: inventor of contour lines.

Plus, Monday 6th June, 6.00pm. ‘Charles Hutton: scientist, mathematician and the density of the Earth’, talk by Prof. Robin Johnson.

And Saturday 11th June, 10am till noon ‘Fantasy Maps’ FREE creative drop-in for families.

Shape of a Mountain

A photo of Schiehallion is an impressive thing, with great hunk with spine aloft, the mountain rises magnificently out of its surroundings. But before photography – and prior to contours – depicting a mountain and suggesting its elevation had quite a history. According to Ainslie’s map of 1783 Schiehallion was but a heap of absently poured salt on a flat, flat table top. Each Scottish peak appears as a little salt pile drawn in profile, each the same size. Rivers are dispensed with so ‘Tumel Bridge’ is simply a mile marker. As the ‘road atlas’ of its day this can be forgiven.  What I find harder to understand is his revised map just 6 years later. Although rivers are now present – a useful guide to travellers – and mountains are no longer in relief, it’s painful to behold; the hachuring gives the whole land surface the appearance of angry teenage acne.A lot depends on who you are drawing a map for; Lempriere’s from 1731 has a more contemporary feel, probably due to its function which was to describe: “…the situation of the several clans and the number of men able to bear arms, as also ye forts lately erected and roads of communication and military ways carried on by his majesty’s commands…” Here, if the map was a table-cloth it is un-ironed, the highlands of Scotland appear foreboding; ‘Chechalian’ dominates surrounding hills.I’m on the splendid NLS online map service darting across a century of map making, comparing depictions of Schiehallion. This quest has led to a series of drawings that will be on show (alongside the 4ft map, models and other materials) in the exhibition later this week.

After Lempriere comes Roys’ Military map, this is incredible, detailed, exquisite  map-making for its day, not least because it looks so modern, ‘google earth’ rendered in pen and ink. All these maps are pre Maskelyne’s experiment, pre Hutton; none gives an indication of altitude. The first post Hutton map I find is Arrowsmith’s in 1807, here the hachuring is more refined, like the whorls of a thumb print, rivers run like veins, all very expressive compared to his perfunctory treatment of roads and place names. And there is a ‘spot height’, only one: Schiehallion. He has sheared off the whole mountain top, almost as though creating a plinth for his magnificent text:

‘Schiehallion, 2000Ft. above the Valley, 3550 above the Level of the Sea’

The text curves slightly and ‘sea’ is beginning to slip down the mountainside. Not until Carrington’s map in 1846 is another ‘spot height’ added, (he includes Ben Lawers at 4015ft and has also raised ‘Schichallion’ to 3564).As the need for military maps receded so those giving the geology grew, some like MacCulloch in 1840 simply added colours to pre-existing maps. Others started again, flattening the land as though the mountains have lost all importance. Necker in 1808 squeezes in as many place names as he can, and in between slots chains of hills, unlike Ainslie’s little salt heaps 25 years earlier, Necker’s at least are ‘hill shape’… though Schiehallion is not shown at all.