The research is taking me all over the place, quite literally: Thursday week presenting a talk for the International Conference on the History of Cartography in Amsterdam, then Tokyo the following day for the International Cartographic Conference (see Events for two-places-at-once explanation).
As preparation for the above, a recap is handy: first there were isobaths – submarine contours – possibly ‘invented’ by Bruins – or Ancelin – either way, definitely in the Netherlands where the need to understand qualities of water drove innovation. And they fitted so well: swirling, fluid, ‘horizontal’ lines that looked so similar to conventional depictions of water-bodies; it is impossible to mistake ‘lake’ with ‘land’ on these maps. Here (see below) ‘pictorial’ water-lining and ‘scientific’ isobaths work together hand in hand.
The question was, could horizontal lines ‘climb out of water’ and encircle mountain-sides? There was no doubting the value of contour lines ‘scientifically’, the question was one of perception; could we ‘read’ them? In the 1770’s Hutton used them to show altitude, though we don’t have his map. The French were toying with the idea (more on them another time). But at issue is a mismatch: when mountains have always been represented with vertical lines ^^^ (including hachures), how can watery, fluid, horizontal lines be readily perceived as rugged shoulders and lofty peaks?
An early – tentative – foray was made by Robert Dawson. A fabulous draftsman, rather than scientist (or writer; he calls his watercolours “essays” and one can track his thinking through his drawings). In 1803, required to teach cadets drawing skills, he planned a ‘course of instruction’ for the Ordnance Survey. As this entailed working in ‘the classroom’, he advised: “Stones may be taken as Models of Hills, their Surfaces being frequently varied by accidental frictions, to a direct similitude of Features, with those, which Hills display.” (See? Bit clumsy with words.)
Tucked inside his hand-written ‘instructions’ are these beautiful little drawings of stones, some employing traditional vertical lines, in others he also experiments with a pictorial use of horizontal lines. These are not ‘scientific’ contour lines displaying accurate elevation, but you ‘see’ him figuring out whether mountains could be drawn ‘horizontally’. Forty years later he was still not convinced (more on that another time, or come to Amsterdam and hear: “A line drawn: the tortuous progress of contours onto British Maps”).