Horizontal hills
: A creative historical geography of the emergence of contour lines in nineteenth-century Britain and Ireland

  • Karen Rann

Student thesis: Doctoral ThesisDoctor of Philosophy


Now taken for granted, the history of the contour line’s emergence onto British maps was tortuous and contentious. This thesis explores the contingent twists and turns of that history by examining the surveying and drawing practices of the Ordnance Survey in Britain and Ireland. It pulls into focus the novel transition from drawing hills in ‘the vertical style’, to what were termed ‘horizontal’ methods, as well as other systems trialled by the OS for the depiction of three-dimensional relief. The vertical style consisted of lines sketched, or etched, running down hillsides as water would. The new horizontal style – introduced early in the nineteenth century – required descriptive lines to be drawn around hillsides. As such, they mimicked the appearance of contour lines on maps. Sketched in by eye, the OS used horizontal hachures consistently for hill-sketches made in the field for at least twenty years, before they first trialled contouring with measuring instruments in County Donegal, Ireland.

The places and spaces in which mapping activities occurred affected results. To reflect this, the four chapters roughly divide between outdoor and indoor activities, apart from the first, which considers some precursors to OS horizontal styles, as trialled across Europe. The subsequent chapters focus on the OS in Britain and Ireland. Chapter two explores exercises set for trainee draftsmen and surveyors in classrooms, as well as some of the theoretical standpoints written on in treatises. Chapter three considers hill-sketching, surveying, and the act of contouring, as developed in the field. The fourth returns to indoor settings to consider the methods and processes trialled and developed in Drawings offices and Print rooms. It also examines the arguments that took place, for and against contours, in Parliamentary Select Committee meetings. Through consideration of the spaces and places of activities, a pattern emerged of indoor processes lagging behind (or hindering) those in the field. In hindsight, contour lines offer an obvious solution to conveying relief in two-dimensions, providing a shorthand, that once understood, are easy to read. However, as this thesis demonstrates, their emergence on British maps was neither straightforward nor inevitable.

An interdisciplinary approach has combined investigation into the historical geographies of science (with its emphasis on the placed nature of knowledge practices and production), with scrutiny of maps, models, drawings, and sketches from a visual arts perspective. In certain instances, research has entailed creative reconstruction of visual artefacts. As such, this thesis offers a creative historical geography of the ‘horizontal’ method for flattening the third dimension. 

Thesis is embargoed until 31 December 2027.
Date of AwardDec 2022
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SponsorsAHRC Northern Bridge DTP
SupervisorDiarmid Finnegan (Supervisor) & Keith Lilley (Supervisor)


  • Contour lines
  • history of cartography
  • historical geography
  • drawing
  • maps
  • ordnance survey
  • nineteenth-century Britain
  • nineteenth-century Ireland

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