Emphasising the Unknown. The Emergence of Blank Spaces on 19th-century Maps of Africa

European exploration of Africa in the 19^th century was based on the assumption that only little was known about the interior of the continent. For decades, geographical societies, cartographers, travellers and others repeatedly emphasised that the maps consisted of little more than just blank spaces which should be filled out in order to open up new trade opportunities, extend political influence, spread the gospel and European virtues (Pratt 1992: 69f.). On the one hand, blank spaces were a metaphor that soon became a winged word that has survived to the present day. On the other hand, blank spaces could indeed be found on actual maps, indicating the areas that remained to be explored. However, earlier maps of Africa are surprisingly colourful and full of various information about peoples, places and topography. Blank spaces had not always been there, they first had to be created by cartographers. This article explains this development and its reasons by contrasting comparatively well-filled 18^th-century maps of Africa with strikingly blank 19^th-century maps.

Colourful Early Modern Maps of Africa

Fig. 1 shows a map of Africa, drawn by the German cartographer Johann Matthias Hase in 1737. Here the continent does not appear to be empty because of different colours, topographical representations such as mountains and rivers, and the rich textual information. As stated at the bottom of the map, its main source was the writings of Leo Africanus, a widely travelled North African (Zemon Davis 2007) who wrote a geography of Africa in Italian in the 16^th century (Africanus 1550). It must be noted that much of the information provided on the map was highly speculative and did not correspond to the actual topography. This can be seen all over the map, for example in the course of the Niger (“Nilus Nigrorum”), which flows from west to east and does not empty in the Gulf of Guinea, but into a lake in central Africa, that somehow reminds of Lake Chad but is too far east.

In addition, it cannot be overlooked that some parts, especially in the centre, are less filled than others and at times marked as unknown (“incognita”). Unlike later maps, however, the cartographer does not appear to have sought to emphasise geographical deficiencies. On the contrary, the use of large letters, short descriptive texts and the colouring do not give the impression that there are any significant blank spaces. Finally, contemporary viewers of the map would not have been struck at first glance by a drastic lack of knowledge. Instead, they would have gained an impression, or rather an imagination, of the continent’s geography.

The Creation of Blank Spaces

Some 80 years later, in 1819, another German cartographer, Johann Schmidt, drew a map of Africa that showed most of the continent empty and white (fig. 2). Colourful and detailed maps like Hase’s still existed at that time, but, as an analysis of British mapmaking has shown (Kennedy 2013: 7–12), they were the exception rather than the rule. There were several reasons for this rigorous erasure of data. First, as a new understanding of science emerged, characterised by standards of objectivity and verifiability, geographers and cartographers stuck closer to what was known for certain and banned much information that was mere speculation from their maps. What they did not want to leave out altogether could be inscribed with markers of uncertainty, such as a dashed line or the use of words like supposedly or probably (on this map: muthmaßlich and wahrscheinlich). These also served as clues to exploration desiderata.

Second, the requirements for what was considered useful information changed. Whereas until the second half of the 18^th century mapmakers referred to African or ancient European geographers as well as to European adventurers, later credibility depended heavily on the categories of race and class. To be broadly accepted as secured knowledge, information had to be acquired, preferably by visual observation, by a European traveller on the spot. A map based mainly on Leo Africanus would not have been possible anymore. Moreover, European travellers had to belong to a higher social class, usually to the educated bourgeoisie. This can be illustrated by the case of René Caillée, a French shoemaker, who travelled to the long sought-after Timbuktu and back, but was not believed until the academically educated Heinrich Barth confirmed his descriptions a few decades later (Viguier 2008: 7).

A third reason for the removal of data from maps of Africa was that it served the purposes of the cartographers themselves, of geographical societies and other promoters of the exploration of Africa. The more details a map contained and the better it was filled with colours, letters, symbols etc., the less it could convince its viewers of the necessity of sending out costly expeditions. Blank spaces, on the contrary, not only helped to imagine vast parts of the continent as entirely unknown but also indicated the priorities for future explorations. By leaving parts of a map blank, cartographers could effectively highlight one or another region that they wanted future travellers to investigate.

Mapping a Research Agenda

These three reasons are clearly represented in a map made in 1860 by the influential German cartographer August Petermann (fig. 3). It is minimalist, using only black, white and two shades of red. The lighter red, according to the legend, indicates the “more or less explored areas” (“mehr oder weniger erforschte Gebiete”), while the deep red lines show “the main travel routes that were directed towards the unknown interior of central Africa” (“die hauptsächlichen Reiserouten, die gegen den großen unbekannten Kern von Inner-Afrika gerichtet waren”). This is contrasted with the “white space in the centre” which “indicates the area that has not been explored or entered by any European” (“Der weisse Raum im Innern bezeichnet das Gebiet, welches noch von keinem Europäer untersucht oder betreten war.”). To emphasise this point, and to indicate the favourable direction of further European enterprise, the white space is labelled in bold red letters: “unexplored territory, never entered by Europeans” (“unerforschtes, von Europäern nie betretenes Gebiet”). While there are only few dashed lines in the red area, nearly all information given in the white area indicates uncertainty. The culmination of this is perhaps a dashed arrow in the centre of the map labelled “large, westwards running river” (“Grosser, nach W. fliessender Strom”), providing hardly any useful information. Rather, it is an appeal to explore a region where it is likely to find something interesting like such a river.

What is interesting about the red parts is that the the north-west and the south of Africa are represented as “more or less explored” although they contain only one travel route respectively. This is presumably because all endeavours not “directed towards the unknown interior” had been omitted. Nevertheless, on the one hand, the viewer of the map is left with the impression that the whole of north-west Africa had only been explored by Barth’s expedition to Timbuktu. On the other hand, with regard to central Africa, the travel routes already mark the border to the blank space, as can be seen from Browne’s and Hornemann’s itineraries in the north-east. As a result, any attempt to gather knowledge about central Africa seems to have ended almost within the traveller’s visual range. Furthermore, non-European travels cannot be found at all, although they would actually be significant. A good example is Mohammad of Tunis who crossed large parts of northern central Africa on his journey to Wadai and Darfour between 1804 and 1814. At least since his travelogue was translated into French and English – a few years before Petermann drew his map – he was well known to European geographers (Tūnisī 1845; 1851; 1854).

Finally, the map’s dichotomous distinction between a known outer part of Africa and the unknown centre can be explained by its publication context. It was an appendix to a call for donations for an expedition to central Africa, co-organised by Petermann himself. In addition to geographical discoveries, its purpose was to find the missing traveller Eduard Vogel (Struck/Kuhn 2019: 81–86), whose supposed route to Wadai is inscribed as a dashed red line, being a particularly highlighted marker of uncertainty. After discovering Vogel’s whereabouts, the travellers were instructed to split up into a grid of routes, covering almost the entire area marked as unknown. This plan was visualised in a second version of the map, to which the projected itineraries were added in green lines (fig. 4). By making the lines several times thicker than those of the earlier journeys, the expected outcome was further promoted. However, the expedition was ultimately unsuccessful, neither finding Vogel nor making any significant contributions to geographical knowledge (cf. Marx 2021: 262–274).

The two versions of Petermann’s map mark a peak of the representation of Africa as a continent unknown to Europeans. As the number of expeditions increased significantly in the second half of the 19^th century, more geographical knowledge about the continent was brought to Europe and, being observed or at least inquired by Europeans on the spot, publicly accepted as valid. Equally important, cartographers and other expedition promoters were keen to demonstrate the progress resulting from their struggles. In other words, not filling in one blank space after another would have meant admitting failure.

Further Reading

Africanus, Leo: Della descrittione dell’Africa et delle cose notabili che ivi sono, Venice 1550.

Kennedy, Dane: The Last Blank Spaces. Exploring Africa and Australia, Cambridge (MA) 2013.

Marx, Christoph: Von Berlin nach Timbuktu. Der Afrikaforscher Heinrich Barth, Göttingen 2021.

Petermann, August, Bruno Hassenstein: Inner-Afrika nach dem Stande der geographischen Kenntniss, in: Petermanns Geographische Mitteilungen (Ergänzungshefte) 2, 7, 8, 10 (1862–1863).

Pratt, Mary Louise: Imperial Eyes. Travel Writing and Transculturation, London 1992.

Struck, Wolfgang, Kristina Kuhn: Aus der Welt gefallen. Die Geographie der Verschollenen, Paderborn 2019.

Tūnisī, Muḥammad Ibn-ʿUmar: Voyage au Darfour, Paris 1845.

Id.: Voyage au Ouadây, Paris 1851.

Id.: Travels of an Arab Merchant in Soudan, London 1854.

Viguier, Pierre F.: Sur les traces de René Caillé. Le Mali de 1828 revisité, Versailles 2008.

Zemon Davis, Natalie: Trickster Travels. A Sixteenth-Century Muslim between Worlds, London 2007.

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