Mapping Airspace: On the Visual Imagination of the Atmosphere

by Luca Scholz

With the rise of global history, historians have continuously expanded the spatial scope of their studies in a horizontal movement. In recent decades, however, a growing body of literature has begun to discuss the human exploration of the atmosphere and outer space in a distinctly vertical dynamic. A widespread assumption in this literature is that the history of airspace begins with the history of aviation. This case presents a set of early and late modern maps that show how airspace was visually imagined before humans used it for flight.

Early modern cartographers were particularly concerned with the atmospheric circulation because the maritime surface winds powered Europe’s imperial conquests. On maps, winds outlined the possibilities of navigation, but they also operated as cartographic markers of direction and orientation. A different perspective on the “gaseous sea” can be found on vertical depictions of the Earth. Whether represented as wind deities, as clouds, or as airspace, atmospheric phenomena enveloped the Earth and separated it from the celestial spheres and outer space. If contemporary flight maps illustrate the role of airspace as a key arena of late modern globalization, early modern maps show that the cartographic imagination of the atmosphere as globally connected and connecting has a long tradition.

An important difference between early and late modern understandings of the atmosphere is the close connection between events underneath, on, and above the surface of the Earth assumed by early modern scholars. Aristotelian meteorology and its early modern reformers argued that events below and above the crust of the Earth, such as earthquakes and storms, were determined by the same forces. Visually and conceptually, volcanoes – which appear on several of the following maps – were a particularly salient element of vertical connection between the subterranean and the sublunary spheres.

Vernunfftmässige Beschribung der Erd-Kugel

Vernunfftmässige Beschribung der Erd-Kugel. Theodor Schoon. Zürich: c. 1690. Image courtesy of the Zentralbibliothek Zürich.

This is one of the earliest maps to represent the air – otherwise represented through proxies like clouds or winds – as a distinct spatial feature (marked with R). The boundary between the atmosphere and outer space is defined by dense clouds that only allow the sun and the moon to shine through. The space above the crust of the Earth depicts a variety of atmospheric phenomena and their interaction with the sea and the forces in the interior of the Earth. The map’s legend explains that all these phenomena – rain, wind, tornados, earthquakes, and volcanoes – were animated by interactions between “subtle” and “inflammable” matter. The author assumes they are closely related, offering a good illustration of early modern meteorologists’ fixation with motion and disorder. In an early reflection of Cartesian meteorology, the air is described as composed of small “dendritic” particles.

Carte de la direction des vent généraux et des Moussons

The representation of maritime surface winds was one of the most common contexts in which the atmosphere became an object of cartographic attention. Because the control of Europe’s “Aeolian empires” depended on the trade winds, ocean wind maps were particularly common. This map visualizes wind patterns and monsoons on the oceans of the Southern hemisphere. The hatching and the arrows indicate the winds’ directions, assigning them an important place in the map’s visual hierarchy. Scholars often assume that the eighteenth century saw a gradual “normalization” of meteorological phenomena, with observers increasingly focusing on the regular and global instead of the local and exceptional. Wind maps with their focus on the global dimension of atmospheric circulation and the regularity of wind patterns are early examples of this development.

Charta Cosmographica, Cum Ventorum Propria Natura et Operatione

Following a common format, this heart-shaped projection of the Earth’s surface is surrounded by twelve wind deities arranged according to the Aristotelian schema. Depictions of personified winds were common in early modern maps and allowed to represent both the atmospheric circulation and the cardinal directions. Placing the personified winds into a separate sphere allowed to avoid recurring three-dimensional perspectives or overloading the map. The wind blowing out of the divine mouths reflects the notion that wind originated from closed chambers and conveys the common interpretation of weather events as an expression of divine moods.

Die Erde und ihre Atmosphäre

Attempts to explain the problem of atmospheric refraction led cartographers to visualize the atmosphere as a conduit of light between outer space and the terrestrial surface. This map from a celestial atlas illustrates how the variation of air density deviates light waves from a straight line as they pass through the atmosphere, making the sun appear higher than it actually is. The mid-nineteenth century visualization reflects the decreasing density of air and a more fluid boundary between the atmosphere and outer space.