We have divided space into meridians not only to orient ourselves, but also to demarcate borders or distribute resources. A very Western way of getting your hands on the world.
Known stories, new story
How do human societies find their way in space and time? ? On a global scale and for almost a century, the Greenwich meridian was both the time and time zone controller and a common reference line for measuring longitudes. The meridians, imaginary lines connecting the two poles of the terrestrial globe, are tools used to orient oneself and to delimit sovereignties, usage rights or access to resources. Fabrice Argounès retraces their very rich history. Taking and reweaving known historical facts, he creates an original story, composed from a geo-historical perspective and brought to life by frequent citations of sources. As other researchers have been able to choose the world map or a globalized consumer product to address a large-scale question, the author proposes an investigation whose entry is a single object, but of shared use by different cultures at different times. This approach is proving fruitful. The investigation is carried out by a voluntary decentering of the story, going against the histories of science traditionally centered on the European space: the making of meridians is not an exclusively Western fact. This intention to embrace the meridian object over the long term and on a global scale makes the work original.
It is all the more regrettable that the edition of it leaves something to be desired. The central notebook includes twelve color illustrations, unnumbered and to which the text does not explicitly refer. These images are poorly captioned and could undoubtedly have been better used to support or clarify the point. The text contains a number of typos. Finally, the book does not offer a final bibliographic section in which the references and sources, scattered throughout the footnotes, could be easily found. However, the work addresses very diverse eras, cultural areas and subjects, many of which are not necessarily well known to potential readers.
Measure, impose, integrate and exclude
Although it relies largely, for some of its developments, on a history of the most classic sciences, the work goes little into the technical details of intellectual and scholarly construction, except in a brief foreword. The reader will therefore have to resort to other sources if he seeks to understand in detail the processes by which navigators establish the measurement of longitudes at sea, or the method of surveyors and astronomers to know the curvature of the meridians. The central object of the book is elsewhere, in the account of the uses made of the meridians over the centuries.
The subject is articulated in five stages and generally follows a chronological logic, largely reorganized by the particular approach chosen for each chapter, always ordered around an action (“ trace “, “ share “, “ measure », etc.), and by the comings and goings between different regions of the world. The author addresses the intellectual creation of the meridian tool in ancient Greece, its reception and circulation in different languages and cultures of the Middle Ages, its implementation as a legal and imperial dividing line from the XVe century. It inventories the uses of the meridian as a line of reference in time and space, as an object of negotiation and contestation between rival European powers, as the backbone of the great works of geodesy, surveying and cartography over the centuries, as a line for fixing military positions and negotiating peace.
This journey allows the author to revisit known moments in European history and the history of science and technology. For example, we recall the establishment of a dividing line between Castilian and Portuguese sovereignty during the treaties of Tordesillas (1494) and Zaragoza (1529), the great scholarly expeditions to measure the meridians in the Andes and Lapland in XVIIIe century, or the long-term enterprise led by four generations of the Cassini dynasty to establish a map of France based on the Paris meridian and systematic measurements of geographic coordinates. A line of reference and separation in space, the meridian also serves as a reference in time since astronomical phenomena, from the most common (like sunrise and sunset) to the rarest (like eclipses), are not observed at the same time in different points on the globe. This is why the measurement of longitude is given in times, minutes and seconds. Fabrice Argounès narrates, in this respect, the essential challenge posed by the calculation of longitude at sea, which was the subject of a competition launched by the Longitude Act British of 1714. Alongside the numerous solutions proposed by various European scientists, the history of technology remembers the development of marine watches by John Harrison. The mobilization of the meridian as a marker of time also explains why the Greenwich line was chosen as a benchmark for universal time and world time zones during the International Conference in Washington in 1884.
Negotiations, protests and alternative proposals
The making of knowledge and the uses of the meridians were essentially approached in the light of a European history of science and technology on the one hand, and of colonization and imperialism on the other. Fabrice Argounès’ work, while repeating this story, provides it with numerous details and nuances, which make it richer and more complex. The first nuance is that of the challenges to which most lines established in an authoritarian or unilateral manner have been subject. The most widely popularized accounts maintain the existence of a single and shared benchmark, largely imposed, while historical works, particularly the most recent, highlight a number of alternative practices or benchmarks. The line of the treaties of Tordesillas and Zaragoza was thus almost systematically contested by the European nations whose colonial ambitions arose a little after those of the Iberian nations. France, England or later the United Provinces established “ friendship lines ”, beyond which racing and piracy against opposing ships were considered legal. They also promoted and used counter-meridians of reference, particularly in cartography. In the same way, the establishment of the Greenwich meridian as the universal meridian of reference to the XIXe century results from the observation of the progressive unification of space and time, following the development of faster means of transport and communication, such as the railway and the telegraph. It also takes note of the global extension of the British Empire, but also of practical and scholarly arguments. But it is also the subject of numerous disputes. The global acceptance that ends up taking hold is explained by the pragmatic adherence to an essential universal reference system, which also sometimes coexists with secondary systems.
Negotiation and protest may be more discreet phenomena, long kept silent and brought to light by recent historiographical work. The post-colonial narrative thus readily underlines the authoritarian and artificial character of the establishment of meridians, or more broadly straight lines, as land borders in an imperial and colonial context, particularly in the new American worlds, in Africa or in Australia. Contrary to this widely accepted idea, the author recalls that even when the route is decided by the colonial power, it often takes into account the historical and social depth of the places, the result “ compromise or forms of co-production between colonial agents and indigenous authorities “.
Can we escape the Euro-centric narrative ?
Finally, many developments in the book give pride of place to non-European or non-Western spaces and cultures. These passages show that the notion and the technical, scholarly and legal object that constitutes the meridian was mobilized, received and used outside Europe independently or in a mix of scholarly and technical practices and knowledge. The Kangxi Atlas, a vast mapping project of the Chinese Empire carried out at the beginning of the XVIIIe century under the Qing dynasty, is an example. This work hybridizes European and Asian sciences and techniques, and jointly mobilizes Chinese scholars and Jesuit scholars from Europe, vectors of the reception in China of Western geodetic knowledge. The notion of meridian is also received in Japan from the end of the XVIIIe century, notably through Chinese treaties. It allowed Inō Tadataka to carry out a huge campaign of surveying Japan between 1800 and 1818.
Fabrice Argounès finally recalls the importance of intermediaries or “ go-between » of scholarly production. A paradigmatic example of this is given by the survey campaigns carried out in the British Indian Empire during the XIXe century. It is necessary to underline the essential, but often overlooked, role of the indigenous actors in this work, at the same time surveyors, geometers, cartographers, explorers and spies.
The history of the meridians raises questions of geography, law, commerce, science and technology. It reveals a substantial part of the practices and representations of space in the world since Antiquity. The meridians have rightly been associated with the constitution and then the forced acceptance of a Western culture in a colonial and imperial context. Fabrice Argounès’ book shows that even in a position of dependence or asymmetry, a number of actors, countries or institutions were able to counter, refuse, negotiate or appropriate the establishment and use of these lines. The story nevertheless almost always takes place in the crucible of the meeting or confrontation between competing or dominant Western powers and other nations and regions of the globe, thanks to the circulation and reception of the multifaceted tool that constitutes the meridian. In this sense, the proposed story, perhaps despite everything depending on the knowledge drawn from the histories of science and traditional techniques, does not completely escape the teleological perspective: the meridian still appears there as the symbol of modernity and scientific efficiency whose adoption and implementation take place gradually over the centuries. In essence, the work therefore also draws the geohistories which remain to be written for certain centuries and certain regions of the world, those of the knowledge, techniques and representations implemented to represent and understand space and time, and to which the notion of meridian remains foreign.