The Minard System

#statistics #visualization #flow_maps #forebears

16 October 2018

 

“The Minard System,” a book to be published in November 2018, features “the complete statistical graphics of Charles-Joseph Minard — from the collection of the École nationale des Ponts et Chaussées”. In the text that follows, which constitutes the preface of the book, Sandra Rendgen explores how Minard’s oeuvre is much larger than the few (and beautiful) pieces that have become to be known as the “best statistical graphic ever drawn,” and how the French civil servant created a truly novel method to display stunning and accurate statistic drawings.

by Sandra Rendgen

Author and editor of The Minard System. www.sandrarendgen.de

As for my maps, I have heard people say that illustrative maps have been made for a long time. My maps do not just show, they also count, they calculate for the eye; that is the crucial point, the amendment I have introduced through the width of the zones in my figurative maps and through the rectangles in my graphic tableaus. 

— Charles-Joseph Minard, 1861

The French civil engineer Charles-Joseph Minard, whose long life spanned the final years before the French Revolution through the latter half of the nineteenth century, left behind an impressive body of statistical graphics and maps. Motivated by the intellectual problems he encountered during his professional practice, Minard embarked on a quest to create compelling visualizations to support the analysis of statistical results. He conducted in-depth studies over many decades, and his efforts finally led him to create one of the most famous information graphics ever made: a statistical map of Napoléon’s Russian campaign of 1812.

Published in 1869, one year before Minard’s death, this graphic eloquently summarizes Napoléon’s disastrous military endeavor. On a basemap of what are now Lithuanian, Belarusian, and Russian territories, it visualizes one particularly telling statistical variable: the sharp and steady loss of soldiers that Napoléon’s army suffered during the roughly six months covered in the graphic. Though 420,000 men triumphantly invaded Russia in June 1812, the army was already significantly reduced by the time it arrived in Moscow three months later. When Napoléon ordered the troops to retreat from Moscow in the fall, he sent his men to certain death, as they faced an extremely harsh winter in the wide plains of western Russia without any support or infrastructure. The map shows that only some ten thousand soldiers survived.

This work has stood out from Minard’s extensive oeuvre for a long time and continues to do so today. Its fame has even produced some curious mementos, such as a T-shirt featuring the Napoléon flow (currently available, along with other Minard-related merchandise, in several online shops) [1]. With its singular rhetorical power, the graphic is often treated as an isolated effort, which ignores the fact that Minard had originally published it alongside a second campaign map recounting an event from antiquity. Much of this selective fame can be traced back to the enthusiastic praise that the American statistician and political scientist Edward Tufte bestowed on this graphic. He reasoned that “it may well be the best statistical graphic ever drawn,” and published a facsimile of it [2]. Tufte, through his groundbreaking books on the principles of designing statistical graphics, can be credited with having brought the work of Minard to the attention of a wider contemporary audience.

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Carte figurative des mouvements des langues anciennes avant l’ère moderne
No date. Lithographic print, hand-colored. 97.2 × 67.6 cm.
The collection of the École Nationale des Ponts et Chaussées

Tufte was by no means the first author to ardently praise Minard’s work. As early as 1878, the French scientist Étienne-Jules Marey reproduced the Napoléon map in his comprehensive compendium, La méthode graphique dans les sciences expérimentales et particulièrement en physiologie et en médecine (The graphic method in the experimental sciences and particularly physiology and medicine). He also recognized the immediate visual power of this work, celebrating it with the much quoted remark about “its brutal eloquence, which seems to defy the pen of the historian.” [3] Marey also referred to Minard’s larger body of work, labeling his method “the Minard system” and stating that it had inspired numerous imitations and applications [4]. Over the course of the twentieth century, cartography and statistical visualization historians—namely Howard Gray Funkhouser, Arthur Howard Robinson, François de Dainville, Josef W. Konvitz, Gilles Palsky, and Michael Friendly—provided more extensive accounts of Minard’s oeuvre of statistical maps [5]. Unfortunately, despite these historians’ groundbreaking work, many of Minard’s maps have remained unknown to the broader public; all the while, general interest in the history of thematic mapping and statistical graphics has grown exponentially following the surge in information visualization since the 1990s.

It is no coincidence that we should take a renewed interest in Minard’s impressive body of work. There are several powerful forces shaping his oeuvre that resonate in our contemporary culture. One of these is an unprecedented abundance of data. The early nineteenth century saw the rise and establishment of the new science of statistics, and Minard, as well as many of his contemporaries, viewed it as a fertile source of information and began to work with this data. Though statistics is now a well-established scientific field, we too are experiencing an unprecedented abundance of structured data, brought about by the rise of digital technology—and it is no coincidence that visualization research has seen a massive rise over the past decades.

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Embranchement de Grenoble. Aperçu de la circulation actuelle des voyageurs dans les voitures publics
January 1846. Lithographic print, hand-tinted. 34.8 × 47.8 cm.
The collection of the École Nationale des Ponts et Chaussées

Another factor that shaped Minard’s oeuvre was the profound change that new communication and transit technologies—such as steam locomotion, the railroad, and the telegraph—brought to the nineteenth century. We also find ourselves in the middle of a technological revolution, which has led to an urgent need to discuss, reflect, and understand the machines that pervade ever more aspects of our lives and create an atmosphere of unprecedented complexity. Minard worked within a sphere of well-educated people who embraced the challenge of grappling with the new developments. He was a pioneer in a movement that aspired to make statistical data useful in the face of monumental cultural changes, and he contributed more works to the emerging field of information visualization than any other single person in the nineteenth century.

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Carte figurative et approximative du mouvement des voyageurs sur les principaux chemins de fer de l’Europe en 1862
October 2, 1865. Lithographic print, hand-colored. 116.2 × 77.8 cm.
The collection of the École Nationale des Ponts et Chaussées

Although he worked with various methods, Minard is particularly associated with the development of the flow map [6]. However, he was neither the first nor the only one to attempt an integration of cartography and the “graphical method” in the form of the flux [7]. We know today that at least one man preceded Minard in creating a flow map: the engineer Henry Drury Harness, who created an atlas of six thematic maps relating to railroad traffic in Ireland in 1837 [8]. A few years later, and seemingly parallel to Minard’s, the Belgian railway engineer Alphonse Belpaire produced a flow map of his own [9]. Regardless of these instances, the flow method can be considered Minard’s major theme in and contribution to information visualization, with forty-one such maps in large-format by his hand alone.

↬ Sandra Rendgen.