URL originale : https://books.openedition.org/editionscnrs/27700
From Manual Art to Scientific Profession: Technical Books On Land Surveying in Eighteenth-century France
Des arts manuels à la profession savante : les livres techniques d’arpentage au xviiie siècle en France
p. 121-136
Résumés
Cette contribution analyse la standardisation des instruments d’arpentage afin de comprendre comment l’art de l’arpentage passe d’un « art » local à une profession savante et nationale, celle de l’ingénieur géographe. Nous étudions sept des plus influents manuels d’arpentage publiés en France entre les années 1690 et 1760, ainsi que des documents peu connus du Bureau national du cadastre (1791-1802) et de l’École nationale des ingénieurs géographes (1794-1802). La documentation technique sur l’arpentage analysée montre que la définition d’un ensemble d’instruments standardisés (en particulier le graphomètre et la trigonométrie géodésique) participe de façon significative à la construction de l’identité d’une profession scientifique. Enfin, cette contribution explore les liens entre la diffusion de la littérature technique sur l’arpentage, la création d’organisations professionnelles et le déploiement d’une nouvelle forme institutionnelle, le premier cadastre national de la France à la fin du xviiie siècle.
This paper analyzes the standardization of land surveying instruments to offer a better understanding of the transformation of land surveying from a local manual art into a national scientific profession: the engineer-geographer. The paper studies seven of the most influential manuals of land surveying published between the 1690s and the 1760s in France as well as little known documents of the National Bureau of the Cadastre (1791-1802) and the National School of Engineer-Geographers (1794-1802). The technical literature on land surveying analyzed here provides a compelling historical example of how the identity of an emerging scientific profession can be built by means of defining a set of standardized instruments (especially the graphometer and geodetic trigonometry). Finally, the paper discusses some connections between the spread of technical literature on land surveying, the creation of professional organizations, and the undertaking of a new institutional form, the first national cadastre of France in the late eighteenth century.
Entrées d’index
Mots-clés : Arpentage, manuels, instruments, ingénieur géographe, cadastre
Keywords : Land-Surveying, Manuals, Instruments, Engineer-Geographer, Cadastre
Texte intégral
Introduction
1In the mid-eighteenth century, a land surveyor working alone in the countryside about 600 kilometers south of Paris was killed by a group of villagers. The unlucky surveyor carried with him a series of odd-looking instruments, which he used in a no less odd fashion. Villagers were suspicious of the surveyor’s manners and instruments and decided to assassinate him.1 It was not unusual for Old Regime land surveyors to be at work alone and even carry a sword to protect themselves. Public distrust toward them was common in France and elsewhere. This “evil […] profession”, a tenant lamented, brought poor men to servitude and slavery. Land surveys were the reason, he concluded, why sometimes “men loose their land.”2
2Due to this widespread public suspicion, it is possible to suggest that the unlucky surveyor could also have been killed because locals reviled surveyors. Nonetheless, killings of surveyors remained rare. Assaults and insults were more common.3 Meanwhile, surveyors complained that locals hid or gave them false information and argued that their surveys often unveiled frauds. Surveyors’ primary goal was to be impartial arbiters. Thus, if done correctly, their surveys would bring peace and justice to the land.
3One of the reasons for this tension between locals’ distrust of surveys and surveyors’ concern with impartiality was, in part, due to the lack of uniform professional practices in general and the use of non-standardized instruments in particular. Technical books, especially land-surveying manuals, played an important role in overcoming that tension. They helped to progressively uniform land-surveying instruments and their use. This process started decades before the creation of key professional organizations, notably the National Bureau of the Cadastre (1791-1802) and the National School of Engineer-Geographers (1794-1802).4 Hence, taking as a theoretical anchor Elias’s5 emphasis on manuals as a vehicle for the uniformization of manners, this chapter highlights the role that technical literature on land surveying played in standardizing land surveyors’ professional manners. This standardization was critical to transforming land surveying from a local manual art into a national scientific profession: the engineer-geographer operating with a uniform set of measurement instruments.
4This chapter is divided into two parts. The first deals with the description of technical instruments in seven land-surveying manuals. This section finds that the increasing professionalization of land surveying paralleled the standardization of its instruments. While in the early eighteenth century, manuals described the undertaking of land surveying by referring to multiple and heterogeneous instruments, toward the end of that century the graphometer became the main instrument used to define the identity of the engineer-geographer. The second part analyzes key references to land-surveying instruments in the documentation of two short-lived organizations: the National Bureau of the Cadastre and the National School of Engineer-Geographers. This part argues that both organizations were crucial to complete the professionalization of land surveying and in particular the standardization of technical instruments. In the conclusion, this paper suggests that technical literature and new organizations contributed to effectively make uniformity, equality, and impartiality key principles of the profession, as confirmed by the undertaking of the first fully national cadastre of France in the late eighteenth century.
Land Surveying in the Time of Old Regime Technical Manuals
5This section studies seven of the most influential manuals of land surveying in eighteenth-century France: L’École des arpenteurs (1689) by Philippe de La Hire; Méthode facile pour arpenter ou mesurer toutes sortes de superficies (1699) and Méthode de lever les plans et les cartes de terre et de mer (1693) by Jacques Ozanam; L’Arpenteur forestier (1764) by Guiot; La Science de l’arpenteur dans toute son étenduë (1766) by Louis Charles Dupain de Montesson; Manuel de l’arpenteur (1770) and Supplément au Manuel de l’arpenteur (1775) by N. Ginet.
6The first two authors were cabinet theoreticians under the spell of the newly founded Royal Academy of Sciences (1666). The mathematician Philippe de La Hire (1640-1718) became an academician in 1678, more than a decade before releasing the first edition of his École des arpenteurs; and Jacques Ozanam (also, 1640-1718) was a professor of mathematics, a prolific writer, and elected to the Academy of Sciences in 1701, two years after publishing his bestselling Méthode facile pour arpenter. The other three authors were outdoor empiricists, that is, active practitioners of land and forest surveys. Ginet was a surveyor in the maîtrise des eaux et forêts of Paris; Guiot was a garde-marteau in the maitrîse des eaux et forêts of Rambouillet and geographer for the duke of Penthievre, admiral of France; and Dupain de Montesson was an infantry captain and an engineer-geographer of champs et armes of the king in Paris. None of them became a member of the Academy of Sciences. Throughout the eighteenth century, not only the authorship of land-surveying manuals shifted from texts written by cabinet theoreticians to outdoor practitioners, but also changes in authorship revealed a trend toward increasing professional specialization, for which outdoor, practical knowledge became a clear marker of land surveyors’incipient professional identity.6
7Professionalization took time. The last century of the Old Regime the land surveyor was generally considered an artiste (a technician), not a professional; he was more an in situ verifier of property titles and declarations than an expert measurer of space via practical, outdoor techniques such as triangulation (fig. 1); and a worker whose practice was primarily constrained by moral principles rather than by expert use of a uniform scientific method during fieldwork. His art, land surveying, first, was not standardized in actual practice (several master procedures co-existed as well as diverse instruments and on-site practices); second, despite some privileges, it was not a highly regarded occupation for it involved manual and strenuous labor (left to the non-privileged orders); and third, as a knowledge practice, it was not really controlled by the state or scientific organizations, but rather via local power structures.
8Being a land surveyor required a certain level of instruction, but in actual practice acting as one neither required a technical degree nor did it demand any kind of corporate specialization. Basic knowledge of arithmetic and geometry was presumed for land surveying, but in reality the job was often in the hands of non-experts. Knowledge about surveying was passed from father to son, surveys usually covered small areas, and triangulation was rarely used, not only in France but in Old Regime Europe.7 Partly to correct this situation, at the end of the seventeenth century, a specialized literature on land surveying began to spread under the form of technical manuals. In this section, I will focus on how seven of these manuals referred to surveying instruments, because the pace at which the latter changed gives us a good proxy about the progressive professionalization of land surveying.

Fig. 1. Triangulation of a Large Area. La Hire ([1689] 1692, p. 178). Land surveyors regularly took windmills, bell towers, big trees, and the like as reference points.
Instruments in Land Surveying Manuals
9One way of uniformizing surveyors’ manners was to describe how they had to perform operations with an increasingly standardized set of instruments. But some instruments had nothing to do with practical measurement or mathematics. Reading skills in Latin and knowledge of property laws were prevalent for most of the Old Regime because land surveyors had to read and verify property declarations in situ.8
10Because of their diversity, these documents were often arcane and difficult to decipher, requiring the surveyor’s expert reading to clarify them. They could include Latin formulas and legal terminology he had to be familiar with, so that he could detect whether people hid or gave him false information. For the task of verifying tenants’ information, no knowledge of mathematics was required. In other words, during the Old Regime land surveyors were deemed “experts” not because of their applied knowledge of mathematics, but because of the juridical requirements of the occupation; including the surveyor’s capacity to provide expertise on property matters in front of judges, since he was a justice auxiliary. Indeed, the dictionaries commonly defined him as “an official who has sworn to justice” and was called arpenteur juré (sworn land surveyor).9
11Writers of land surveying manuals were aware of the legal controversies surrounding property surveying and wanted to provide not a juridical but a scientific solution to them. It was precisely during this period, with the spread of technical books on land surveying, when the occupational label of arpenteur juré disappeared in favor of that of engineer-geographer.10
12The manuals under analysis show that the technical, mathematical dimension of land surveying started to gain prominence over the legal dimension. Accordingly, the main focus of attention was the teaching of instrument use, the internalization of knowledge practices (in particular practical geometry, geodesy, and leveling), and finally the material expression of such internalized knowledge and expert instrument use in the form of plans and maps.
13Along with the chain (the most widespread measuring instrument), the manuals indicate that land surveyors had at their disposal four main instruments. They were, from the least to the most technical, the surveyor’s cross (équerre); the cercle d’arpenteur (fig. 2 “fig. 17”); the surveyor’s plane (planchette) (fig. 3 “fig. 31”); and the graphometer (fig. 2 “fig. 16”). Customarily, they were placed on a supporting stick (fig. 2 “fig. 18”) or, later in the century, on a tripod.
14The four instruments permitted to calculate distances and surfaces visually by measuring the angle of several points from a reference point. Along with one of these instruments, land surveyors and their helpers regularly used a toise or rope, plus range poles (jalons) and pickets (piquets) to measure distances on the ground (preferably, the base or at least one side of a triangle). To level the main measuring instrument and to calculate the terrain’s unevenness, land surveyors relied on different types of levels. Finally, the use of a magnetic compass became more common to orient observations and draw maps.

Fig. 2. Land Surveying Instruments and Standardized Geometrical Procedures. Encyclopédie, Diderot and d’Alembert (1751-1772, vol. 5, plates, arpentage).
15As they spread, the use of instruments that measured angles (especially the graphometer) made it unnecessary to survey the terrain by placing lines of range poles or pickets, but rather it was only necessary to place one range pole or picket in the points to be measured. One of these instruments was the équerre, an octagonal metal case with a narrow, rectangular hole on each side. With this octagonal prism, the surveyor sighted an object (a point) and lined it up by looking through the hole on the opposite side. If it was correctly placed on a straight line, the surveyor should see both points at the end of the line by looking alternatively through both sides of the équerre. For this operation, the instrument was also placed on a stick.

Fig. 3. Land Surveying Instruments and Standardized Geometrical Procedures. Encyclopédie, Diderot and d’Alembert (1751-1772, vol. 5, plates, arpentage).
16Another instruments some called équerre, too, was the surveyor’s circle. This instrument was also known as the surveyor’s cross (croix d’arpenteur). As figure 2 shows, it consisted of two metal bars crossing each other at right angles and forming, as the name indicated, a cross. To add strength, the cross could be fixed to a circular plate. One arm, with vanes at both ends and each vane with a rectangular hole, was aligned to form a straight line, which usually was the base of the triangle. The second arm, which was perpendicular to the first arm, had to be placed on the exact point of the base where a straight line from the opposite vortex would cut the base in a straight angle. Exactly placed at that intersecting point, the surveyor’s cross permitted to calculate the area of a triangle by using the length of its height and base. Unlike the planchette or graphometer, these circular instruments (the équerre and the cross) had no moveable parts.11 Using instruments with moveable parts, mainly the alidade (a turning board or rule), made it possible to displace the measurement operation from the intersecting point of a triangle’s base and height to the vortexes (to measure their angles). The writers of manuals agreed that measuring the angles yielded more accurate results, and thus the équerre and the cross fell slowly out of favor throughout the eighteenth century.
17Unlike these two instruments, descriptions of the planchette and the graphometer were more prominent in the manuals under study. In its most basic form, the planchette, was a plane mounted on a tripod. As in the case of the previous instruments, formal heterogeneity characterized the planchette, especially in the early manuals. La Hire,12 for instance, described a planchette with a circular plane. The quest for exactitude took the form of a mobile arm or alidade. Depending on the author, it could already be fixed to the plane or placed on it during fieldwork. Unlike the équerre and the surveyor’s circle, customarily placed on a simple stick, the planchette had to be placed on a tripod. Furthermore, the manuals insisted on the correct assemblage of the plane to the tripod, so that they formed “no more than the same body”13 and the instrument would be “incapable of any vacillation”.14
18The planchette permitted an accurate measurement of the angles of a triangle if placed on two different points (each called “station”) and then to calculate the area of the triangle with trigonometric rules, after measuring at least one of its sides with a chain. But the greatest advantage of the planchette was to make it possible to draw in the field plans of a property or the sections of a larger map, which could be assembled together with “great facility and with a lot of fairness”.15
19Dupain de Montesson argued that the planchette permitted to measure a territory and draw its plan faster. He included an illustration after the frontispiece to supplement his textual explanation. As in the Encyclopedia’s plates on the mechanical arts,16 this illustration (fig. 4) describes in two separate scenes two important manual operations in land surveying: the use of the planchette and the measurement of a line with the chain, range poles, and pickets. Also, as in the Encyclopedia’s plates, the surveyor and his team are represented hands-on, that is, with the instruments of their art and in their space of work, the countryside. In the foreground scene, the individual on the left is the surveyor. He is using the planchette (placed on a tripod) and holding a compass (compas de proportion) on his right hand. One of his helpers is standing next to him, holding a range pole on his right hand and an alidade under his left arm. he third man, another helper, is rolling drawings on the ground; they are probably plans drawn during the ongoing land survey. As Dupain de Montesson described it, the surveyor is represented at a crucial moment: when he is performing the operation of matching one point on the plan drawn on the planchette with its corresponding real point, located right below the planchette in a straight line. It is the same point. To ensure a perfect correspondence between the point on the terrain and the point on the plan, the surveyor puts one tip of the compass on the point on the plan and he puts the other tip hanging vertically on the point on the ground – a level made of lead is hanging from the thread tied to the end of that tip. Dupain de Montesson explained that the surveyor should not conclude the operation until the line connecting both points was perfectly straight. Only then could the helper place the alidade on the planchette and the surveyor continue measuring and drawing the parcel.

Fig. 4. Land Surveyor and Helpers at Work. Dupain de Montesson (1766, n. pag.).
20In the background scene, two people are marking out the parcel (bornoyer). The person on the right is represented exactly at the moment when, with his right hand he is sinking the picket in the ground, while with his left hand he is holding the chain to ensure that he does not deviate from the straight line. This helper is half way to the picket on the right side, with a white mark on top. This picket signals the end of the line being measured. The person on the left is supervising the correct alignment of the picket by bending his body slightly and by making sure that his eye can verify that the small white cards on the pickets are aligned in a straight line.
21This detailed illustration and Dupain de Montesson’s explanation were particularly important because, despite La Hire’s and Ozanam’s call for the use of the graphometer in the 1690s, surveyors with ample fieldwork experience like Dupain de Montesson were still opting in the 1760s for the planchette in the field.
22Yet, the quest for impartiality and exactitude in land surveying transformed the planchette into an inexact instrument, limited by serious inaccuracies, such as the movement of the hand. In fig. 4, while the surveyor is holding the compass on his right hand, he uses his left hand to grab the other side of the planchette – his left thumb can be seen on the corner. This telling manual movement suggests that the planchette was not completely stable in that position. Grabbing with one’s hand an instrument that had to provide the most exact measures would be soon considered by professional land surveyors an inexact and imprecise movement. In short, it would be an unacceptable manner. Manual interference with the stability of the measuring instrument should be kept to a minimum, something the graphometer permitted. With the exception of Dupain de Montesson, in the manuals under analysis, authors acknowledged that the graphometer was not only more accurate17 but also the instrument that could define the surveyor’s identity as a professional of space measurement.
23The graphometer was a semicircle divided into 180 degrees with two vanes on both sides of the diameter (each vane with a slit, in French called fenêtre) and an alidade placed on the center of the diameter (and with two vanes and slits). It could be mounted on a stick but preferably on a tripod. By being placed on the vortexes of a triangle, it permitted a more accurate measurement of the angles and thus to calculate the full surface of a triangle, if one of its sides was measured, too. The procedure was similar to that of the surveyor’s circle with the only but decisive difference that the graphometer had the alidade. As figure 5 shows, the graphometer was placed on point C. The base of the semicircle had two vanes that, by looking through them (point D and the opposite vane outside the triangle), permitted to align in a straight line points C and A (the latter would be marked with a range pole in the field). Then, the alidade would be moved to align in a straight line points C and B by looking through the vanes (point E and the opposite vane outside the triangle). Once the surveyor performed that movement, he would read the degrees of the angle on the scale engraved on the base of the semicircle. (In the case of fig. 5, it was 90 degrees.) Then, the surveyor would perform the operation by placing the graphometer on a second point (either A or B) and measure the second angle. After knowing the degrees of two of the angles and the length of one of the sides (line AC, CB, or BA), he could calculate the total surface with more accuracy than the surveyor’s circle. In the case of large surfaces and long distances, Ozanam recommended using not the graphometer with vanes (graphomètre à pinnules) but the graphometer with lenses (graphomètre à lunettes d’approche). The latter was a technical improvement adapted from astronomy that paved the way for the modern-day theodolite equipped with macroscopic lenses.

Fig. 5. Measurement of the Angle of a Triangle with a Graphometer. La Hire ([1689] 1692, p. 165).
24Although the practice of land surveying (even for larger cadastral initiatives)18 could lag behind the procedures described in the technical books, in the long term these books contributed to reducing and standardizing the instruments and techniques (including units of measurement) necessary for accurate and scientific fieldwork. Most of these books became long-sellers for several decades and received the endorsement not only of professional surveyors but also of readers interested in essential land-surveying techniques. The publisher Charles-Antoine Jombert, who printed the 1758 edition of Ozanam’s Méthode facile pour arpenter (published sixty years before), celebrated the fact that land-surveying mathematics was “in vogue” thanks to Ozanam’s treatises, which sought technical simplicity and clarity. To potential readers, the publisher offered in the back of Ozanam’s manual the full catalogue of other books on land surveying, mapping, and mathematics available at his bookstore. In the 1779 edition, M. de Audierne added a new treatise on arithmetic and informed of changes in instrumentation and in the techniques required to use them accurately. Rather than only targeting prospective and active surveyors, de Audierne also addressed these changes to a growing public sphere of readers interested in the trendy science of agronomics.19 Similarly, Dupain de Montesson stated that the audience he had in mind for his manual were those who wanted to “amuse themselves with land surveying”.20 Finally, in the Supplement to his Manuel de l’arpenteur (1770), Ginet congratulated himself for the fact that “the public, honest judge” had favored his works.21 Public success encouraged him to publish the Supplement in 1775.
25The standardization of land-surveying techniques and instruments that these books contributed to was completed with the creation of practical schools and government bureaus. In the next section, I will focus on the school and the bureau created to undertake the first national cadastre of France.
Land Surveying at the Bureau of the Cadastre and the School of Engineer-Geographers
26The National Bureau of the Cadastre was established in October 1791; a month after the National Assembly decreed the execution of a general cadastre of France. Gaspard de Prony was named its director. Thus, the Bureau was the main organization in charge of executing the general cadastre. The Assembly demanded that the department of Paris, created in 1790, would be surveyed first. The life of the National School of Engineer-Geographers (École nationale des ingénieurs-géographes) paralleled that of the Bureau.22 The School opened in 1794 and its creation was part of a larger campaign to establish national schools of public service. This School in particular was founded to advance the professionalization of engineer-geographers. The goal was to produce an army of national land-surveying engineers. To train them, the School relied on a teaching system that was hands-on and practical. Although Old Regime technical manuals of land surveying used a similar system, they were now insufficient to teach professional techniques to students. This did not mean that such manuals were unavailables to new generations of readers, including students at the School and workers at the Bureau. With the exception of La Hire’s L’École des arpenteurs (whose last known edition appeared in 1740), the majority of the other manuals were sold and reissued in the late eighteenth and early nineteenth century. In 1803, publisher Didot released an updated edition of de Audierne’s 1779 edition of Ozanam’s Méthode facile pour arpenter (1699). In 1805, Didot also released an updated edition of de Audierne’s 1781 edition of Ozanam’s Méthode de lever les plans (1693). In fact, an employee of the cadastre was responsible for this particular update. Guiot’s L’Arpenteur forestier (1764) was reissued in 1770 and Ginet added a Supplément in 1775 to his Manuel de l’arpenteur (1770) and a complete edition of this work was released in 1783. Dupain de Montesson’s La Science de l’arpenteur (1766) reached more editions, at least four; the last one published in 1813. Although there is no evidence to deny that students at the School could not have access to these manuals, their hands-on and practical training required techniques of knowledge of a different kind. They were based on discipline: lectures, homework, exams, and internships at the B u r e a u. The s e became the primary techniques to inculcate prospective professionals with knowledge about scientific land surveying.
27The Bureau and the School closed in 1802. Despite their short life, they had a significant impact. They are critical to understand the professionalization of land surveyors. Furthermore, by relying on standardized bodily practices, institutionalization of the principles of impartiality and uniformity, and with the input of standardized instruments, these organizations contributed to the production of a new object of knowledge: the first fully national cadastre of France23. Like other scientific organizations founded at the time, the School and the Bureau epitomized the growing synergy between political administration and scientific impartiality.24
Instruments at the Bureau of the Cadastre and the School of Engineer-Geographers
28Although there was progress toward more accurate instruments,25 the documents of the Bureau and the School show that instrument use became more standardized and knowledge about them deeper. Students at the School learned how to use them and also studied the history of their technical improvement. One of such instruments was geodetic trigonometry. Land-surveying manuals showed that trigonometry was already known and used in the execution of land surveys and territorial maps. However, some of the manuals struggled to teach one operation: how to reconcile surface measurement with the curvature of the Earth. Pre-national cadastral maps were small and rarely transcended the boundaries of the locality. Thus, they could afford to ignore that operation and not correct for the curvature of the Earth. But the Cassini Map of France confirmed that the curvature had to be taken into account to produce an error-free depiction of a large territory, such as the kingdom.26 However, the Cassini map lacked detail, for its scale was too small (1: 86400), and in the 1790s the national state needed to move closer. Namely, it needed, first, impartial depictions of space at the local level and, second, the possibility of synchronizing the local and the national by inserting local maps in the national geodetic grid.27
29The nationalization of the cadastre played a pivotal role in the development of a national geodetic grid because it could connect local topographical detail (observations of angles and distances) with the national geodetic canvas. Teaching that operation at a local scale was beyond the scope of the land-surveying manuals analyzed above because it required unprecedented levels of measurement uniformity and verification between large and small scales. That operation could be attained via disciplinary training at practical schools and via work at government bureaus.
30In his “Mémoire sur le cadastre,” included in the Laffon de Ladebat report,28 Prony (the director the Bureau of the Cadastre and the School of Engineer-Geographers) insisted that surveyors had to connect local plans and maps to the geodetic network of triangles. Since the small scale of the Cassini map did not permit topographical verifications, he argued that the nation needed a full geodetic network. For its exactitude and perfection, the cartography produced at the Bureau could deliver that representation of the nation.
31To draw those maps, cadastral surveyors needed instruments during fieldwork operations. But their acquisition was cumbersome. The Bureau struggled to obtain the necessary funds from the Ministry of Interior to purchase them. Also, some instruments needed gadgets added to them or to be adapted to the decimal scale, which was the basis of the new metric system. For instance, Prony and Charot (an engineer of mathematical instruments) purchased a “decimal astronomical circle” that required the installation of a “lens” (lunette), which was 4 centimeters long with a diameter of 3 centimeters. The lens would serve to calibrate the other lenses on the circle according to the basis of the instrument.29 As if bureaucratic problems with the minister were not enough,30 the devaluation of paper money (assignats) during the Revolution prevented the acquisition of geodetic equipment such as a horizontal circle.31 The School also needed instruments. To complete their training on geodesy, the director demanded a horizontal circle as well, which he deemed “indispensable” for mapmaking tasks.32
32Another demand on that front was issued shortly after the competition for the twenty-five engineer-geographers in charge of the cadastral mapping of the department of Paris, which was part of the national cadastre approved in 1791. Among the instruments needed, the report listed 15 planchettes. The Bureau of the Cadastre knew that the École Polytechnique had 20 planchettes with their corresponding alidades. Prony requested them so that engineer-geographers could conduct their operations, and he added that they would be advantageous to students of land surveying.33 However, months later the Bureau realized what most Old Regime land-surveying manuals warned about: the planchette was not a reliable instrument. Hence, the Bureau demanded “simple graphometers”.34 They were better suited for triangulation operations, since they had a semicircular shape, which could be easily divided into degrees. On the contrary, planchettes had a squared shape, which rendered them more prone to inaccuracies, especially when triangulating large surfaces.
33Along with the difficulty of acquiring instruments, the Bureau faced a related problem: outside requests for its instruments. As organizations in the service of the emerging nation-state, the Bureau and the School had to lend their instruments. Thus, for instance, not only people but instruments for geodetic trigonometry landed with Napoleon’s army in Egypt.35
34When the Bureau closed it had quite a modest ensemble of instruments: 1 graphometer with lenses, 1 geographical circle with tripod (cercle répétiteur), 4 planchettes, 5 alidades with vanes or lenses, 4 regular alidades, 5 ten-meter long chains (plus 10 iron pickets), 2 regular lenses, 1 achromatic lens, 1 chassis in copper made of 4 rulers on a wooden table, 3 wooden levels, 3 copper rulers (with scales), 1 ebony pantograph, 2 ebony rulers, and 3 tubes of white iron to store maps.36 Prony was asked to deliver the instruments to the chief of the archives of the Ministry of Interior.37 But after receiving approval from the minister,38 he took them with him to the École des ponts et chaussées.
35Despite their short life, the School and the Bureau gave an important impulse to the professionalization of land surveyors, especially in connection to the nationalization of the cadastre. This section in particular showed how engineer-geographers took a final step into professionalization (1) by discarding the planchette as an inexact instrument and embracing the graphometer, as a more exact instrument, capable of producing standardized cadastral facts39 and (2) by opting for geodetic trigonometry as the key technique for the exact measurement of the national territory.
Conclusion
36The analysis of seven of the most influential manuals of land surveying as well as little known documents of the Bureau of the Cadastre and the School of Engineer-Geographers revealed the growing need for exact and grounded land surveying in eighteenth-century France. Despite the disdain for productive manual work, which was characteristic of Old Regime culture, these manuals contributed to change surveyors’ manners. Indeed, instructions on how to use standardized instruments became an important component of these manuals. In particular, these manuals contributed to the penetration of the epistemic principles of uniformity and exactitude in circles of state power, where the project of a general cadastre, based on a uniform surveying of natural and man-made spaces, was being discussed. As this chapter contended, this was partly achieved by moving toward fully standardized land-surveying instruments, as they were used, for instance, in the execution of the first national cadastre of France in the late eighteenth century.
Notes de bas de page
1 Sheehan J., “The Origins of the Legible State: Map Making, Census Taking, and the Codification of Early Modern Europe”, Vanderbilt University, History Department (unpublished paper), 2013, p. 10.
2 Norden J., Surveiors Dialogue, London, R. Montagu, [1618] 1725, p. 1 and 4.
3 Branco R., “Fieldwork, Map-Making, and State Formation: A Case Study in the History of Science and Administration”, in Figures of Authority: Contributions Towards a Cultural History of Governance from the Seventeenth to the Twentieth Century, edited by P. Becker and R. von Krosigk, Brussels, Peter Lang, 2008, p. 201-228.
4 Bret P., «L’autonomisation d’une profession: de l’ingénieur surnuméraire à l’École d’application des ingénieurs-géographes (1763-1809)», Bulletin du Comité français de cartographie, no 139, mars 1994, p. 43-46.
5 Elias N., Über den Prozess der Zivilisation: Soziogenetische und Psychogenetische Untersuchungen, Frankfurt am Main, Suhrkamp, [1939] 1997.
6 Santana-Acuña A., The Making of a National Cadastre (1763-1807): State Uniformization, Nature Valuation, and Organizational Change in France, Doctoral dissertation, Harvard University, Department of Sociology, 2014.
7 Lindgren U., “Land Surveys, Instruments, and Practitioners in the Renaissance”, in The History of Cartography: Cartography in the European Reinassance, vol. 3, edited by J. Harley and D. Woodward, Chicago, University of Chicago Press, 2007, p. 477-508.
8 Touzery M., «Naissance et crépuscule de l’arpenteur-juré. De l’État royal à la Révolution», Géomètres, no 1 (1), 2000, p. 36-46.
9 Cited in ibid., p. 36. Until the monarchy obtained the right of appointing land surveyors in the late seventeenth century, feudal lords, local authorities, and bailliages could also appoint them. Yet surveyors had to make an oath in front of the respective legal authority in any of the three jurisdictions (feudal, municipal, or royal).
10 Touzery found that, of the 82 land surveyors employed by Bertier de Sauvigny in his cadastre by masses of land use in the generality of Paris (1776-1791), only two called themselves arpenteurs. The rest opted for geometrician or geographer. Touzery M., op. cit.
11 Kiely E., Surveying Instruments, Their History and Classroom Use, New York, Bureau of Publications, Teachers College, Columbia University, 1947; Touzery M., L’Invention de l’impôt sur le revenu: la taille tarifée, 1715-1789, Paris, Comité pour l’histoire économique et financière de la France, 1994.
12 La Hire Ph., L’École des arpenteurs, Paris, T. Moette, [1689] 1692.
13 Dupain de Montesson, L. C., La Science de l’arpenteur dans toute son étenduë, Paris, S. Jaillot, 1766, p. 33.
14 Ozanam J., Méthode de lever les plans et les cartes de terre et de mer, Paris, Alex Jombert, [1693] 1781, p. 393.
15 La Hire Ph., L’École des arpenteurs, op. cit., p. 190.
16 Diderot D. and d’Alembert J., Encyclopédie, ou, Dictionnaire raisonné des sciences, des arts et des métiers, Geneva, Paris and Neufchastel, Chez Briasson [and others], 1751-1772.
17 See e.g., Ginet N., Supplément au Manuel de l’arpenteur, Paris, Brunet, 1775, p. 7.
18 During a cadastre in the generality of Limoges in the 1740s, Aubert de Tourny, the intendant of Limoges, and Dutillet de Villars, subdelegate of Angoulême, witnessed how most land surveyors used only the chain and some of them the équerre as their instruments, not even the planchette. Although surveyors used triangulation to measure property areas, the measurement of angles was quite archaic if compared to the manuals of La Hire and Ozanam. Even local officials knew that there were more accurate surveying instruments available at the time. Touzery M., op. cit., 1994.
19 Shovlin J., The Political Economy of Virtue: Luxury, Patriotism, and the Origins of the French Revolution, Ithaca, Cornell University Press, 2006.
20 Dupain de Montesson, L. C., La Science de l’arpenteur, op. cit., n. pag. (préface).
21 Ginet N., Supplément au Manuel de l’arpenteur, op. cit., 1775, p. iii.
22 Bret P., “Du concours de l’an II à la suppression de l’École des Géographes: la quête identitaire des ingénieurs géographes du Cadastre de Prony, 1794-1802”, in Cardoso de Matos A., Diogo A., Gouzévitch I. and Grelon A. (dir.), Jogos de identidade profissional: os engenheros entre a formação e a acção, Lisbon, Edições Colibri, CIDEHUS, Universidade de Evora, CIUHCT, 2009, p. 121-154.
23 Santana-Acuña A., op. cit.
24 Brian E., La Mesure de l’État: administrateurs et géomètres au xviiie siècle, Paris, Albin Michel, 1994; Picon A., L’Invention de l’ingénieur moderne: l’École des ponts et chaussées, 1747-1851, Paris, Presses de l’École nationale des ponts et chaussées, 1992.
25 Branco R., op. cit.
26 Levallois J., Mesurer la terre: 300 ans de géodesie française, Paris, Presses de la École nationale des ponts et chaussées, 1988.
27 Edney M., Mapping an Empire: The Geographical Construction of British India, 1765-1843, Chicago, University of Chicago Press, 1997.
28 Laffon-Ladebat, Rapport fait par Laffon-Ladebat, 21 May 1797 (2 prairial Year V). Archives de l’École nationale des ponts et chaussées (hereafter AENPC), Ms. 2150.
29 Prony G., Report to the minister of interior, Paris, 17 November 1797 (27 brumaire Year VI), Archives Nationales (hereafter AN), F17 1393.
30 Santana-Acuña A., op. cit.
31 Prony G., Report to the minister of interior, Paris, 6 September 1798 (20 fructidor Year VI), AN, F17 1393.
32 Prony G., Report to the minister of interior, Paris, 25 August 1798 (8 fructidor Year VI), AN, F17 1393.
33 «Supplément à la note sur le Bureau du Cadastre», March-February 1796 (Ventôse Year IV), AN, F4 1013.
34 «Notes sur les opérations du cadastre», 21 April 1796 (2 floréal Year IV), AN, F4 1013.
35 See especially AENPC, Ms. 2213 boîte 2.
36 «État des instruments appartenant au ancien bureau du cadastre», Paris, 11 May 1803 (21 floréal Year XI), AN, F17 1052b (1787-1810).
37 Minister of interior, Arrêté, Paris, 6 April 1802 (16 germinal Year X), AENPC, Ms. 2148.
38 Councillor of state, Letter to the minister of interior, Paris, 17 May 1803 (27 floréal Year XI), AN, F17 1052b (1787-1810).
39 Hennet A., Recueil méthodique des lois, décrets, règlemens, instructions et décisions sur le cadastre de la France, Paris, Imprimerie impériale, 1811.
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