Custom-Made Contours: The Brief Trajectory of the Hat Conformateur in the Anthropological Society of Paris.

by Marina L. Sardi

At the session of February 5th, 1879, in a meeting of the members of the Anthropological Society of Paris, its general secretary, the physician Paul Broca (1824-1880) (1879b), proclaimed the exclusion of the “conformateur”, used by hatters, as an instrument for measuring heads. He accused it of being misleading, offering one empirical evidence. Broca had his head measured twice, five minutes apart, by the same instrument and hatter, resulting in two cephalic curves that had nothing to do with each other.

The purpose of studying heads was based on the assumption —not without dissent— that brain size and shape were indicators of greater or lesser intellectual development among human races, or sexes, or social classes, with the understanding that educated European men had the greatest intellectual development. Several works have highlighted these debates, but less attention has been paid to how the nascent anthropology promoted the development of rigorous and precise practices — measurement, nomenclature, and statistics — and, with them, the creation of instruments to establish the methods of a positive science.

In those years, there was no consensus on how to measure the brain, whether through its weight, its length, or the complexity of the convolutions. It was also difficult to obtain well-preserved brains from people who had not suffered long illnesses and were not elderly. Hence, valid options were measuring cranial capacity —through liquids or solids—, or the external dimensions of skulls or heads. Occasionally, if the results were not convincing, scholars could introduce comments about the size of hats. They believed that all these measurements had some degree of direct association; that is, people with larger brains would have larger intellects, heads, and hats[1].

In the context of the debates about whether hats were indicators of something more than the size of the wearer’s head, and if customs and practices did modify them, the conformateur was introduced to address instrumental and methodological issues. These issues were partly rooted in the theoretical assumptions held by these scholars in the mid-19th century. In the pursuit of objective measurements, they did not hesitate to adopt, and eventually adapt or discard, instruments used in various trades or industries.

The study of the cranial conformation involved measuring curves and perimeters with a measuring tape, but also graphing it, in order to study the relationships between parts, detect cranial types, and confirm the existence of asymmetry between the right and left sides. Who, then, but a hatter, would have the practical knowledge of all the shapes and sizes of heads?


[1] The debate between Paul Broca and Louis Gratiolet and the conclusions surrounding Georges Cuvier’s hat — which was not abnormally large, as they had expected, judging by the magnitude of his intelligence — were highlighted by palaeontologist and science communicator Stephen Jay Gould (1980, 1981) in the 1980s to denounce biological determinism and the use of intelligence tests in the United States.

In fact, in the 1840s, the conformateur was created by a Parisian hatter, M. Allié, to make custom-made hats. Allié had already invented another device that made it possible to obtain the anteroposterior and transverse curves, as well as the horizontal circumference, but it was difficult to handle (Broca 1865). The new instrument was composed of spokes of equal length which, when placed on a head, adjusted to the perimeter (where the hat would sit) (Fig. 1a, b) and perforated a sheet of paper on which the horizontal curve was drawn to scale, allowing the negative of the skull contour to be obtained (Fig. 2). This was then placed at the center of a formillon, enabling the restoration of both size and shape (Fig. 1b).

Figure 1a. Allié-Maillard conformateur, belonging to the Parisian hatter Pauline Brosset Royer (Pauline Chapelière, n.d.). The vertical spokes can be seen, reinforced by lateral supports, joined at right angles to metal rods that end in points. These spokes move when the conformateur is placed on the head. By placing a piece of paper over the points and lowering the lid, they perforate it, allowing the contour to be defined.

Figure 1b. Formillon. The contour obtained with the conformateur is placed at the center, and by previously determining the cephalic perimeter, it allows the original shape to be restored.

Figure 2. Contours obtained with the conformateur on different subjects, including that of the author of this text.

On December 19, 1861, two years after the founding of the Anthropological Society of Paris, a meeting was held to discuss how to accurately record cranial contours. Broca (1861a) presented a craniograph that allowed for the construction of cranial curves and the analysis of the relative development of different parts (Fig. 3). He then introduced another craniograph, created by Louis Mathieu (1817-1879), a manufacturer of surgical instruments, followed by an exchange on practical matters (Broca 1861b). The naturalist Paul de Jouvencel (1817-1897) informed him about Allié’s conformateur. Broca claimed to be familiar with it but was skeptical. He deemed the contours produced by the apparatus as “caricatures”, although he acknowledged that the formillon allowed for the restoration of the original shape. He also stated that he was familiar with the first device Allié had created, which he considered superior to the second, and, for this reason, he had met with Mathieu to modify it, although the outcome remains unknown.

Following these considerations, a discussion ensued regarding the use of lead sheets to obtain cranial contours, which Broca approved, versus the graphing of silhouettes, which he rejected. He argued that silhouettes projected on a single plane points that were actually on different planes, without accounting for the effect of hair or the influence of sunlight (the only widely available light source at the time) on the resulting silhouette. He believed that his craniograph would help overcome “artistic” evaluations, which depended on the observer’s perceptiveness or preconceived ideas, by enabling precise comparisons that would allow for classification into series, statistical analysis, and the calculation of averages, thus avoiding the misleading influence of individual variations (Broca 1871).

Figure 3. The device intended to graph contours consisted of the craniophore (left), designed for holding skulls in position, and a craniograph (right), to obtain contours on a sheet of paper. Source: Broca 1871, p. 72.

Despite Broca’s criticism of the conformateur, some researchers adopted it in their studies and sent their observations to the Anthropological Society of Paris. This is evidenced by a letter found in the society’s archives, in which the physician Gustave Le Bon (1841-1931) wrote to Broca in 1877, reporting observations on 200 individuals. He noted that the apparatus made it possible to determine the cranial longitudinal axis and to delineate the right and left halves of the horizontal cephalic profile. By superimposing both halves, he was able to observe which parts were more prominent on either side (Le Bon 1877): in other words, to demonstrate that the head was not symmetrical.

His results did not appear to be random. In two-thirds of the cases, greater parietal development was observed on the left side, accompanied by greater frontal development on the right. However, Le Bon did not consider it necessary to present his findings to scientific societies, as his method could be subject to criticism, which he preferred to avoid. While offering Broca the recorded contours, he stated that “hatters do not ensure great precision in the way they position the conformateur, and a slight deviation to the right or left is enough to shift the main axis of the instrument and distort the data it provides” (Le Bon 1877).

Broca’s verdict did not take long (Broca 1879a). He first pointed out, and rightly so, that the circumference measured by anthropologists did not correspond to the location of the hat. Then, responding to Le Bon, he noted that the asymmetries in the contours were due to the uneven pressure exerted by the hatter’s hands. The hatter would stand in front of the observed subject, often applying more pressure with his right hand, which resulted in an asymmetry on the left side of the head contour. Lastly, Broca stated that cranial asymmetries, in fact, were more prevalent on the right side.

Finally, in the revised version of his Instructions générales pour les recherches anthropologiques, published in 1879, Broca included the conformateur in a list of 22 devices for laboratory measurements—though solely to discourage its use, in order to ‘avoid useless waste of time for people who have the unfortunate idea of using it’ (Broca 1879b, p. 74). He declared it to be an empirical rather than a geometrical instrument, although excellent for making hats. In fact, conformateurs continued to be sold well into the 20th century (Fig. 4), and one remains in use in a Parisian atelier (Pauline Chapelière, n.d.), as wooden molds, commonly used in the trade, do not fit all heads (Pauline Brosset Royer, personal communication).

Figure 4. Advertisement for the sale of the Allié conformateur (Revue de la Chapellerie, October 20, 1929).

A century and a half later, the theoretical assumptions about cranial conformation have changed. However, the idea that studying cranial surfaces and contours can reveal something about human variation remains, although the geometric principles and tools, many of them based on medical imaging technologies, are now different.

The case of the conformateur illustrates how scholars, in their pursuit for studying the skull and ultimately testing their theories, remained open to various methodological approaches and did not hesitate to turn to individuals with empirical knowledge of bodies and heads, if their instruments were precise enough. Thus, hatters’ ateliers were spaces—outside traditional scientific cabinets—where, albeit occasionally, anthropological knowledge was attempted to be constructed.

In this case, the question remains as to why Broca so quickly dismissed the conformateur instead of adapting it to his purposes, as he did with the numerous instruments he introduced in the 1860s and 1870s for measuring and tracing contours. Most of these, however, would not endure for long, as researchers in many countries proposed alternative instruments over the following decades.

Paris, March 28, 2025.

Acknowledgements. To the Parisian hatter Pauline Brosset Royer, who enabled me to visit her atelier and talk about the conformateur.

Bbibliography

Broca, P. 1861a. Sur le craniographe et sur la détermination de plusieurs angles nouveaux nommés angles auriculaires. Bulletins de la Société d’Anthropologie de Paris, 2, 473-680.

Mathieu M. 1861b. Sur un nouveau céphalographe présenté par M. Mathieu. Bulletins de la Société d’Anthropologie de Paris, 2, 680- 686.

Broca, P. 1865. Instructions Générales pour les recherches et observations anthropologiques. París: Victor Masson et fils.

Broca P. 1879a. Instructions Générales pour les Recherches Anthropologiques à faire sur le Vivant. 2da ed. París, G. Masson.

Broca P. 1879b. Sur la fausseté des résultats céphalométriques obtenus à l’aide du conformateur des chapeliers. Bulletins de la Société d’anthropologie de Paris 2, 101-106. doi : https://doi.org/10.3406/bmsap.1879.5207

Gould SJ. 1980. The Panda’s Thumb: More Reflections in Natural History. New York, WW Norton & Company

Gould SJ. 1981. The Mismeasure of Man. New York, WW Norton & Company.

Le Bon G. 1877. Carta dirigida a la Société d’Anthropologie de Paris. Fondos documentales de la Société d’Anthropologie de Paris, 13 K, 2274, Museum National d’Histoire Naturelle.

Pauline Chapelière s.f. En : https://www.paulinechapeliere.com/

Revue de la chapellerie, 20 octobre 1929, n° 413. Available on gallica.bnf.fr


OpenEdition suggests that you cite this post as follows:
alexiacomte (April 9, 2025). Custom-Made Contours: The Brief Trajectory of the Hat Conformateur in the Anthropological Society of Paris. SciCoMove — Scientific Collections on the Move. Retrieved June 12, 2025 from https://doi.org/10.58079/13prt


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