Thinking About Craniometry- a Tale of Two Traditions (continued)

By the turn of the nineteenth century, anatomists who shared Blumenbach’s curiosity about human variation were supplementing his procedure with a geometric technique devised by his Dutch colleague, Peter Camper. A talented artist as well as comparative anatomist, Camper had found that the shape of human heads and skulls could be accurately drawn by imagining a base line running from the front of the incisor teeth to the most prominent part of the forehead. A ‘facial angle’ could then be recorded by imagining a second line, this one running from the base of the nose to the entrance of the ear. Camper believed that this procedure enabled even the most subtle differences between heads or skulls of peoples of different ethnic origin to be accurately drawn, believing that all other features of the head and face were closely correlated with the degree of protrusion or recession of the lower jaw. Accuracy was assured irrespective of whether skulls in medico-scientific collections were drawn at leisure, or heads of living subjects had to be hurriedly sketched in contexts of exploration and cross-cultural encounters.(Camper 1794, 33-44, 45-51; Meijer 1999, 96-98)

Both Blumenbach and Camper regarded their respective ways of accurately determining differences in the form of heads and skulls as in no way presuming marked differences in intellectual capabilities between the main varietal types into they believed humanity had branched. However, as Londa Schiebinger has shown, what was implicit in their respective observational and geometric approaches to examining skulls was the enculturated assumption that the heads of ancient Greek statues - the facial angle of which came close to 100 degrees - most closely approached an ideal standard of beauty; whereas the heads of contemporary Europeans, Asian peoples, African peoples and higher apes were imagined to comprise a continuum of increasing ugliness. (Schiebinger 1993, 150-52) Even so, Camper was aware that his facial angle risked being interpreted as empirically confirming the ancient dictum, monstrum in fronte, monstrum in animo (monstrous in appearance, monstrous in spirit). In examining the sum of his writings on differentiating crania, Miriam Meijer has drawn attention to his taking care to stress that his technique was an invaluable tool for investigating varietal differences, which in its outcomes would clearly refute the idea that variations were contrary to the ordinary course of nature, so as to challenge ‘…the racial prejudices of Europeans concerning the naturalness, unnaturalness or beauty/ugliness of non-European physiognomies.’ Meijer has also shown that Camper also rejected the idea of any great or stable differences mental powers between Africans and Europeans different peoples. (Meijer 1999, 3, 172)

Blumenbach’s holistic visual determination of varietal signatures by viewing crania from above - the norma verticulis - was employed by numerous comparative anatomists and anthropologists throughout the nineteenth century. For some, the preference for this and other non-metric observational procedures stemmed from scepticism about the possibility of accurately determining variations in surface curvatures and other structural features of the twenty-two bones of the face and cranium by geometric means. Alexander Monro (1773-1859), for example, Edinburgh University’s professor of anatomy from the late 1790s until 1846, agreed with Blumenbach and Camper that comparative investigation of skull forms was likely ‘ … to bring to light many curious circumstances with regard to the history of mankind, by supplying data which may lead to the detection of the origin of particular nations.’ But he cautioned several generations of the many students he taught that ‘…all craniometers made of wood or metal are objectionable; such unyielding materials not adapting themselves to the inequalities of the surface of the skull.’ (Monro 1825, 1, 201) He also raised the problem that Blumenbach himself had identified: the growth of global networks of trade and exchange were certain to accelerate rates of inter-varietal reproduction, resulting in the effacement of what, historically, had been relatively stable racial traits. Hence there was a need to actively encourage the collecting of ‘national’ skulls as systematically as circumstances allowed.

Even so, many adopted Camper’s geometric approach to investigating cranial variations. For example, Monro’s colleague, the respected extra-mural anatomy teacher, John Barclay (1758-1826), collaborated with fellow Edinburgh surgeon, Edmund Leach (n.d.) on creating a calliper-like instrument which they believed better determined the degree of angular variation. As Barclay and Leach saw it, what needed to be measured was the angle between a line imagined to run vertically down through the face, and a second line intersecting with the forward projection of the lower jaw. (Grant ) By around 1812 they had also sought to integrate measurement into Blumenbach’s mode of differentiating cranial shape by means of a device similar to that then in use by Scottish shoemakers to estimate foot sizes. (Brewster 1830)

Barclay and leach were credited with having shown that it was possible ‘… with unerring certainty, discover the nation to which the skull belongs.’ (Brewster 1830) However, not all of their peers were convinced that craniometry was yet on a sure footing. The American physician, Samuel George Morton (1799-1851), worked with John S. Phillips (1800-1876), a fellow member of Philadelphia’s Academy of Natural Sciences, on crafting instruments building on Camper’s technique. One was a ‘goniometer’, a means of measuring angles traditionally used in land surveying, but adapted Morton so as to gain more accurate readings of facial geometry than devices such as that invented by Barclay and Leach. Morton’s goniometer comprised an ‘F’ shaped wooden frame with an upright bearing cross-piece attached to one corner by a hinge. When a skull was put in the frame by and the cross-piece placed on its frontal bone, an angle could be read from a protractor at the joint of the upright of the frame. Another of Phillips’s instruments enabled Morton find the internal volume of crania. (Morton and Combe 1839, 253-56) Morton also sought to bring more more accuracy to drawing the surface outlines of skulls. The ‘craniograph’ as he and Phillips called it, was a wooden plank six feet long and a foot wide, on which a skull was mounted on a stand one foot from one end. By placing a vertical sheet of glass about one fifth from the other end of the board, one could use an eye-piece mounted at end of the board to draw the outline of skull onto the glass in ink ‘with great rapidity and accuracy.’ The ink drawing could then be traced onto paper. (Morton and Combe 1839, 294)

By the late 1850s, Morton’s devices were in wide use, along with instruments that sought to improve on their design, as well as new tools for comparing cranial breadth and length. The latter were designed in response to the invention of a new measurement by the Swedish anatomist, Anders Retzius (1796-1860). Retzius believed that the racial ancestry of heads and skulls could best be determined by comparing the length and breath of the cranium, then recording the difference as simple ratio expressed as a percentage, which he called its ‘cephalic index’. He also believed, incidentally, that Swedes were intellectually and morally superior to all other Europeans on the basis of their supposedly having their highly developed anterior lobes (Carson 2007, 102) Adopters of Retzius' method included the influential Estonian born Karl Ernst von Baer (1792-1876), who was active in both Russian and German anthropological circles, and championed the cephalic index as superseding all previous non-metric observational and metric ways classifying human varietal types. (Tammiksaar and Kalling 2018)

By this time craniometry was no longer employed solely to accurately represent differences in the form of skulls. Camper’s geometric approach to registering cranial variations had not, as he had hoped, initiated research that served to refute long ingrained European prejudices concerning the mental abilities and physical appearance of peoples of other continents. Quite the opposite. As is well illustrated by the positive reception greeting Samuel Morton’s ambitious projects through the 1830s and early 1840s of measuring Native American then ancient Egyptian skulls. Craniometry had become a means of measuring and classifying supposedly racial differences in intelligence and moral judgement. (Morton and Combe 1839; Morton 1844)