CRANIOMETRY  . The application of precise methods of measurement marks a definite phase in the development of most branches of

modern science, and thus craniometry, a comprehensive expression for all methods of measuring the skull (cranium), provides a striking landmark in the progress of anthropological studies . The origin of craniometry appears to be twofold . Certain artists made measurements of heads and skulls with a view to attaining greater accuracy in their representation of those parts of the human frame . Bernard de Palissy and A . Durer may be mentioned as pioneers in such researches . Again, it is clearly shown in the literature of this subject, that anatomists were led to employ methods of measurement in their study of the human skull . The determining cause of this improvement in method is curious, for it appeared at the end of a famous anatomical controversy of the later middle ages, namely the dispute as to whether the Galenic anatomy was based on the study of the human body or upon those of apes . In the description of the dissection of a chimpanzee (in 168o) Tyson explains that the measurements he made of the skull of that animal were devised with a view to exhibiting the difference between this and the human skull . The artists did not carry their researches very far . The anatomists on the contrary continued to make measurements, and in 1764 Daubenton published a noteworthy contribution to craniometry . Six years later, Pieter Camper, distinguished both as an artist and as an anatomist, published some lectures containing an account of his craniometrical methods, and these may be fairly claimed as having laid the foundation of all subsequent work .

That work has been described above as anthropological, but as the studies thus defined are very varied in extent, it is necessary to consider the subdivisions into which they naturally fall . In the first

place (and omitting further reference to the contributions of artists), it has been explained that the measurements were first made with a view to elucidating the comparison of the skulls of men with those of other animals . This wide comparison constitutes the first subdivision of craniometric studies . And craniometric methods have rendered the results of comparisonmuch more clear and comprehensible than was formerly the case . It is further remarkable that among the first measurements employed angular determinations occur, and indeed the name of Camper is chiefly perpetuated in anthropological literature by the " facial angle " invented by that artist-anatomist (fig . I) . It appears impossible to improve on the simple terms in which Camper describes the general results of the employment of this angle for comparative purposes, as will appear from the following brief extract from the translation of the original work: " The two extremities of the facial line are from 70 to 8o degrees from the negro to the Grecian antique: make it under 70, and you describe an ourang or an ape: lessen it still more, and you have the head of a dog . Increase the minimum, and you form a fowl, a snipe for example, the facial line of which is nearly parallel with the horizon." (Camper's Works, p . 42, translated by Cogan, 1821.) In the 9th century the names of notable contributors to the literature of craniometry quickly increase in number; while it is impossible to analyse each contribution, or even record a complete list of the names of the authors, it must be added that for the purposes of far-reaching comparisons of the lower animals with mankind, craniometric methods were used by P . P . Broca in France and by T . H .

Huxley (figs . 2 and 3) in England, with such genius and success as have not yet been surpassed . The second division of craniometric studies includes those in which the skulls of the higher and lower races of mankind are compared . And in this domain, the advent of accurate numerical methods of recording observations brought about great advances . In describing the facial angle, it will be seen that the modern European, the Greek of classical antiquity and the Negro are compared . Thus it is that Camper's name appears as that of a pioneer in this second main division of the subject . Broca and Huxley cultivated similar comparative racial fields of research, but to these names that of Anders Retzius of Stockholm must be added here . The chief claim of Retzius to distinction rests on the merits of his system of comparing various dimensions of the skull, and of a classification based on such comparisons . These indices will be further defined below . It is convenient to mention here that the first aim of all these investigators was to obtain from the skull reliable data having reference to the conformation or size of the brain once contained within it . Only in later days did the tendency to overlook this, the fundamental aim and end of craniometry, make its appearance; such nevertheless was the case, much to the detriment of craniometric science, which for a time seems to have become purely empirical . The third subdivision of craniometric researches is one in which the field of comparison is still further narrowed .

For herein the various sub-racial types such as the dark and

fair Europeans are brought together for the purposes of comparison or contrast . But although the range of research is thus narrowed and restricted, the guiding principles and the methods remain unchanged . In this department of craniometry, Anders Retzius has gained the foremost place among the pioneers of research . Retzius's name is, as already mentioned, associated not with any particular angle or angular measurement, but rather with a method of expressing as a formula two cranial dimensions which have been measured and which are to be compared . Thus for instance one skull may be so proportioned that its greatest width measures 75% of its greatest length (i.e. its width is to its length as three to four) . This ratio (of 75%) is termed the cephalic or breadth-index, which in such an instance would be described as equal to 75 . A B C From Tylor's Anthropology, by permission of Macmillan & Co., Ltd . A skull providing a breadth-index of 75 will naturally possess very different proportions from another which provides a corresponding index equal to 85 . And in fact this particular index in human skulls varies from about 58 to go in undistorted examples (fig . 4) . Such is the general scheme of Retzius's system of classification of skulls by means of indices, and one of his earliest applications of the method was to the inhabitants of Sweden . 373 One striking result was to exhibit a most marked contrast in respect of the breadth-index of the skull, between the Lapps and their Scandinavian neighbours, and thus a craniometric difference was added to the list of characters (such as stature, hair-colour and complexion) whereby these two types were already dis- tinguished .

Since the publication of Retzius's studies, the cephalic or breadth-index of the skull has retained a premier position among its almost innumerable successors, though it is of

historical interest to note that, while Retzius had un- doubtedly devised the method of comparing " breadth-indices," he e C. always qualified the results of its use by reference to other data . These qualifications were over-looked by the immediate successors of Retzius, much to the disadvantage of craniometry . In addition to the researches on the skull forms of Lapps and Swedes, others dealing with the comparison of Finns and Swedes (by Retzius) as well as the investigation of the form of skull in Basques and Guanches (by Broca) possess historic interest . Thus far little or nothing has been said with regard to instruments . Camper devised a four-sided open frame with cross-wires, through which skulls were viewed and by means of which accurate drawings could be projected on to paper . The methods of Retzius as here described require the aid of callipers of various sorts, and such instruments were quickly devised and applied to the special needs of the case . Such instruments are still in use, and two forms of simple craniometer are shown in the accompanying illustrations (figs . 5 and 6) . For the more accurate comparison required in the study of various European types, delicate instruments for measuring angles were invented by Anthelme in Paris (1836) and John Grattan in Belfast (18J3) . These instruments enabled the observer to transmit to the plane surface of a sheet of drawing paper a correct tracing of the contour of the specimen under investigation . A further modification was devised by the talented Dr Busk in the year 1861, and since that date the number and forms of these instruments have been greatly multiplied . With reference to contributors to the advance of knowledge in this particular department of craniometry, there should be added to the foregoing names those of Huxley, Sir W .

H .

Flower and Sir W . Turner in England, J . L . A. de Quatrefages in France, J . C . G . Lucae and H.Welcker in Germany . Moreover, the methods have also been multi-plied, so that in addition to angular and linear measurements, those of the capacity or cubical contents of the cranium and those of the curva- FIG . 6.—Flower's Craniometer as moditure of its surface demand fled by Dr W . L . H .

Duckworth. reference . The masterly work of Cleland claims special mention in this connexion . And finally while two dimensions are combined in the cephalic index of Retzius, the combination of three dimensions (in a formula called a modulus) distinguishes some recent work, although the employment of the modulus is B 1'homme et dans les animaux," Comptes rendus de l'academie des sciences (Paris, 1764); Camper, Works (1770, translated by Cogan, 1821); Broca, Memoires (1862 and following years); Huxley, Journal of Anatomy and Physiology, vol . 1 (1867); Retzius, Uber die Schadelformen der Nordbewohner (Stockholm, 1842) ; Anthelme, Physiologie de la pensee (Paris, 1836) ; Grattan, Ulster Journal of Archaeology, vol . I (1853) ; Busk, " A System of Craniometry, Transactions of the Ethnological Society (1861); Flower, Catalogue of the Hunterian Museum, Osteology, part 1(London, 1879) ; Turner, ' Challenger ' Reports," Zoology, vol. x. pt . 29, " Human Crania " (1884) ; de Quatrefages, Crania ethnica (Paris, 1873) ; Lucae, Architectur des menschlichen Schddels (Frankfort, 1855) ; Welcker, Bau and Wachsthum des menschlichen Scheidels (1862); Cleland, " An Inquiry into the Variations of the Human Skull," Phil . Trans . Roy . Society (187o), vol . 16o, pp . 117 et seq.; von Baer, " Crania selecta," Academie imperiale des sciences de S . Petersbourg (1859); His and Rutimeyer, Crania Helvetica (Basel, 1866) ; Ecker, Crania Ger- manise meridionalis (1865) ; Thurnam and Davis, Crania Britannica; von Torok, Craniometrie (Stuttgart, 1890) ; Benedikt, Manuel technique et pra- tique d'anthropometrie cranio-cepha- lique (Paris, 1889) ; Pearson, Biome- trika, from vol .

1 (in 1902) onwards; Sergi, " The Varieties of the Human

Species," English translation, Smith- i sonian Institution (Washington, IMOA r ,' N _ . ~• 1894) ; Schwalbe, " Der Neander- ~~ C thalschadel," Bonner Jahrbdcher,Heft ~A B Io6; also Sonderheft der Zeitschrift fur Morphologic and Anthropologie; native (male) 62°; B, a gorilla (male) 5o°; C, a dog 42° . This angle has now replaced the facial Mensch von Krapina (Nagele, Stutt- gart, 1901); Sollas, " The Cranial Characters of the Neanderthal Race," Phil . Transactions of the Royal Society, vol . 199, Series B, p . 298, 1908 ; Klaatsch, " Bericht fiber einen anthropologischen Streifzug nach London," Zeitschrift fur Ethnologie, Heft 6, 1903, p . 875 . Handbooks.—Topinard, Elements d'anthropologie generale (Paris, 1885) ; Schmidt, Anthropologische Methoden (Leipzig, 1888) ; Duck-worth, Morphology and Anthropology (Cambridge, 1904) . Journals.—Bulletins de la Societe d'Anthropologie de Paris, Journal of the Royal Anthropological Institute of Great Britain and Ireland, Archiv fur Anthropologie, Zeitschrift fur Morphologie and Anthropologie . (W . L . H .