The ethnology of ancient Britain has been studied from many points of view. Writers of a past generation relied simply upon the notices which are to be found in the works of Caesar, Strabo, Tacitus, and other ancient writers. In the last century the science, if it may now be so called, of physical anthropology came into being. The barrows in which our prehistoric ancestors had buried their dead were opened; and the skeletons which had been left in them by earlier explorers were systematically measured. The physical characters of the living population were noted as far as possible in the hope that they might help to solve the problems of the past. Archaeologists collected the pottery, the tools, the weapons, and the ornaments which were found beneath the soil, in the beds of rivers, in barrows, cairns, caves, earthworks, and elsewhere, described them, classified them, and compared them with those of other countries. Philologists studied the forms of the Celtic dialects, and endeavoured to discover in them traces of dialects older still. Finally, folk-lorists formed an association, and joined the army of inquirers. The united efforts of all these seekers after truth have stored up a huge mass of information; and those who may read this article will, I believe, agree with me that there is no reason to expect that any additional facts which may be ascertained will throw much new light upon the questions which we are about to consider:[1512] but no serious attempt has yet been made to co-ordinate the materials which exist. To do this is the aim of the present article. If the problems of British ethnology can be solved, history, physical anthropology, archaeology, and philology must combine.
A lay reader who takes up a treatise on ethnology ought to understand the methods by which anthropologists differentiate the various human types. I may be allowed to reproduce a paragraph which I wrote a few years ago in another volume, and to which I shall have something to add.
‘Anthropologists are obliged to make use of technical terms, more or less uncouth; and they are guided in their observations by very precise and minute rules, framed with the object of eliminating, as far as possible, the chance of error. But it is unnecessary for my purpose to trouble the reader with more than a few of these things. What I shall have to say about stature, complexion, hair and eyes, will need no explanation; and in regard to the skull I shall, as a rule, only have to deal with that measurement which fixes the proportion between its length and its breadth. In this measurement the length is represented by 100; and the proportion which the breadth bears to the length is called the cephalic index. Thus, if the breadth is four-fifths of the length, the index is 80. According to the system formulated by the great French anthropologist, Paul Broca,[1513] skulls are grouped, according to the cephalic index, in five classes. Skulls whose index exceeds 83·33 are brachycephalic; those whose index falls between 83·33 and 80 are sub-brachycephalic; those between 80 and 77·77 mesaticephalic; those between 77·77 and 75 sub-dolichocephalic; and those below 75 dolichocephalic ... it is necessary to bear in mind that measurements of living heads invariably yield a higher cephalic index--the average difference being as much as 2--than those of skulls[1514] [of the same form]. Another important character of the skull or head is _gnathism_, that is to say, the degree of projection of the upper jaw. The word _orthognathous_ denotes that this projection is comparatively slight; for absolute orthognathism does not exist. The remaining technical terms which it is necessary for general readers to understand are those which describe the structure of the nasal skeleton. _Platyrrhinian_ means that it is wide, _mesorrhinian_ intermediate, and _leptorrhinian_ narrow.’[1515] I should have added that the orbital index, which is important, denotes the relation of the breadth of the orbit to its length; and, since we are dealing with the ethnology of Britain, it will be convenient to adopt for cephalic indices the notation which is prevalent in this country, and according to which skulls whose indices exceed 80 are called brachycephalic, those between 80 and 75 mesaticephalic, and those under 75 dolichocephalic.
