36 



LABORATORY MANUAL OF ANTHROPOMETRY 



since a skull with the mandible attached rests at a very different angle 

 from one without this part, and in the latter case it is impossible to make 

 the proper substitution, or to know the height and other proportions 

 of the missing part. Again, granting that a skull with mandible could 

 be thus treated, the angular slant of the facial profile and of the forehead, 

 characters essential to comparisons, would depend largely upon such 

 points as the length of the chin, and the length or condition of the teeth, 

 points which are of little anthropological importance, and have no 

 reference to the more essential measurements of the skull. 



The need was early felt, then, of the establishment of a standard plane 

 defined in terms of topographical landmarks existing on the skull deprived 

 of mandible, upon which a skull could always be placed preparatory to 



Fig. 17. — Skull placed on the horizontal used by Petrus Camper (1786). 



examination, photography, tracing of contours, or any similar procedure, 

 involving comparison. The early Dutch anthropologist, Petrus Camper, 

 in his classical investigation of the facial angle, published posthumously 

 in 1786, employed as the base a line drawn through the nasal spine and 

 the center of the auditory meatus, and compared with this a line roughly 

 tangent to the profile. The angle included between these two was the 

 facial angle, while the lower line, which could be converted into a plane 

 by including both meatuses, formed a horizontal plane upon which 

 different skulls could be placed for comparison (Fig. 17). This plane, or 

 "horizontal" was modified a few years later by Geoffroy de St. Hilaire 

 (1795), who retained the auditory opening for the more posterior point, 

 but changed the anterior one from the nasal spine to the free margin of 

 the incisor teeth (Fig. 18). This was in two particulars a change for the 

 worse, as it tilted the skull much too far back to be natural, and employed 



