ANTHROPOMETRY 107 



THE VAULT 



Maximum length: The maximum glabello-occipital diameter of the 

 vault. Instrument: c.e.,^ any pattern. 



Method: As specified by International Agreements (p. 14) and on the 

 living (p. 68). 



Maximum breadth: The greatest transverse diameter of the vault 

 above the mastoids and roots of zygomae. Instrument: c. e. 



Method: As specified by I. A. (p. 14) and on living (p. 69). 



Basion-bregma height. — c. e. 



Method: Place left forefinger in foramen magnum, press ball of finger 

 lightly against anterior border of the foramen, apply one point of 

 compass so that it rests on the lowermost point of the border in the 

 middle and against the finger, apply other point to bregma, and read 

 measurement. Or, apply point of right branch of compass to bregma 

 and bring point of left branch to basion. 



Remark. — The maximum height of the vault is less desirable than 

 the basio-bregmatic, because used by fewer observers, and on account 

 of the not infrequent thickening and ridging of the bone in the sagittal 

 region. 



Thickness: Thickness of left parietal, 1 cm. above and along the 

 squamous suture. — c. e. 



Method: Introduce one branch of compass into the cranial cavity, 

 apply to anterior part of the lower portion of the parietal approximately 

 1 cm. above the squamous suture, bring other branch in contact with 

 the bone externally, and pass backwards at about the same distance 

 from the sutures, watching the scale of the instrument. Record 

 observed minimum and maximum. These give a mean which is 

 useful for comparison, and which must be taken account of in estimates 

 of skull capacity from external dimensions. 



Minimum frontal diameter. — c. e. or c. g. Landmarks and method 

 as given by the I. A. (p. 16). 



Capacity. — This measurement, corresponding closely to the volume 

 of the brain, is one of considerable importance, and as it is also beset 

 with difficulties it demands special attention. 



An ideal method of obtaining the capacity would be by some liquid, 

 water or mercury, which could be easily and directly measured; 

 but attempts at such a procedure have met thus far with unsurmounted 

 difficulties due to the porosity of the bones, the numerous canals and 

 foramina, and the sharp processes on the inside of the skull. 



' Compas d'epaisseur. 



