osteometry; the measurement of the bones 69 



V. INDICES OF "WEIGHT AND CAPACITY 



[Various indices of weight and capacity have been employed, but 

 comparisons can be made only in the case of skulls in about the 

 same condition with respect to dryness, and where nothing of 

 the bone substance has been lost through decay or weathering. 

 The following are some of the most important, and are suggestive 

 of further study along this line]. 



35. Calvario-cerebral weight index 



weight of skull, without mandible_X^ 100 

 cranial capacity 



[Here, as elsewhere when capacity is compared with weight, the 

 weight must be in grams, the capacity in cubic centimeters] 



, ., 7 , , . 7 . , weight of mandible X 100 



36. M and ibiUo-cerebraL weiqnt index -r-: — — rr 



cranial capacity 



[Here, and in all indices involving the weight of the mandible, as 

 in the two below, the mandible is supposed to have a full com- 

 plement of teeth. Some operators have a lot of odd teeth and 

 find a corresponding tooth for each one gone, which is to be 

 weighed with the jaw. Others add an average weight (1.25 g.) 

 for each tooth missing]. 



„ ^ 7 . 7 ., 7 • t, • , weight of mandible X 100 



3/. Cahario-mandibidar weight index - — ^r- — ^—. — ^— -, 



weight ot skull alone 



„ _ -7.7-7 weight of skull without mandible XI 00 



38. b emero-craniat weiqht index - — ^-rr — e ,, ^ 



weight ol the two femora 



Angles 



Angles. — The great majority of the cranial angles in use, either now 

 or formerly, lie in the median sagittal plane. These, in the early practice, 

 were rendered available for study by the drastic method of sawing the 

 skull in two along the median plane, a practice which had the advantage 

 of laying bare internal as well as external proportions, yet presented the 

 disadvantages of rendering the specimen practically useless for many 

 other data, especially breadth measures, involving points upon both 

 moieties, and measured across the bisected skull. Prof. Huxley, however, 

 at one time advocated this procedure so strongly that he declared that 

 the time would come when it would be considered a disgrace for an anthro- 

 pological collection to possess as much as a single skull that had not been 

 thus treated. 



Fortunately for the science of anthropometry the introduction of the 

 diagraph, with the possibility of obtaining an accurate profile tracing 

 of the outer contour, without injury to the skull itself, has rendered 

 available the study of all external curves and of angles involving only 

 external parts, without recourse to bisection; while, by means of recently 



