110 



ALES' HRDLIKA 



this lever the disk closes or opens the funnel. A number of extra fun- 

 nels, of the same dip but of different sizes, are provided, from which to 

 choose if another substance than mustard seed is used for the filling. 

 The vessel with the cranial contents is placed on the top of a 2,000-c.c. 

 graduated glass tube (such as used by Ranke), which is fixed in a vertical 

 position. The zinc vessel is provided with a groove in its bottom which 



FIG. 17. Hrdlidka's apparatus for measuring cranial capacity. 



exactly fits the border of the glass, the opening of the funnel being 

 central. Then the lever is rapidly pushed to either side, opening the 

 funnel at once and completely, and the flow left to itself; the level 

 which the seed reaches (determined simply by the eye or, preferably, 

 the careful aid, without any shocks or pressure, of a niveau finder, such 

 as comes with Ranke's tube) is the skull capacity. The measuring 

 part of the capacity determination is thus reduced to a mechanical 

 procedure, which not only makes it easy, but eliminates from it practi- 

 cally all source of error due to personal equation. What the student 

 needs to learn is some method by which a complete and uniform filling 

 of the skull can be effected, and then, working with the aid of standard 



