60 LABORATORY MANUAL OF ANTHROPOMETRY 



In filling, either the skull or the cylinder, the main point is, not to 

 pack. There is a great temptation to do so, and the beginner will almost 

 invariably press on the seed, through .the occipital foramen, with his 

 finger, with the intention of completely filling the space. In all cases, 

 however, the rule must be invariable, to let the medium fall naturally, 

 the separate granules arranging themselves as they will, without forcing 

 them to fit together more tightly than they do under the influence of 

 gravitation. In the same way neither skull nor cylinder is to be shaken 

 or thumped down upon the table, for such procedures tend to pack the 

 medium more tightly together, and cannot well be administered in both 

 skull and cylinder to the same degree. To insure a uniform fall of the 

 medium into the cylinder a simple apparatus has been devised in the 

 form of a large tin cup of about 2000 cm. capacity, and with a funnel- 

 shaped bottom having a round hole, 2 cm. in diameter, precisely in the 

 center. This hole may be opened or shut from the outside by means of 

 a simple rod apparatus, which slides a flat cover to and from the hole. 

 The cup receives the seed, or other medium, directly from the skull, 

 poured from the occipital foramen, and is then placed upon the 2000 cm. 

 glass cylinder, exactly centered with it and the whole apparatus placed 

 upon a perfectly level table. The hole is then opened, and the seed pours 

 down in a uniform column through the center of the cylinder, falling at 

 the bottom in the center and distributing itself evenly upon all sides. 

 When properly done the surface of the seed should present a slightly con- 

 vex surface, which can be readily made level by the use of a flat disc 

 of wood on the end of a rod, the disc being a little smaller in diameter 

 than the inner dimensions of the cylinder itself. Even here care should 

 be taken not to compress the seed, but to simply level the surface so 

 that it can be more accurately read, which is done by a gentle patting, 

 accompanied by a slight twisting of the rod. 



Unfortunately the same precision cannot be obtained in filling the skull, 

 but a result similar to that obtained by the tin cup may be produced by 

 dropping the medium through the occipital foramen through a tin fun- 

 nel which is kept supplied with seed, and held up so that the stream of seed 

 falls from a like distance. Towards the end, a slight use of either the 

 finger, or a small wooden cylinder, is required, to fill the lateral spaces at 

 the top, but no especial pressure is to be exerted, and the action is to be 

 limited to about the same amount that is used in the cylinder in leveling 

 the top. By thus employing merely the natural amount of packing inci- 

 dent to the material used when falling naturally, and taking care not to 

 exert pressure, the result should be uniform in skull and cylinder, and 

 the latter should register the actual cranial capacity of the skull thus 

 measured. 



As a check on the method, and a test as to whether the results are 

 accurate or not, the method of using a "control skull "is advocated. This 

 is either a real human skull of known capacity, or one made of bronze, 



