25^ 



CRANIA AMERICANA. 



all other modes of ascertaining the facial angle. The following diagram represents 

 the instrument, which may he called the Facial Goniometer, as applied to a 

 cranium for the purpose of measurement. 



The letters A, A, A represent the rectangular hasal limhs of the instrument, 

 (which is made of brass,) the front limb sliding at B, so as to increase or diminish 

 the distance between the right and left limbs. In order to fix the goniometer to 

 a skull, there is attached to each of the lateral limbs a slide with a conical pivot 

 attached, C, which enters the meatus of the ear. The limb D, D, is attached by 

 a hinge to the base, and can be brought to form any angle with it. G is a scale 

 of one hundred degrees, attached by a hinge at I, and let through the limb D, D, 

 at H. E is a horizontal limb, at right angles with D, D, on which it slides at F. 

 The thin piece of wood, K, K, has an opening at L, to admit the nasal bones to 

 pass through it. Now this piece of wood necessarily touches the most prominent 

 parts of the forehead and upper maxillary bone, and therefore represents the facial 

 line. To measure the facial angle, bring the upper surface of the anterior basal limb 

 of the instrument on a horizontal plane with the nasal spine ; then let the limb D, 

 D, fall back until the lateral limb E, touches the facial line K, K, when the facial 

 angle will be at once designated on the scale. For the purpose of greater accuracy 

 the lateral basal limbs of the instrument are graduated in inches and parts of inches, 



