A Sketch of his Work as a Craniologist. 



same objection as the length-height index which we have just 

 discussed. Thus, in some skulls the greatest transverse diameter 

 is high up on the parietal bones, this means that the sides of the 

 skull have a slight inclination outwards from the base until near 

 the top ; in other specimens the lateral walls begin to slope inwards 

 from near the base, so that the greatest transverse diameter is 

 much lower. Further, the maximum transverse diameter may be 

 the same in two skulls, but towards the anterior or smaller end of 

 the oval one of these skulls may be much narrower than the other. 

 To correct these sources of fallacy the transverse diameter is often 

 taken in the frontal as well as the parietal regions, and the level of 

 the greatest transverse diameter is roughly indicated by stating 

 whether this occurs high up between the parietals, or nearer the 

 base between the temporals. It is interesting to see how Grattan 

 recorded these variations of the transverse diameter at different 

 points from before backwards and from below upwards. With his 

 craniometer lines are drawn on the skull from one external ear, 

 opening to the other, opposite selected angular intervals from the 

 nasion. The cranium is thus blocked out into a series of wedges, 

 each having a convex base on the vaulted part of the skull and a 

 sharp straight edge at the auditory axis at the base of the skull. 

 The arched lines over the surface of the skull from one ear opening 

 to the other he called coronal arcs, and he selected for special 

 examination the arcs at intervals of io°, 30°, 6o°, 90 , 120 and 

 150 from the ear-nasion arc. He divided each of these arcs into 

 three parts of equal vertical elevation, by two lines parallel to their 

 bases, and the extremities of these lines and the base line furnished 

 so many fixed points between which the transverse diameters could 

 be taken. 



I must admit that this part of Grattan's method looks somewhat 

 complicated, but it is not so laborious in actual practice as it might 

 at first sight appear. Grattan's own remarks on this point are 

 very characteristic. He writes as follows : — " It may possibly be 

 objected to this method that it involves too large an array of 

 arithmetical figures and demands too great an expenditure of 

 labour ; but what was ever yet accomplished, of any value, without 



