12 ANIMAL MECHANICS 



surface, you see nothing of this kind ; the bones 

 are here laid simply in contact, and this line by 

 anatomists is called harmonia, or harmony : archi- 

 tects use the same term to imply the joining by 

 masonry. Whilst the anatomists are thus curi- 

 ous in names, it is provoking to find them negli- 

 gent of things more interesting. Having over- 

 looked the reason of the difference in the tables 

 of bone, they are consequently blind to the pur- 

 pose of this difference of the outward and inward 

 part of a suture. 



Suppose a carpenter employed upon his own 

 material, he would join a box with minute and 

 regular indentations by dovetailing, because he 

 knows that the material on which he works, from 

 its softness and toughness, admits of such adjust- 

 ment of its edges. The processes of the bone 

 shoot into the opposite cavity with an exact re- 

 semblance to the foxtail wedge of the carpenter 

 a kind of tenon and mortise when the pieces 

 are small. 



But if a workman in glass or marble were to 

 inclose some precious thing, he would smooth the 

 surfaces and unite them by cement, because, even 

 if he could succeed in indenting the line of union, 

 he knows that his material would chip off on the 

 slightest vibration. The edges of the marble 

 cylinders which form a column are, for the same 

 reason, not permitted to come in contact; thin 



