NATURAL THEOLOGY. 101 



[Here the tooth-like process of the second vertebra, which is 

 called dentata, is passed through the ring of the first, and is held 

 there by a transverse ligament, like a spindle in the bush. No 

 doubt the object of this complexity is to permit the free motion of 

 the head, without too great a laxity at any one joining, and there- 

 by to protect the most vital organ of the body, the medulla oblonga~ 

 ta, or spinal marrow, which passes from the head into the tube of 

 the spine.] 



We see the same contrivance and the same 

 principle employed in the frame or mounting of 

 a telescope. It is occasionally requisite that the 

 object-end of the instrument be moved up and 

 dovsrn, as well as horizontally, or equatorially. For 

 the vertical motion, there is a hinge, upon which 

 the telescope plays ; for the horizontal or equato* 

 rial motion, an axis upon which the telescope and 

 the hinge turn round together. And this is exact- 

 ly the mechanism which is applied to the motion 

 of the head ; nor will any one here doubt of the 



and mortise are terms used for the tirm joining of beams, as in the 

 carpentry of a roof; not for rotatory motion. 



9* 



