60 



the alternate posterior (here left) point of applica- 

 tion, theil the bearers of the front C in the new 

 curve — the head end of each S being the most 

 weighted and the sustaining force having ex- 

 hausted itself — would be the first to reach the 

 ground. 



§ 65. It may here be remarked that, to ensure 

 smooth action and to maintain the head in un- 

 swerving steadiness, it would seem requisite that 

 two or three vertebrae immediately behind the 

 head should be free from the ground, and thus act 

 as a neck, or adjusting connection between the head 

 and the median point between the two first ribs 

 which, as their articulations, alternately come to 

 the centre line, must otherwise give it a certain, 

 lateral motion. 



§ QQ. The Scutce, or ligamentous connections 

 between the ground ends of each pair of ribs 

 (before alluded to) being flexible, accommodate 

 themselves to the position of the bevels. They 

 act, we should suppose, as follows : When the 

 propellers come to the ground, on their outer 

 bevels, the posterior edges of their sides of the 

 scutse press against it, when they take appui on 

 their inner bevels this edge is pressed downward 



