48 



terior line point of pressure back to the centre from 

 its inclination to the left mentioned under (a). 



(b) The continuation of the active working of 

 the right rear point of appHcation next, causes its 

 secondary section, which is the nascent reverse 

 cui've to begin in the anterior C, spreading from 

 the upper end of the cross-line, as its formation 

 forces this end backward from the forward position 

 into which it has been drawn by the formation of 

 the primary section of the anterior line. This 

 nascent curve gives the second turn to the ribs 

 along the convex of this C, as the partial develop- 

 ment of h', which is the nascent reverse ciu've for 

 the posterior C, did to the ribs on its convex. 



Finally the commencement of the alternate (here 

 the right anterior luinding line by the raovement of 

 the right anterior point of ai^plication, beginning with 

 the development of its secondary section (a) tvill first 

 discharge the rear C, and so on ; the old right rear 

 winding line becoming the new anterior winding 

 line, by cutting through the articulations. But a 

 closer examination of the action of the ribs, <fec., 

 will show more clearly how each point discharges 

 its spring. 



It is evident that, if the head were gi'aduaUy 

 shifted to the right so as to bring the posterior 



