46 Vital Physics. 



two equal parts, P C K A and P C K B, each to each. 

 But the true axis of the earth by the motion of the tangent, 

 shifts from the line X A E to the line X A N, and a 

 straight line from the sun's centre through the earth from 

 S to O bisects the earth into two unequal parts, whereof the 

 section O D L B is less than the section O D L A, the 

 amount of difference being included between the lines 

 O D L and P C K. 



As the attractive force acts equally through all parts of 

 the earth from A to B when at rest, when in motion, the 

 direction of attraction being from A to B, there is an excess 

 of attraction from N to A plus that of N to E, by reason of 

 the acceleration of the tangental motion from X to X', 

 whereby in forces seeking their equilibrium the planet or 

 earth E would be drawn from O towards A in the direction 

 of A to K, and the axoidal motion would be in the reverse 

 order to that of the line of the earth's orbit ; for upon the 

 hypothesis of tangental force being the initiative of orbital 

 motion, and attraction the deflecting force which determines 

 orbital direction, it follows that the axoidal motion of the 

 earth would be in the reverse direction to that which is known 

 to exist, and that it would move from east to west, which is 

 not the case. 



That it is viewed as the antagonism of an active to a pas- 

 sive force which determines the earth's orbit, and that that 

 force is the tangental, a short quotation from Airy's " Ipswich 

 Lectures " will suffice, page 80. Airy says : " The theory 

 is this, that if we suppose the planets to be once set in 

 motion (by some cause which we do not pretend to know), 

 then the attraction of the sun accounts for the curved form 

 of their orbits and for all their motion^ in those orbits." It 

 is to be observed, that they are first started in the tangental 

 course for them, or, after the tangental has started, to repeat 

 then the attraction of the sun accounts for the curved form 



