Vital Physics. 45 



earth to be moving in a tangent, always tending, to a greater 

 or lesser degree, in a direction external to the earth's orbit. 



It will be said : This law of tangental force, or no force, 

 is merely axoidal, and cannot interfere with the tangent of 

 orbital motion. So far from its not affecting the subject, 

 it is a subject upon which the entire doctrine of inertia rests, 

 since, as we recede from the centre of a planet to its circum- 

 ference, every particle of matter is increasing in its ratio of 

 acceleration of motion, and, if not restrained by the force of 

 attraction, would fly off at various degrees of acceleration 

 in the line of the tangent the planet happens to be moving 

 at the time, and in every direction, as dust from a carriage 

 wheel when running with great rapidity. 



Moreover the orbital motion and axoidal cannot both be 

 west to east, if there were no force, but that of the tangent 

 in the direction originally given, and from which it is by 

 attraction constantly deflected, as may be easily shown by 

 diagram No. I. 



Let S stand for sun and E for earth, Z Z' for the earth's 

 orbit, and X X' for the line of the tangent. Let A G and 

 A S, E G, E F, B S, B F represent the entire direction of 

 the attractive force between the earth and sun. Grant that 

 the line X X is the line of direction of the tangent from X 

 to A and then to B. 



If, then, in all motion of the earth, in its orbit round the 

 sun, or any other planet, the tangent takes the initiative, it is 

 slightly in advance of the attractive force, or that the sun 

 is attracting the earth towards its centre, but never directly 

 into its centre, because of the ever-shifting position of the 

 earth in its orbit, by reason of its tangental motion ; then the 

 centre of the earth, by such onward motion of the tangent, 

 will be slightly in advance of the centre of attraction of the 

 earth as given at the point E, whilst a straight line drawn 

 from S to P through E would exactly bisect the earth into 



