318 KANSAS CITY REVIEW OF SCIENCE. 



then he knows something that proves that the Sun does not move as here as- 

 sumed. 



To diagram the whole solar system moving in any of these directions, and 

 at any of these rates, we have but to give the several planets their respective dis- 

 tances, giving to each such position on this plane, as its time, its distance, and 

 the inclination of its orbit demands. Then find how far the Sun will move at 

 the assumed rate during the revolution of the planet, divide this into four sec- 

 tions, and proceed as in the case of the Earth. 



Before passing, a word in explanation of the figures on Plate VI. They are 

 horizontal views of the movement as represented on Plate V. In the figures on 

 Plate VI, E must be regarded as above the plane, and P below it. Imagine you 

 take the figures on Plate V and roll them over toward the south till P is down, 

 and E up, or till X and D are in this plane at X^ and D\ and then you have the 

 figures on Plate VI. These figures are interesting in that they show how differ- 

 ent may be the movement in making a revolution. Each planet has a figure of 

 its own, some more hke one of these, others more like another. 



Plates VII and VIII are introduced for the purpose of illustrating principles. 



Plate VII is on the plane of the solstitial colure. Plate VIII is on the plane 

 of the equinoctial colure. Comparing the figures on one plate with those on the 

 other, we see the effect of a motion toward different longitude. Comparing the 

 figures on the same plate with each other we see the effect of a change of latitude. 

 The effect as regards the form of coil. The effect as regards the planets velocity. 

 Its velocity as related to the movement of the Sun. Its velocity at one time, as 

 compared with another. Its real velocity as compared with its apparent velocity. 

 We see under these different conditions, the different methods of producing ap- 

 parent velocity, and apparent movement. This thing followed up will show that 

 every new hypothesis as to direction, will require a new form of diagram, involv- 

 ing changes affecting all these relations. For example, in the diagram on Plate 

 VII in the direction of 66}^° north, the successive revolutions of the earth give 

 us a spiral coil. This is the only direction that will allow of such a coil. Or 

 rather the only line in the heavens, for we may have the same movement on the 

 line, in either direction. It is the only line of movement which will allow the 

 ecliptic to be made up of lines from a succession of parallel planes. It is the only 

 line in the heavens where the earth can possibly, in harmony with known phe- 

 nomena, keep pace with the Sun, as it advances through space. It is the only 

 line in the heavens that allows of a regular correspondence between the real, and 

 the apparent velocity of the earth, in the several parts of its orbit. 



If we believe that constantly acting forces govern every planetary movement, 

 and look after the cause of the onward movement of the planet in the light of our 

 diagrams, we will soon have a decided partiality for some line of movement near 

 the plane of the ecliptic. So here we can study centrifugal force, from a new base 

 of observation. 



Here we may get a well-defined conception of the ecliptic, as a plane of rela- 



