THE PRIME RESULTANT 107 



tion, they are as a matter of fact continually shifting in 

 position. This they do, not arbitrarily or capriciously, 

 but rhythmically, and in strict amenity to gravitational 

 law. All the stars are continuously tending together, and 

 as they progress in their various courses it is inevitable 

 that their composite attraction, varying as this does, not 

 simply inversely as the distances, but as the squares of 

 these distances, must likewise continuously undergo var- 

 iation both as to locus and intensity. In short, our earth 

 will never reach the end of her journey; wherever she 

 may arrive, she will always be solicited toward some more 

 distant point. Were she indeed this instant by fiat trans- 

 ported to her present Vertex, or gravitational goal, she 

 could not there rest stationary, but would be obliged to 

 resume her cosmic wanderings ad infinitum. In this pro- 

 cess of translation we may discern some analogy to the 

 circulation of the blood in the living animal ; the systole 

 and diastole of the heart, even, finding their counterparts 

 in the gravitational contraction of the star and its reac- 

 tion by explosion. 



It is a habit with astronomers, repeating in their way 

 the awkward method of geographers, to imagine them- 

 selves surveying the ecliptic from the north. According 

 to their way of looking, the motions of the earth on its 

 axis, of the planets around the sun, and of the moon 

 around the earth, are all contra-clockwise (like a clock 

 dial reflected from a mirror), whereas viewed from the 

 south, as I advise, these motions all turn clockwise. It 

 is well to get clearly in mind right at the very outset the 

 fact that all of these motions run in the same direction. 

 This is the rule throughout the system (with a very few 

 minor exceptions among the satellites, which will be sub- 

 sequently considered). 



My object in viewing the ecliptic from the south in- 

 stead of from the north is, however, of much greater 

 significance than merely to aid the memory by substitut- 

 ing a right-handed motion in place of a left-handed one. 

 In fact, it is for the same reason that I recommend the 

 printing of terrestrial maps inverted, namely, to instill 



