388 THE BEAUTIES OF NATURE CHAP. 



Mercury, Venus, Mars, Jupiter, and Saturn 

 two large ones, Uranus and Neptune, and a 

 group of minor bodies, have since been added. 

 The following two diagrams give the rela- 

 tive orbits of the Planets. 



Mars 



/Venus v> Mercury 



--- 



687 days 

 Fig. 51. Orbits of the inner Planets. 



MERCURY 



It is possible, perhaps probable, that there 

 may be an inner Planet, but, so far as we 



