THE MINOR PLANETS. 



Classification of the Planets. Mercury. Transit over the Sun. Relative Position with /egard to 

 the Sun. Difficulty of observing it. Venus. Diurnal Motion of Venus and Mercury indicated 

 by the Shadows of Mountains. Direction of the Axis of Rotation. Seasons, Climates, and 

 Zones. Orbits and Transits of Mercury and Venus. Mountains on Mercury and Venus. Influ- 

 ence of the Sun at Mercury and Venus. Twilight on Mercury and Venus. Mars. Atmosphere 

 of Mars. Physical Constitution of Mars. Has Mars a Satellite ? Appearance of the Sun at 

 Mars. Its Close Analogy to the Earth. 



.J 





