The Reader Already Knows What The Solar System Is: An Immense
Central Body, The Sun, With A Number Of Planets Revolving Round It
At Various Distances. On One Of These Planets We Dwell. Vast,
Indeed, Are The Distances Of The Planets When Measured By Our
Terrestrial Standards. A Cannon-Ball Fired From The Earth To
Celebrate The Signing Of The Declaration Of Independence, And
Continuing Its Course Ever Since With A Velocity Of Eighteen
Hundred Feet Per Second, Would Not Yet Be Half-Way To The Orbit Of
Neptune, The Outer Planet.