The Principles of the Visible World
This part talks about the principles of macro-phenomena such as heavenly bodies
Drifting Stars and The Solidity and Agitation of Bodies
Articles 121-125
How Comets are Born
Articles 126-127
The Phenomena of Comets
Articles 128-130
Comet Visibility
Articles 131-133
The Comet's Tail and Its Various Phenomena
Articles 133-139
Why The Tails Of Comets Are Not Straight
Articles 137-139
Planetary Motion
Articles 140-145
How Are Planets Formed?
Articles 146-148
The Motion of the Moon
Articles 149-153
The Poles of the Equator
Articles 154-157