27.(Pg. [76]) Has it any influence on the sun's apparent size?
28.(Pg. [76]) Are the summer and winter, half years, of the same length; what is their difference, and what is the cause?
29.(Pg. [76]) What are the planets?
30.(Pg. [77]) What circumstances render it probable that they are habitable globes?
31.(Pg. [77]) What is believed respecting the fixed stars?
32.(Pg. [77]) What discoveries have been made in the moon?
33.(Pg. [77]) What prevents our seeing the planets, if there are any, which revolve round the fixed stars?
34.(Pg. [77]) What prevents our seeing the stars and planets in the day-time?
35.(Pg. [78]) What other motions have the earth and planets, besides that in their orbits?
36.(Pg. [78]) What is the imaginary line called, round which they revolve?