67.(Pg. [104]) The greatest heat of summer is after the solstice, and the greatest heat of the day, after 12 o'clock, although the sun's rays are then most direct, how is this accounted for?
68.(Pg. [105]) Is there any change of seasons in the other planets?
69.(Pg. [105]) What is said respecting the axes of Jupiter, of Mars, and of Saturn?
70.(Pg. [105]) In 365 days, how many times does the earth revolve on its axis?
71.(Pg. [105]) How is this accounted for?
72.(Pg. [105]) Do the fixed stars require the same time as the sun, to return to the same meridian?
73.(Pg. [106]) How is this accounted for?
74.(Pg. [106]) What is meant by the solar and the sidereal day?
75.(Pg. [106]) What is the difference in time between them?
76.(Pg. [106]) What is the length of the tropical year?