7.(Pg. [72]) What is the law respecting the time required for motion in the diagonal?

8.(Pg. [73]) What portion of a year is represented by the three diagonals in the figure?

9.(Pg. [73]) How will what you have learned respecting motion in a curve, apply to the earth's motion?

10.(Pg. [73]) In what form are you directed to cut a piece of card to aid in illustrating the two forces acting upon the earth?

11.(Pg. [73]) How must you apply it to this purpose? ([fig. 2. plate 6.])

12.(Pg. [73]) If these two forces did not exactly balance each other, what would result?

13.(Pg. [73]) Does the earth revolve in a circular orbit?

14.(Pg. [73]) What results from its motion in an ellipsis?

15.(Pg. [74]) What is represented by the lines A C, A B, in [fig. 3. plate 6]?

16.(Pg. [74]) Were the projectile force to carry the earth from B to D, ([fig. 3.]) what would result?