27.(Pg. [94]) How are degrees of latitude measured, and to what number do they extend?

28.(Pg. [94]) On what circles are degrees of longitude measured, and to what number do they extend?

29.(Pg. [94]) What is a parallel of latitude?

30.(Pg. [95]) Degrees of longitude vary in length; what is the cause of this?

31.(Pg. [95]) What is the length of a degree of latitude, and why do not these vary?

32.(Pg. [95]) What causes the equator to be somewhat larger than a great circle passing through the poles, and what effect has this on degrees of longitude measured on the equator?

33.(Pg. [95]) What is the cause of this form being given to the earth?

34.(Pg. [96]) What would have been a consequence of the centrifugal force, had the earth been a perfect sphere?

35.(Pg. [96]) A body situated at the poles, is attracted more forcibly than if placed at the equator, what is the reason?

36.(Pg. [97]) What effect would be produced upon the gravity of a body, were it placed beneath the surface of the earth, and what supposing it at its centre?