38.(Pg. [115]) In what two parts of the world is it high water at the same time?

39.(Pg. [115]) What circumstances respecting the decrease of attraction are taken into account, in explaining the tides?

40.(Pg. [115]) How are the high tides at A and D, and the low ones at B and C, in [fig. 3. pl. 12], accounted for?

41.(Pg. [116]) Has the sun any influence on the tides, and why is it less than that of the moon?

42.(Pg. [116]) What is meant by spring tides, and how are they produced?

43.(Pg. [116]) What by neap tides, and how are they caused?

44.(Pg. [116]) What circumstances affect the time of the tide in rivers, bays, &c.?

45.(Pg. [117]) Why in the open ocean, is it high water, some hours after the moon has passed the meridian?

46.(Pg. [117]) Why are the tides three-quarters of an hour later every day?