The second question is: What does "speculations" mean in this sentence?
"He would delight them equally by his anecdotes of witchcraft, and of the direful omens and portentous sights and sounds in the air, which prevailed in the earlier times of Connecticut; and would frighten them woefully with speculations upon comets and shooting stars; and with the alarming fact that the world did absolutely turn round, and that they were half the time topsy–turvy!"