11.(Pg. [56]) How may a pair of scales be false, and yet appear to be true?

12.(Pg. [56]) If the fulcrum be removed from the centre of gravity, how may the equilibrium be restored?

13.(Pg. [56]) How is this exemplified by [fig. 3. plate 4]?

14.(Pg. [56]) What proportion must the weights bear to the lengths of the arms?

15.(Pg. [57]) On what principle do we weigh with a pair of steelyards, and what will be the difference in the motion of the extremities of such a lever?

16.(Pg. [58]) How is this exemplified by [fig. 4. plate 4]?

17.(Pg. [58]) What line is described by the ends of a lever? [fig. 4. plate 4].

18.(Pg. [58]) How many kinds are there; and in the first how is the fulcrum situated?

19.(Pg. [58]) When may the fulcrum be so situated that this lever is not a mechanical power, and why?

20.(Pg. [59]) What is represented by [fig. 5. plate 4]?