27.(Pg. [202]) How does the solar microscope, ([fig. 1 plate 23.]) operate?

28.(Pg. [202]) Why may minute objects be greatly magnified by this instrument?

29.(Pg. [202]) In its more perfect form it has other appendages, as seen in [fig. 2], what are they? and what their uses?

30.(Pg. [203]) What is added when opaque objects are to be viewed? [fig. 3.]

31.(Pg. [203]) In what does the magic lanthorn differ from the solar microscope?

32.(Pg. [203]) What are the use and structure of the telescope, as shown in [fig. 4]?

33.(Pg. [204]) When terrestrial objects are to be viewed, why are two additional lenses employed?

34.(Pg. [204]) What part of the telescope performs the part of a microscope?

35.(Pg. [204]) In what does the reflecting, differ from the refracting telescope?

36.(Pg. [204]) What advantages, do reflecting, possess over refracting telescopes?