37.(Pg. [176]) Why does an object appear to be lessened by a convex mirror, ([fig. 2.])?

38.(Pg. [176]) What is a concave mirror, and what its peculiar property?

39.(Pg. [176]) How are parallel rays reflected by a concave mirror, as explained by [fig. 3, plate 18]?

40.(Pg. [177]) Where is the focus of parallel rays, in a concave mirror?

41.(Pg. [177]) If rays fall on it convergent, how are they reflected?

42.(Pg. [177]) How if divergent?

43.(Pg. [177]) How, and why, may concave, become burning mirrors?

44.(Pg. [178]) Why may rays of light coming from the sun, be viewed as parallel to each other?

45.(Pg. [178]) If a luminous body, as a burning taper, be placed in the focus of a concave mirror, how will the rays from it, be reflected? ([fig. 6.])

46.(Pg. [178]) What fact is explained by [fig. 7, plate 18]?