very truly wrought and quick-silver'd over on the backside; and set in the Tube VXYZ which must be very black within. Let EFG represent a Prism of Glass or Crystal placed near the other end of the Tube, in the middle of it, by means of a handle of Brass or Iron FGK, to the end of which made flat it is cemented. Let this Prism be rectangular at E, and let the other two Angles at F and G be accurately equal to each other, and by consequence equal to half right ones, and let the plane sides FE and GE...

2F8A          ; mapped                 ; 8272          # 3.0  KANGXI RADICAL COLOR
2F8B          ; mapped                 ; 8278          # 3.0  KANGXI RADICAL GRASS
2F8C          ; mapped                 ; 864D          # 3.0  KANGXI RADICAL TIGER
2F8D          ; mapped                 ; 866B          # 3.0  KANGXI RADICAL INSECT