Fig. 1. Interference patterns formed by the analyzer when traversed by polarized light. A. Kigua- 

 produced by circularly polarized light having a counterclockwise rotation; if its rotation \scre ckvk- 

 wise, the pattern would have a dark centre instead of a light one. B. Figure obserNed with imcariv 

 polarized light produced by a type Fi Polaroid filter. The interruptions in the isochromatic rings are 

 parallel to the electric and magnetic vectors of the incident light. The plane of the c vector is hori- 

 zontal, as labelled, and coincides with the clockwise edge of the dark central sectors. 



