1886.] 



Light by Reflection from Iceland Spar. 



183 



Table VI. 



Iceland Spar in Water. 



Azimuth 

 of the 

 principal sec- 

 tion of the 

 crystal. 



Azimuth 



of the 

 plane of 

 polarisation. 



Angle of 

 polarisation. 



Azimuth 

 of the 

 principal sec- 

 tion of the 

 crystal. 



Azimuth 

 of the 

 plane of 

 polarisation. 



Angle of 

 polarisation. 



Difference 

 in the values 



of the 

 polarising 

 angle at 9 

 and. 

 0+180°. 

 







+ 



o 



- 



08 



o 



48 



z 



43 



o 



180 



+ 



o 

 



35 



o 



48 



25 



/ 



+ 18 



5 



+ 



17 



48 



38 



185 



+ 



l 



32 



48 



17 



+ 21 



10 



+ 



32 



49 



04 



190 



+ 



3 







48 



39 



+ 25 



15 



+ 1 



45 



48 



56 



195 



+ 



5 



35 



48 



43 



+ 13 



20 



+ 



50 



49 



09 



200 





5 



47 



49 



27 



-18 



25 



+ 1 



15 



49 



32 



205 



+ 



7 



47 



49 



15 



+ 17 



SO 



+ 



47 



50 



14 



210 



+ 



9 



07 



49 



47 



+ 27 



35 



+ 



55 



49 



53 



215 



+ 



9 



27 



50 



10 



-17 



40 



+ 



12 



51 



14 



220 



+ 



9 



40 



50 



46 



+ 28 



45 



- 



13 



51 



14 



225 



+ 11 



50 



50 



57 



+ 17 



50 



- 



20 



51 



33 



230 



+ 12 



50 



52 



09 



-36 



55 



- 1 



15 



51 



52 



235 



+ 12 



12 



52 



19 



-27 



60 



- 2 



15 



52 



38 



240 



+ 13 







53 



05 



-27 



65 



- 3 



25 



53 



43 



245 



+ 14 



27 



53 



23 



+ 20 



70 



- 4 



38 



53 



50 



250 



+ 13 



15 



54 



08 



-18 



75 



— 5 



45 



54 



32 



255 



+ 12 



30 



54 



28 



+ 4 



80 



- 7 



50 



54 



45 



260 



+ 12 



07 



55 



08 



-23 



85 



- 7 



13 



54 



18 



265 



+ 10 



57 



54 



55 



-37 



90 



-10 



23 



55 



19 



270 



+ 10 



32 



55 



20 



- 1 



95 



- 9 



55 



54 



25 



275 



+ 



9 



30 



55 



34 



-69 



100 



-10 



58 



54 



22 



280 



+ 



9 



40 



55 



40 



-78 



105 



-11 



15 



53 



35 



285 



+ 



7 



22 



54 



45 



-70 



no 



-11 



45 



54 



15 





+ 



6 



15 



54 



07 



+ o 



115 



-10 



58 



53 



35 



295 



+ 



5 



15 



54 



12 



-37 



120 



-11 



43 



53 



05 



300 



+ 



3 



40 



52 



39 



+ 26 



125 



-10 



43 



52 



15 



305 



+ 



2 



27 



52 



45 



-30 



130 



-10 



58 



51 



23 



310 



+ 



1 



22 



52 



05 



-42 



135 



-10 



55 



51 



25 



315 



+ 



1 



37 



52 



16 



-51 



140 



-10 



08 



51 



07 



320 









30 



51 



25 



-18 



145 



- 9 







49 



54 



325 









33 



50 



29 



-35 



150 



- 8 



48 



50 



01 



330 









13 



50 



07 



- 6 



155 



- 6 



15 



49 



36 



335 



+ 







07 



49 



55 



-19 



160 



- 5 



13 



49 



13 



340 









05 



49 



26 



-13 



165 



- 3 



48 



49 



02 



345 



+ 







10 



49 







+ 2 



170 



- 2 



13 



48 



38 



350 



+ 







15 



48 



59 



-21 



175 



- 1 







48 



43 



355 









05 



48 



30 



+ 13 



o 2 



