( 9 



III. Corresponding Degrees in the 

 Fahrenheit and Centigrade 

 Scales. 



(3.) PoLAKiziNG Angles. 



Diamond 

 Phosphorus 

 , Bisulphide of carbon 

 Flint glass 

 Crown glass 

 Kock salt 

 Canada balsam 

 Linseed oil (sp .gr. -932) 

 Oil of turpentine (sp. gr. * 880) 

 Alcohol 

 Sea water 

 Pure water 

 Air 



03 

 73 



08 



a 



