The Sea-water and its Physical and Chemical Properties 



57 



wm'////myMMM'/M//m}/m'M- 



Fig. 31. Reflection and refraction of radiation at the interface between air and water. 



Table 21. Values of the refractive index for sea-water and for pure water 

 (After SoRET and Sarasin, 1889) 



besides this it is much stronger dependent on the temperature. More recent investiga- 

 tions on the dependence of the refractive index of sea-water on the temperature and 

 saHnity have been carried out by Bein (1935) at the Physikalisch Technische Reichs- 

 anstalt in Berlin. Table 22 shows the deviation of the refractive index of sea- water «s 

 from the refractive index for pure water, /z„. = 1-333338 (at 15°C, A = 587, 6 m/ii) at 

 different temperatures and sahnities. The dependence on the wavelengths of the light 

 used is not as large and only has to be taken into consideration for more accurate 

 treatment. 



Table 22. Variation of the refractive index {n^ — «„.) x 10® 



with temperature and salinity 



(According to Bein, 1935) 



