12 



U. S. COAST AND GEODETIC SUEVEY 



with the 31.25. the 33.90, and the 40.22 samples were plotted on one 

 sheet, with scale readings as abscissas and temperatures as ordmates; 



PiQ_ 4. — Dipping refractometer 



the results with distilled water and the 5.34 sample were plotted on 

 another such sheet. By interpolation between the 31.25, 33.90, and 



