CONTENTS 



Page 



Preface ii 



Introduction 1 



Hydrometer method 2 



Chemical titration method 5 



Dipping refractometer method 11 



Other methods for use on board ship 15 



Electrical conductivity method 15 



Method of balancing columns of liquids 16 



Methods for laboratory use 17 



Pycnometer method 19 



Sinker method 19 



Salinity by evaporation to dryness 20 



ILLUSTRATIONS 



1. Hydrometer set 2 



2. Chart for conversion from specific gravity and temperature to salinity- 4 



3. Chemical titration outfit 6 



4. Dipping refractometer 12 



5. Preliminary refractometer calibration curves for sea water 13 



6. Preliminary refractometer calibration curves for boiler vpater 13 



7. Electrolytic cell used for preliminary measurements of resistance of 



sea-water samples of various salinities 17 



8. Apparatus for measuring salinity by the method of balancing columns 



of liquids 18 



TABLES 



1. Table for conversion from specific gravity and temperature to salinity- 3 



2. Independent determinations by several observers of the salinity of a 



given sample of sea water, by the hydrometer method 4 



3. Independent determinations by several inexperienced observers of the 



salinity of a given sample of sea water, by the chemical titration 



method 10 



4. Independent determinations by several inexperienced observers of the 



salinity of a given sample of sea water, by the dipping refractometer 



method 14 



5. Variation with salinity of the electrical resistance of a column of sea 



water : 16 



ni 



