Subject: How would salinity in water be tested in the early 1960?

researching for a novel and need to know what methods of testing salinity in bay 
water would have been available in the late 1950s,early 1960s.  Do not know if 
hand held refractometers would be used, or hydrometers, or would samples have 
been taken for analyzer in a lab or a combination of the above.  What other 
factors might be important - temperature?  water depth of sample?  Please help 
if possible or direct me to the correct location.  Can find current material, 
but not anything relating to the past, and the field of Marine Biology / 
Oceanography was relatively new at that time.  Thanks!

Re: How would salinity in water be tested in the early 1960?