The sea is fed by the rivers which run into it. These rivers by gradually wearing away all kinds of soft rocks which contain salt and limestone, carry the salt to the sea. Owing to the action of the sun, the sea is continually evaporating. The sea becomes more and more salty by this process of gradual evaporation by the sun and the continual deposits of salt from rivers
Card no.22 in the ‘What do You Know?’ series of tea cards published by Lyons, 1957.
I remembered the image on the tea card when I got to the section on salinity in the University of Southampton’s FutureLearn course Exploring Our Oceans.
Link
University of Southampton’s FutureLearn course Exploring Our Oceans