he basic principle i that of balanced weights.
I cubc foot of son water weilhl 04.0) lih.
I cubic froot of fresh water wvighs 62.5 IbNs.
thus salt water is 4. or 1025 tine as leavy as 12.5
fr h water and a column ofr it water foot in height will balance a column of fresh water (I.025) 1 feet
In height.
I
Sea Level
H L
(o'inec the salt antd fresh water columnts shown inl A by a connectinig tube and add a reservoir to the top of the salt water :olunl. The result is shown above.
hen as xplaitined in A.
I 1.025 I,
or h t I -1.025 L 1.025 hI
(1.(25 I) .o)25
When I 4 1. h 40.
Hence for every fotl of fresh water shove sa level there are 40 feet of freih water below sea level.
Figure 12. Thec hydrostatic relationship between salt and fresh water, known as the C;hyben-Herzbcrg Princlple (Black, A.P., Brown, Eugene, and Pearce, J.M.. 1953, "Salt water intrusion in Florida, 1953": Fla. State Board of Conservation water survey and research paper no. 9).