ABSTRACT
In geodetic levellings, however, this error must be taken Into consideration owing to the great distance that may separate the containers.
A partlcular but rather common case to consider is that of error due to pressure or loss of pressure caused in the free surface of the liquid of the containers by dynamic wind action. Thus, if one of the containers is located at a place with openings, or kept near any surface exposed to wind, pressures or pressure losses influencing the equilibrium of the two communicating vessels may occur.
