Fig. 1. A system containing a pure homogeneous vapour and liquid in equilibrium. In a “thought experiment” a non-wetting tube is inserted into the liquid, causing the liquid in the tube to move downwards. The vapour pressure above the curved interface is then higher than that for the planar interface. This picture provides a simple conceptual basis for the Kelvin equation.
<a href="//commons.wikimedia.org/wiki/User:%D0%94.%D0%98%D0%BB%D1%8C%D0%B8%D0%BD" title="User:Д.Ильин">Д.Ильин</a>: vectorization
<a href="//commons.wikimedia.org/wiki/File:Balance_of_Hydrostatic_Forces_in_a_Closed_System.jpg" title="File:Balance of Hydrostatic Forces in a Closed System.jpg">File:Balance of Hydrostatic Forces in a Closed System.jpg</a> from <a rel="nofollow" class="external autonumber" href="http://www.sciencedirect.com/science/article/pii/S000925090500268X">[1]</a> by K. P. Galvin