Describe a simple experiment for the measurement of the surface tension of a liquid.

(N/A) fluid will stick to a solid surface if the surface energy between the fluid and the solid is smaller than the sum of the surface energies between the solid-air and fluid-air interfaces.
Measuring Surface Tension:
$1$. $A$ flat vertical glass plate,suspended from one arm of a balance,is positioned such that its lower horizontal edge just touches the surface of the liquid in a vessel.
$2$. The plate is initially balanced by weights on the other side of the balance.
$3$. The vessel is raised slightly until the liquid just touches the glass plate. The surface tension of the liquid exerts a downward force on the plate.
$4$. Additional weights are added to the other side of the balance until the plate just clears the liquid surface.
$5$. Suppose the additional weight required is $W = mg$,where $m$ is the additional mass and $g$ is the acceleration due to gravity.
$6$. The surface tension $S_{la}$ of the liquid-air interface is given by $S_{la} = \frac{W}{2l} = \frac{mg}{2l}$,where $l$ is the length of the plate edge. The factor of $2$ appears because the liquid acts on both sides of the plate.
$7$. By substituting the values of $m$,$g$,and $l$,the surface tension $S_{la}$ can be determined.