The force of surface tension of water (due to top meniscus) can lift a water column of length $\mathrm{h}<\mathrm{l}$. So with the help of two surfaces (top and bottom meniscus), we will be able to hold a length $2\mathrm{h}$

          
     $\Delta \text{P}=2\times \frac{2\text{T}}{\text{r}}=\frac{4\text{T}}{\text{r}}$

     $\frac{2\text{T}}{\text{r}}=\rho \text{gh}$

and $\Delta \text{P}=\rho {\text{gh}}^{\prime }$

$\therefore {\text{h}}^{\prime }=2\text{h}$