\begin{table}%t3
%\centering
\par
\caption{Spatial distribution of \ebv\ colour excess as measured
in the South field. In Col.~3 we report the measured rms of the \ebv\
distribution, in Col.~4 the mean error on \ebv\ resulting from the
fitting procedure (see text), whereas Col.~5 lists the intrinsic reddening
dispersion, computed as the quadratic difference of the first two quantities.
The number of stars with direct extinction determination is shown in the
last column. \label{tab:south_ebv}}
\begin{tabular}[b]{*{6}{c}}\hline\hline
Chip & Mean & rms & Error & Dispersion & No. of stars\\\hline
{PC}  & 0.233 & 0.117 & 0.037 & 0.112 & 33\\
{WF2} & 0.210 & 0.093 & 0.027 & 0.089 & 401\\
{WF3} & 0.157 & 0.089 & 0.031 & 0.083 & 427\\
{WF4} & 0.168 & 0.077 & 0.028 & 0.072 & 344\\\hline
     All  & 0.180 & 0.091 & 0.029 & 0.086 & 1205\\
     \hline
\end{tabular}
\end{table}