\begin{table} %t1
%\centering
\par
\caption{Average main sequence fiducial points, colour width and number
of field stars.}
\small%\centering
\par
\begin{tabular}{cccc}
\hline \hline
 $m_{\rm 814}$ & $m_{\rm 606}-m_{\rm 814}$ & $\sigma_{\rm 606-814}$ &
$N_{\rm F}$ \\ 
\hline
 18.75 &  0.592 &  0.035 & 12 \\
 19.25 &  0.608 &  0.035 & 20 \\
 19.75 &  0.642 &  0.035 & 28 \\
 20.25 &  0.692 &  0.037 & 24 \\
 20.75 &  0.765 &  0.041 & 22 \\
 21.25 &  0.850 &  0.043 & 27 \\
 21.75 &  0.952 &  0.050 & 29 \\
 22.25 &  1.057 &  0.050 & 27 \\
 22.75 &  1.152 &  0.050 & 23 \\
 23.25 &  1.223 &  0.050 & 29 \\
 23.75 &  1.274 &  0.061 & 36 \\
 24.25 &  1.332 &  0.079 & 25 \\
 24.75 &  1.385 &  0.097 & 15 \\ 
\hline
\end{tabular}
\label{tab1}
\end{table}