\begin{table}%t9
\caption{Coefficients  of the adopted regression lines.  In Cols.~2 and~3 
are given the coefficients~$a$ and~$b$ of the relation [X/Fe]~= $a$~[Fe/H]~+ $b$. In Col.~4 is given the scatter measured in the total interval, and in 
Cols.~5 and~6 the scatter in two different intervals of 
metallicity. Column~7 lists an estimate of the scatter expected from 
measurement errors only.  For some elements the total scatter is hardly larger 
than the expected error.}
\label{tab-dispel}
%\centering
\par
\begin{tabular}{crrcccc}
\hline
\hline
        &     &     &$-4.1<$ &$-4.1<$ &$-3.1<$&\\
        &     &     &[Fe/H]  &[Fe/H]  &[Fe/H] & \\
        &
\multicolumn{2}{c}{Regression line} &$<-2.0$ &$<-3.1$ &$<-2.1$&\\
  & \multicolumn{1}{c}{$a$} & \multicolumn{1}{c}{$b$} &$\sigma_{{\rm reg}}$ &$\sigma_{{\rm reg}}1$
  &$\sigma_{{\rm reg}}2$&$\sigma_{{\rm mes}}$\\
\hline
Na & 0.403 $ \pm $ 0.010 & 1.420 $ \pm $ 0.101 & 0.25 &0.32 
&0.18 &0.10\\
Mg & 0.035 $ \pm $ 0.003 & 0.380 $ \pm $ 0.029 & 0.13 &0.11 
&0.15 &0.09\\
 Al & 0.047 $ \pm $ 0.005 &$-$0.534 $ \pm $ 0.052 & 0.18 &0.14 
&0.21 &0.10\\
 Si & 0.032 $ \pm $ 0.004 & 0.541 $ \pm $ 0.036 & 0.15 &0.20 
&0.11 &0.10\\
  K & 0.176 $ \pm $ 0.002 & 1.020 $ \pm $ 0.023 & 0.11 &0.13 
&0.10 &0.10\\
 Ca & 0.074 $ \pm $ 0.002 & 0.565 $ \pm $ 0.015 & 0.10 &0.11 
&0.09 &0.07\\
 Sc & 0.034 $ \pm $ 0.002 & 0.178 $ \pm $ 0.019 & 0.11 &0.14 
&0.08 &0.07\\
 Ti &$-$0.014 $ \pm $ 0.001 & 0.185 $ \pm $ 0.013 & 0.09 &0.09 
&0.10 &0.05\\
 Cr & 0.117 $ \pm $ 0.000 & 0.004 $ \pm $ 0.004 & 0.05 &0.04 
&0.06 &0.07\\
 Mn & 0.030 $ \pm $ 0.003 &$-$0.346 $ \pm $ 0.020 & 0.12 &0.15 
& 0.08 &0.09\\
 Co &$-$0.131 $ \pm $ 0.002 &$-$0.121 $ \pm $ 0.024 & 0.13 &0.12 
&0.13 &0.08\\
 Ni &$-$0.003 $ \pm $ 0.002 &$-$0.048 $ \pm $ 0.020 & 0.11 &0.13 
&0.11 &0.09\\
 Zn &$-$0.271 $ \pm $ 0.002 &$-$0.559 $ \pm $ 0.018 & 0.11 &0.14 
&0.08 &0.10\\
\hline
\end{tabular}
\end{table}