\begin{table}%t8
\caption{\label{tab8}Helium abundances.}
\par
\small%%\centerline

 {
\begin{tabular}{lccccccc} 
\hline\hline
 &  \multicolumn{6}{c}{0335--052E}  & \\ 
 \cline{2-7}\\[-8pt]  
Property                           &Nos. $1+2^a$&Nos. $1+2^b$&Nos. $1+2^c$& Nos. $4+5^c$&No.7$^a$&No.7$^b$& 0335--052W$^b$\\
\hline
\multicolumn{7}{c}{a) Benjamin et~al. (2002) emissivities}  \\ 
$\Delta$$I$(H$\alpha$)/$I$(H$\alpha$)& 0.0004          & 0.0013          & 0.0177          & 0.0007          & 0.0500          & 0.0491          & 0.0490           \\
$T_{\rm e}$(He$^+$)                        & 19520           & 20250           & 20410           & 20330           & 19110           & 18970           & 17030            \\
$N_{\rm e}$(He$^+$)                        &   162           &   132           &    53           &    12           &    12           &    10           &    14            \\
$\tau$($\lambda$3889)                &   4.59          &   5.01          &   5.01          &   1.24          &   0.01          &   0.02          &   0.02           \\
$y^+$($\lambda$4471)                 &0.0834 $\pm$ 0.0021&0.0820 $\pm$ 0.0013&0.0827 $\pm$ 0.0013&0.0834 $\pm$ 0.0028&0.0858 $\pm$ 0.0118&0.0812 $\pm$ 0.0030&0.0935 $\pm$ 0.0086 \\
$y^+$($\lambda$5876)                 &0.0852 $\pm$ 0.0014&0.0839 $\pm$ 0.0013&0.0777 $\pm$ 0.0012&0.0798 $\pm$ 0.0015&0.0816 $\pm$ 0.0035&0.0802 $\pm$ 0.0020&0.0780 $\pm$ 0.0065 \\
$y^+$($\lambda$6678)                 &0.0768 $\pm$ 0.0017&0.0798 $\pm$ 0.0014&0.0818 $\pm$ 0.0017&0.0792 $\pm$ 0.0016&0.0876 $\pm$ 0.0092&0.0812 $\pm$ 0.0049&0.0791 $\pm$ 0.0137 \\
$y^+_{wm}$                          &0.0822 $\pm$ 0.0010&0.0821 $\pm$ 0.0008&0.0805 $\pm$ 0.0008&0.0801 $\pm$ 0.0010&0.0826 $\pm$ 0.0031&0.0806 $\pm$ 0.0016&0.0831 $\pm$ 0.0048 \\
$y^{2+}$($\lambda$4686)              &0.0011 $\pm$ 0.0001&0.0012 $\pm$ 0.0000&0.0026 $\pm$ 0.0000&0.0041 $\pm$ 0.0002&        ...      &0.0012 $\pm$ 0.0001&        ...       \\
$ICF$                                &0.9936           &0.9935           &0.9933           &0.9928           &0.9928           &0.9929           &0.9896            \\
$y$($\lambda$4471)                   &0.0839 $\pm$ 0.0021&0.0827 $\pm$ 0.0013&0.0848 $\pm$ 0.0013&0.0868 $\pm$ 0.0028&0.0852 $\pm$ 0.0117&0.0818 $\pm$ 0.0030&0.0926 $\pm$ 0.0085 \\
$y$($\lambda$5876)                   &0.0857 $\pm$ 0.0014&0.0846 $\pm$ 0.0013&0.0798 $\pm$ 0.0012&0.0833 $\pm$ 0.0015&0.0811 $\pm$ 0.0035&0.0809 $\pm$ 0.0020&0.0772 $\pm$ 0.0064 \\
$y$($\lambda$6678)                   &0.0774 $\pm$ 0.0017&0.0805 $\pm$ 0.0014&0.0838 $\pm$ 0.0017&0.0827 $\pm$ 0.0016&0.0870 $\pm$ 0.0092&0.0819 $\pm$ 0.0049&0.0783 $\pm$ 0.0135 \\
$y_{wm}$                            &0.0828 $\pm$ 0.0010&0.0828 $\pm$ 0.0008&0.0825 $\pm$ 0.0008&0.0835 $\pm$ 0.0010&0.0820 $\pm$ 0.0031&0.0812 $\pm$ 0.0016&0.0822 $\pm$ 0.0048 \\
$Y$                            &0.2486 $\pm$ 0.0030&0.2486 $\pm$ 0.0024&0.2481 $\pm$ 0.0024&0.2503 $\pm$ 0.0032&0.2470 $\pm$ 0.0097&0.2452 $\pm$ 0.0049&0.2474 $\pm$ 0.0148 \\ 
\hline
\multicolumn{7}{c}{b) Porter et~al. (2005) emissivities}    \\ 
$\Delta$$I$(H$\alpha$)/$I$(H$\alpha$)& 0.0010          & 0.0027          & 0.0322          & 0.0002          & 0.0488          & 0.0493          & 0.0497           \\
$T_{\rm e}$(He$^+$)                        & 19520           & 20260           & 20360           & 20330           & 19060           & 18850           & 16910            \\
$N_{\rm e}$(He$^+$)                        &   197           &   162           &    86           &    10           &    11           &    11           &    11            \\
$\tau$($\lambda$3889)                &   4.52          &   5.00          &   5.01          &   1.44          &   0.02          &   0.02          &   0.04           \\
$y^+$($\lambda$4471)                 &0.0853 $\pm$ 0.0021&0.0841 $\pm$ 0.0013&0.0849 $\pm$ 0.0013&0.0862 $\pm$ 0.0028&0.0884 $\pm$ 0.0118&0.0835 $\pm$ 0.0030&0.0958 $\pm$ 0.0086 \\
$y^+$($\lambda$5876)                 &0.0860 $\pm$ 0.0014&0.0848 $\pm$ 0.0013&0.0792 $\pm$ 0.0012&0.0816 $\pm$ 0.0015&0.0835 $\pm$ 0.0035&0.0820 $\pm$ 0.0020&0.0800 $\pm$ 0.0065 \\
$y^+$($\lambda$6678)                 &0.0771 $\pm$ 0.0017&0.0800 $\pm$ 0.0014&0.0831 $\pm$ 0.0017&0.0796 $\pm$ 0.0016&0.0882 $\pm$ 0.0092&0.0818 $\pm$ 0.0049&0.0803 $\pm$ 0.0137 \\
$y^+_{wm}$                          &0.0831 $\pm$ 0.0010&0.0831 $\pm$ 0.0008&0.0821 $\pm$ 0.0008&0.0814 $\pm$ 0.0010&0.0844 $\pm$ 0.0031&0.0824 $\pm$ 0.0016&0.0851 $\pm$ 0.0048 \\
$y^{2+}$($\lambda$4686)              &0.0011 $\pm$ 0.0001&0.0012 $\pm$ 0.0000&0.0026 $\pm$ 0.0000&0.0041 $\pm$ 0.0002&       ...       &0.0012 $\pm$ 0.0001&       ...        \\
$ICF$                                &0.9936           &0.9935           &0.9933           &0.9928           &0.9928           &0.9929           &0.9896            \\
$y$($\lambda$4471)                   &0.0858 $\pm$ 0.0021&0.0848 $\pm$ 0.0013&0.0869 $\pm$ 0.0013&0.0897 $\pm$ 0.0028&0.0877 $\pm$ 0.0117&0.0842 $\pm$ 0.0030&0.0948 $\pm$ 0.0085 \\
$y$($\lambda$5876)                   &0.0865 $\pm$ 0.0013&0.0854 $\pm$ 0.0012&0.0812 $\pm$ 0.0012&0.0851 $\pm$ 0.0015&0.0829 $\pm$ 0.0035&0.0827 $\pm$ 0.0020&0.0792 $\pm$ 0.0064 \\
$y$($\lambda$6678)                   &0.0776 $\pm$ 0.0017&0.0807 $\pm$ 0.0014&0.0851 $\pm$ 0.0017&0.0831 $\pm$ 0.0016&0.0876 $\pm$ 0.0091&0.0825 $\pm$ 0.0049&0.0794 $\pm$ 0.0135 \\
$y_{wm}$                            &0.0836 $\pm$ 0.0009&0.0838 $\pm$ 0.0008&0.0842 $\pm$ 0.0008&0.0849 $\pm$ 0.0010&0.0838 $\pm$ 0.0031&0.0831 $\pm$ 0.0016&0.0842 $\pm$ 0.0048 \\
$Y$                            &0.2506 $\pm$ 0.0029&0.2510 $\pm$ 0.0023&0.2518 $\pm$ 0.0024&0.2533 $\pm$ 0.0031&0.2509 $\pm$ 0.0096&0.2493 $\pm$ 0.0048&0.2518 $\pm$ 0.0148 \\ \hline
\end{tabular}}
\medskip
$^a$~Low-resolution FORS observations;
$^b$~high-resolution FORS observations;
$^c$~UVES observations. 
\end{table}