\begin{table}%t15
\par
\caption{Comparison of abundances in several elliptical PNe.\label{tab15}}
%\centerline
 {\begin{tabular}{lrrrrrrr}
  \hline
\hline\\[-3mm]
Elem.  & 3242$^{\dagger}$ & 6369$^{\dagger}$ & 2392$^{\dagger}$ & 6826$^{\dagger}$ & 7662$^{\dagger}$ & 418$^{\dagger}$ & 2022$^{\dagger}$  \\ 
\hline  
He(--1)  & 0.92 & 1.02  & 0.80 & 0.95 & 0.88 &      & 1.06  \\
C(--4)  & 1.95  &        & 3.3   & 5.3   &  3.6  & 6.2  &  3.7   \\
N(--4)  & 1.35  & 0.79   & 1.85  & 0.50 &  0.67  & 0.95 &  0.99  \\
O(--4)  & 3.8   & 4.0    & 2.9   &  4.0  &  4.2  & 3.5  &  4.7  \\
Ne(--5) & 9.0   & 9.7    & 8.5   & 15    & 6.4   & 8.8  &  13.4   \\
S(--6)  & 2.8   & 6.0    & 5.0   & 2.8   & 6.6   & 4.4  &  6.3   \\   
Ar(--6) & 1.7   & 1.6    & 2.2   & 1.4   & 2.1   & 1.8  &  2.7   \\
Cl(--7) & 0.70 & 1.2     & 1.3   & 0.9   &       & 1.2  &  1.3   \\
P(--8)  & 4.5   & 7.0    & 6.5   & 17    &       &      &      \\
Fe(--7) &       &        & 8.0   & 6.1   &       &      &       \\
\hline  
\end{tabular}}
\par
\smallskip
$^{\dagger}$ References: NGC~3242 and 6369: this paper, NGC~2392: Pottasch 
et~al. (\cite{pott8}), NGC~6826: Surendiranath et~al. (\cite{nath}), NGC~7662:
Pottasch et~al. (\cite{pott4}), IC~418: Pottasch et~al. (\cite{pott6}), 
NGC~2022: Pottasch et~al. (\cite{pott7}).
\par
\end{table}