\begin{table}%t1
  \caption {IRS spectrum of \object{NGC~3242}. The measured line intensity is
    given in Col.~3. The last column gives the ratio of the line
    intensity to H$\beta$(=100).\label{tab1}}
%\centerline
 {\begin{tabular}{lrcc}
\hline
\hline\\[-3mm]
Identification &  $\lambda$($\mu$m) & Intensity$^{\dagger}$ & $I$/H$\beta$ \\
\hline
\ion{[Ar}{iii]} & 8.992 & 904~$\pm$~30 & 8.48 \\
\ion{[S}{iv]} & 10.511 & 8220~$\pm$~160  & 70.3\\
\ion{H}{i}(9--7) & 11.306 & 38.4~$\pm$~2.3 & 0.22 \\
\ion{[Cl}{iv]} & 11.760 & 70.8~$\pm$~3.5 & 0.616 \\
\ion{H}{i} (7--6~+~11--8) & 12.370 & 112.1~$\pm$~4.6 &    \\
\ion{[Ne}{ii]} & 12.810 & 150~$\pm$~3.9  & 1.31 \\
\ion{[Ar}{v]} & 13.099 & 81.5~$\pm$~4.7 &  0.710   \\
\ion{[Ne}{v]} & 14.319 & 35.6~$\pm$~1.6 & 0.31 \\
\ion{[Ne}{iii]} & 15.553 & 13~320~$\pm$~216 & 116.0 \\
\ion{H}{i} (10--8) & 16.203 & 14.2~$\pm$~3.4 & 0.15 \\
H$_{2}$    &  16.881 & 17.3~$\pm$~9.7 &     \\
H$_{2}$    &  16.976 & 5.2~$\pm$~3.3 &       \\
\ion{[P}{iii]}  & 17.890 & 37.0~$\pm$~2.0 & 0.322 \\
\ion{[S}{iii]} & 18.711 & 957~$\pm$~22  & 8.33 \\
\ion{H}{i} (8--7) & 19.065 & 43.0~$\pm$~5.0 & 0.401 \\
\ion{[Cl}{iv]} & 20.312 & 57.0~$\pm$~2.66  & 0.497 \\
\ion{[Ar}{iii]} & 21.818 & 39.6~$\pm$~6.4 & 0.345 \\
\ion{[O}{iv]} & 25.884 & 15~724~$\pm$~278  & 137 \\
\ion{[S}{iii]} & 33.473 & 363:~$\pm$~22  & 3.16: \\
\ion{[Ne}{iii]} & 36.014 & 785:~$\pm$~98 & 6.84: \\ 
\hline
\ion{[O}{iii]}  & 51.8 & 34~700~$\pm$~1400 & 162 \\
\ion{[N}{iii]}  & 57.3 & 3100~$\pm$~140   & 14.5 \\
\ion{[O}{iii]}  & 88.4 & 15~500~$\pm$~430  & 72.4 \\
\hline
\end{tabular}}
\par
\smallskip
$^{\dagger}$ Intensities measured in units of 10$^{-14}$~erg~cm$^{-2}$~s$^{-1}$.  The intensities below 19~$\mu$m have been
increased by a factor of~3.96 to bring them on the same scale as the LH
intensities measured through a larger diaphragm. The intensities below 10~$\mu$m
are measured with the low resolution \mbox{instrument}.
\\
: Indicates an uncertain value.
 \\The last three measurements are taken from ISO.
\end{table}