\begin{table}%t1
%\centering
\par
\caption{\label{t1}Log of observations.}
\begin{tabular}{llcccc}
\hline\hline
   Date &
   Observatory &
   Telescope &
   Range &
   Resolution &
   Observed PNe \\
\hline
   2001, July      & CTIO & 4m + RC-spectrograph & ~~3900--7580~\AA\ & $\sim$1000 & 35 \\
   2002, April/May & CTIO & 4m + RC-spectrograph & ~~3700--7390~\AA\ & $\sim$1000 & 37 \\
   2002, July      & ESO  & 3.5m + EFOSC~II     & ~~3600--7350~\AA\ & $\sim$2000 & 23 \\
\hline
\end{tabular}
\end{table}