\begin{table}%t1
  \caption{Description of VLBA maps of 3C~66A shown in Fig.~\ref{fig:1}.
  \label{tab:1}}
%\centerline
 {  \begin{tabular}{ccccccc}
\hline  \hline\noalign{\smallskip} &&&\multicolumn{3}{c}{Restoring Beam}\\ \cline{4-6}
   $\nu$ & Epoch      & $S_{\rm peak}$      & Major     & Minor     & PA& Contours   \\
   (GHz)  & (yr)   & (Jy/beam) &(mas)   &(mas)   &(deg)&(mJy/beam)  \\
   (1)    &(2)        &(3)        &(4)     &(5)     &(6)  &(7)        \\
  \hline\noalign{\smallskip}
2.3~GHz   & 2001.20    & 0.678      & 5.78    & 3.67 &--1.21&1.70~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2001.48     & 0.641      & 5.96    & 3.68 &--1.24&1.88~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2001.86     & 0.748      & 5.39    & 3.87 &--5.16&1.70~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2002.11     & 0.718      & 5.4    & 3.9 &--7.06&1.42~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2002.14     & 0.598      & 5.47    & 3.87 &--7.1&1.79~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2002.45     & 0.584      & 5.33    & 3.98 &--3.55&1.72~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256) \\\hline
8.4 GHz   & 2001.20    & 0.653      & 1.6    & 1.04 &--0.34&1.74~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2001.48     & 0.719      & 1.61    & 1.01 &--2.06&2.34~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2001.86     & 0.696      & 1.44    & 1.08 &--4.23&2.18~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2002.11     & 0.623      & 1.46    & 1.09 &--7.81&2.27~$\times$~(--1, 1, 2,4, 8, 16, 32, 64, 128, 256)  \\
   &2002.14     & 0.586      & 1.43    & 1.07 &--6.05&2.28~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2002.45     & 0.494      & 1.42    & 1.06 &--4.22&2.63~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128) \\\hline
22.2 GHz   & 2001.20    & 0.718      & 0.64    & 0.41 &0.57&2.73~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128, 256)  \\
   &2001.48     & 0.638      & 0.71    & 0.38 &--0.80&3.50~$\times$~(--1, 1, 2, 4, 8, 16, 32, 64, 128)  \\
\hline
  \end{tabular}}
\par
\smallskip
Notes: (1) Observing frequency;
      (2) observing epoch;
      (3) peak flux density;
      (4), (5), (6) parameters of the restoring Gaussian beam: the full
width at half maximum (FWHM) of the major and minor axes and the position angle (PA) of the major axis.
      (7) Contour levels of the map. The lowest contour level is three times the rms noise in the
      maps.
\end{table}