\begin{table}%t3
\par
\caption{\label{motions}Derived proper motions of the IRAS 4B maser spots.}
%\centerline
{
\small\begin{tabular}{ccccc}
\hline\hline
Spot & $\Delta  \alpha$ & $\Delta  \delta$ & $V_{\rm \alpha}$ & $V_{\rm \delta}$ \\
     & (mas) & (mas) & (km s$^{-1}$) & (km s$^{-1}$) \\
     \hline
a    & --0.96 &  +1.33 & 15.1 W &  20.9 N \\
b    & --0.59 &  +0.53 &  9.3 W &   0.8 N \\
c    & --1.86 &  +1.73 & 28.9 W &  27.1 N \\
h,~k  &  +1.50 & --3.02 & 23.5 E &  47.0 S \\
i,~m  &  +1.50 & --1.91 & 23.5 E &  28.9 S \\
\hline
\end{tabular}}
\end{table}