\begin{table}%t4
\par
\caption{\label{tgradient}Results of velocity gradient fits.}
%\centerline
{
\begin{tabular}{lccc}
\hline\hline
Line & ${\cal G}$ & $\Theta ^{a}$ & $\langle{\cal G}_{\rm l}\rangle ^{b}$  \\
     & (km s$^{-1}$ pc$^{-1}$) & (deg) & (km s$^{-1}$ pc$^{-1}$) \\
\hline
\NTHP~(1$-$0)   & 0.366~$\pm$~0.005 & $-$133.6~$\pm$~0.7 & 1.9~$\pm$~0.1 \\
\NTHP~(3$-$2)   & 1.1~$\pm$~0.1 & $-$168~$\pm$~9 & 2.7~$\pm$~0.3  \\
\NTDP~(2$-$1)   & 0.95~$\pm$~0.06 & $+$145~$\pm$~5 & 3.5~$\pm$~0.2 \\
\NTDP~(3$-$2)   & 0.4~$\pm$~0.2 & $-$128~$\pm$~27 & 4.7~$\pm$~0.4  \\
\hline
\end{tabular}}
\smallskip
NOTE: $^{a}$ Direction of increasing velocity, measured East  
of North. $^{b}$~Mean~values of the magnitude of local 
 velocity  
 gradients and corresponding standard error.
\end{table}