\begin{table}%t4
    \caption{Model parameters derived to fit the inner knots NK~1 and SK~1 with a~J-type shock.
$n = n({\rm H}) + 2n({\rm H_2})$ is taken as the hydrogen nucleon density.}
\label{jmodels}
\small%%\centerline

{
\begin{tabular}{ll}
\hline \hline
 Parameter & NK~1/SK~1 \\
\hline
~~~~~~~~Size,~{\it L}$_{\rm bow}$ & 3.9 $\times$ 10$^{15}$~cm   \\
(1)~H~density,~~~{\it n}  & 9.0 $\times$ 10$^{4}$~cm$^{-3}$ \\
(2)~Molecular~fraction~~~{\it f}~$^{\ast}$ & 0.2  \\
(3)~Alfv\'en~speed,~~~$v_{\rm A}$ & 8~km~s$^{-1}$ \\
~~~~~~~~Magnetic~field & 1.3~mG \\
(4)~Bow~velocity,~~~$v_{\rm bow}$ & 36~km~s$^{-1}$ \\
(5)~Angle~to~l.o.s. & 90$^{\circ}$ \\
(6)~Shape~parameter~~~s & 1.5 \\
(7)~Field~angle,~~~$\mu$& --54$^{\circ}$  \\
\hline 
\end{tabular}}
\medskip
$\ast$ The molecular fraction is given by $f=n({\rm H_2})/n$ so when $f=0.5$ the gas is fully molecular.
\end{table}