\begin{table}%t6
  \caption{\label{table:radio:ext}Extinction in~K  (2.2~\mum) calculated by (1) using Eq.~(\ref{eq:radio:ak}), and~(2) using the Br$\beta$/Br$\alpha$~decrement 
    observed by ISO (unless otherwise is indicated).}
%\centerline
{
    \normalsize
    \begin{tabular}[h]{lclcclclc}
      \hline \hline \\[-5pt]
    \multicolumn{1}{c}{Source}&
    \multicolumn{2}{c}{$A_{\rm K}$ (1)$^\natural$} &
    \multicolumn{1}{c}{$A_{\rm K}$ (2)} & &
    \multicolumn{1}{c}{Source}&
    \multicolumn{2}{c}{$A_{\rm K}$ (1)$^\natural$} &
    \multicolumn{1}{c}{$A_{\rm K}$ (2)} 
\\[5pt] \cline{1-4} \cline{6-9} \\[-5pt]
   IRAS  01045 &$3.2 \pm 1.4 $ &(1)& $\ddagger$ & &
   IRAS  17160 &$5.6 \pm 0.3 $ &(1)& $5.8 \pm2.3^\star$\\
   IRAS  10589 &$1.3 \pm 0.1 $ &(4)& $1.5 \pm 0.5$& &
   IRAS  17221 &$1.8 \pm 0.2 $ &(2)& $1.8 \pm 0.4$\\
   IRAS  11143 &$0.8 \pm 0.1 $ &(2)& $<$0.6 & &
   IRAS  17279 &$2.2 \pm 0.5 $ &(1)& $\ddagger$\\
   IRAS  12063 &$1.5 \pm 0.1 $ &(6)& $0.8\pm0.5$ & &
   IRAS  18032 &$1.1 \pm 0.3 $ &(1)& $\ddagger$\\
   IRAS  12073 &$1.47 \pm 0.06$&(9)&$ 0.8\pm0.2$ & &
   IRAS  18479 &$ 7.8 \pm 0.2 $ &(1)& $\ddagger$\\
   IRAS  12331 &$ 1.3 \pm 0.3 $ &(1)& $\ddagger$ & &
   IRAS  19442 & $<$1.8        &   & $\ddagger$\\
   IRAS  15384 &$1.53 \pm 0.09$&(6)&$1.3 \pm 0.3$& &
   IRAS  19598 &$2.49 \pm 0.05$&(9)&$1.6 \pm 0.2$ \\
   IRAS  15502 &$ 3.1 \pm 0.2 $ &(3)& $2.7\pm0.6$ & &
   DR21      &  $ 2.6 \pm 0.3 $ &(1)& $ 3.1\pm0.7^\star$\\
   IRAS  16128 & $\Diamond$    &(2)& $\rhd$ & &
   IRAS  23133 & $0.4\pm0.1$   &(2)& $\sim$0
\\[3pt] \hline 
      \end{tabular}}
{\smallskip
$^\natural$ Given in brackets is the number of \HI\ lines used in the
calculation (see text).
$^\ddagger$~Only Br$\alpha$ is available from the SWS spectrum.
$^\Diamond$~Two lines (Br$\alpha$ and Br$\beta$) are observed by the ISO-SWS,
but the \ak\ extinctions derived from them are very different
($2.3 \pm 0.3$ and $0.8 \pm 0.2$, respectively).
$^\rhd$~The Br$\alpha$/Br$\beta$ decrement is not consistent with a 
$\lambda^{-\alpha}$ law.
$^\star$~Calculated using the Pf$\alpha$/Br$\alpha$ decrement.
}
\end{table}