\begin{table}%t4
%\centering
\par
\caption{\label{tab:abun}Average total gas column densities and fractional abundances of CH$_3$OH.}
\begin{tabular}{l r r r r r r}
\hline\hline \noalign{\smallskip}
Source & $N_{\rm DUSTY}^a$ & $N_{\rm SCUBA}^b$ &
$x$(CH$_3$OH)$_{\rm DUSTY}^c$ & $x$(CH$_3$OH)$_{\rm SCUBA}^c$ &
$x$(CH$_3$OH)$_{\rm out}^{c,d}$ & $x$(CH$_3$OH)$_{\rm in}^{c,d}$\\
 & (10$^{23}$~cm$^{-2})$ & (10$^{23}$~cm$^{-2}$) & $\times10^{-9}$ &
$\times$$10^{-9}$ & $\times$$10^{-9}$ & $\times$$10^{-8}$ \\
\hline
SMM1 & 1.3  & $3.5 \pm 0.3$ & $3.6 \pm 0.9$ & $1.3 \pm 0.4$ & 1 & $\le$0.3 \\
SMM3 & 0.83 & $2.0 \pm 0.13$ & 2.8$\pm$0.7 & 1.2$\pm$0.3 & 4 & $\le$50  \\
SMM4 & 1.1  & $1.2 \pm 0.07$ & 13$\pm$3    & 12$\pm$3    & 5 & $\le$5  \\
S68N & 1.2  & $1.7 \pm 0.10$ & 28$\pm$2    & 21$\pm$2    & 10 & $\le$40 \\
\hline
\end{tabular}
\tablefoot{\tablefoottext{a}{Gas column density, $N$(H$_2$), obtained from D{\sc usty} modelling over a region of $22\farcs5 \times 22\farcs5$ assuming a
gas:dust ratio of 100.}
\tablefoottext{b}{Gas column density, $N$(H$_2$),obtained from SCUBA emission at 850~$\mu$m   assuming a constant dust temperature of 20~K.} 
\tablefoottext{c}{Fractional CH$_3$OH abundance summed over A- and E-type CH$_3$OH.}
\tablefoottext{d}{Inner and outer abundance in the R{\sc atran} jump-model.}}
\end{table}