\begin{table}%t3
%Table 3\\
\caption{IUE spectrum of NGC~40.}\label{t3}
%\centerline
{
\begin{tabular}{llccccc}
\hline
\hline
\multicolumn{1}{c}{$\lambda$} & Ion & \multicolumn{2}{c}{Intensities}& &\multicolumn{2}{c}{Ratio}\\ \cline{3-4} \cline{6-7}
\multicolumn{1}{c}{(\AA)}& & (1) & (2) & & (3) &(4)  \\
\hline
1550 & \ion{[C}{iv]} & 5.13 & 1.69 & & 0.246 & 0.268\\
1663 & \ion{O}{iii]} & $\leq$0.7   & 1.54  & & $\leq$0.033 & $\leq$0.034 \\
1762 & \ion{C}{ii}   & 1.35 & 1.34 & & 0.101 & 0.061\\
1883 & \ion{Si}{iii]}& 0.45 & 1.01 & & 0.026 & 0.022\\
1909 & \ion{C}{iii]} & 11.2 & 0.87 & & 0.72  & 0.564\\
2325 & \ion{C}{ii]}  & 10.1 & 0.49 & & 0.873 & 0.636\\
2470 & \ion{[O}{ii]} & 2.31 & 0.67 & & 0.142 & 0.094\\
2740 & \ion{C}{ii}   & 0.59 & 1.14 & & 0.021 & 0.015\\
2841 & \ion{C}{ii}  & 1.36  & 1.26 & & 0.049 & 0.031\\
\hline 
\end{tabular}}
(1) $I$(line) -- all intensity units 10$^{-13}$ erg cm$^{-2}$ s$^{-1}$;\\
(2) $I$(continuum) -- all intensity units 10$^{-14}$ erg cm$^{-2}$ s$^{-1}$;\\
(3) $I$(line)/$I$(H$\beta$) from continuum measurement;\\
(4) $I$(line)/$I$(H$\beta$) from \ion{[O}{ii]} ratio. 
\end{table}