\begin{table}%t3
\par
\caption {\label{tab:fields}The mean longitudinal magnetic field measurements for our sample
of Herbig Ae/Be and debris disk stars observed
with FORS~1.
%In the first two columns we give the object name
%and the modified Julian date of the middle of the exposures.
%The measured mean longitudinal magnetic fields $\left<B_{\mathrm z}\right>$
%using all lines and hydrogen lines are presented in Cols.~3 and 4. 
}
%\centerline
 $${\begin{tabular}{rcrr @{$~\pm~$} lr @{$~\pm~$} lc}
\hline
\hline
\multicolumn{1}{c}{Object} &
\multicolumn{1}{c}{MJD} &
\multicolumn{1}{c}{SNR} &
\multicolumn{2}{c}{$\left< B_z\right>_{\rm all}$} &
\multicolumn{2}{c}{$\left< B_z\right>_{\rm hydr}$} &
\multicolumn{1}{c}{Comm.} \\
\multicolumn{1}{c}{name} &
 &
 &
\multicolumn{2}{c}{[G]} &
\multicolumn{2}{c}{[G]} &
 \\
\hline
PDS~2  & 54~610.399      & 1790 & {\bf 103}    & {\bf 29} & $-$4          & 70       & ND \\
47839  & 54~609.968       & 3375 & 134          & 52       & 141           & 62       & \\
%53179  & 54608.977       & 2190 & {\bf 73}     & {\bf 11} & {\bf 93}     & {\bf 14}  & ND \\
%85567  & 54609.012       & 3560 & {\bf 83}     & {\bf 16} & {\bf 119}    & {\bf 19}  & ND \\
95881  & 54~609.993       & 3745 & 47           & 25      & 24            & 20      & \\
97048  & 54~609.137       & 2980 & {\bf 164}    & {\bf 42} & {\bf 188}    &{\bf 47} & ND \\
97300  & 54~609.047       & 2495 & 109          & 50       & 96           & 53       & \\
100453 & 54~610.022       & 3820 & 1            & 14       & $-$30        & 28       & \\
100546 & 54~610.046       & 4195 & {\bf 89}     & {\bf 26} & {\bf 87}     & {\bf 28} & ND \\
101412 & 54~609.190       & 3280 & {\bf $-$312} & {\bf 32} & {\bf $-$454} & {\bf 42} & CD \\
       & 54~610.081       & 3525 & {\bf $-$207} & {\bf 28} & {\bf $-$317} & {\bf 35} & CD \\
135344B& 54~609.243       & 4020 & 32          & 15       & 41           & 30       & \\
       & 54~610.145       & 3970 & {\bf $-$38}  &{\bf 11}  & {\bf $-$37}  & {\bf 12} & ND \\
139614 & 54~610.201       & 4010 & $-$40        & 25       & $-$58        & 32       & \\
144432 & 54~609.383       & 2595 & 36           & 22       & 32           & 42       &  \\
144668 & 54~610.238       & 3710 & {\bf $-$62}  & {\bf 18} & {\bf $-$92}  & {\bf 27} & CD\\
150193 & 54~609.092       & 3300 & {\bf $-$144} & {\bf 32} & {\bf $-$252} & {\bf 48} & ND \\
152404 & 54~609.275       & 2815 & $-$107       & 37       & $-$53        & 23      & \\
158643 & 54~609.275       & 4165 & 32           & 20       & 14           & 23       & \\
163296 & 54~610.255       & 3535 & 40           & 30       & 105          & 40       & \\
169142 & 54~610.175       & 3875 & 50           & 25       & 23           & 32       & \\
VV~Ser & 54~610.332      & 1050 & 200          & 75       & 376          & 141       & \\
176386 & 54~610.272       & 3230 & {\bf $-$119} & {\bf 33} & {\bf $-$121} & {\bf 35} & ND\\
179218 & 54~609.360       & 3855 & 51           & 30       & 28           & 34       & \\
190073 & 54~609.410       & 3900 & {\bf 104}    & {\bf 19} & {\bf 120}    & {\bf 30} & CD\\
\hline
\multicolumn{8}{c}{Stars with debris disks}\\
9672   & 54~345.389       & 4365 & 50           & 22       & 42           & 32       &  \\
39060  & 53~455.193       & 4205 & $-$16        & 14       & $-$36        & 22       & \\
109573 & 54~610.438       & 3815 & 56           & 30       & 41           & 32       & \\
164249 & 54~610.301       & 2970 & 19           & 14       & 1            & 25       & \\
172555 & 54~610.287       & 3875 & $-$35        & 20       & $-$31        & 28       & \\
181327 & 54~610.364       & 3495 & $-$38        & 16       & $-$75        & 26       & \\
%strange features in spectrum of hd181327
\hline
\multicolumn{8}{c}{ Standard Ap star with a weak magnetic field}\\
162~725 & 54~549.413       & 2435 & {\bf 128}  & {\bf 30} & {\bf 158}   & {\bf38}       & \\
\hline
\end{tabular}}$$
\par
\smallskip
Notes:
All quoted errors are 1$\sigma$ uncertainties.
In Col.~6 we identify new detections by ND and confirmed detections by CD.
We note that all claimed detections have a significance of at
least 3$\sigma$, determined from the formal uncertainties we derive. 
These measurements are indicated in bold face.
\end{table}