\begin{table}%t1
\par
\caption {\label{table:fields}Characteristics of the 29 fields which were monitored 
in the EROS spiral arm program:
locations of the field centers, average sampling $N_{\rm meas}$
(number of photometric measurements per light curve and per color)
and number of stars monitored for each field $N_{\rm obs}$.}
\par
%\centerline
 {\begin{tabular}{cc cc ccc}
\hline\hline
\multicolumn{1}{c}{\bf Field}&
\multicolumn{2}{c}{$\alpha ^{\circ},~~\delta ^{\circ}~(J2000)$} & 
$b^{\circ}$ & $l^{\circ}$ & $N_{\rm meas}$  & $N_{\rm obs}~(10^6)$ \\
\hline
\multicolumn{5}{c}{$\bf \bsct\  Exposure=120~s.\  f.o.v.=4.3~\rm deg^2.$} & 268 & 3.00 \\    
bs300 & 280.8417	& --7.6814 & --1.75 & 25.20 & 269 & 0.48 \\        
bs301 & 280.8625	& --6.2283  & --1.11 & 26.51 & 266 & 0.47 \\        
bs302 & 281.5667	& --7.3792  & --2.25 & 26.80 & 272 & 0.50 \\         
bs303 & 281.5833	& --5.9264  & --1.60 & 27.09 & 261 & 0.47 \\         
bs304 & 282.3375	& --6.7642  & --2.70 & 26.71 & 269 & 0.52 \\        
bs305 & 283.1083	& --6.5956  & --3.26 & 27.19 & 271 & 0.54 \\ \hline  
\multicolumn{5}{c}{$\bf \gsct\  Exposure=120~s.\  f.o.v.=3.6~\rm  deg^2.$} & 277 & 2.38 \\ 
gs200 & 277.0125	& --14.8517 & --1.64 & 17.72  & 282 & 0.47\\        
gs201 & 277.8125	& --14.2439 & --2.12 & 18.00  & 266 & 0.49\\        
gs202 & 277.8875	& --12.8147 & --1.52 & 19.30  & 291 & 0.49\\        
gs203 & 278.5917	& --14.5275 & --2.92 & 18.09  & 281 & 0.46\\         
gs204 & 278.6167	& --13.0753 & --2.28 & 19.40  & 267 & 0.47\\ \hline     
\multicolumn{5}{c}{$\bf \gnor\  Exposure=120~s.\  f.o.v.=8.4\ deg^2.$}  & 454 & 5.24 \\ 
gn400 & 242.4375	& --53.1175  & --1.17 & 330.49 & 496 & 0.42 \\         
gn401 & 244.5917	& --51.7453  & --0.99 & 332.04 & 475 & 0.41 \\         
gn402 & 243.7375	& --53.0764  & --1.59 & 330.74 & 463 &0.45\\
gn403 & 245.6167	& --52.1056  & --1.69 & 332.24 & 420 &0.42\\         
gn404 & 244.7875	& --53.4439  & --2.29 & 330.94 & 435 &0.43\\         
gn405 & 246.7167	& --52.3506  & --2.35 & 332.54 & 445 &0.44\\         
gn406 & 245.9750	& --53.7314  & --2.99 & 331.23 & 443 &0.46\\         
gn407 & 247.8792	& --52.4789  & --2.95 & 332.93 & 443 &0.47\\         
gn408 & 247.1750	& --53.8661  & --3.60 & 331.63 & 453 &0.47\\         
gn409 & 243.9625	& --54.8125  & --2.86 & 329.82 & 482 &0.47\\         
gn410 & 245.1250	& --55.0717  & --3.59 & 329.93 & 443 &0.46\\         
gn411 & 242.4042	& --55.1686  & --2.54 & 328.78 & 449 &0.48\\ \hline  
\multicolumn{5}{c}{$\bf \tmus\  Exposure=180~s.\  f.o.v.=3.8~\rm  deg^2.$} & 375 & 2.28 \\   
tm500 & 201.7667	& --63.0383 & --0.47 & 306.98 & 391 &0.44 \\          
tm501 & 202.8250	& --63.5781 & --1.07 & 307.37 & 355 &0.44 \\      
tm502 & 203.7167	& --64.1750 & --1.72 & 307.66 & 376 &0.47 \\      
tm503 & 200.9917	& --64.9978 & --2.36 & 306.38 & 375 &0.36 \\          
tm504 & 198.0500	& --64.1136 & --1.35 & 305.22 & 392 &0.43\\          
tm505 & 199.0625	& --64.6806 & --1.96 & 305.60 & 360 &0.43 \\ \hline
\multicolumn{6}{r} {\bf Total} & 12.9 \\ 
\hline  
  \end{tabular}}
\par
\smallskip
{Note:} the total numbers of observed stars towards $\gnor$ and $\tmus$ are smaller
than the sum of the numbers given for each field because of
some overlap between contiguous fields.
The total fields of view (f.o.v.) are the areas effectively monitored
($0.71~\rm deg^2$ per field, see text),
corrected for the overlap between fields.
\end{table}