\begin{table}%t1
\caption{\label{tab:si4temp}Methods used to estimate the effective temperature scale for the
B0.5--1.5 spectral-types.}
\small%\centering
\par
\begin{tabular}{lcl}
\hline\hline
Spec.\ type& \teff     & Method \\
 \hline 
B0.5 V     & 27~000 K & Si {\sc iii/iv} ionization balance (6611-012)\\
B1.0 V     & 25~000 K & Si {\sc iii/iv} ionization balance 
(3293-018; 4755-015; 6611-021 and -033)\\
B1.5 V     & 22~500 K & Interpolation between B1 V and B2 V \\
B2.0 V	   & 20~000 K & Average of the effective temperature estimate for 
11 stars based on their helium spectra  \\
\noalign{\medskip}
B1.0 III   & 21~500 K & Si {\sc iii/iv} ionization balance (3293-003, 
-007 and -010) \\
B1.5 III   & 20~500 K & Interpolation between B1 III and B2 III \\
B2.0 III   & 19~500 K & Average of the effective temperature estimate for 
2 stars based on their helium spectra  \\
 \hline
\end{tabular}
\end{table}