\begin{table}%t7
\caption{\label{tabg29}Diffusion data for the variable ZZ~Ceti star G~29-38.}
\small%\centerline
 {
\begin{tabular}{rrrrrrr}
\hline
\hline
 el  & $\tau$ [yrs] & $\log \epsilon_{\rm atm}$ & 
$\log X_{\rm atm}$ & $ \log X_{\rm acc}$ & $\log X_\odot$\\
\hline
Ca    & 0.79 & 0.00  &  0.00 & 0.00 & 0.00 \\
Mg    & 0.97 & 1.10  &  0.88 & 0.79 & 1.00 \\
Fe    & 0.80 & 0.61  &  0.82 & 0.81 & 1.33 \\
\hline
\end{tabular}}
\medskip
Column~2 gives the time scale in years, Col.~3 the observed number abundances relative to Ca, Col.~4 the observed abundances by mass, also relative to Ca. Column~5 is the predicted abundance in the   accreting material, {\em assuming  steady state between accretion and diffusion}. The final column shows the solar abundances on the same scale. All abundances are in decadal logarithms.
\end{table}