that should obey the same scaling law as $\chi^{\rm c}$ and $\chi$ at $\beta_c$. The results are compiled in Table 2. Our three estimates for $\eta$ barely agree in the 2$\sigma$ range, but this is mainly due to the low estimate of $\eta$ coming from the $\chi^{\rm c}$-fit. This behavior of the $\chi^{\rm c}$ scaling law is in agreement with the findings of refs. [@r18; @r23], who also observed that the $\chi^{\rm c}$-fit results in a noticeably lower $\eta$ value. As our final estimate we take the result from the best fit of $\chi$ at $\beta_c = 0.6930$, yielding $$\eta = 0.0271 \pm 0.0017.$$ This in turn implies $\gamma/\nu = 2 -\eta = 1.9729(17)$ and, using again our value of $\nu$, $\gamma = 1.389(14)$.

From the temperature locations $T_{\chi^{\rm c}_{\rm max}}$ of the (connected) susceptibility maxima one can get another estimate of $\beta_c$ by using the scaling prediction $T_{{\chi}_{\rm max}^{\rm
c}}=T_c + aL^{-1/\nu}+\dots$. Using our previously determined value of $\nu =0.704$ we get from the linear fit shown in Fig. 7 the estimate $\beta_c
=0.6930(3)$, with $Q$=1, which is in excellent agreement with our result (\[eq:16\]) for $\beta_c$ obtained from the $U_L$ crossing points. The data for the fit is 