Experimental investigation on the temperature dependence of the maximum Josephson current (dc) has been performed on both symmetrical and asymmetrical junctions. Agreement with the Ambegaokar and Baratoff calculations has been found for both $\mathrm{Sn}\ensuremath{-}{\mathrm{Sn}}_{x}{\mathrm{O}}_{y}\ensuremath{-}\mathrm{Sn}$ and $\mathrm{Sn}\ensuremath{-}{\mathrm{Sn}}_{x}{\mathrm{O}}_{y}\ensuremath{-}\mathrm{Pb}$ junctions. Experimental results on $\mathrm{Sn}\ensuremath{-}{\mathrm{Sn}}_{x}{\mathrm{O}}_{y}\ensuremath{-}\mathrm{In}$ structures have also been obtained.