S. Nakanishi gave some interesting results on the weak convergence of measures on the union $X$ of metric spaces $(X_{\alpha}, d_{\alpha}) \ (\alpha \in \Sigma),$ endowed with the finest topology for which all the canonical injections of $X_{\alpha}$ to $X$ are continiuous. Our aim in this note is to extend her results to the case where each component space $X_{\alpha}$ is simply a Hausdorff space.