 In several cases the surveys were also conducted outside the territory of the electorate.Anywhere Saxon land was interrupted by other territories, roads used by the Saxon post office were surveyed, with the permission of the territorial owner.Surveying was especially difficult in Upper Lusatia because landowners of the estates of the realm there tried to impede Zürner's activity.Zürner was able to begin surveying Upper and Lower Lusatia only on 29 June 1723.