1918 German field post, cartography department “Vermessungs-Abteilung 18”, Dorpat/Tartu – Plassen

Very scarce cartography unit “Vermessungs-Abteilung 18” and scarce Dorpat field post postmark with “* a *” littera (typically “***”). Inscribed “FP 689”. See H/O supplement pages 21-22. Vermessungs Abteilung 18 published topography maps of Estonia.