Official entire letter printed "ΒΑΣΙΛΕΙΟΝ ΤΗΣ ΕΛΛΑΔΟΣ/ΝΑΥΤΙΚΟΝ ΔΙΕΥΘΥΝΣΗΡΙΟΝ/Εν Πόρω τη 18 Ιουνίου 1850", canc. "ΚΑΛΑΥΡΙΑ" (type I), via "ΓΕΝΙΚΟΝ ΤΑΧΥΔΡΟΜΕΙΟΝ ΑΘΗΝΑΙ*23.ΙΟΥΝΙ.1836" to Thessaloniki. Signed by G.Sahtouris, commander of the Poros Naval Station. Very fine and scarce.