Air Mail cover 1915 (March) bluish-grey Feldpost card to Ecser (26.3 arrival) carried by unmanned mail balloon from the Fortress, landing at Turje-Remete (now part of Ukraine) and showing straight-line "Ballonpost Przemysl/1915" cachet in violet, put into the Fieldpost system at F.P.O. 47; vertical crease, very scarce. Photo