1860 (Dec. 11) New York, N.Y. to Schweidnitz, Prussian Silesia, cover bearing 1859, 10¢ green, type V, pair and single, some trimmed perfs, tied by red NYFM circular grids, red "N. York Br. Pkt. '7 Paid' Dec 11" exchange credit cds, carried by Cunard Line Arabia from Boston Dec. 12 to Queenstown arriving Dec. 22, F.-V.F. Scott No. 35  Estimate $200 - 300. The New York exchange office weighed the letter and determined two rates were required. Existing regulations permitted sending the letter if at least one full rate was prepaid, with the remaining postage to be collected at destination. New York credited Prussia 7¢ for the one rate paid and debited Prussia 23¢ (black manuscript. rating) for the one rate paid. Aachen marked "2f" in upper left, for "zweifach" or double rate and 13 silbergroschen postage due, the remaining unpaid rate. Since letters with one rate paid and one rate due were seldom seen, a further explanation was penned in under the lower stamps, "Sonst Frei" meaning "usually free". This cover was referenced in Chronicle 181, parcel post. 58-67. $0 (Image)