Belgium
Short Paid Aerogramme

This aerogramme (Greiner no. 11, watermark II) was sent from NAMUR (cds 6 1 56) to Standford, U.S.

The aerogramme rate to the U.S. was 6 F, so the aerogramme was short paid 2 F. Double the deficiency (4 F) was converted into UPU gold centimes at an exchange rate of 1 F = 4.75 UPU gold centimes for a total of 19 UPU gold centimes. This was endorsed on the right hand side of the “T” stamp.

3 UPU gold centimes = 1 U.S. cent. Hence the postage due was 6.33 cents which was rounded up to 7 cents. The U.S. postal authorities h/s “Postage due  .. cents / AMF New York, N.Y.” and endorsed “7”.


References
Greiner stands for Greiner/Greiner, Aerogramme von Europa, 3e, 1993