Israel: Aerogramme with enclosure - Incorrectly taxed as an airmail letter

Israel RUSS # 6

Sent from HAIFA 7.7.53 to Zurich, Switzerland. According to the message on the writing panel the aerogramme contained an enclosure, a photograph.

Both the “AEROGRAMME” type designation and the “PAR AVION” routing instruction were crossed out with blue crayon, indicating that the aerogramme was diverted to surface mail. Not compliant to the rules, though, it was also taxed as a short paid ordinary airmail letter.
The airmail letter rate to Switzerland was 110 Pr. So the airmail letter was short paid 55 Pr. Double the deficiency was converted into UPU gold centimes at a rate of 95 Pr = 20 cmts. After rounding up, 110 Pr is equivalent to 24 ctms, as endorsed on the left hand side of the indicium.

The Swiss postal authorities, however, made their own calculations based on the ratio of the respective surface mail tariffs and double the deficient postage for transfer by surface mail (80 Pr). The first weight step international surface mail rate in Israel was 95 Pr and 40 Rappen in Switzerland. So the postage due calculated in Switzerland was 40/95 x  80 = 33.68 Rappen. 

According to Wilms (2004), the Swiss postal authorities devaluated the arithmetical postage due by ⅝ (“⅝ rule”) since July 1, 1953. This results in a postage due of 21.05 Rappen, which was rounded (down) to the nearest 5 Rappen to give the 20 Rappen postage due collected.

The Swiss postage due stamp was cancelled on July 27, 1953.



 
References
Russ, Peter (1988): Katalog der Israel Aerogramme
Wilms, Wolf (2004): Schweizer Nachporto ab 1910