The Postal Union Congress is the main meeting of the Universal Postal Union to discuss various postal service matters. Usually held every four years, the XIVth Congress took place in Ottawa from August to October 1957, and was attended by approximately 350 delegates from over 90 member countries.
The Canadian post office issued a set of two stamps (5 cent and 15 cent denominations) to commemorate the event. In addition, the P.O. Department opened a post office at Congress headquarters in Ottawa for the exclusive use of the 350 delegates. (Delegates also received souvenir presentation books from the Canada Post Office Department. I've scanned a few pages from the book and posted it as an addendum to this article.)
This article shows examples of mail from UPU delgates.
Opening Day of Congress
U.P.U. Otawas to Bonn, Germany, August 14, 1957
Legal size air mail envelope with Congress logo:
U.P.U. Delegate First Day Cover
The cover below was sent by a Dutch delegate who applied the two UPU stamps to the letter size delegate envelope and arranged to have the Ottawa "First Day of Issue" cancellation applied.
August 14, 1957 to Hilversum, Netherlands
Letter written opening day
The letter below was written by a delegate on UPU congress writing paper, August 14. She explains that she is sending the addressee a cover on the opening day of the Congress and expects that he will appreciate its philatelic significance. She then goes on to ask him to make sure that the work on her apartment is completed by September 1.
Mail to Italy
U.P.U. Ottawa to Poggiodomo, Italy, August 22, 1957
Mail to Belgium
U.P.U. Ottawa to Brussels, July 20 1957
UPU Ottawa to Brussels, August 31, 1957
Mail To Germany
U.P.U. Ottawa to Bonn, September 19 1957
Mail To Canada
Egyptian delegate to Saskatoon, August 15, 1957
The addressee may have written to delegates requesting the UPU congress cancellation.
Mail to the United States
U.P.U. Ottawa to Ernest Kehr, New York Herald Tribune, New York, September 17 1957
7 cents air mail letter rate to the United States
Ernest Kehr was a prolific philatelic writer and commentator who had philatelic columns in several newspapers, including the New York Herald Tribune.
a) Circular Date Stamp
U.P.U. Ottawa circular date stamp (steel hammer)
September 24, 1957
Addressed to E. Kehr
Circular date stamp, September 24 1957
UPU Ottawa machine cancellation September 27, 1957
b) Money Office Order Number (MOON)
The UPU post office was assigned MOON number 4003
Favour MOON cancellation, October 8 1957
c) Registration Handstamp
The registration handstamp used on Congress mailings did not identify the post office of origin:
The registered cover below was mailed by Belgian Delegate Richir on September 11, 1957.
UPU Congress steel hammer
Registered mail to Berne, Switzerland
15 cents air mail rate + 20 cents registration fee
Canada Post Office Department Presentation Book in Red Slipcase
The presentation book (20.5 cm x 15.4 cm) contains definitive and commemorative stamps is blocks of four. The lovely light brown suede portion of the front cover is contrasted by the red side of the cover on with the gold-stamped Canadian crest.
A few pages from the presentation book: