Arfken, George B. (1992). Canada and the Universal Postal Union 1878-1900.

The Universal Postal Union, the UPU, was established by the 1874 Treaty of Berne, effective July 1, 1875. The provisions were almost a necessity for a world where commerce and fast, reliable and inexpensive communication were perceived as vital. On August 1, 1878 Canada adhered to the Postal Union rates and regulations and started to enjoy the privileges of membership in the Union.

UPU membership did not affect the 5¢ rates to the United Kingdom, Germany and Newfoundland. However, the rates to most other overseas countries fell dramatically. Most of this book is devoted to the UPU rates and regulations for overseas mail sent from Canada. The basic letter rate was 5¢ per 2 oz., but the Union permitted lower rates by mutual agreement. The 2¢ Imperial penny postage rate was a prime example.

Other subjects discussed are: penalties and postage due charges (and postage due stamps); a Union permitted surtax to cover high transit costs and “extraordinary services”, as well as registration and the seldom used “avis de reception”.

Canada had authorized sending 2¢ post cards to the United Kingdom in 1877. Under the UPU, post cards became an interesting and important part of Canadian overseas mail. Careful attention is also paid to transient newspapers, other printed matter and to parcel post sent overseas. Where postal material exists, these Postal Union rates and regulations are fully illustrated.