'From Duplex to Mechanical': The Evolution of Experimental and Early Machine Postmarks Worldwide ... 1857 to 1920s
by Jerry H. Miller
This exhibit, created by Jerry Miller,
is available on this website in several forms, including searchable PDF.
Introduction
This postal history exhibit is a chronological presentation of the evolution of important postmarks applied by early experimental postmarking machines tested or evaluated by post office authorities worldwide between 1857 -- 1920s.
Shown postmarks are from devices or machines considered to be of philatelic and historic importance with impact worldwide in the evolutionary process with many lesser important machines tried or tested worldwide not included in this exhibit, nor are all the postmarks of each indicated machine shown.