A short silent film showing the Multi-Position Letter Sorting Machine (MPLSM). MPLSM operators used 20-key keyboards to type in two or three numbers from the ZIP code, so the machine could then sort the mail into one of 277 or more bins representing sections of the country. These operators sorted mail at rates of 60 letters per minute. Visit the online exhibit: http://npm.si.edu/systemsatwork
Video Duration:
1 min 8 sec
YouTube Keywords:
Smithsonian "postal museum" "National Postal Museum" stamps philately post office history
