 | ||
Clapper Post (German: Klapperpost) was an urban postal service which existed in Vienna, the capital of Austria, from 1772 and in other cities of that country. Its name refers to an instrument, a clapper (a type of rattle), which a mailman used to signify his arrival. In Vienna, the Clapper Post existed for more than ten years.
References
Clapper Post Wikipedia(Text) CC BY-SA