Today's lecture is about the history of the postal service. In the 19th century, the introduction of the penny post in Britain revolutionized communication. Before that, the recipient, not the sender, usually paid for the mail, which made it expensive and often led to refusal. The penny post, introduced in 1840, made prepayment compulsory and lowered the cost to just one penny for any letter under half an ounce. This change increased the volume of mail dramatically. However, one challenge was that many people could not write, so they dictated letters to professional scribes. Interestingly, the first adhesive postage stamp, the Penny Black, was also introduced at this time, but it was not the first in the world; that honor goes to Switzerland's Zurich stamp.