Duplicating machines were the predecessors of modern document-reproduction technology. They have now been replaced by scanners, laser printers and photocopiers, but for many years they were the primary means of reproducing documents for mass distribution.

Like the typewriter these machines were children of the second phase of the industrial revolution which started near the end of the 19th century. The second phase of the industrial revolution is also called the Second Industrial Revolution. This second phase brought to mass markets things like the small electric motors and the products of industrial chemistry without which the duplicating machines would not have been economical. By bringing greatly increased quantities of paperwork to life the duplicating machine and the typewriter gradually changed the forms of the office desk and transformed the nature of office work.

http://en.wikipedia.org/wiki/Duplicating_machines

Photocopier:
http://en.wikipedia.org/wiki/Photocopier

Calvin & Hobbes had a different way of doing things :)
http://en.wikipedia.org/wiki/Duplicator#Cardboard_boxes