††A breakthrough occurred in 1840, when Roland Hill thought of charging people according to weight, rather than distance, when they sent a letter. The first postage stamps were introduced at a cost of a penny, and the postal service soon became much more popular.
Today the task of sorting mail has been made much easier by the introduction of machines. A machine reads and postmarks the stamps, so that they cannot be used again. A keyboard operator translates the post code on each letter into a series of phosphor dots that can be sorted automatically. The latest machines can sort letters at the rate of 350,000 an hour.
