|At the Post Office mail men unload the mail trucks.
The mail bags are opened.
The letters are tipped out on to long tables.
Each letter must be turned so that the stamp is facing up.
When all the letters have been turned so that the stamps are facing up they are put into a large machine.
This machine prints the name of the Post Office and the date in a circle on the top of each letter.
It makes wavy lines across the postage stamps.
The postage stamps cannot be used again.
They have been cancelled.