Mr. Clinker makes nails and rivets and for many years he worked by hand, just as his father had before him. Making nails by hand is a slow, intricate process, and Mr. Clinker often worked well into the night to meet his orders. Together with an engineer friend, Mr. Clinker formulated plans to revolutionise his business by building a machine that could make his products. Within a few months, there it stood in all its glory, engineered from materials scavenged from a nearby scrap yard. He then constructed a building around the steam-powered machine, so that he could live on the premises.
   At first, the roof was clad in clay tiles, but after a while, the constant pounding of the machine had shaken most of them to the ground. Without delay, Mr. Clinker and his pal removed the remaining tiles and re-roofed the building with sheets of corrugated iron.