' "What did you do, dad?" the son asked him. "The speedometer", Mr Wormwood said, "is run off a cable that is coupled up to one of the front wheels. So first I disconnect the cable where it joins the front wheel. Next, I get one of those high-speed electric drills and I couple that up to the end of the cable in such a way that when the drill turns, it turns the cable backwards. You got me so far? You following me?" "Yes, daddy," young Michael said. "These drills run at a tremendous speed," the father said, "so when I switch on the drill the mileage numbers on the speedo spin backwards at a fantastic rate. I can knock fifty thousand miles off the clock in a few minutes with my high-speed electric drill. And by the time I've finished, the car's only done ten thousand and it's ready for sale. 'She's almost new,' I say to the customer. 'She's hardly done ten thou. Belonged to an old lady who only used it once a week for shopping.' " "Can you really turn the mileage back with an electric drill?" young Michael asked. "I'm telling you trade secrets," the father said. "So don't you go talking about this to anyone else. You don't want me put in jug, do you?" "I won't tell a soul," the boy said. "Do you do this to many cars, dad?" "Every single car that comes through my hands gets the treatment," the father said. "They all have their mileage cut to under under ten thou before they're offered for sale. And to think I invented that all by myself," he added proudly. "It's made me a mint." Matilda, who had been listening closely, said, "But daddy, that's even more dishonest than the sawdust. It's disgusting. You're cheating people who trust you." "If you don't like it then don't eat the food in this house," the father said. "It's bought with the profits." "It's dirty money," Matilda said. "I hate it." Two red spots appears on the father's cheeks. "Who the heck do you think you are," he shouted, "The Archbishop of Canterbury or something, preaching to me about honesty? You're just an ignorant little squirt who hasn't the foggiest idea what you're talking about!"