Sir: In my distant youth in east and then north London, I never heard any mention of a clockwork orange. What I did hear was "All Lombard Street to a China orange," although it was hardly on everyone's lips. Nor was it used only in London, as my wife, a foreigner (Tyne & Wear), also knew it. I believe "clockwork orange" is entirely an invention of the novelist.
PHILIP N O'DONOGHUE
New Barnet, Hertfordshire