Even if one has the ready cash available one of the most difficult things to buy is a four-penny stamp. On arrival at the post office you join the queue. After twenty minutes of doing a slow forward shuffle, and having your trousers gummed up by the half-sucked lollypop being wielded like a tennis racket by the small boy behind you, you arrive at the counter just in time to see the clerk put up the notice 'Position closed', and since it's now 5.31 so is the rest of the post office. Then, you rush outside to the stamp machines, jam your four-pence into this one, lift the little flap and find you're now the proud owner of an 18-strip of ha'penny stamps. And that's when you wish you'd used a bigger envelope. It also means you're going to cop seven extra licks of horrible fish glue. A flavour that even Able Seaman Johnson finds it very hard to develop a taste for.