The other day I met a man who didn't know where Tripoli was. Tripoli happened to come into the conversation, and he was evidently at a loss. 'Let's see,' he said. 'Tripoli is just down by the - er - you know. What's the name of that place?' 'That's right,' I answered, 'just opposite, Thingumabob. I could show you in a minute on a map. It's near - what do they call it?' At this moment the train stopped, and I got out and went straight home to look at my atlas.