The greatest invention

'Personally,' said Sean, 'I think the greatest invention was the vacuum flask. It keeps hot things hot and cold things cold, but how does it know the difference?' True,' said Seamus. 'But I reckon the greatest invention is the motor car.'

'Why so?' asked Sean.

'Well, think of a summer's evening when you're out for a spin. In no time at all the windscreen and headlights are smothered in millions of moths. Bearing in mind how many vehicles are on the roads, there must be trillions of little blighters about. And if it wasn't for the motor car we'd be up to our eyelids in moths!'