What is heavier? A pound of feathers, or a pound of British pounds?

It's quite clearly the pound of British pounds. With a pound of feathers, one may feel a sense of 'freedom' as if they could attach the feathers to their bodies or clothes and fly away. A pound of British pounds carries the baggage of capitalism; the holder will not feel the sense of weightlessness, but rather the incessant need of more. You're gonna carry that weight.