I know exactly what you mean about Boyle’s Law and bookshelves. However, I’m biting the bullet and getting rid of books I’ve been lugging around for years but know I’ll never read again.

(And as a fast reader, I can never take enough books on a trip. For I while I carried Herodotus on trips because you can open it at random and read something interesting.

PS I’m a Canadian and can’t get the thing but it does sound like a pretty good idea.