And it’s this: be careful what you throw away.

In among a box of second-hand books bought from a North London dealer in the late 1970s was a thick international railway timetable.

So boring did this tome appear to be that the seller apparently missed the eight small etchings hidden between the pages — a mistake that, in effect, handed the buyer a small fortune when they were identified three years ago as unique works by the visionary artist and writer William Blake.

Tate galleries have now bought these brilliantly executed and disturbing pictures for £441,000 and will exhibit them at Tate Britain in July.

My question is, who buys an old railway timetable from a second-hand bookseller? That guy can’t possibly come up with an interesting use for £441,000 (roughly $712,000).

Now if fate was to drop that much money in my lap, here’s what would happen. It’s not quite enough to set myself up as an independent scholar (i.e., a guy who sits around in his robe and slippers all day long reading books). But I could build the kind of library in my house that would let me forget about the rest of the world for a little while each day.