Could it be true that if you want to read the biography of a writer, you will find it all as random instalments in a procession of their novels? Why not test this premise with the English writer Beryl Bainbridge? Her works are a model of how factual grain gets ground and filtered to become grist to the fictional mill. Sometimes Bainbridge is called an eccentric—a claim she summarily dismisses: What they don’t realise when they say I’m a bit eccentric—and that’s the only time I get hot under the collar—is the discipline needed to get something done and get…