Hidden in the corner of St James' Square is a littleknown architectural gem that is just about to undergo a major refurbishment. The London Library, one of the world's largest subscription libraries, was set up by journalist and writer Thomas Carlyle in 1841 and is a labyrinth of literary rarities and unseen nooks and crannies. And it's bursting at its seams. The tricky task of making extra room for the ever-increasing number of books has been given to architect Haworth Tompkins. It appears one architectural critic has already sneaked inside. Gleaming from among some 14 miles of shelves of ageing tomes dating back to the 19th century was Dan Cruickshank's The Critics' Choice. Worth the annual £180 membership alone?