Since it contains just about every book published in England for at least 200 years, the British Library catalogue is a great way of tracking down a half-remembered title or author, or an incomplete reference. Or checking if there are any books on a particular subject
Some public libraries have only computerised their catalogues for acquisitions in the last 10 years or so. Their card catalogues for older stock are wonderful, but have obvious limitations in this world of search engines. The one in Manchester however has one advantage not afforded by a computer: whole drawerfuls of cards can be date-ranked at a glance, just by the depth of blackness of the dust on their top edges
