One of those 'collections I might one day have' is a collection of London maps. This one came out of a box of ephemera bought today at auction and I love it: it reminds me of one of the tape-measure-maps my grandmother used to have which worked on a similar principle. Sometimes with London maps you have to spend ages pouring over them with lists of dates to see when yours was printed. This one makes it easy, it was issued by the Lloyds Bank staff magazine in 1935.
They call it a "Clock Guide", by which they are referring to the marking of 360 degrees around the outside and the plastic 'hand' which is attached to the centre of the map. All the attractions and utilities named on the verso of the map are identified by a number of degrees first - so you move the clock hand to point at that number on the outside edge of the map - and then by a letter, which indicates where along the plastic pointer you will find what you are looking for.
It's always interesting to look at what a map shows and doesn't show. In this instance, it's perhaps a reflection of the fact that Lloyds was trying to present a certain image, that shops like Aspreys, Fortnum and Mason, and Cartier are all indicated on the map by not just their names but by a drawing of their buildings, putting them on a par with sites of national and historic importance in terms of how they are depicted on the map.