The National Archives in Kew, West London, hold an
amazing variety of documents. Amongst other things, they hold most of the
key original patents from the industrial revolution.
They were mounting an exhibition of 'invention'
celebrating their patents and wanted some working exhibit related to one
of their patents that kids could play with. We chose Wheatstone's ABC
telegraph. The original 1842 version on the left and my version on the
right. In situ, one station is placed in the museum area and one 50 yards
away in the cafe.