22:39m; available on YouTube
Night Mail is a 1936 documentary film about a London, Midland and Scottish
Railway (LMS) mail train from London to Scotland, produced by the GPO Film
Unit. A poem by English poet W. H. Auden was specially written for it, used
in the closing few minutes, as was music by Benjamin Britten. (The two men
also collaborated on a rail-documentary on the line from London to
Portsmouth, The Way to the Sea, also in 1936.)

The film was directed by Harry Watt and Basil Wright, and narrated by John
Grierson and Stuart Legg. The Brazilian filmmaker Alberto Cavalcanti was the
sound director. It starred Royal Scot 6115 Scots Guardsman.

As recited in the film, the poem’s rhythm imitates that of the train’s
wheels as they clatter over the track sections, beginning slowly but picking
up speed so that by the time the narration reaches the penultimate verse the
narrator is speaking at a breathless pace. As the train slows toward its
destination the final verse is taken at a more sedate pace. The famous
opening lines of the poem are “This is the Night Mail crossing the border /
Bringing the cheque and the postal order”.