The mid 1930s: Britain is at peace, leaving time for Jennings to play with trains – model trains from the Science Museum in London. Like other very early Jennings titles made at the GPO Film Unit the film is more edited than directed. But this little film is still important, for it reflects a key obsession with the process and products of the Industrial Revolution and the fusion of science with the world of imagination. “Machines”, Jennings wrote, “are animals made by men”: so here is his homage to the iron horse.

Geoff Brown