The hand-drawing of glass capillary tubes was a craft which had almost disappeared through mechanisation, but the delicate process was still practised at Lemington, where, through the application of hand, eye and lung-power, the skilled craftsmen produced narrow-bore tubes with remarkable accuracy.

The film parallels this activity with that downstairs in the 'pot-loft', where the slow, once closely guarded process of constructing by hand the huge refractory pots is shown from start to finish, the film culminating in the dramatic pot-change.