Model of machine for making drain pipes.

This model, made to scale of 1:4, is a portable pug-mill for the manufacture of earthenware drainage pipes. Wet clay is put into the boxes at each end of the trough. When the wheel is turned a piston expels the soft clay out through the die-plate of chosen cross-section. A wire is then brought down on the roller bed (missing from the model) to cut the fresh pipe to the correct length. An original model from the Great Exhibition, it was probably made to inform the patent for such a machine granted to engineer James Hart in 1851.