The Middleport Pottery of Burgess and Leigh (opened 1888)  

The filtered clay

 

Location 6 on the plan

Next: the pug mill
Previous: the filter presses

The raw clay has been liquefied in the blungers to allow the impurities and grit to be removed.
This slip has been put through the filter press and as can be seen below the result is 'cakes' of clean, filtered and uniform clay.

 

 

The filtered clay - ready for the pug mill
the clay is now clean, free from grit and of a consistent quality

Next: the pug mill
Previous: the filter presses