The Plymouth Kiln

The drawing on the left was made by Richard Champion on October 16th 1770, of a kiln at Plymouth.  It was reproduced by Owen and Sellick.  A note on the drawing refers to the last firing of the enameling kiln, and both these writers assumed that the drawing refers to an enameling kiln.  It is really a combined glost (high temperature) and a biscuit (low temperature) kiln.  The kiln is 6.1 feet in diameter and is formed into three chambers.  The lowest is the furnace having a vertically divided projection of 3.5 feet, for burning wood billets.  Above is a 7 foot high (2.14 m) glost oven and at the top the biscuit oven (or possibly an oven for drying saggars).  The kiln has a through draft, the flames from the furnace entering the glost oven.  An enameling (muffle) kiln does not have a through draft.