Kilns

The process of heating a pot in a kiln turns the clay into a ceramic. As the heat rises, the water in the clay of the pot is driven off,. In the second stage the particles are fused together to produce a waterproof body. The rate of heating in the kiln is critical. A rise of about 100'c per hour allows the pot to expand and contract and the water to escape without the pot breaking from the stress. Most kilns in prehistory were heated using wood
The most common type of kiln is the Romano-British. It has a tunnel on the front that is used as the fire box, with a large chamber at the back that holds the pots. The fire is drawn along the tunnel and into the base of the chamber where the heat rises up between the pots and out of the vent at the top of the kiln.

	This is a view looking down into the top of the firing chamber. The pots at this stage are glowing bright orange with the heat.

This is a reconstruction of a kiln from Denmark. When the kiln was excavated, it still held the pots but the kiln had collapsed on top of them. The fire box is in the base at the front with the pots on a shelf at the rear. There is a small vent in the top at the back of the kiln.