Yes it is a Chimney

Although it seems to be more like a domestic chimney rather than one associated with an industrial process.

Picture 1 is a plan view camera facing East.

Picture 2 shows where the grate is (camera facing South).

Picture 3 shows the metal of the grate and the inside of the box where the ashes would have fallen.

Back to the East End (Toilet Area)

Well, the wheel pit was really hard work so we headed back to the East end of the mill for some light duties!

Our idea was to clear a good area of floor from the whitewashed "toilet" stones South and also South East into what looked like another room. What we thought would happen is that we would pass through a doorway similar to the one we found in the first room. We didn't!

In fact we found no sign of a wall at all that corresponded with the chunky wall adjacent to the midden. Instead the floor deteriorated in quality (more like a cobbled outside area than an indoor floor), started sloping downwards and then ended abruptly.

At this stage we have no idea what this area is. There were however 3 interesting features chiselled into the stone. (In the picture above, not very clear, is marked points A, B and C)

A.

B.

C.