Thanks to all those who responded to this posting. Tom and Ros's charcoal
burn was successful. The process took five days to complete, which is as
long as their previous experiment which contained more wood. The reason
for making charcoal in pits remains a mystery. The pit was about 500mm
deep (based on site evidence elsewhere) so most of the stack was above
ground, and therefore still subject to the vagaries of wind strength and
direction, cracks in the earth and turf cover etc. On ground covered with
boulder clay (as this was) water collected in the bottom of the pit, so the
bottom layer of wood did not burn properly. However they now have enough
charcoal to conduct the experimental bloomery smelt on July 5th, and have
built a furnace for this smelt. The furnace is constructed of stone, with
clay bonding and lining, rather than being purely of clay. The experiments
will be written up on completion.
In response to queries about their work in Teesdale, this is in preparation
for publication in due course. The bloomeries there had no evidence of
water powered bellows, and were not in suitable locations for the
application of water power. The slag heaps were small, suggesting a small
scale mobile industry.
The suggestion that the landscape was wooded comes from the number of
charcoal pits in a relatively small area - the pits will have been within
the woodland, which may or may not have been managed by coppicing.
Ian Forbes
|