I posted about burnt mounds after our first trip to Shetland. This time, we found an amazingly complete excavated and rescued burnt mound by the ferry on Bressay.
Rocks were heated in the furthest chamber.
The hot rocks were transported forwards and put into this water tank at the front. The tank looks to be 1m wide by 2m long by 30cm deep. That makes 0.6 cubic metres or 600kg of water. I was talking about heating 5kg. This is over a 100x smaller. So we would be talking about maybe 300kg of rock, or 100 large pebbles, to get the heating to 60 oC.
