The next stop was at the other end of the mill where a huge pile of beautifully dressed gritstone lay out the side of the lane. This, I was told, was what was left of the engine house. Grandfather never forgot to point out where the line shaft which drove me machinery in what he called the old mill had crossed the road. He remembered the engine working. Nobody ever saw it but the village boys were in awe of the great roar that it emitted as it worked. They called it the "Romping Lion". 
We walked up into Ladygrove past the "Regulator" and the "Fancy", two of the dams that belonged to the mill, and reversing our direction of travel, climbed up the side of the valley to the top of the "Holt" field. From here, directly above the mill, there was a glorious view of the Derwent valley. Much more interesting though was "Moss Castle", a semicircular embankment built into the hillside.
Moss Castle
Curious though a boy of four may be, I never really found out what the Romping Lion was. The days of the Dakeynes were long gone. But their house, the Holt, was like the mill, a permanent memorial. It was however a very clear that they were an important family.

Indeed they had their own bank and issued their own Banknotes. What is more, Mrs Davenport at the Blacksmith's Arms had one
hanging in a frame behind the bar.
It was not until 1971 when the widely respected industrial archaeologist, Frank Nixon, published a book about Derbyshire that I realized the Romping Lion was something quite different.It was neither a water wheel nor a turbine. Nixon called this "ingenious machine" a "disc engine" adding that its most striking characteristic was the difficulty in describing it. He did not try.
Some twenty years later when I retired I thought I might at least understand its mysteries. To my amazement nobody in the intervening years had published anything about it. Certainly it had been touched on in various books but all implied, as had Nixon himself, that the dams at the bottom of Ladygrove supplied the water for the disc engine. I realized this could not be true - there
could not be the 96ft head quoted.
Moss Castle, immediately above the mill, must have been the source of water for the engine. And the large ponds constructed on the flank of the hill, all interconnected by a water channel, that I had seen as a child must have provided the water for Moss Castle.
The Derbyshire Record Office immediately provided the answer. The 1839 Tithe Map showed Moss Castle to be the "Engine Head". Down below in the valley was the mill and across the road from it was the "Engine House". A thin line on the map connected the Engine Head, the Engine House and Mill.