So to the subject of Mather's dam and leat at Eller's Close and its relationship with Foundry Mill
Here I think Warrington Rhino's interpretation is only partly correct.
1577 Surface water previously adequate was not sufficient for a larger mill.
Elizabeth I gave permission for Christopher Mather to make a leat from Ellers Close in Roundhay (where Easterly Road now crosses the Wykebeck) to the mill in Seacroft. This was in return for his (first) draining the colliery and watercourses (in the Killingbeck area) It took the water from Wyke Beck at the bottom of Asket Hill and from the streams which flowed from the Rein and above Fox Wood. It ran along the 188ft contour, which took it towards Asket Crescent, across the lower school playing fields, along Brooklands Drive, over South Parkway, and via Moresdale Lane to the Foundry Mill. In the late 1940’s the leat was filled in to make way for the new Seacroft housing estates, and its water rediverted into the old stream which for 4000 years had taken only the surplus and flood waters.The Foundry Mill was extended
I cannot criticise WR any way for this interpretation as there is documentary evidence confirming a direct connection between the leat and Foundry Mill. For example in the "Records of the parish of Whitkirk" published in 1892 by George Moreton Platt and John William Morkill in a description of one of the parish's most famous sons, describes
In the immediate neighbourhood of his home may still be seen two specimens of Smeaton's ingenuity — the hydraulic ram at Temple Newsam, by means of which water is forced to the level of the hall, a height of twenty-six feet (mentioned by Smiles) ; and a water-wheel at the Foundry Mill, in the parish of Seacroft. The latter, which has a diameter of thirty feet six inches, is turned by a force of water brought by a conduit from a point in the Wyke beck at Roundhay, about a mile distant.
CA Lupton (presumably a member of the Lupton family so closely associated with Roundhay and Leeds) wrote in an account of John Smeaton published in the Publications of the Thoresby Society, Miscellany Vol 15, Part 3 in 1973 states:
However that may be, Queen Elizabeth I in 1577 granted to one Christopher Mather the right to make a leat from Ellers Close in Roundhay to his mill in Seacroft 'which he has latterly built'. This leat, originally a mile long , began where now Easterly Road crosses the Wyke Beck and can be still traced for about half a mile. The remainder has completely disappeared beneath the new Seacroft Estate. In my childhood it was nearly all visible. It seems probable that Christopher Mather rebuilt and enlarged the old mills, increased his water supply by this remarkable leat - a wonderful achievement of calculated levels"
The last sentence is where my old doubts resurface.
WR's excellent diagrams and sections illustrate a huge problem with this interpretation. I have measured the distance along Mathers Leat the assumed link to the junction of Foundry Mills own leat which I reckon is approximately 3500' and to the Foundry Mill itself 6400'. The assumption that the level of the leat from the weir at Ellers Close to the Sluice Paddle at the mill is 188' is wrong.
A leat (and for that matter a trunk foul water sewer) requires a fall otherwise there is very low flow and inevitable silting problems (which in a trunk sewer is a potential serious and very smelly problem
). I would have expected that a leat of this length to have a fall of approximately 1 in 150 dropping the level at the junction at the Foundry Mill leat to 165' making an effective hydraulic connection extremely doubtful.
Smeaton's own report on the workings of the Foundry Mill clearly suggest that the supply of water at the mill were very poor, hence the construction of the fire engine to pump recycled water to the mills wheels
I think the confusion has arisen from the happy coincidence that Christopher Mathers mill at Seacroft is described as having two water wheels under one roof and his grant related to draining mines; while Smeaton designed two water wheels and that water was been obtained from colliery drainage at "Mr Porter's Drain".
From the small amount of information on Christopher Mather I have seen, he was clearly a "big cheese" in the area securing rights to work coal throughout the area including Whinmoor and Brown Moor. So I wonder why would he have attempted, on acquiring rights from the Crown to dam the Wyke Beck and build a leat, to tease water to the vicinity of Foundry Mill when he could simply run his leat along the valley side harvesting all the side streams before turning a right angle back to the Wyke Beck to a mill where he could have a undershot water wheel in the beck and an overshot wheel using the full head of the leat?. Surely the most efficient way to exploit the effort/expense of damming the Beck?
I am certain that the location of Christopher Mather's mill is somewhere in the floor of the Wyke Beck valley below Foundry Mill.
So how do I explain the reference above linking Mather's leat with Foundry Mill. Well my hypothesis is that after the failure of the ironworks, when converting to a corn mill and in a desire to secure more water a deep trench was cut to intercept Mather's leat and a culvert installed (hence some references to a tunnel)
