By John Bolton

In former times Leighton Beck was of considerable economic importance, for it provided water power for Leighton Furnace (1713 to 1806), and probably also for the unique type of nineteenth century limekiln, the remains of which lie hidden in Back Wood, on private ground. (GR. 477782).

Yates’s map of 1786 shows the river following closely its present course between Leighton Beck Bridge (GR 486777) and the Kent Estuary. However, its upper reaches are depicted as describing an arc to the north east of a large area of moss, occupying what is now known as Thrang, White and Hale Mosses, before arriving at its source which is shown a little to the south of Hllderstone. This location of the source is far-more credible than that given by John Lucas in his history of Warton in which he says the source is in the vicinity of Heron Syke. There is in fact a watershed between Hllderstone and Heron Syke.

The current 1:25000 Ordnance Survey map shows the beck flowing in a south-east to north-west direction-to the north of Brackenthwaite (GR 492773) and being fed by a tributary emerging from a limestone scar almost directly north of Brackenthwaite. (The small tarn shown close to the scar is a man-made flight pond for wildfowlers.) East of Brackenthwaite the Beck is shown flowing through Thrang End Wood and connecting to the drainage system on the mosses to the south-east of the Thrang End to Hale Lane.

This part of the watercourse, on the limestone bar in Thrang End Wood is of particular interest. J. Anthony Barnes in his book All around Arnslde (Titus Wilson and Son, Kendal 1933) says of it: ‘At one point only this barrier of hills has been sawn through where Leighton Beck has in process of ages carved out for itself a pretty little ravine and drained what was once probably an enclosed lake, now Hale Moss.’ It is with some diffidence that one casts doubt on Mr. Barnes’s proposition, but nevertheless it does appear to the present writer that it was not the Beck which sawed through the limestone in Thrang End Wood, but men!

The straightness of the channel and the evenness of the walls betray the unnatural processes which created the ravine. Indeed, it would seem the natural source of Leighton Beck is the spring at the foot of the limestone scar to the north of Brackenthwaite and that the channel through Brackenthwaite fields to Thrang End Wood; like the drainage channels on the mosses beyond were all man-made to augment the inadequate water supply to Leighton Furnace. (Today the drainage of the mosses west of the A6 flows northward to the Bela, but before the trunk road was built in 1818- 1820 this area too may have drained into the Leighton Beck.) The drainage would, incidentally, affect land reclamation after the peat had been stripped from the mosses to fuel the furnace. The records of the furnace confirm both the extensive use of peat for fuel and the shortage of water to work the bellows, it being necessary on occasions for men to operate them on the treadmill principle. Thus, there was ample incentive to undertake the considerable task of cutting through the limestone bar in Thrang End Wood and to construct an extensive drainage system on the mosses beyond with a view to augmenting the flow of water to the furnace. It is worth noting that one of the main drainage ditches on the moss is identified by the Ordnance Survey as ‘Furness Runner’: a misspelling of ‘furnace’?

If these suggestions are accepted, there are only about 2 kilometres of natural river between the spring near Brackenthwaite and the northern edge of the Silverdale parish boundary, the rest of the Beck running in-artificial channels across the mosses and in Thrang End Wood.

Published in Mourholme Magazines Issue 14 1990