AR - To save you a trip in to Sheffield, here are the extracts from Jim's books re Silence Sough that you mention.
Extracted from "History & Gazetteer of the Lead Mine Soughs of Derbyshire" by J. H. Rieuwerts published J. H. Rieuwerts 1987, page 21.
"SILENCE SOUGH, 188.777 Bolt, piped into trough
A short shale gate about 900 feet in length. The level has been entered in recent times (c.1950) and was crawling height, with a flat shale roof propped with large poles every few feet. No dates are known for it's construction but it probably dates from the early 18th century."
Extracted from "LEAD MINING IN DERBYSHIRE: HISTORY, DEVELOPMENT & DRAINAGE. 1. Castleton to the River Wye." by J. H. Rieuwerts, published by Landmark Publishing Ltd., 2007. page 100
"SILENCE SOUGH
A shale-gate sough and pumpway for which no documentary evidence seems to have survived. The level was probably driven sometime during the years 1710-1712. Kirkham (1964) recorded seeing the tail section re-opened by the farmer; it had a flat roof of shale, propped at intervals of a few feet by larch poles, but it ran-in again soon afterwards. The sough intersected the mine at a depth of 27 fathoms (162 feet) after a driveage of a little over 1,200 feet. Silence Mine was worked to a depth of 526 feet, 328 feet being in shale and 198 feet - within the limestone. The mine was greatly troubled by water by 1734 but in about 1738 there appeared the curious statement that there was 'a prospect of being very soon relieved of ye water - by means of a Sough or Levell that is now bringing up'. This cannot refer to any sough driven at high level in the shale, or an optimistic forecast about the westward progress of either Stoke Sough or Magsclough Sough. The only feasible explanation appears to be a proposed extension of the deeper sough from New Edge Grove referred to under Speed Level.
SPEED LEVEL
The only documentary references to the Level occur in reckonings relating to Stoke Sough. None of the work appears relevent to events at Stoke Sough and quite why this shale sough was important to them is a mystery.
During October, 1760 driving began at Speed Level, the cost being 5/- per fathom, so obviously excavation must have been through shale. In January, 1762 there is an unexplained item: 'Michael Simpson garding the Water from Dowse Hole [SCL.Bag 391]'. After a driveage of 1176 feet they were 'Making a Water Mark at Have-at-All' and an entry in July, 1763' reads: 'Given the Workmen for getting a hole through to Have-at-All, 5/-'.
The position of the Level is not known, only two solutions seem feasible; either a shale gate sough driven west from Silence Sough, or a continuation of Greenhead Sough eastwards beyond the New Edge Grove title. The latter hypothesis is the more attractive, but there is no supporting documentary evidence. If begun from a forefield at the eastern extremity of the New Edge meers, then 1176 feet would terminate close to Speed Engine Shaft, but well beyond Have-at-All Mine."
Until 1763 when references cease, Speed Level had been driven 1440 feet, always at 5/- per fathom."
N.B. The 1964 reference by Jim to Nellie Kirkham's article in his 2007 book gives the title of the article as "Grindlow mines - Derbyshire Miscellany Bull., Local History Section, Derbyshire Archaelogical Society", however, on checking my copies of Derbyshire Miscellany, the only article printed in the journal at that date is "Silence Mine" by Nellie Kirkham, it will be the same article.
"SCL" refers to Sheffield Archives, formerly Sheffield City Libraries. Local History Library.
"Bag" refers to the Bagshawe Collection held by Sheffield Archives.
5/- (five shillings old money is the equivalent of 25p now - but was worth a heck of a lot more in the 1700's).