Monument record 2864 - Medieval to Modern Collyweston Slate Industry at Easton on the Hill

{2} Famous stone slates of Collyweston, Easton and Kirby. Slates of this description were certainly quarried by the Romans, and have occurred both at Irchester and in the villa at Apethorpe Park. During the Middle Ages they were also in great request eg. At Rockingham Castle c.1376 when 9,500 stone slates were transported from Colyn Weston. Other purchases are also listed, and in 1567 when Elizabeth was firmly established on the throne, loads of slates were bought for repairs to the Queen Majesty’s House at Collyweston. Use of slates outside the county is recorded at Cambridge universities.
The term Collyweston slate is given to a fine-grained, calcareo-areenaceous rock occurring at the base of the Lincolnshire Limestone. It is found and has been worked at other places besides Collyweston, such as Kirby and Easton, between Collyweston and Stamford. The quarries at and near Collyweston have been worked from very early times.
There is only one bed of stone yielding slates, varying from 6ins to 3ft deep. It is worked in open quarries, or in ‘fox-holes’, ie long galleries underground, in the winter. The stones are split with the use of freezing water along the bedding planes, which renders cleaving very easy, though skilful.
In the C18th Easton was much celebrated for its limestone, for which the many old quarries in the parish were principally worked. The parish still has a few lime-burners and slate is also worked to a small extent.

{4} In the north of the county round the slate producing villages of Collyweston and Easton on The Hill the new post-enclosure field boundaries were drystone walls of flaggy limestone, similar to those of the Cotswolds. Elsewhere hedges were much more usual.

{7} The underlying rock is mainly Lower Lincolnshire Limestone, a fissile bed running across the parish in a narrow band, which yields stone slates. Easton lime was long held in high esteem, and the supply of fuel for burning it was plentiful. Lower estuarine clays were used for making pots and tiles in the early C18th.
Roof covering (preface):
At the base of the Lower Lincolnshire Limestone is a bed of fissile stone which is locally suitable for making stone slates. Although it may have been exploited in Roman times, the earliest documentary evidence for its use is in the C13th. The main quarries were at Collyweston, which gave its name to the slates, and Easton on The Hill, but working extended as far west as Kirby, near Gretton. Identifiable late medieval slates are generally about 20mm thick, with an uneven surface, and have a hole about 10mm in diameter formed by drilling. Their weight demands a sturdy roof. The process of frosting was discovered or developed probably in the C16th, the earliest reference to it being in 1611. Post-medieval slates are consequently much thinner, sometimes only 5mm, and have smaller holes, sometimes drilled, but by the C19th always pecked, and up to 7mm across. When laid, slates were hung over riven laths with short wooden pegs, and torched from below or sometimes bedded in mortar.
Slate stone was probably first won from just below the surface, where the fissile beds outcrop, but in time was obtained from progressively deeper pits, and finally from mines. Open pits were being dug at Collyweston in 1633, when the manorial court ordered that those dug in any one year should be filled in the next and returned to agriculture; a limit of 25 pits per year was set to prevent the supply being exhausted. The stone was raised in December and January, and the blocks laid out and kept wet until the action of the forst rendered them ready for splitting. Whe last dug in 1966-7 the slates were won from ‘foxholes’ or galleries in a mine at Collyweston. The slates from Easton were often considered superior to those from Collyweston, and said to be harder.

{9} The higher ground is characteristic of the Lincolnshire Limestone, which has been extensively quarried both for building purposes and for lime burning, the latter at Ketton in particular.

{10} Slates were mainly quarried at Collyweston, Easton, Duddington, Deene Park and Kirby.

{11} Numerous former stone pits around Geddington, Pipewell, Harringworth, Wakerley, Collyweston and Easton, were described by the geologists Samuel Sharp and J.W.Judd in the C19th.
Lower Lincolnshire Limestone is the local building stone of more than 20 villages on or close to its outcrop, and is the source of Northamptonshire’s Collyweston Slates. Lincolnshire Limestone forms a broad plateau from high above the Welland valley at Easton on The Hill, Collyweston and Duddington, across to Wittering, Barnack and Ufford. From Collyweston and Duddington the outcrop continues south-westwards along the Welland escarpment through Wakerley and Gretton, above the villages of Rockingham and Cottingham, as far as Wilbarston.
The county’s famous stone slates come from the area of Collyweston, Easton on The Hill and Wothorpe; some were also obtained for a time at Kirby, near Deene, and locally at Harringworth and Wakerley, all places along a narrow north-east to south-west belt and within 1km to 3km of the east side of the Welland Valley. Geologically they come from the lowest beds of the Lower Lincolnshire Limestone in a few localities where these beds form a sandy limestone with the necessary properties to split into thin plates; in most other places the lowest beds are sandy limestones that are not suitably fissile, or are only partially cemented sands.
When the damp rock is exposed to frost it splits naturally into thin layers. Material for roofing would have been first found where it lay at the surface. In due course the slatestone was obtained by digging into the limestone plateau around Collyweston and Easton on The Hill, and an industry developed which was able to supply for instance 14,000 slates for Rockingham Castle in the C14th and many subsequent consignments for major buildings in the county as well as for several of the Cambridge colleges, conveyed via the fenland waterways.
The industry, which thrived for centuries, developed its own particular skills. Shafts had to be dug, sometimes 8m to 10m through the thickness of Lower Lincolnshire Limestone to reach the soft sand underlying the Collyweston horizon. From the shafts galleries were dug horizontally in the sand, just high enough for the miner to lie on his side, using a foxing pick to undermine the slate bed. He supported it at intervals with stone props, but he would listen for clicks in the bed (known as ‘talking’), indicating that the bed was about to fall, when he would withdraw, removing the props. Working sections of about 4m were determined by natural joints. Lumps of stone (known as ‘logs’) were then raised to the surface, laid out and constantly kept damp, waiting for a succession of frosts to split the stone. Slate mining was therefore mostly carried out in December and January. Later in the year the slaters could tap open the log with a cliving hammer, and begin the skilled work of dressing the slates in a range of sizes.

<1> Sharp S., 1870, The Oolites of Northamptonshire, p.354-375 (unchecked) (Article). SNN74230.

<2> Serjeantson R.M.; Ryland W. (Editors), 1906, The Victoria History of the Counties of England: Northamptonshire, p.296-7+303+564 (part checked) (Series). SNN100369.

<3> RUDD J.W., 1875, The Geology of Rutland and Surrounding Areas, p.182-3 (unchecked) (Book). SNN2558.

<4> Steane J., 1974, The Northamptonshire Landscape, p.232 (checked) (Book). SNN5137.

<5> Morton J., 1712, The Natural History of Northamptonshire, p.79+102-3 (unchecked) (Book). SNN10113.

<6> Purcell D., 1967, Cambridge Stone, p.59-63 (unchecked) (Book). SNN107874.

<7> Royal Commission on The Historical Monuments of England, 1984, An Inventory of The Historical Monuments in The County of Northampton, Preface+p.50 (checked) (Series). SNN77384.

<8> Clifton-Taylor A., 1987, The Pattern Of English Building, p.104 (unchecked) (Book). SNN100724.

<9> Tonks E., 1992, The Ironstone Quarries of The Midlands (History, Operation and Railways): The Corby Area, p.280 (unchecked) (Book). SNN39836.

<10> Brook A.C., 1998, The Past, Present and Uncertain Future of Collyweston Stone Slate, p.9 (part checked) (Dissertation). SNN101796.

<11> Sutherland D.S., 2003, Northamptonshire Stone, p.26+71-76 (checked) (Book). SNN104515.

Record last edited

Jan 30 2012 4:19PM