Dr. Plot, in his “History of Staffordshire,” date about 1686, says—
“The most preferable clay of any is that of Amblecote, of a dark blewish colour, whereof they make the best pots for the glasshouses of any in England; nay, so very good is it for this purpose that it is sold in the place for 7d. the bushel, whereof Mr. Gray (an ancestor of the present Earl of Stamford and Warrington) has 6d. and the workman 1d., and so very necessary to be had that it is sent as far as London, some time by waggon and some time on pack horses to Bewdley, and so down the Severn to Bristol, and thence to London.” “The goodness of which clay and cheapness of coal hereabouts no doubt has drawn the glasshouses both for vessels and broad glass into these parts, there being divers set up in different forms here at Amblecote, Oldwynford, Hollowaysend, and Coburnbrook.”
Stourbridge clay (properly so called) is found only in a comparatively small district, say within a circle of not more than two miles, taking the valley of the Stour at the Lye as the centre, and at depths varying from three or four yards from the surface to one hundred and eighty yards; its position in the strata is in all cases below the thick coal, at distances varying from twelve to twenty-five yards; and it is generally overlaid by a shaly, friable kind of coal, called “batts,” from twelve to twenty-four inches thick. The thickness of the seam varies very much, rarely exceeding thirty-six to forty-two inches, and sometimes thinning down to five or six inches when close to faults or small disturbances in the measures. The quality is very variable, in some instances as hard as stone, having to be blasted with powder, and in others soft and easily workable. There is a great variation in its component parts, arising principally in the proportion of silica; a clay containing only about fifty per cent. of silica being very inferior, and contracting very much on exposure to intense heat. In order to show this difference in a practical form I have had eight clays from as many mines in the Stourbridge district, prepared under precisely similar circumstances, subjected to the same heat, and all burnt in the kiln at one time. The result showing the great variation and power of resisting heat, since, in the eight samples, hardly two are of the same weight and size. The eight bricks all made in one mould.
The usual treatment of clay for glass-house purposes is as follows. After having been carefully selected, it is broken into small pieces by women accustomed to its appearance, who throw on one side all pieces of discoloured and irregular clay; it is finely ground by heavy edge-runners, and mixed with a certain proportion of ground potsherds (old broken burnt pots); the proportion of burnt clay varies according to the purpose for which the clay is to be used; it is then mixed with water, and tempered with the foot, and allowed to lie a considerable time—which should not be less than six or seven weeks—when it should acquire great tenacity before being made into pots.
These pots are built up by hand gradually, great care being taken that the last layer of clay is not allowed to become hard or dry, or it will not unite properly; neglect in this respect causing the pot to give way in the furnace. The pots are dried very gradually, and are seldom fit for use under six to eight months.
The clay, after the selection of the best pot-clay, is allowed to lie in large heaps, subjected to the action of the atmosphere, and is then used in the manufacture of gas-retorts, fire-bricks, &c. The quantity of bricks made annually in the Stourbridge district is about fifty millions.
CHAPTER IX.
Salopian Wares—Uriconium—Caughley Works—Thomas Turner—Introduction of “Willow Pattern”—Worcester Works—Close of Caughley Works—Marks—Transfer Printing—Hancock and Holdship—Coalport Works—Jackfield—John Rose—Swansea and Nantgarw—Productions of the Coalport Works—Marks—“Willow Pattern” and “Broseley Blue Dragon,” &c.—Broseley Pipes—Coalbrookdale Iron Works—Terra Cotta—Madeley—Martin Randall’s China—Jackfield Pottery—Maurice Thursfield—“Black Decanters”—China—Craven Dunnill & Co.’s Tile Works—Broseley—Benthall—Maw’s Tile Works—Broseley Tileries—Benthall Potteries—Coalmoor.
In the midst of one of the most historically interesting districts of the kingdom—a district abounding in spots rendered famous in various ages by the events which have occurred within its boundaries, and full of associations as varied as they are interesting—within a few miles of Boscobel, and Tong, and numberless other places possessing a sad interest as connected with the wanderings and the painful vicissitudes of King Charles II.,—within a short distance of those two glorious monastic ruins, Buildwas Abbey and Wenlock Priory—not far from the “English Nineveh,” Uriconium, and within easy distance of Shrewsbury and Ludlow,—is a group of manufactories whose simple history is as interesting as that of many of these places.