The successors of Elers—Robert Astbury, Joshua Twyford, and especially Dr Thomas Wedgwood—built up the reputation of the salt-glazed stoneware, which for fifty years was the glory of North Staffordshire; and, in the improvements they effected, the first two atoned for anything that to the modern mind was irregular in the manner by which they got their start.

It was to Dr Thomas Wedgwood (1655-1717), and his son Thomas (1695-1737), who made stoneware at “Ruffleys” in Burslem, that local tradition ascribes most of the improvements in salt-glazed wares. Mr Burton writes of the younger Dr Thomas: “It has never been suggested that Dr Thomas Wedgwood, like Twyford or Astbury, learned anything directly from Elers, but as he was a man of intelligence and commercial aptitude, as well as one of the best practical potters of the day, he would naturally adopt such new ideas as were brought in his way. Judging by the fragments of drab salt-glazed stonewares that have been found on the site of his old works in the centre of the town of Burslem, collectors are in the habit of attributing to him, with some show of justice, the finest pieces of this type.”[28][29]

The secret of the salt-glaze process consists in firing the ware, specially composed of clay mixed with some siliceous sand or flint, to a temperature higher than ordinary earthenware will stand, and then, when red hot, shovelling common salt on to it through the top of the furnace. The salt fumes, passing through large holes in the saggars, cover the ware with a fine coat of colourless soda glaze. This glaze can always be distinguished from lead glazes by its peculiar pock-marked roughness, which indeed makes it somewhat unsuitable for plates or dishes for ordinary use; and, although for fifty years salt glaze did more than hold its own in public estimation, improvements in the old earthenware finally drove it out. By the end of the eighteenth century salt glazing had ceased to be practised.

Without Astbury,[30] who is said to have died in 1743, aged 65,[31] it is doubtful whether even salt glazing could have been a really great success. He it was that obtained a body white enough to show off the transparent salt glaze to the best advantage. Dr Thomas Wedgwood had only the drab body to work on—a far less effective medium.

With the object of whitening the clay body, Astbury began to import the white clays of Devonshire.[32] At first he used them only as a wash or dip to whiten the surface of the ware, just as the tin-enamel had been used to conceal and coat the coarse body of the Delft ware. Then he developed the use of the white sands of Baddeley Edge and Mow Cop to harden the body; and, in 1720, according to tradition, he made the really vital discovery of the value of calcined flint stones for both these purposes—to whiten and to harden the clay body from which the stone ware was made. Josiah Wedgwood, writing in 1777, attributed this discovery to a potter of Shelton called Heath instead of to Astbury,[33] but whoever it was that first noticed the whiteness of burnt flints, it was Astbury who first determined the value of the new material and the manner of using it. This discovery marks the first stage in the production of cream-coloured earthenware as well as in the production of the perfect salt glaze.[34]

Astbury and his son Thomas made red and black ware also, after the pattern of Elers, but with this difference, the ornamentation of Astbury’s red or black ware is generally done in white clay,[35] instead of in the same colour as the body; and this is one sign by which collectors distinguish these two makers. Robert (or John) Astbury was succeeded by his son Thomas, who had started potting at Lane Delf in 1725. Their name does not occur among the potters of the latter half of the eighteenth century, but Margaret, Thomas Astbury’s daughter, married Robert Garner, a master potter of Longton, who attained a considerable position.

Joshua Twyford (1640-1729), like Astbury, had his factory in Shelton; one stood on either side of the mound where the church now is. Twyford is best known for his stoneware, chiefly red and black in the style of Elers, but he is also supposed to have made salt-glazed ware.

A particularly full account of the potters of 1710-15, especially of those in Burslem, is preserved in a document drawn up by Josiah Wedgwood in 1765. He gives both the weekly cost-account of a typical pot factory of this period; and also a list of the potters’ names and the kind of ware they produced. The document is in his own handwriting, and it appears from a letter of Wedgwood’s to Lord Auckland in 1792 that he obtained the information given in this document by “having examined some of the oldest men in the pottery here, near thirty years ago, who knew personally the masters in the pottery, and very nearly the value of the goods they got up, fifty years before that.” ... “From these data,” he goes on to say, “I can pretty nearly ascertain the annual value of the goods made here at that time; which was something under £10,000 a year.”[36] He then proceeds to guess at the annual value of the trade in 1792, which he says may be between £200,000 and £300,000. I cannot help thinking that his estimate was purposely on the low side, for the manufacturers of this date always lived in fear of special taxation. In 1821 the export trade alone was worth £423,399 a year,[37] and in 1822 £489,732.

The document runs as follows:

If this list is to be regarded as satisfactory evidence, and it must be remembered that it only professes to be a report of the fifty-year-old recollections of old men, then it would appear that Burslem was still the narrow home of the Potteries. It shows us the master potter of that day, employing 11 hands at wages not exceeding 6s. a week, working himself, and out of his single oven-full a week making a profit of 10s. As represented it is still a peasant industry. But the scope and range of the pottery produced has increased since Dr Plot described “the greatest pottery they have in this County.” The butter-pots; the cloudy, mottled, speckled and black; probably the red dishes and pans; these all existed in Plot’s time; but what is the “moulded” ware made by Cartlich and Thomas Taylor and by Dr Thomas Wedgwood, jun., in the middle of Burslem? The stone ware too is new since Plot’s time. The five biggest factories all make this stoneware, Dr Thomas Wedgwood, sen., Moses Marsh, Aaron Shaw, Moses Shaw, Sam. Edge and Richard Wedgwood, the brother of Dr Thomas.

Undoubtedly this was the new salt-glazed stoneware. The brown stoneware ascribed in the list to Dr Thomas Wedgwood coincides exactly with the drab salt-glazed teapot by him now in the South Kensington Museum. It is supposed to have been made by mixing the lightest burning local clay with the fine white sand from Baddeley Edge or Mow Cop.[40]

The list gives no potworks at all at the Longton end of the district, yet then or shortly afterwards Delft ware was probably made at the place called Lane Delf, now part of Fenton. Shaw says that in 1710 Thomas Heath of Lane Delf was making a strange kind of pottery, and he proceeds to describe a particular dish in such a way as to show that it was really Delft ware.[41] There is no trace of Delft ware having been made anywhere else in the Potteries, or indeed at any subsequent time at Lane Delf itself, so that we may fairly ascribe to this solitary experiment of Thomas Heath’s the name of the locality.[42]

At this Longton end, soon after 1710, there was also made white ware of a greenish type, called Crouch Ware. It was made from clay found in Derbyshire that bore this name, and survived as a fairly white ware till Astbury drove it out with his whiter body. In 1725 Thomas Astbury, the younger, set up his new factory in Fenton, and from this date we may say that the whole of the present Pottery area was engaged in the production of Earthenware.[43]

In fact all that was wanted to convert the peasant pottery of North Staffordshire into a great business was the stimulus given by the refined hand of Elers, and the new demand in the new clubs and coffee houses. When once improvements in manufacture began, invention followed invention; and though the records during the second quarter of the eighteenth century are full of entries of patents, registered for the performance of every possible and impossible pottery process, yet most of the improvements—especially the vital changes in body and glaze made by Astbury and Booth—became public property unchecked by patent law.

First there was Astbury’s new white body, made with a fixed mixture of powdered flint and Devon clay, imported on horseback from the sea-port of Chester. Twenty years earlier the idea of bringing clay from Devon would have been regarded as madness, and, even in 1720, carts could not get to Burslem, and the clay must have been brought inland on pack saddles. But the invention of the calcined flint body meant also the invention of that terrible disease known as “potter’s asthma” or “potter’s rot,” which used to cause an even greater mortality than lead poisoning. When white flints were first used they were ground and powdered in the dry state, in an atmosphere of flint dust, in underground cellars, so that the secret of this valuable new preparation should not leak out.[44] This state of things was soon partially remedied, for between 1726 and 1732 several patents were taken out—by Gallimore, Bourne, and finally by Benson—for grinding the flint stones in water.[45] Benson’s final process has survived to this day as the universal form of flint mill. A vertical shaft with four radiating arms revolves in a circular horizontal pan. The pan, with a hard stone bottom of chert, is filled with water, and similar chert blocks, pushed round by the arms, grind the flints down to a cream. Flint grinding became an industry, and in the well-watered valleys of North Staffordshire, wherever there was both water-power and flint, these flint mills sprung up and flourished. Though most of them are now closed down through the progress of railways and steam, there are some still to be seen working in the Moddershall valley, whence the creamy slip is sent in by water-cart to Longton.

About this same time a workman named Alsager perfected the potter’s throwing wheel as we know it at this day.[46] And now that potters were using these mixed ingredients, Devon clay, ground flint syrup, and native clay in special and patented proportions, the old method of evaporating the slip under the sun in an open pan had to go. It is said to have been Ralph Shaw, a most litigious personage, who began specially to mix clays in a liquid form in a fire-heated trough—locked, of course, that no neighbour might discover the “mystery.”[47] This same Ralph Shaw, of Burslem, took out a patent in 1732, professing—as was almost common form in those days—to make earthenware like Chinese Porcelain. It was to be white within, and white when required without. It was made in reality by dipping the ordinary ware in a white clay dip—just the process Astbury had invented some twenty years before. But there was this that was new to North Staffordshire; Shaw scratched away the white dip on the outside of the jug so that the blue ground became visible. He produced indeed what the mediæval Italians called “graffiato” ware, and very beautiful much of it is.[48]

Shaw, however, tried to prevent anybody using the white slip at all, and became such a nuisance to his neighbours that they united in 1736 to take up the case of John Mitchell, of Burslem Hill Top, who was prosecuted by Shaw for infringing his patent.[49] Great was the rejoicing in the Potteries when the Judge at Stafford declared, or is reported to have declared:—“Gooa whomm, potters, an’ mak what soourts o’ pots yoa leykin.” “An,” says our narrator, “when they coom ’nto’ Boslum, aw th’ bells i’ Hoositon (Wolstanton), and Stoke, and th’ tahin, wurn ringin’ loike hey go’ mad, aw th’ dey.” Ralph Shaw is said to have been so disgusted at the result that he emigrated to Paris, where he made pots for many years.[50]

Ralph Shaw’s ware was known as “bit-stone ware.” The “bit-stones” were put between two pieces of ware when they were fired in the saggars in order to keep them from sticking to each other. They were the more necessary in that Shaw’s ware was dipped in a light slip. The “bit-stones” have long since been replaced by “spurs” and “stilts” and other small earthenware objects, the special manufacture of which is now a great industry by itself. The single stilt and spur factory of Thos. Arrowsmith in Burslem employs now 230 hands on this manufacture alone.

If the old potters had had to rely only on the thrower’s wheel for their shapes, no improvement in whiteness of ware, or in the salt glaze, would have availed much to increase the demand for earthenware. The development of the various use of moulds became of the greatest importance. The six workmen required at such a potworks, as is shown on the 1710 list, would be—slipmaker, thrower, turner, “stouker,” to put on handles and spouts, fireman and warehouseman. A good workman, such as the master, could throw, turn and stouk. But the fresh developments of the salt-glazed stoneware arising from the use of moulds converted potting into a specialized industry.

We have seen that Elers used metal seals to press his ornamental “spriggs” on to his teapots. Such metal moulds could only be used for small articles or ornaments, for the mould stuck to the clay, and had to be carefully oiled. Both for the “sprigging on” of ornaments, and for the shaping of ware, a new form of mould was wanted. At first the alabaster of Derbyshire supplied the want. It was carved into shaped blocks, and from the blocks were made “pitcher,” or porous clay moulds, which could be replaced when worn out from the blocks, and could be used in various ways for the manufacture of ware: for sprigging, pressing, or “casting.” Then—a last step—about 1745, Ralph Daniel, of Cobridge, brought from France the secret of plaster of Paris moulds which replaced both pitcher and alabaster.[51]

Under competition, the Staffordshire potters were getting critical. The white salt-glazed ware was competing with Chinese porcelain, and had to be made as thin and light and transparent as possible. The ware made by pressing the clay into the moulds sufficed for plates, basins and any lead-glazed ware, but it came out much too heavy for complicated shapes such as sauce-boats, teapots and vases, etc. To get these shapes Elers would have had them thrown and turned down in the lathe: they would all have been round. The process known as “casting” in a mould produced a finer result, and gave infinite scope for variation. In casting, the clay is run in a liquid form into a porous mould. After standing a few minutes, the slip is run out again, leaving behind a clay shell. This “cast” shell, taken out when dry, may be as fine and as varied in shape as the skill of the potter and the heat of his furnace will permit.

The process of casting came into use about 1730, and the carving of these moulds (in alabaster first, from which the “pitcher” mould could be made), became the most critical operation of all the potter’s work. This work required all the skill and artistic instinct of the carver and of the designer. Block-cutters, as they were called, became famous. The best known were the two brothers, Aaron and Ralph Wood of Burslem. Aaron Wood (1717-85) was bound apprentice in 1731 to Dr Thomas Wedgwood, some of whose best models he is supposed to have made.[52] He afterwards worked for J. Mitchell, of Burslem,[53] and for Wheildon of Fenton, acquiring such a reputation that he was allowed to work in a locked room, that his art might thereby be kept secret.