The early medieval kilns appear to have been very similar in construction to those just described, or of even simpler construction. If we may take literally the statement that a potter at Skipton paid 6s. 8d. in 1323 'for dead wood and undergrowth to burn round his pots'[385] it would seem that here a primitive combination of furnace and kiln in one was in use. At a later date the usual construction was probably something similar to those found at Ringmer, in Sussex,[386] which seem to belong to the fifteenth century. Here the kilns were built of bricks or blocks of clay cemented by a sandy loam which vitrified under the influence of the heat to which it was subjected. The beds of the kilns enclosed longitudinal passages covered in with narrow arches, the spaces between which served to transmit the hot air to the superimposed clay vessels. The hearths were charged through arched openings at their ends with charcoal fuel.
To render the pottery non-porous, it was necessary to glaze it,[387] and from an early period lead has been used for this purpose. A twelfth-century description of the process says[388] that the surface of the vase is first to be moistened with water in which flour has been boiled, and then powdered with lead: it is then placed inside a larger vessel and baked at a gentle heat. This process gives a yellow glaze, but if green is required—and green was the colour most often used in England in the medieval period—copper or bronze was to be added to the lead. The same authority gives a recipe for a leadless glaze: baked potter's earth is powdered and washed and then mixed with half its weight of unbaked earth, containing no sand; this is then worked up with oil and painted over the surface of the vase.
Potters are mentioned at Bladon (Oxon.), Hasfield (Gloucs.), and Westbury (Wilts.), in Domesday,[389] but apart from casual references in place names[390] and in descriptions of individuals[391] the documentary history of early English pottery is scanty. Kingston on Thames may have been an early centre of the trade, as in 1260 the bailiffs of that town were ordered to send a thousand pitchers to the king's butler at Westminster.[392] At Graffham, in Sussex, in 1341, one of the sources of the vicar's income was 'a composition from the men who made clay pots, which is worth 12d.,'[393] but the most common form of entry is a record of sums paid by potters for leave to dig clay. Thus at Cowick in Yorkshire,[394] in 1374, as much as £4, 16s. was 'received from potters making earthen vessels, for clay and sand taken in the moor of Cowick.' Similar entries occur here every year for about a century, while at Ringmer, in Sussex, small dues of 9d. a head were paid yearly by some half a dozen potters for a period of well over two hundred years.[395] Still earlier, in 1283, a rent of 36s. 8d., called 'Potteresgavel,' was paid to the lord of the manor of Midhurst.[396]
The type of pottery produced does not seem to have varied to any great extent in the different districts.[397] At Lincoln it seems to have been the custom to decorate some of the vessels by means of stamps: some of these stamps, in the form of heads, may be seen in the British Museum. But the use of stamps for decorating pottery is found also at Hastings. One distinctive variety of earthenware, however, arose about the beginning of the sixteenth century: it is a thin hard pottery, dark brown in colour, well glazed, and usually decorated with elaborate patterns in white slip. From its being found in large quantities in the Cistercian abbeys of Yorkshire—Kirkstall, Jervaulx, and Fountains—it has received the name of 'Cistercian ware,' but there is at present no direct evidence of its place of manufacture.[398]
Closely connected with pottery is the manufacture of Tiles, the material being in each case clay, and the kilns used being practically identical. At what period the manufacture of tiles, which had ceased with the Roman occupation, was resumed in England is not certain, but from the beginning of the thirteenth century they play an increasing part in the records of building operations. The frequency and devastating effect of fires, where thatched roofs were in use, soon led to the use of tiles for roofing purposes in towns even when the authorities did not make their use compulsory, as was done in London in 1212, and at a much later date, in 1509, at Norwich.[399] The importance, for the safety of the town, of having a large supply of tiles accessible at a low price was recognised, and in 1350, after the Black Death had sent the prices of labour and of manufactured goods up very high, the City Council of London fixed the maximum price of tiles at 5s. the thousand,[400] and in 1362, when a great tempest had unroofed numbers of houses and created a great demand for tiles, they ordered that the price of tiles should not be raised, and that the manufacturers should continue to make tiles as usual and expose them for sale, not keeping them back to enhance the price.[401] It was probably the same appreciation of the public advantage that led the authorities at Worcester in the fifteenth century to forbid the tilers to form any gild, or trade union, to restrain strangers from working in the city, or to fix a rate of wages.[402]
The Worcester regulations also ordered that all tiles should be marked with the maker's sign, so that any defects in size or quality could be traced to the party responsible. Earlier in the same century, in 1425, there had been many complaints at Colchester of the lack of uniformity in the size of the tiles made there,[403] and at last it became necessary in 1477 to pass an Act of Parliament to regulate the manufacture.[404] By this Act it was provided that the clay to be used should be dug, or cast, by 1st November, that it should be stirred and turned before the beginning of February, and not made into tiles before March, so as to ensure its being properly seasoned. Care was to be taken to avoid any admixture of chalk or marl or stones. The standard for plain tiles should be 10½ inches by 6¼ inches with a thickness of at least ⅝ inch; ridge tiles or crests should be 13½ inches by 6¼, and gutter tiles 10½ inches long, and of sufficient thickness and depth. Searchers were to be appointed and paid a penny on every thousand plain tiles, a half-penny on every hundred crests, and a farthing for every hundred corner and gutter tiles examined. Infringement of the regulation entailed fines of 5s. the thousand plain, 6s. 8d. the hundred crest, and 2s. the hundred corner or gutter tiles sold. 'The size of the tiles is probably a declaration of the custom, the fine is the price at which each kind was ordinarily sold in the fifteenth century.'[405]
These regulations throw a certain amount of light upon the processes employed in tile-making, and further details are obtainable from the series of accounts relating to the great tileworks in the Kentish manor of Wye,[406] extending from 1330 to 1380. In 1355 the output of ten kilns (furni) was 98,500 plain, or flat, tiles, 500 'festeux'[407] (either ridge or gutter tiles), and 1000 'corners.' The digging of the clay and burning of the kilns was contracted for at 11s. the kiln, a thousand faggots were bought for fuel[408] at a cost of 45s., and another 10s. was spent on carriage of the clay and faggots. The total expenses were therefore £8, 5s., and as plain tiles sold here for 2s. 6d. the thousand, festeux at three farthings each, and corners at 1s. 8d. the hundred, the value of the output was about £14, 15s. In 1370, when thirteen kilns belonging to two tileries turned out 168,000 plain tiles, 650 festeux, and 900 corners, we have a more elaborate account. Wood was cut at the rate of 15d. for each kiln; clay for the six kilns of one tilery was 'cast' at 14d. the kiln and 'tempered' at the rate of 1s. 6d., but for the seven kilns of the other tilery payment was made in grain. The clay was carried to the six kilns for 4s., and prepared[409] for moulding into tiles for 7s.; the actual making and burning[410] of the tiles was paid for at 14s. the kiln, and an extra 12d. were given as gratuities to the tilers. Next year the output was considerably reduced, because in one tilery 'the upper course of the kilns (cursus furni) did not bake the tiles fully, nor will it bake them until extensive repairs are done,' and in the other tilery only four kilns were prepared, and one of these had to be left unburnt until the next year, owing to the lack of workmen. It was possibly for the defective kiln just mentioned that a 'new vault' was made in 1373 at a cost of 6s. 8d.—with a further 8d. for obtaining loam (limo) for the work. Two years later repairs were done to the buildings of a tilery, which had been blown down by the wind. But the chief blow was struck to the industry here by the increasing difficulty of obtaining workmen. The work may have been unhealthy, for it is noteworthy that the Ringmer potters were on more than one occasion wiped out by pestilence:[411] the effects of the Black Death in 1350 on the Wye tilers are not recorded, but in 1366 as a result, apparently, of the second pestilence two small tileries, one of three roods, and the other of 1½ acres, which had been leased for 7d. and 14d. respectively, lost their tenants, and in 1375 mention is made of the scarcity of workmen, 'who died in the pestilence at the time of tile making.' In 1377 Peter at Gate,[412] who for the past few years had hired a number of kilns at 20s. a piece, only answered for four kilns 'on account of hindrance to the workmen, who had been assigned to guard the sea coast, and on account of the great quantity of rain in the autumn, which did not allow him to burn more kilns.' In the same year, and also two years later, another tilery was unworked for lack of labour.
The tileries at Wye belonged to the Abbot of Battle, and there were tile kilns at Battle itself in the sixteenth century,[413] and probably much earlier, as in the adjoining parish of Ashburnham in 1362, there was a 'building called a Tylehous for baking (siccandis) tiles.'[414] Just about the same time, in 1363, we find 'a piece of land called Teghelerehelde' in Hackington,[415] close to Canterbury, granted to Christian Belsire, in whose family it remained for over a century, as in 1465 William Belsyre leased to John Appys and Edmund Helere of Canterbury 'a tyleoste with a workhouse' lying at Tylernehelde in Hackington for two years for a rent of 26s. 8d.[416] With the 'tyleoste' William Belsyre handed over 15,000 'tyle standardes'—worth 18d. the thousand, eighty 'palette bordes and three long bordys for the kelle walles.'[417] Various building accounts show that there were extensive tileries at Smithfield; for Guildford Castle the tiles came from Shalford, and for Windsor chiefly from 'la Penne.' In the north tiles were made before the end of the thirteenth century at Hull, amongst other places, but one of the chief centres was Beverley. About 1385 the monks of Meaux complained that 'certain workmen of Beverley who were called tilers, makers and burners of the slabs (laterum) with which many houses in Beverley and elsewhere are covered,' had trespassed on the abbey's lands at Waghen and Sutton, taking away clay between the banks and the stream of the river Hull without leave, to convert into tiles. The monks seized their tools, their oars, and finally one of their boats, but the Provost of Beverley, on whose fee the tileries were, supported the tilers in their claim to dig clay in any place covered by the waters of the Hull at its highest.[418] Some thirty years earlier, in 1359, the list of customary town dues at Beverley included 'from every tiler's furnace fired ½d.,'[419] and in 1370 Thomas Whyt, tiler, took a lease of the tilery of Aldebek from the town authorities for four years, at a rent of 6000 tiles.[420]