Fig. 100.—Potter’s Kiln, Normangate Field, Castor.
Fig. 101.—Potter’s Kiln, Normangate Field, Castor.
The kilns for firing the Castor ware, discovered by Mr. Artis, are among the most interesting of all the remains of Roman arts which have been brought to light. The kilns which were removed in the course of the investigations were “all constituted on the same principle: a circular hole was dug from three to four feet deep, and four in diameter, and walled round to the height of two feet. A furnace, one-third of the kiln in length, communicated with the side. In the centre of the circle so formed was an oval pedestal, the height of the sides, with the end pointing to the mouth of the furnace. Upon this pedestal and side walls the floor of the kiln rests. It was formed of perforated angular bricks, meeting at one point in the centre; the furnace was arched with bricks, moulded for the purpose; the side of the kiln was constructed with curved bricks set edgeways (see Fig. [100]) in a thick slip (the same material made into a thin mortar) to the height of two feet. The process of packing the vessels and securing uniform heat in firing the ware was the same in the two different kinds of kilns—namely, that before described, called ‘smother kiln,’ and that for various other kinds of pottery. They were first carefully loose-packed with the articles to be fired, up to the height of the side walls. The circumference of the bulk was then gradually diminished, and finished in the shape of a dome. As this arrangement progressed, an attendant seems to have followed the packer, and thinly covered a layer of pots with coarse hay or grass. He then took some thin clay, the size of his hand, and laid it flat over the grass upon the vessels: he then placed more grass on the edge of the clay just laid on—then more clay—and so on until he had completed the circle. By this time the packer would have raised another tier of pots, the plasterer following as before, hanging the grass over the top edge of the last layer of plasters, until he had reached the top, in which a small aperture was left, and the clay nipped round the edge; another coating would then be laid on as before described. Directly after, gravel or loam was thrown up against the side wall where the clay wrappers were commenced—probably to secure the bricks and the clay coating. The kiln was then fired with wood.[9] In consequence of the care taken to place grass between the edges of the wrappers, they could be unpacked in the same size pieces as when laid on in a plastic state; and thus the danger in breaking the coat to obtain the contents of the kiln could be obviated. In the course of my excavations I discovered a curiously constructed furnace, of which I have never before or since met an example. Over it had been placed two circular vessels; the next above the furnace was a third less than the other, which would hold about eight gallons; the fire passed partly under both of them, the smoke escaping by a smoothly-plastered flue, from seven to eight inches wide. The vessels were suspended by the rims fitting into a circular groove or rabbet, formed for the purpose. They contained pottery, both perfect and fragmentary. It is probable they had covers, and I am inclined to think were used for glazing peculiar kinds of the immense quantities of ornamented ware made in this district. Its contiguity to one of the workshops in which the glaze (oxide of iron) and other pigments were found confirms this opinion.”
Fig. 102.—Potter’s Kiln, Castor.
Fig. [102] is a kiln of a different construction. “In it, instead of modelling or moulding bricks for the kiln, the potters, after forming a tolerably round shaft, commenced plastering it three inches thick with clay, prepared for that purpose, leaving a flange twenty inches above the furnace floor to receive the floor of the kiln; a mode of construction unnoticed by me before in these kilns. In the centre was placed an oval pedestal, for the double purpose of dividing the fire and of giving support to the centre of the floor. To attach the pedestal to the back of the kiln, and to shut out the cold air which would lodge in the angle formed by the pedestal being so placed, the angle was filled with coarse materials, which were stopped up with clay, so as to draw the flame more towards the centre, and induce a union with the flame and heat entering the front part of the kiln.” The more usual plan with the potters of this district in packing their kilns was, when the contents had reached the surface of the earth, to form a dome by covering the urns and vases lightly with dry grass, sedge, or the like, and plastering it over with patches of prepared clay, divided by strewing a small quantity of hay between each portion to facilitate removal. In place of this usual process, in this kiln bricks were used of an oblong shape, four inches by two and a half inches, wedge-shaped at one end, with a sufficient curve to traverse the circumference when set edgeways, with the wedge ends lapped over each other. The sides would be thus raised for three or four courses or more, as circumstances might require, and probably be afterwards backed up with loose earth. These bricks were modelled and kneaded with chaff and grain.”[10] The numbers indicate as follows:—1, front of the pedestal supporting the floor of the kiln; 2 2, slopes, probably intended to produce a more uniform heat; 3 3, part of the kiln floor; 4, bricks, before used; 5, area of the furnace; 6, mouth of furnace; 7, wall of kiln; 8, top of the pedestal. The mouth of the furnace, No. 6, was arched over.
The ware of the Durobrivian potteries was superior both in style of art and in form and material to that of Upchurch, and has an especial interest over it in the fact that it bears figures and various ornaments in relief, in the same manner as on the Samian ware. The ornament, especially the scrolls, &c., were laid on “in slip.” The vessel, after having been thrown on the wheel, would be allowed to become somewhat firm, but only sufficiently so for the purpose of the lathe. In the indented ware, the indenting would have to be performed with the vessel in as pliable a state as it could be taken from the lathe. A thick slip of the same body would then be procured, and the ornamentation would proceed.
Fig. 103.