INDUSTRIES 



The clays used in this pottery were the Purbeck, 

 Cornish china, and Wareham clays ; for the plain 

 quarries, clay from the Canford estate was largely 

 utilized.^* 



The Bourne Valley Pottery, owned by 

 Messrs. Sharp, Jones, & Co., produces glazed 

 stoneware sewage and sanitary pipes, terra-cotta 

 vases, figures, chimney-tops, and garden edgings, 

 &c.2^ 



The Kinson Pottery, Limited, was established 

 at Kinson, near Poole, in the middle of the last 

 century, with twelve kilns, a boiler, engine- 

 house, drying-sheds, stables, and offices. Closed 

 for a few years, it was acquired by the present 

 company in 1867, and since this date they have 

 manufactured stoneware drain pipes, also various 

 goods in terra-cotta. Twenty-seven acres of 

 clay of three different qualities are at the disposal 

 of the potter at this site, some of the beds being 

 40 ft. in thickness.^* 



In i8i2 there were two potteries at Bea- 

 minster producing a coarse ware, which was also 

 manufactured at Cranborne.°° 



It is hard to discover when tiles were first 

 made in Dorset in modern times ; probably the 

 Romans made them, but after that the mists 

 descend, and the glimpses that can be caught of 

 the industry are vague and unsubstantial. How- 

 ever, between 1770 and 1780, the oldest firm in 

 Dorset took over its present business from its 

 predecessors. This business was even then a 

 ' going concern.' ^' 



At the present time tile-making is one of the 

 special features of the clay industry in Dorset. 

 These tiles are used all over the world in shops, 

 restaurants, and bathrooms, in stations, hotels, 

 ocean-liners, and government offices. To ensure 

 perfect tiles, attention has necessarily to be paid 

 to the nature of the clay employed and to the 

 processes of manufacture. The clay pits now 

 worked are situated round Wareham, near Corfe 

 Castle, near Poole, near Corfe Mullen, and near 

 Hamworthy. The clay is not used by itself, but 

 is mixed with various other ingredients. It is 

 to a certain extent coloured naturally by oxide 

 of iron ; this gives to the clay, when burnt, tints 

 varying from light bufF to deep red, chocolate, or 

 even black. Clay has a peculiar property which 

 has to be reckoned with in making tiles ; unlike 

 most bodies it shrinks when exposed to heat 

 owing to the loss of moisture, so that a 6-in. 

 tile must measure say 6^ in. before being burnt. 

 Some clays shrink less than others because, among 

 other reasons, they contain a larger proportion of 

 silicate. These points must be noticed in 

 choosing the raw material, or the colour, shape 

 and size of the tile will be uncertain. 



" Jewitt, Ceramic Art, 236. ^ Ibid. 238. 



'^ Ibid. 239. 



^' Stevenson, Agric. of Dors. 450. 

 '* From information kindly supplied by Messrs. Pyke 

 Eros., Wareham, and others. 



When the material is chosen, the process of 

 manufacture is most interesting. The clay has 

 first to be changed into a meal-like dust suitable 

 for the tile-maker, and for this different clays, or it 

 may be different ingredients, such as ground flint 

 or china stone with clay, are carefully blended, 

 as experience may suggest, and are then « slipped,' , 

 i.e. placed with water in a machine called a 

 * blunger,' where the mixture is tormented until 

 the solution is thoroughly diffused. It is then 

 passed through a set of sieves of extreme fineness 

 and finally forced through a filter-press of cloths 

 to expel the moisture, which drips from the press 

 into a tank, leaving the solid matter between the 

 cloths. This water is driven back into the 

 blunger, only to go through the round with a 

 fresh mixture. There are also other ways of 

 drying the 'slips' as the mixture is called. 

 When dry the solid matter is ground, and, after a 

 final sifting, becomes dust ready for the tile press. 

 This machine is, in its essentials, a steel box 

 of the shape and size inside of the required tile, 

 and a very powerful screw-press applied by means 

 of a large fly-wheel, worked by hand, as steam- 

 presses are often unsatisfactory. The box is 

 filled with the fine dust slightly damped, and 

 pressure is applied ; after this a compact tile with 

 a firm smooth face is taken out of the press. Of 

 course the dust is not of the same clay, nor of 

 the same ingredients for all tiles. The tiles 

 described are those in which blended clays have 

 been turned into dust, which may also be coloured 

 by a stain. For these tiles the upper die or 

 stamp must have a true, firm face, but if an 

 embossed tile be required the upper die has the 

 pattern in reverse like a seal. The tiles are dried 

 at a temperature of about 80 degrees for some 

 days after being made, and are then placed in 

 open fire-clay boxes called ' seggars ' or often 

 ' saggers.' These, when placed in the kilns, 

 practically close one another. The ' seggars ' are 

 stacked in the kilns to be ' fired,' a process which 

 takes about a week, after which they emerge 

 hard and fit for use as unglazed or biscuit tiles. 



Buff, red, and salmon tiles are produced by 

 blending naturally colouring clays according to 

 the proportion of iron they contain ; grey, 

 chocolate, and black tiles by using ironstone and 

 manganese as a stain. White tiles cannot be 

 obtained by burning a simple clay, but this has 

 to be mixed with white ball clay which is 

 found in Dorset and Devon, ground flint and 

 china clay, felspar and stone. The whole 

 mixture has to pass through the * slipping ' pro- 

 cess. The ' slip ' is coloured blue with cobalt 

 and green with chromium. Encaustic tiles which 

 have on them patterns of floral or other designs 

 in two or more colours are much more com- 

 plicated to manufacture. They were formerly 

 made of plastic clay, the pattern being stamped 

 on the partially hardened clay, and then filled 

 up with clay of a different colour, after which 



365 



