the pipes are conveyed on boards to the potting room where prior to passing into the kiln, they are packed into what are technically called "seggars" - circular fire-clay pots about nine inches deep and twelve inches in diameter, and capable of holding three gross of pipes each. The manufacture of these seggars, which are made in a manner similar to earthenware pots, is carried on in a separate department, and the pipes are placed in them to radiate from the centre. They are placed on top of each other in the kilns, where they remain subjected to intense heat for about twelve hours.
The kilns, which are of large dimensions, are near the potting-room. They are admirably constructed, on a system of Mr. McLardy's own devising. The heat is furnished by four fires placed at equal distances round the kiln, at a considerable elevation from the ground, and extending some distance inside the kiln, whilst they are fitted with bars and an earthenware sliding door, the whole forming a close furnace of unique design. The internal construction of these kilns, and the arrangement of their flues, are an entire speciality in this industry, and doubtless the superiority and high reputation Mr. McLardy's pipes have gained may in a great measure be attributable to these very superior kilns.
Their principal features consist in an arched fire-brick crown and fretwork brick floor, communicating with underground flues, which are supplied with regulating dampers.
The crown performs the important function of reflecting the heat down through the array of seggars. The crown is also furnished with an adjustable damper. By this ingenious mode of construction the amount of heat obtained can be doubled, yet it is at all times under full control. A further economy is effected by working the kilns in pairs, and arranging the dampers in such a way that the heat can be intercepted from the chimney and passed through the second kiln, thus gradually heating the pipes placed there to a very considerable temperature before the fires are lighted. Mr. McLardy estimates that by this novel construction of his kilns a saving of 30 per cent. in coal is effected, besides a proportionate economy in the requisite labour.
The furnaces for burning the long pipes are of a totally different character. They are built round in "steps," each step being larger in circumference than the one underneath. In the centre of this brick structure is what is called the "standard," which consists of round clay dishes, or bowls, made of fine clay in the shape of "sugar loafs," corresponding in size with the steps in the furnace, and upheld by clay pillars in the centre. The long slender clay pipes are here safely piled, 150 gross being burned in each furnace at one time.
Other modes of burning are also adopted at these works to great advantage.
The enamelling kiln which is specially constructed for burning what is known as French clays, &c, and in no respect resembles either of the kilns already described. The burning of the pipes in these kilns is effected on the radiation principle,the fire being wholly confined in flues, which extend all round the kilns. (Anon 1881, Jan 8, 53-4)
The kilns and furnaces are of novel construction and circular in shape, the kilns for the short pipes being altogether different from the furnaces in which the long ones are burnt. Before being placed in the kilns the short pipes are arranged in circular "seggars," or pots of fire clay, about twelve inches in diameter and nine in depth, each one holding about three gross. These are piled in heaps one upon another in the kiln from floor to crown to the number of 360, and baked twelve hours. The heat is furnished by four fires ranged round at equal distances, communicating with underground flues having regulating dampers by means of which the heat is regulated and allowed to ascend through the floor to the seggars, at discretion. The furnaces for burning the long pipes are entirely different. They are circular in shape, and are built round inside in steps, each step being larger in circumference than the one immediately below it. In the centre is a clay standard supporting an inverted fire-clay mug, or cap, upon which are laid,all round and close together, the pipes to be burned, the ends of all the stems pointing to the centre. When ranged round they are covered with very thin sheets of clay backed with paper, as protection. Another cap is then fitted on, another range of pipes laid round, and so on until the furnace is filled, by which time it contains about 150 gross. The fires are underneath, and the most elaborate precautions are taken to insure uniformity of graduated heat, and to prevent damage to the quality of the pipe. Burning is a very critical operation, and does much to make or mar the finished goods. If too soft they are brittle. and if over-hard and flinty they are unpleasant to smoke. Much of the superiority claimed for our own clay pipes over those of French make is attributable to the better burning. In these kilns the pipes are burned, or baked rather, during fourteen to sixteen hours. In the same building with these furnaces is a peculiar stove arrangement for vitrifying the coloured enamel on the ends of certain of the pipes. Those we saw being operated upon had the ends coated with what appeared to be red paint, but which, when burnt, came out a beautiful green enamelling. (Anon 1887, July 1, 191)
In an open space surrounded by a high boundary wall are four large kilns, circular in shape, and in their internal construction possessing several "improvements" made by Mr. McLardy, which no other manufacturer has the right to use. The pipes, after being moulded, are taken to the drying-rooms, the heat of which varies from 80o to 120o, and in two or three days are ready for the kilns. Before being put in the kiln they are placed in what are called "seggars," consisting of earthenware pots, circular in shape, about an inch thick, a foot in diameter, and nine inches in depth, each when full containing three gross. These are placed in rows all round the kiln one on top of the other until they reach from floor to the crown. The average time for burning is fifteen hours, but the kilnman or burner has a means of testing the contents of the "seggars" and of ascertaining when they are "enough," as the housewife would say in baking her bread. If the pipes have not had enough fire they are over-brittle, and if they have had too much they are hard and flinty and unpleasant for the smoker. This process applies only to the short pipes. The long clays such as the "churchwarden" require a differently constructed kiln and very careful manipulation lest the long stems be broken or put out of shape. Two of these, which are called "pot-kilns," are constantly at work. (Anon 1894, Nov 1)
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