Chap. IV.

BRICKS AND TIDES.

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put into small wooden moulds, and, in order to give them firmness, they are plunged intoa vessel of water, in which is a quantity of chopped straw, and after two or three hours’ im-mersion, they are laid out in the shade, where they remain until they become dry. Whenwalls are constructed with them they are coated with a layer of clay and chopped straw,which protects them from the rain ; sometimes a coat of lime and plaster, beaten and mixedtogether is substituted, where a better effect is desired.

Brick-making. — Tile earth usually selected by brick-makers is of a tenacious character,and partakes of the quality of loam ; a stiff clay makes a brick that falls to pieces inburning, whilst a milder earth is made by adding a quantity of sand to that which is toostrong. The clay dug in the autumn is wheeled in barrows to a piece of ground previouslylevelled to receive it, where it has a quantity of breeze added, which renders it partly com-bustible, when submitted to the heat, which converts the clay into a brick. It is necessarythat the brick should become red-hot throughout, and which would be difficult withoutthe breeze, which also gives colour, hardness, and durability. After this mixture of clay,sand, and breeze is rendered ready for use by being worked together with the spade, andcontinually softened by water, it is exposed to the action of the frost, and usually smallheaps are thrown up, so that the weather may penetrate them, and form one uniform, soft,and yielding mass : it is then tempered by adding water, or spreading it to dry; then thewhole mass is pressed down, and preserved by a covering to prevent the sun or air furtheraffecting it.

The clay is now generally wheeled at the commencement of the spring from the placewhere it has been exposed to the action of the frost to the pug-mill, where chalk, sand, orother materials are incorporated with it, the mill being supplied with a quantity of water,which reduces the whole into a thin paste, running through a sieve or wire strainer into areservoir formed for the purpose ; when this is full the whole is suffered to subside, andthe water is gradually drawn off: after it has acquired sufficient consistence, this finelydivided paste is moved by barrows, and mixed with sifted breeze; a few days’ exposureto the air makes it sufficiently dry for the moulder’s use.

The pug mill is a conical tub, secured by iron hoops, about 6 feet in diameter at thetop, and as much in height: the bottom is made of clay, or some other material imper-vious to water, and constructed so as to be perfectly firm and steady. The clay is put intoit, and then, by means of revolving rakes, with iron teeth, like those of the harrow’, andmade in such a form that in their revolution they lift up the clay, which falls down againtowards the bottom; the masses so separated, and supplied with abundance of water,are soon reduced into a paste. The whole is prevented from adhering to the bottom by aconstantly revolving scraper, w’hich allows the pugged clay to find its way to the orifice atthe bottom, where it is discharged.

A long beam of timber, keyed on the upright shaft, has a yoke, to which a horse is at-tached, that walks round in a track not exceeding 16 feet in diameter; if larger the propermotion would not be maintained. A pump worked by hand, or by the machinery, throw’sthe required quantity of water into the mill: the clay is put in from barrows, wheeled upa platform made for the purpose.

The Moulder's Bench is usually attended by a lad or assistant, who cuts the clay into por-tions sufficient to fill the mould ; these are taken up by the moulder, and thrust into it,w’hich is previously passed through a mass of sand, to prevent the clay from adhering to it :after the clay has been well forced dow*n, a flat wooden strike is made use of to remove allthat is superfluous; the brick is then turned out upon a board, and taken away by a boy tothe track in a barrow, covered with thin laths or strips of wood : one moulder’s benchwill supply 5000 bricks or more per day.

The bricks are then laid upon each other in the hacks, arranged on their edge, and placeddiagonally, so that the sun and air pass freely around them ; they remain here some time,after which their position is changed, and in a week or 10 days, if the weather be favourable,they are fit to be burnt.

The clamp is the general system adopted for burning them, which is formed by makinga foundation of place bricks, and then arranging those to be burnt in layers, with a stratumof breeze or cinders, 2 or 3 inches in thickness between them.

A fireplace is generally at the west-end, about 3 feet in height, from which variousflues branch out that run in a straight direction throughout the clamp; these flues, filledwith coals or breeze, are placed at distances of 5 or 6 feet apart: when the weather isfavourable a month is sufficient to burn ofF a considerable quantity.

Kilns containing 20,000 are in the country often preferred for burning bricks ; these aremade 13 feet in length, 11 feet in width, and 12 feet in height; the outer walls inclineinwards as they rise, and are a brick and a half in thickness throughout.

The furnace is formed of three arches, which have apertures at the top to allow theheat to pass through to the charge, which is placed on a floor of lattice; a moderate andgentle heat is applied for the first three or four days, to drive off the water ; the mouthof the furnace is then blocked up by a shinlog composed of brick, and room only left to

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