Chapter III: The Walls. Bricks and Brick-Work

We now come to that material which is, in England, a more important agent than stone in the construction of dwelling-houses; namely, _bricks_ made from clay. There were three millions and a half of houses in Great Britain in the year 1841; and there can be no doubt that of this number those which were built of brick constituted a vast majority. It is only in a few particular districts that stone is a more available material for houses than bricks. In other countries, too, as well as our own, the arts of brick-making and bricklaying are carried on more extensively than the operations of the stone-mason.

Bricks and Brick-work in Early Times.

It has been observed that “the art of making bricks is so simple, that it must have been practised in the earliest ages of the world; probably before mankind had discovered the method of fashioning stones to suit the purposes of building.” It is stated in the Book of Genesis that burnt bricks were employed in the construction of the Tower of Babel. Now, as this structure appears to have been raised about four hundred years after the Deluge, it is scarcely an exaggeration to say that the art of making bricks was invented almost as soon as men began to build. Bricks seem to have been in common use in Egypt while the Israelites were in subjection to that nation; for the task assigned them was the making of brick, and we are informed in the Book of Exodus, that the Israelites built two Egyptian cities. No particulars are given in Scripture of the method of making bricks; but as straw was one of the ingredients, and as very little rain falls in Egypt, it is probable that their bricks were not burned, but merely baked by the heat of the sun. The same mode of baking bricks seems still to be practised in the East. The ruins of the tower near Bagdad are formed of unburnt bricks. The art of brick-making was carried to considerable perfection among the Greeks. Pliny states that they made use of bricks of three sizes, distinguished by the following names: _didoron_, or six inches long; _tetradoron_, or twelve inches long; and _pentadoron_, or fifteen inches long. That the Romans excelled in the art of making bricks there is the amplest evidence, since brick structures raised at Rome seventeen hundred years ago, still remain nearly as entire as when first built.

A remarkable kind of _floating brick_, used by the ancients, has been made the subject of investigation in modern times, with a view to the suggestion of improvements in the making of bricks for particular purposes. Pliny states that at various places in Spain, in Asia Minor, and elsewhere, bricks were made which, besides possessing considerable strength and a remarkable power of enduring heat, were yet of such small specific gravity, that they floated on the surface of water. Like many of the arts of the ancients, the method of making these bricks, as well as the material of which they were made, were forgotten for many ages. About the year 1790, however, an Italian, named Fabbroni, turned his attention to the subject, and after various experiments on minerals of small specific gravity, he came to the conclusion that these bricks must have been composed of a substance called “mountain-meal;” or, at least, he found that he could make of this substance bricks which appeared to agree in every respect with those described by the ancients. This mountain-meal is an earth composed of flint, magnesia, clay, lime, iron, and water, in certain definite proportions. The bricks which Fabbroni formed of this material had the property of floating in water; they could not be fused by any ordinary degree of heat; and so low was their conducting power, that while one end of the brick was red-hot, the other could be held in the hand without the smallest inconvenience. It has been supposed that a peculiar kind of earth, found in some parts of Cornwall is the same as that with which Fabbroni experimented on in Italy, and that both are analogous to the kind of which the ancients made their floating bricks. Proceeding on this supposition, it has been proposed to make such bricks for the construction of _floating houses_ upon ornamental waters. At present such structures can be made only of timber; and, however the owner may decorate them, they have always a flimsy and unsubstantial appearance, and they are soon injured by the weather. If, however, a platform of good timber were employed as the base of the whole, and the weight so contrived as to keep this platform constantly under water, it would last a long time. The upper part of the structure formed of the floating bricks, might have all the appearance, and, indeed, all the stability of a brick house upon land; for this description of brick resists the influence of the atmosphere as well as the action of fire; and although it is not absolutely so strong as the heavy brick in common use, it is far more so in proportion to its specific gravity. We do not know whether these conjectures have yet been put to the test.

That the early inhabitants of many countries in the eastern and central parts of Asia were acquainted with the use of bricks in building, we have abundant proof from the descriptions of intelligent travellers; and there are even grounds for attributing to them a very high degree of mechanical skill both in the making of the bricks and the formation of brick walls. Dr. Kennedy, in his _Campaign of the Indus_, says:--“Nothing I have ever seen has at all equalled the perfection of the early brick-making, which is shown in the bricks to be found in these ruins [ancient tombs near Tatta]: the most beautifully chiselled stone could not surpass the sharpness of edge, and angle, and accuracy of form; whilst the substance was so perfectly homogeneous and skilfully burned, that each brick had a metallic ring, and fractured with a clear surface, like breaking freestone. I will not question the possibility of manufacturing such bricks in England, but I much doubt whether such perfect work has ever been attempted.”

Making Bricks by Hand.

In the mechanical arrangements for making bricks two very different systems are adopted; the one handicraft, and the other by machinery. The former has always been and still is far more extensively adopted than the latter.

In the selection of materials for brick-making, a brown loamy clay, that is, clay which contains a small quantity of calcareous matter, is considered best for ordinary bricks, but the ingredients vary according to the purposes for which the brick is required; and every one must have remarked the difference in colour between the light yellow _marl stocks_, as they are called, employed in the facing of houses of the better kind, and the dark red brick used in Lancashire and other northern counties. The colour also varies with the proportion of ashes or sand employed in the mixture, and with the degree of heat they are subjected to in drying. The general process is, however, much the same everywhere; and we shall describe that used in England, where bricks are always burnt.

The proper kind of clay being found, the top vegetable mould is removed, and the earth dug and turned over to expose it as much as possible to atmospheric action, and for this purpose it is left for the winter. In spring, a quantity of fine ashes, varying in proportion to the clay from one-fourth to a fifth, according to the stiffness of the latter, is added by degrees, and well incorporated by digging and raking, water being poured on to render the mass soft. When the union is effected, the clay is carried in barrows to a rude mill, erected near the shed, in which the brickmaker works.

This mill consists usually of a vat, or circular vessel, fixed on a timber frame; an upright iron axle is placed in the centre of the vat, and carries some iron plates, or rakes with teeth, to stir up the soft clay when placed in the mill: this axle is turned round by a horse harnessed to a horizontal shaft which proceeds from the axle. The clay being put into the vat, the rakes or _knives_ complete the incorporation of the ashes, and thoroughly temper the whole mass, which is gradually squeezed out through a hole in the bottom of the vat.

A better kind of mill is used in tempering the material for the better bricks; it only differs, however, in being larger. An iron harrow loaded with weights is dragged round in a circular pit lined with brick-work. The clay in this case is diluted with water sufficiently to allow of the stones sinking to the bottom; and the fluid is drawn off into pits, where it is left to settle and thicken, to the proper consistence.

The prepared clay is first separated into masses, each large enough to make a brick, by the _feeder_, or assistant, who sands the pieces ready for the _moulder_; the _mould_ is an open rectangular box, the four sides of which are made to separate from the bottom, to allow of the brick being turned out. The bottom is now made with a lump raised on it, by which a slight depression is formed on one side of the brick, to admit a mass of the mortar being received and detained in it when the wall is built.

The moulder takes the piece of clay prepared for him, and dashing each into the mould so as to cause it to fill it, removes the superfluous quantity by means of a flat piece of wood which he draws across the open side of the mould; this _strike_ is kept in a bowl of water to wet it, and prevent the adhesion to it of the clay. The man then lifts off the sides of the mould, and deposits the brick on a flat _pallet-board_, and this is removed by a boy who ranges the bricks on a lattice frame set sloping on the barrow in which they are to be taken to the field to dry; fine sand is strewed on the frame and over the bricks, to prevent their adhering together.

The bricks are taken to the field, and piled in long lines called _hacks_. This is a nice operation, as the soft bricks, if handled roughly, would become twisted, and rendered useless; the bottom course of bricks is raised a few inches to keep it from the wet; and the ground is prepared to receive them by being covered with dry brick-rubbish or ashes, and raked smooth. The bricks are set alternately in rows lengthwise and crosswise, with intervals between them of an inch or more, to allow a thorough circulation of air: the hack, when raised about a yard high, is covered over with straw to throw off the rain.

If the weather be favourable, ten or twelve days are enough to dry the bricks in the hacks sufficiently to prepare them for burning, but they should be thoroughly dry, or the subsequent process will fail.

Ordinary bricks for building are burnt in _clamps_, which are large oblong masses, built up of the unburnt bricks, laid regularly in layers, with large flues or passages at intervals, in which ashes, cinders, coal, and brush-wood are laid; layers of ashes are strewed over those of the bricks. The object is, that the fire, when the fuel is ignited, may penetrate every part of the mass, and bake every brick equally; even the ashes mixed up in the clay are intended to be partly burnt by the heat. In clamps well constructed the outside is coated with clay or plaster to keep in the heat, and when the fuel is thoroughly lighted, the external apertures should be stopped up.

The clamp when completed contains from 100,000 to 500,000 bricks. The fire will continue burning about three weeks, if the pile has been well constructed: when all smoke ceases to rise, the clamp is taken down when cold, and the bricks sorted; for, even with the utmost care, it must happen that the bricks are not all equally burnt. The best are those in the centre. The under-burnt ones are reserved to be rebuilt into a new clamp for further baking, and those which are over-done, and have run together by partial vitrification, are sold at a cheap rate for making foundations for houses, roads, &c.

The better or peculiar kinds of bricks, as well as tiles of all kinds, are burnt in kilns instead of clamps. These kilns, though of a peculiar form, according to the purpose to which they are applied, yet do not differ in principle from the lime-kiln, &c. In the kiln, the fire is not intermixed with the bricks, but is applied beneath; nor are ashes mingled with the clay of which kiln-burnt bricks are made.

As the general principles are the same in making tiles and bricks, we shall class all these coarse pottery-works together here, in an enumeration of the most important kinds used in Britain.

_Place-Bricks_ are the worst of the clamp-burnt stocks, and are used for common walls, and the poorest kinds of work; they are soft and unequally burnt; they sell from 20_s._ to 30_s._ a thousand.

_Stock-Bricks_ are those from the centre of the clamp, and are regularly burnt, of an equally hard texture, and even colour; they are used for good work of all kinds; the price varies from 30_s._ to 40_s._ a thousand.

_Malm-Stocks_ are clamp bricks, but made with more care from clay to which ooze, chalk, or marl is added; and the whole carefully tempered; they are of a fine clear yellow colour, and are used for facing the walls of good houses, and for making arches over doors and windows in general, where they are to be seen. The softest kind are called _cutters_, from their admitting of being cut, or trimmed, with the trowel with nicety. The prices of these bricks vary greatly.

_Fire-Bricks_ are made of a peculiar kind of clay, found in perfection at Windsor, Stourbridge, and parts of Wales, whence the varieties derive their names. They are formed from the clay without any admixture of ashes, and are always kiln-burnt. They vary in size, and are used for building furnaces, ovens, boilers, &c.

_Pan-Tiles_ are tiles, the cross section of which may be represented thus. They are used for roofing outhouses, stables, &c., the edges of one row overlapping those of another next it, and they are always set in mortar: the end of the tile is formed with a projecting knob or fillet, by means of which the tile is hooked on to the batten or lath. These tiles are much larger than the _Plain-Tiles_, which are used in roofing dwellings, &c.; they are flat, as the name indicates, and are fixed to the laths of the roof by wooden pegs, two holes being left in the tile for that purpose. Foot and ten-inch tiles are thick square tiles of those dimensions, used for paving, hearths, &c., or for coping walls. All tiles are burnt in a kiln.

Bricks made in Great Britain are charged with a duty, and as it constitutes an important item in the revenue, the manufacture is laid under strict surveillance by the Excise. The duty on tiles was repealed in the year 1833. Bricks can only be made at certain seasons, in certain quantities, and even the screen through which the ashes are sifted, to be mingled with the clay, must be made of wire of a certain mesh. Bricks made larger than the standard measure of 8½ inches long, 4 wide, and 2½ thick, pay a higher duty than the common ones; if the bricks are smaller than the proper size, the maker is fined heavily. No duty is charged upon bricks made in Ireland.

About 1500 millions of bricks, 42 millions of plain, 23 millions pan, and 6 millions of other tiles, are made annually in Britain. A good moulder can make from 5000 to 6000 bricks in a day, from five A.M. to eight P.M.

Within the present century, the annual use of bricks in Great Britain has more than doubled, owing to the increase of manufactories, and to the construction of railroads and other public works.

Making Bricks by Machinery.

Within the last few years the making of bricks and tiles by machinery has occupied much attention. A large number of patents has been taken out for contrivances having this object in view. In some cases the patentee has directed his attention chiefly to the preparation of bricks for houses; while in others the making of tiles for draining has been the chief object. A description of one or two of these contrivances will give an idea of the general character of the whole.

The Marquis of Tweeddale, having his attention drawn to the importance of employing draining tiles in agriculture, directed his talents to the invention of a machine which should make them so quickly as to enable them to be sold at a low price. After many attempts, he perfected a machine which worked out this object, and at the same time possessed all the facilities for making common bricks. The machine is not constructed on the principle of imitating the manual operation, by forming the bricks in moulds; but it arrives at the same end in a different and remarkable manner. The principle adopted is, to form and protrude, by mechanical means, a continuous fillet of clay, of the proper width and thickness for a brick, and to stop this act of protrusion for a moment, whilst a length of the fillet equal to that of a brick is cut off. This is effected by the following mechanical arrangements:--Two vertical roller-wheels, one of them being placed over the other, and having an interval between them equal to the thickness of the intended bricks or tiles, are made to revolve in contrary directions; consequently they draw between them the clay with which they are fed on the one side (either by hand or by any mechanical contrivance), and deliver it on the other in a highly compressed state, and in the form of a straight, smooth, and even fillet of the width of the rollers. To provide for the squareness and smoothness of the sides of the fillet, the sides of the aperture through which the clay passes are made square and neat, so as to prevent the clay from spreading out laterally. The clay is supported in a horizontal position whilst delivered to and received from the rollers, upon a short endless band on each side revolving on rollers rather close together; and in order to facilitate this object the rollers themselves have bands, which are prolonged in the direction of the endless bands in such a manner as to meet them, and form one horizontal line of support. These bands are made of fustian, the nap of which prevents the adhesion of the clay. The rollers are so acted on by the working power that they protrude a length of clay equal to the required length of the brick or tile, and then stopping, they allow time for a straight stretched wire to descend and cut off the brick or tile, after which the motion between the rollers is resumed, until another length is protruded, and so on continuously. The fillet of clay is double the width for a brick, and a wire is kept constantly stretched in the middle of its path, dividing it into two fillets, so that two bricks are cut off at once. Two boys are sufficient to remove the bricks as fast as they are produced, which is at the rate of from fifteen to eighteen hundred in an hour. The consistence of the clay is so much stiffer than that used for hand-made bricks, that only half the time is required in the drying. From there being so little water in the clay, and from its undergoing so much compression, the bricks produced are remarkably dense and strong, weighing half as much again as the ordinary brick, and absorbing only one-seventh as much water.

Many machines have been contrived, having for their object the formation of bricks on a principle somewhat analogous. Another class of machines have effected the desired end in a different way,--viz., by forming each brick separately in a mould. A slight description of one machine of this kind will illustrate all the others. The main part of the machine is a horizontal wheel of large diameter. Round the periphery of this wheel is a series of moulds, the exact size and shape for bricks, placed nearly close together. Each mould has a loose bottom, incapable of falling below the mould, but capable of rising to its upper edge. The clay for the bricks, being properly prepared in vessels at one side of the wheel, is made to fall into one of the moulds, and the superfluous quantity is scraped off by a flat edge which passes over the mould. The wheel rotates, and in its movement it passes over a circular inclined plane, so constructed as to lift the bottom of the mould up, so as to protrude the newly-made brick above the mould, where it can be conveniently taken off by the hand. All the different moulds, perhaps thirty or forty in number, are at any given instant in different conditions as to their quota of clay; one is receiving the clay, another is having the superfluous clay scraped off, another has travelled so far round as to have the brick lifted halfway out of it, another presents the brick wholly out of the mould, ready to be taken off, while the others are travelling on empty to receive a new supply of clay, all the moveable bottoms gradually sinking to their proper position as the wheel proceeds, so that one rotation of the wheel carries each mould through all its different stages of position.

The Processes of Bricklaying.

When we consider that a wall forty or fifty feet high, and not more than two feet thick at the bottom, and fourteen or fifteen inches thick at the top, is constructed of such small bodies as bricks, we may well suppose that considerable nicety in workmanship must be requisite to give stability to such a structure. The uniformity in size in the bricks themselves, arising from their being _copies_ of one mould, is obviously the first condition that tends to the object; the next is, that they should be put together in such a way as to cause them mutually to adhere, independently of the tenacity of the mortar employed; and lastly, the bricks must be set with great attention, that their surfaces may be perfectly parallel and perpendicular to the direction of gravity, for otherwise the wall composed of them, instead of being truly perpendicular, would lean over on one side and fall. We shall enter into some particulars on these points, but first we must describe the tools and materials used in Bricklaying.

The _trowel_ is the first and most indispensable of these tools. It is a thin, flat, lozenge-shaped blade of steel, fixed into a handle. It is with the trowel the workman takes up and spreads the layer of mortar put between each brick, and with it he also _cuts_ the bricks so as to fit into any corner, or to adapt them to some particular form; and to enable it to cut, or rather chip, such a hard substance as burnt clay, and yet not break, it is necessary that the blade should be of well-tempered hard steel. The _square_ and _level_ are made of wooden rules put together; the first at a true right angle, to enable the bricklayer to set out his walls correctly perpendicular to each other,--the second is framed like a ⟂, with a plummet hanging in a slit in the upright piece; now, as the two rules are correctly perpendicular to each other, it is clear that when the first is set by means of the plumb-line perpendicular to the horizon, the other will be truly horizontal. By means of this important instrument, the workman guides his work, so that the wall he is building shall be upright, and the courses of bricks composing it horizontal. By means of this important instrument, the workman guides his work, so that the wall he is building shall be upright, and the courses of bricks composing it horizontal.

_Mortar_ is the name given to the composition with which the bricks are put together. Good mortar should be made of newly-burnt quicklime from grey limestone, and of clean river-sand, in the proportions of one-third lime to two-thirds sand. The lime is _slaked_ by pouring a little clean water on it, and when it falls to powder by the chemical action, the sand is added gradually, and the whole well mixed up with a spade, more water being used till the mass is of the proper consistence for spreading easily. As the adhesion of the bricks depends on the mortar being applied before it begins to _set_ or harden, it should not be mixed till it is to be used. When these simple precautions are attended to, the mortar becomes in time as hard as stone, and the brick-work constructed with it is nearly as indestructible. It was by taking this care with their materials that our forefathers built walls that have stood uninjured for centuries. In some of the cheap common buildings of the present day, mortar is too often made from lime which has been so long from the kiln, that it is nearly reconverted into a hydrate, and has lost the chemical quality which renders it valuable; the sand, too, is taken from the road with all its impurities, and the water from the nearest kennel. With such materials a mass of mortar is made, and suffered to stand for several days before it is used; the consequence is, that such buildings are neither safe nor durable.

The mortar is made up by an assistant, called a bricklayers’ labourer, and is taken by him to the spot where the workman wants it in what is called a _hod_: this utensil, which consists of three sides of a rectangular box fixed edgeways at the end of a long handle, is expressly contrived to be carried on the man’s shoulder, and leave his hands disengaged, to enable him thus loaded to ascend and descend a long ladder; the hod being held standing upright on the handle, the labourer can put bricks into it with his right hand, or another assistant fills it with mortar.

The manner in which the bricks are arranged in the work, is termed _bond_, and is of different kinds, according to the thickness of the wall, and the purposes for which it is intended. The bond most generally used is termed _Flemish_, in which the bricks are laid alternately lengthwise and across the thickness of the wall, the broadest side of the brick being laid horizontal, and never edgeways, in building _walls_ of every thickness. It was formerly usual to lay a whole course of bricks lengthwise, and that above it across; this disposition may be seen in old walls, and was termed _English-bond_. In every kind of bond, the joints of the bricks of one course are always made to fall over a brick in that beneath, or so that one joint may never be immediately over another.

The site of a wall, or the walls of a building, being _set out_ or marked on the ground, a trench is dug in the earth for the foundations, the width and depth being determined on from the thickness and height of the superstructure, and from the nature of the soil. If this be loose or soft, and the edifice be an important one, it is often necessary to drive piles into the bottom of the trench, and lay a course of oak planking on the tops of these timbers, to form a firm foundation for the wall; but if the nature of the ground do not require such precautions, it is only necessary to level the bottom of the trench carefully, as on this the stability of the wall will entirely depend. A course of bricks is then laid dry on the earth, forming a band twice the width of the lowermost thickness of the wall to be built. This and the subsequent courses of the foundations should be constructed of the best bricks; but unfortunately in common houses this obvious requisite is entirely neglected. When this course is laid, thin mortar, or mortar almost fluid and having but little sand in it, is poured over the bricks, so as to flow into the joints and bind them together by hardening: a second course is then laid on the first, only narrower in width, and each subsequent course diminishes in the same regular manner on each side, till the width is reduced to the thickness at which it is proposed that the lower part of the wall should be built. A cross section of these foundations thus constructed would present the outline of a truncated pyramid, diminishing by regular sets-off or steps; this part of a wall is called the _footings_. For garden walls, or such as have no weight to carry, the footings need not be made of so many courses, nor so broad, but every wall must have two courses at least for a foundation.

The bricklayer makes use of a string stretched between two pins, to enable him to keep his work straight; and he lays the outermost bricks, those forming the face of the wall, carefully by this guide, setting each brick alternately lengthwise and transversely, and spreading a layer of mortar on the brick beneath, to form a bed for the new one to lie on, and also a layer between each upright joint. It is usual only to lay the outer bricks in this manner, and to fill up the interstices of those forming the interior of the wall by pouring mortar on each course previously laid dry with sufficient interval between them. The workman as he proceeds, repeatedly makes use of his level and square; by the former, he examines whether the face of his wall, and all the corners, or _arrises_, are correctly perpendicular, and whether the courses of bricks are laid horizontal.

Apertures, such as windows or doors which are to be formed in the wall, are marked out on the wall when the work is built up to the height where they are to commence; in carrying up the _piers_ between these windows, it will frequently happen that the width of the pier is not precisely commensurate with a certain number of bricks or half-bricks, but that a brick must be cut to bring the work to the correct dimensions. This smaller piece is termed a _closure_, and is usually placed within a brick or two of the arris of the window or door, and preserves its place for the whole height of the pier.

The thickness of brick walls is described by the number of bricks’ length they contain in that direction: thus a nine-inch wall is one-brick thick; a brick-and-a-half wall is fourteen inches; a two-brick wall is eighteen inches thick, and so on. The walls of small houses are often only one brick thick, even when they are two stories high; but usually a wall to be steady should decrease in thickness half a brick at least every story, and for a large substantial building of four or five stories, the main walls should be two-and-a-half bricks at least on the basement story, and one-and-a-half at the top; but of course the size of the apartments, or, in fact, the area of wall which is to remain without any lateral support, must govern the strength of it, as well as the total height to which it is to be raised.

When the wall is raised as high as the tops of the windows, &c., which were left in it, these apertures must have arches turned over them, to support the brick-work above. This leads us to consider the different modes of constructing brick arches. When the width of the opening is not above three or four feet, the arch over it is frequently straight in its outline, or but slightly curved in the intrado or lower line. The bricks which are to form the arch are rubbed down on a board till they are brought to the proper wedge form. A piece of wood for a centering is supported in the opening by upright slips: the upper side of this centering is, of course, cut to the true _camber_ or curve the intrado of the arch is to have: the bricks are set upright on this centre, and alternately, so as to break the joints. The face of the arch, which is seen in the street over the windows and doors, is constructed of the best bricks, carefully cut to a mould and set in _putty_, or in thin mortar made of lime only: the rest of the arch behind this face is less carefully constructed, and the bricks are often not cut at all, but made to form an arch by the intervening layer of mortar being spread unequally thick, or in a wedge shape. When, however, a large arch is to be built of bricks, these are cut to the proper level to form the wedge-shaped voussoirs. The construction of groined arches in brick-work is the most difficult operation in the trade. Each brick that forms the arris or intersection of the cross vaults requires to be cut to a true form given by a drawing made to the full size on a board. Another perhaps still more delicate piece of workmanship for a bricklayer to execute is an oblique arch, such as are often seen in the bridges over railroads and canals, which cut established roadways obliquely. These arches are portions of a cylinder, but the ends of the cylinder, instead of being perpendicular to the axis, are oblique to it, and this requires that the courses of bricks composing the arch shall also not be parallel to the axis, and therefore not in straight lines: hence, every brick has to be cut or rubbed to a wedge form in two directions, and great nicety in this and the subsequent operations are requisite in these structures.

Formerly columns, pilasters, cornices, niches, and similar architectural embellishments, were constructed in brick-work, but stone has now superseded brick for all embellishments; and the bricklayer’s greatest skill is only required in the construction of arches, or occasionally building a circular wall. The best specimens of elaborate brick-work of the old school may be seen at the conservatory of Kensington Palace, at Burlington House, and many other edifices of the time of William and Mary, and Queen Anne, throughout the country. The series of arches extending for nearly four miles on the Greenwich Railway, and those for nearly an equal distance on the Blackwall Railway, are perhaps among the best and most imposing specimens of modern brick-work, and afford, in many places, beautiful examples of the oblique arch. There are brick arches of a large span at each end of the new London and Waterloo bridges.

Brick-work is measured by the _rod_, which is a superficial area of sixteen and a half feet each side, or 272 square feet, at a thickness of one-and-a-half brick, and all plain wall-work is reduced to this standard for valuation. A rod of brick-work contains 4500 bricks, and together with the mortar required to build it, weighs about 15 tons 8 cwt. It differs in value from 10_l._ to 15_l._, according to circumstances.

Besides building walls, bricklayers are employed to tile roofs, set coppers, pave stables, &c., build drains, and, in short, on all occasions where bricks or tiles are the materials used.

Defects of Modern Brick Houses.

A writer in the _Encyclopædia Britannica_ endeavours, with much ingenuity, to show that the quality of English bricks and the system of bricklaying are very much influenced by the customary leasehold tenure of land. His remarks are as follow:--“Brick-making has been carried to great perfection by the Dutch, who have long been in the habit of forming their floors, and even, in some cases, of paving their streets with bricks. And it is remarkable how long their bricks will continue unimpaired in such situations. Though brick-making has long been carried on in England, and especially in the neighbourhood of London, upon a very great scale, and though the process upon the whole is conducted in this country with very considerable skill, yet it must be acknowledged that English bricks are by no means so durable as Dutch bricks. We are disposed to ascribe this inferiority not so much to the nature of the materials employed in the manufacture of English bricks, as to the mode most frequently adopted in London of building houses. Few of the London houses, comparatively speaking, are freeholds. Most of them are built upon ground let for a lease of a certain number of years, which seldom exceeds ninety-nine years. After the expiration of this period the house becomes the property of the landlord who let the ground. Thus it becomes the interest of the builder to construct the house so that it shall last only as long as the lease. Hence the goodness of the bricks becomes only a secondary object. Their cheapness is the principal point. The object, therefore, of the brickmaker is not to furnish durable bricks, but to make them at as cheap a rate as possible. Accordingly, the saving of manual labour and of fuel has been carried by the makers of London bricks to very great lengths. We cannot but consider this mode of proceeding as very objectionable, and as entailing a much heavier expense upon London than would have been incurred had twice the original price been laid out upon the bricks when they were first used, and had the houses been constructed to last a thousand instead of a hundred years. No doubt certain advantages attend these ephemeral structures. The inhabitants are enabled, once every century, to suit their houses to the prevailing taste of the day; and thus there are no (few?) antiquated houses in London. But as the increase of the price of all the materials of building has more than kept pace with the increase of the wealth of individuals, it is to be questioned whether the houses are always improved when they are pulled down and rebuilt.”