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not to use any mortar until clear of the earth. This left the walls quite dry above. The next method is to bed a course of sound whole slate slabs, a quarter of an inch thick, in cement. When the soil is very damp. two or even three courses of ordinary slates may be laid in and well bonded, not only in the main walls, but in all cross partitions and dwarf walls. For some reason, probably that of the slates and cement having separated or crushed with the weight of the walls, allowing the damp to pass through, this method has fallen into disuse. As Portland cement will adhere to slate, probably in solid works, if used instead of Roman cement, the result would be more satisfactory.

1886c. Sheet zinc bedded in loam has been found to decay. In extensive works, finegritted asphalte, applied in a hot state, is introduced as a layer, about half an inch in thickness. This material is stated, in the Appendix to the Report of the Fine Arts Commissioners, to have kept out the effects of damp, which would have shown themselves, as the foundations of the building referred to were always in water about 20 inches below the level of the ground floor. The brickwork should be dry and protected from rain during the operation, to prevent the asphalte becoming honeycombed. In buildings already erected, the walls can be underpinned to introduce the material. At the New Palace at Westminster the joints are only half filled with mortar, the asphalte filling the remainder when poured over the bricks. The bricks for the next course, having been heated at a coke fire, were placed on the asphalte in its fluid state, and the joints half flushed up. The outer courses, however, should be first laid for short distances, that they may set before the middle is filled in. In rubble masonry, it will be necessary to fill up all inequalities on the surface with fine concrete; when this has set sufficiently, the asphalte is to be laid as described for brickwork. Gas tar mixed with lime is said to be impervious to wet.

1886d. Two centuries ago, thin sheet lead was laid on the top course of a wall to prevent damp coming down it from the gutters; of late years, a layer of 4 lb. milled lead has been proposed to prevent it rising; no doubt the best and most efficacious remedy, but the cost would be greater than usually allowed. But the best invention, having price also in its favour, is the damp-proof course, formed of brown stoneware, perforated through

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out its entire width, with a half air space, which remains open after the mortar beds are laid, on each side of the slab. In an executed work, a course of bricks can be cut out and the stoneware be inserted. This is one of the many building inventions of Mr. John Taylor, junior. Fig. 615a. shows one for an 18-inch wall; other sizes as well as angle blocks are provided. Each foot superficial is stated to be equal to the support of 25 tons or 600 feet of vertical brickwork. Jennings has patented earthenware sleeper blocks, "nonconductors of damp and a cheap substitute for brick sleeper walls; " they are also useful for carrying stone paving: Figs. 615b., 615c., and 615d. describe themselves.

1886e. Precautions are also necessary to prevent the access of damp from the surface of the ground next the outside face of the wall. If the dry area be carried up sufficiently high, the two measures are effected at once. If not, a facing of stone or slate is the best remedy. The former need not be very thick; but it is well for both to be from two to three feet high. If a small interval be left between this facing slab and the outside surface of the wall, it will provide for a circulation of air being kept up in the space. By this provision, although the facing slabs may be temporarily damped by rain, they will soon be again dried without having communicated the damp to the body of the wall.

1886f. A preventive against the effects of damp in the inside of the building is to cover the whole area within the walls with a layer of concrete, about 4 to 6 inches thick (from 6 to 9 inches is better); but as concrete is of a honey-comb character even when fixed or set, being full of little fissures or holes, there is some danger in placing it in wet soils, for it will often weep, and if cut, water will be seen to ooze through the joint. Also, when placed under the basement floor to keep out damp, water will invariably find its way through if there be any pressure, as from springs. To prevent vapours rising from decomposed matter in the soit, a good practice, even in dry localities, is to cover the soil before the floor boards are laid, with a layer of two inches of unslaked lime, which on slaking with damp or damp air destroys any vegetation that may have been left on the surface.

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1887. We, perhaps, might have more properly spoken first of the subject of DRAINAGE and SEWERS, whereof it now becomes our duty to give some information, inasmuch as before a brick or stone of any building be laid, the architect neglects his duty if he has not provided for perfect drainage in the lowest parts of the structure. This must not be by the aid of a small stagnant tank, called a cesspool, often the cause of much disease in a family; but by means of a drain into some running stream at a distance from the building, or, if that be not practicable, into some far removed pond, whose exhalations shall not be blown by the prevalent winds of the spot back upon the place where they were generated, in a different form. Neither does the health alone of the family whose comfort is to be provided for, demand this consideration of drainage; for the durability of the structure is quite as much involved in good drainage as is the health of the family whose dwelling-place the house is to become: hence we are the more earnest in pressing the point. In cities, the architect cannot always accomplish this important object; but in the country he is unpardonable if he neglect it. London with its suburbs is now probably the best drained capital in Europe. The lines of sewers forming the main drainage may be deemed completed, and to have relieved the noble river of nearly all the sewage matter. Every street has its public sewer, acting more or less perfectly, and nearly every house its separate drain into the sewer, although for a time, a few years back, this rule of a separate drainage, which had long been in force, was annulled.

1888. The main drain necessary for the service of the largest house (we suppose the case of one in the country), if the fall be even but moderate, requires no large dimensions. When we see a small river draining considerable tracts of country, often in section only 8, 9, or 10 feet superficial; it may easily be conceived that the surplus water from, and rain falling on, a mansion is a quantity, even in pressing times, that exacts no large area of discharge to free the place from damp. There are few cases in which the greatest mansion would demand an area exceeding 5 feet, which a, sewer 2 ft. by 2 ft. 6 in. would afford, supposing it to have a parallelogrammic section; but of course when the fall permits, a greater height would be preferable. Drains should, as well for their durability as on other accounts, be constructed with curved bottoms, but not with the lower part egg-shaped; for instance, as respects flat bottoms, take the lower parts of two drains, whose depth of running water is 1 foot, one whereof is formed with a semicircular bottom, 2 feet wide. The area of the column of water will, therefore, be 1.5708, and the length of the half curve will be 3·1416. To obtain with one foot depth of water, the same area in a drain whose bottom is flat and sides upright, we must have the width 1-5708, and the sum of the three sides touched by the water will be 3:5708. Then 3·5708-3·1416=4292 represents roughly the difference of friction or impediment in favour of the semicircular bottom in the case stated, nearly of the power being lost by the use of a flat bottom.

18884. Since the introduction, about 1845, of pipes into the sewerage and drainage systems, brick drains have been discarded. But easy as it may appear to lay down pipes, unless it be done under careful supervision, the fall may hereafter be found insufficient; the fall perhaps reversed; the effective drainage stopped by carelessness in forming the joints; and so on. The chief point to be here noticed respecting this familiar subject is, that great difference exists between the vitrified stoneware pipe drains, and the glazed or unglazed earthenware pipe drains, substituted for cheapness. The sewage in the latter soon corrodes the glazing, which being removed, the half burnt earthenware sucks in the foul water and decays. Nor is it nearly so strong as the stoneware article.

18886. Great diversity of opinion exists as to the effective size of a pipe required for a building. One person urges that his ten roomed house and outbuildings have never been inconvenienced by the use of a 3 inch drain, whilst other houses, with 6 inch and even 9 inch drains, have been seriously affected. Much depends, as noticed in the previous paragraph, on the fall, and on the careful laying of the pipes, and something on the quantity of water used for household purposes. Where a water closet is placed at or near the head of a drain, a stoppage of its pipe often occurs; while grease from the kitchen sink incrusting in the pipe, for want of occasional flushing with hot water, is another frequent cause. Sewers also occasionally require that assistance by flushing them from their head. One of the best arrangements proposed is that of an iron tilting cistern, to hold about 90 gallons, inserted in a brick pit at the head of a pipe sewer. This cistern with its brass bearings and plates, brickwork, stone cover, and water tap, costs about nine pounds, and if one were placed at the head of each pipe sewer in a town, and all were turned off at the same time, a material assistance in keeping the main line also clear, would be found.

1888c. Various arrangements are advertised for obtaining access to drains for inspection, without the necessity for breaking into them. A velocity of 2 feet per second is the least which will keep sewers clear of all ordinary obstructions; while house drains and small pipes require a velocity of 3 feet per second to keep them clear (Hurst). No new sewer can now be made in London without the previous approval of the Metropolitan Board of Works; and no drain can be laid into a sewer without the previous approval of the vestry

or district board, which has to apply to the Metropolitan Board of Works for their sanction in both cases. Many towns in England have now their Board of Health supervising the drainage of the streets and houses, pursuant to The Public Health Act, 1848," and The Local Government Act, 1858."

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SECT. II.

BRICKLAYING AND TILING.

1889. Bricklaying, or the art of building with bricks, or of uniting them by cement or mortar into various forms, includes, in the metropolis, and mostly in the provinces, the business of walling, tiling, and paving with bricks or tiles, and sometimes plastering; but this last is rarely, if ever, undertaken by the London bricklayer; though in the country the trades of bricklaying and plastering are usually united, and not unfrequently that of masonry also. The materials used have been described in a previous part of the work, to which the reader is referred (1811. et seq.).

1890. The tools used by the bricklayer, who has always an attendant labourer to supply nim with bricks, mortar, &c., are-1. A brick trowel, for taking up and spreading the mortar, and also for cutting the bricks to any required length. 2. A hammer, for cutting holes and chases in brickwork. 3. The plumb rule, being a thin rule, 6 or 7 inches wide, with a line and plummet swinging in the middle of it, in order to ascertain that the walls are carried up perpendicularly. 4. The level, which is about 10 or 12 feet long, with a vertical rule attached to it, in which a line and plummet are suspended, the use whereof is to try the level of the walls at various stages of the building as it proceeds, and particularly at the window cills and wall plates. 5. The large square, for setting out right angles. 6. The rod, for measuring lengths, usually 5 or 10 feet long. 7. The jointing rule, about 8 or 10 feet long, as one or two bricklayers are to use it, and 4 inches broad, with which they run or mark the centre of each joint of the brickwork. 8. The jointer, which is of iron, shaped like the letter S. 9. The compasses, for traversing arches and vaults. 10. The ruker, a piece of iron having two knees or angles, dividing it into three parts at right angles to each other, the two end parts being pointed and equally long, and standing upon contrary sides of the middle part. Its use is to rake out decayed mortar from the joints of old walls for the purpose of replacing it with new mortar, or, as it is called, pointing them. 11. The hod, which is a wooden trough shut close across at one extremity and open at the other. The sides consist of two boards at right angles to each other, from the meeting whereof a handle projects at right angles to their union. It is used by the labourer for conveying bricks and mortar to the bricklayer; for which purpose, when he has the latter office to perform, he strews dry sand on its inside, to prevent the mortar from sticking. 12. The line pins, which are of iron, for fastening and stretching the line at proper intervals of the wall, that each course may be kept straight in the face and level on the bed. The pins have a line attached to them of 60 ft. to each pin. 13. The rammer, used for trying the ground, as well as for beating it solid to the utmost degree of compression. 13. The iron crow and pick axe, for breaking and cutting through walls or moving heavy weights. 14. The grinding stone, for sharpening axes, hammers, and other tools. The following ten articles relate entirely to the preparation and cutting of guaged arches. 15. The banker, which is a bench from 6 to 12 ft. long, according to the number of workmen who are to work at it. It is 2 ft. 6 in. to 3 ft. wide, and about 2 ft. 8 in. high. Its use is for preparing the bricks for rubbed arches, and for other guaged work. 16. The camber slip, a piece of wood usually about half an inch thick, with at least one curved edge, rising about 1 inch in 6 feet, for drawing the sofite line of straight arches. When the other edge is curved, it rises about half that of the other, that is, about half an inch in 6 feet, for the purpose of drawing the upper line of the arch, so as to prevent it becoming hollow by the settling of the arch. The upper edge is not always cambered, many preferring it straight. The slip being sufficiently long, it answers the width of many openings; and when the bricklayer has drawn his arch, he delivers it to the carpenter to prepare the centre for it. 17. The rubbing stone. This is of a cylindrical form, about 20 inches diameter, but may be less. It is fixed at one end of the banker, upon a bed of mortar. After the bricks for the guaged work have been rough-shaped by the axe, they are rubbed smooth on the rubbing stone. The headers and stretchers, in return, which are not axed, are called rubbed returns and rubbed headers and stretchers. 18. The bedding stone, which is a straight piece of marble 18 or 20 inches in length, of any thickness, and about 8 or 10 inches wide. It is used to try the rubbed side of a brick, which must be first squared to prove whether its surface be straight, so as to fit it upon the leading skew back, or leading end of the arch. 19. The square, for trying the bedding of the bricks, and squaring the sofites across the breadth of the bricks. 20. The berel, for drawing the sofite line on the face of the bricks. 21. The mould, for forming the

face and back of the brick, in order to reduce it in thickness to its proper taper, one edge of the mould being brought close to the bed of the brick when squared. The mould has a notch for every course of the arch. 22. The scribe, a spike or large nail, ground to a sharp point, to mark the bricks on the face and back by the tapering edges of the mould, for the purpose of cutting them. 23. The tin saw used for cutting the sofite lines about one eighth of an inch deep, first by the edge of the level on the face of the brick, then by the edge of the square on the bed of the brick, in order to enter the brick axe, and to keep the brick from spalting. The saw is also used for cutting the sofite through its breadth in the direction of the tapering lines, drawn upon the face and back edge of the brick; but the cutting is always made deeper on the face and back of the brick than in the middle of its thickness, for the above-mentioned purpose of entering the axe. The saw is also used for cutting the false joints of headers and stretchers. 24. The brick are, for axing off the sofites of bricks to the saw cuttings, and the sides to the lines drawn by the scribes. The bricks being always rubbed smooth after axing, the more truly they are axed the less labour will be requisite in rubbing them. 25. The templet. This is used for taking the length of the stretcher and width of the header. 26. The chopping block, for reducing the bricks to their intended size and form by axing them. It is made of any piece of wood that comes to hand, from 6 to 8 inches square, and generally supported upon two 14-inch brick piers, if only two men work at it; but if four men, the chopping-block must be lengthened and supported by three piers, and so on according to the number employed at it. It is about 2 ft. 3 in. in height. 27. The float-stone, which is used for rubbing curved work to a smooth surface, such as the cylindrical backs and spherical heads of niches, to take out the axe marks. It is, before application to them, made of a form reversed to the surface whereon it is applied, so as to coincide with it as nearly as possible in finishing.

1891. Before adverting to the bond, as it is technically called, of brick walling, which is the form of connection of the bricks with each other, we will stop to observe, that in working walls, not more than 4 or 5 feet should be brought up at a time; for as, in setting, the mortar shrinks and a general subsidence takes place, the part first brought up, if too large in quantity, will have come to its bearing before the adjacent parts are brought up, and thus fissures in the work and unequal settlements will take place. In carrying up any particular part above another, it should always be regularly sloped back to receive the adjoining parts to the right and to the left. On no account should any part of a wall be carried higher than one scaffold, except for some very urgent object.

1892. Previous to the reign of William and Mary, all the brick buildings in this island were constructed in what is called English bond; and subsequent to the reign in question, when, in building as in many other cases, Dutch fashions were introduced, we regret to say, much to the injury of our houses' strength, the workmen have become so infatuated with what is called Flemish bond, that it is difficult to drive them out of it. To the introduction of the latter has been attributed (in many cases with justice) the splitting of walls into two thicknesses; to prevent which, expedients have been adopted, which would be altogether unnecessary if a return to the general use of English bond could be established.

1893. In chap. i. sect x. of this book (1550. et seq.) we have spoken generally on walls; our observations here, therefore, in respect of them, will be confined to brick walls and their bond.

1894. English bond is that disposition of bricks in a wall in which (except at the quoins) the courses are alternately composed of headers and stretchers. In brick walling, and indeed

ELEVATION.

in stone walling also, a course means the horizontal layer of bricks or stones whereof the wall is composed, being contained between two faces parallel to the horizon, and terminated on each side by the vertical face of the wall. The mass also formed by brick or stones in an arch are also termed courses, but receive the name of concentric courses. The term header is applied to a brick or stone whose small head or end is seen in the external face of the wall; and that of stretcher, to a brick or stone whose length is parallel to the face of the wall. We are therefore to understand by English bond, a continuation either of header or stretcher, continued throughout in the same course or horizontal layer, and hence we have described it as consisting of alternate layers of headers and stretchers (fig. 616.), the former serving to bind the wall together in a transverse direction or widthwise, and thus prevent its splitting, whilst the latter binds it lengthwise, or in a longitudinal direction. None but the English bond prevents the former occurrence, as work executed in this way, when so undermined as to cause a fracture, separates, but rarely breaks through the solid brick, as if the wall were composed of one entire piece.

1895. The ancient Roman brickwork was executed on this

Fig. 616.

FIAN.

principle; and its extraordinary durability is as much to be attributed to that sort of work being used for bonding it together, as to its extraordinary thickness.

1896. In this, as well as Flemish bond, to which we shall presently come, it will be ob served, that the length of a brick being but 9 inches, and its width 44 inches, in order to break the joints (that is, that one joint may not come over another), it becomes necessary near the angles to interpose a quarter brick or bat, a, called a queen closer, in order to preserve the continuity of the bond in the heading course. The bond, however, may equally be preserved by a three-quarter bat at the angle in the stretching course, in which case this last bat is called a king closer. In each case an horizontal lap of two inches and a half is left for the next header. The figure above given is that of a two-brick or 18-inch wall, but the student will have no difficulty in drawing, on due consideration of it, a diagram of the bond for any other thickness of wall; recollecting, first, that each course is formed either of headers or stretchers. Secondly, that every brick in the same course and on the same face of the wall must be laid in the same direction, and that in no instance is a brick to be placed with its whole length against the side of another, but in such way that the end of one may reach to the middle of the others that lie contiguous to it, excepting in the outside of the stretching course, where three-quarter bricks, or king closers, will of course be necessary at the ends, to prevent a continued upright joint in the face of the work. Thirdly, that a wall crossing at right angles with another will have all the bricks of the same level course in the same parallel direction, whereby the angles will be completely bonded. We shall close these observations with a recommendation to the young architect, founded on our own experience, on no account, in any building where soundness of work is a desideratum, to permit any other than English bond to be executed under his superintendence.

1897. Flemish bond is that wherein the same course consists alternately of headers and stretchers, which, in appearance, some may fancy superior to that just described. Such is not our opinion. We think that the semblance of strength has much to do with that of beauty in architecture. But there is in the sufferance of Flemish bond a vice by which strength is altogether lost sight of, which we shall now describe. It was formerly, though now partially, the practice to face the front walls of houses with guaged or rubbed bricks, or with at least a superior species of brick, as the malm stock; in the former cases, the bricks being reduced in thickness, and laid with a flat thin joint frequently, what the workmen call a putty joint, for the external face, the outer and inner work of the same courses in the same wall, not corresponding in height, could not be bonded together except where occasionally the courses fell even, where a header was introduced from the outside to tie or bond the front to the internal work. Hence, as the work would not admit of this, except occasionally, from the want of correspondence between the interior and exterior courses, the headers would be introduced only where such correspondence took place, which would only occur in a height of several courses. Thus a wall two bricks in thickness, if faced on both sides, was very little indeed better than three thin walls, the two outer half a brick thick, and the middle one a brick or 9 inches thick. Bricklayers having little regard for their character will, if not prevented by the architect, not only practise this expedient, but will also, unless vigilantly watched, when a better sort of brick is used for the facing, cut the headers in half to effect a paltry saving of the better material. In walls of one brick and a half in thickness, the strength of the wall is not diminished by the use of Flemish bond so much as in those of greater thickness, as may be seen by the diagram (fig. 617.). Many expedients have been invented to obviate the inconveniences of Flemish bond; but we think it rather useful to omit them, lest we should be considered as parties to a toleration of its use, for the continuation whereof no substantial reason can be assigned. As we nave before observed, all that can be alleged in its favour is a fancy in respect of its appearance: but were the English mode executed with the same attention and neatness bestowed on the Flemish method, we should say it was equally beautiful; and therefore we shall thus close our notice of it.

ELEVATION.

Fig. 617

PLAN,

1898. The two principal matters to be considered in brick walling are, first, that the wall be as strong as possible in the direction of its length. Secondly, that it be so connected in its transverse direction that it should not be capable of separating in thicknesses. To produce the first, independent of the extraneous aid of bond timbers, plates, &c., it is clear that the method which affords the greatest quantity of longitudinal bond is to be preferred, as in the transverse direction is that which gives the greatest quantity of bond in direction of the thickness. We will, to exemplify this, take a piece of walling 4 bricks long, 4 bricks high, and 2 bricks thick, of English bond: in this will occur 32 stretchers, 24 headers, and 16 half headers to break the joint, or prevent one joint falling over another. Now, in an equal piece of walling constructed in Flemish bond, there will occur only 20

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