468 BUILDING [MASON-WOKK. e, the lower half of which is thus immersed in water, com pletely bars the passage. It is evident, however, that if the well should leak the water in it may fall below the lower edge of the stone, and the efficiency of the trap be destroyed ; but if it be made perfect in the first instance, there can be no danger of any inconvenience that a bucket of water thrown into the sink will not cure. It is from the drying up of the fluid in water-traps that uninhabited houses are so frequently offensive. These well-traps form an effectual bar to vermin, and they may, therefore, be advantageously placed at the entrance of water-closet drains, to prevent rats from getting at the soil-pipes, which they will gnaw and destroy if they can get access to them. Internal drains, or those which go through a house, should always pass under the doorways if possible, in external walls at least. If, however, circumstances should render it absolutely necessary that a drain be taken through a wall, an arched ring or bull s eye should be made for it to pass by Veutila- All the traps to the drains should be ventilated, as well tion - us the head of the drain itself, by a tube carried up to the top of the house, and away from any opening where the foul air could be blown into any of the rooms. The sewers should also be ventilated, if not by the gully or side gratings, then by a grating placed over them in the centre of the roadway There have been numerous sugges tions for ventilating shafts in the lines of main drainage, but nothing beyond a tall lamp-post has been carried out, and no doubt this is sufficient. Cesspools In country houses where the drainage is used for manure ami tanks, to the gardens or land, the drain from the closets may be led into a brick or iron tank or cesspool, the surplus water being carried off by an overflow drain. Cesspools are strongest if made cylindrical, and should be bricked round and domed at the top, with a manhole in it for access, which should be fitted with a stone, having a ring in it by which the stone can be raised. But whether they are made to retain fluids or not is not a matter of conse quence, if they be placed in a secluded situation, where, if the object be not to get rid of the waste, there is seldom, at least, any desire to retain it. In towns and cities where the common sewering is as complete as it ought to be, and water-closets are used instead of privies, cesspools are unnecessary, as the soil becomes so much diluted by the water that goes down with it, that it flows readily enough through the private drains to the common sewer, and so on with the rest, to the common receptacle. Some times, indeed, it may be found necessary to clean out the well-traps before described, but this cannot often occur. Galvanized tanks are occasionally used in some parts of the country, with pumps attached, by which the sewags Earth can be rendered available r the garden. Earth closets closets on Dr Moule s system, or the cinder-sifting ash closets, are valuable for preventing the waste of an important manure. For workmen s cottages in large towns and villages they must be of great service, but whether they are adapted to a town house, or are applicable on an extensive scale for the relief of town drainage, is a question which still remains unsolved. The principal publications on Brickwork are as follows : Moxon, Mechanick Exercises, 4to, 1682 ; Langley, London Prices of Brick layers Work, &c., 2d edition, 8vo, 1750 ; Saunders, Observations on Brick Bond, 8vo, 1805, and reprinted in vol. i. of the Civil Engineer and Architect s Journal, 1838 ; Elmes, Foundations, 8vo, 1808 ; Nicholson, Architectural Dictionary, 4to, 1819 ; Davy, Construc tion of Foundations, 8vo, 1839 ; Dempsey, Builder s Guide, 8vo, 1852. The foreign publications are mostly comprised in the list at the end of the Mason-work. For Ornamental Brickwork, see Degen, Constructions en Briques, 4 to, no date ; Essen wein, Norddeutsch- lands Backstein Ban itn Mittelalter, folio, 1863 ; Runge, Essai sur les Constructions en Briques en Italic, folio, 1849 Street, Brick and Marble Architecture in Italy, 8vo, 1855. MASON-WOBK. The word mason Is derived directly from the French ma$on, which signifies indifferently a bricklayer or mason. Du Cange attributes the origin of the word to the low Latin maceria, a wall ; but a more probable derivation is that from the old German meizan, to cut. Among our selves, at present, we reckon three sorts of artificers rubble or rag-stone masons, freestone masons, and marble masons. This last branch, however, is rather that of the carver or statuary. The art of working or reducing stone to the proper shape for the mason to set, i.e., to place them in the walls, &c., has generally been called stone-cutting, and depends very much on the nature of the stone for its details. Stone masonry is the art of building in stone. The mason s tools consist of a handsaw, for cutting soft Tools, stones ; a drag, which is a flat piece of iron wherewith to finish its surface ; chisels and gouges for forming mould ings, gauges and moulds for sinking them to the proper foims; a mallet, chisels, tools, and points for working the harder stones ; a level, a plumb-rule, a square, a bevel, with rules of various sorts wherewith to try the surfaces in the progressive stages of the work. Granite is brought to a face by the scabbling hammer or granite axe, and the operation is called nidging. In rubbed work a surface is obtained by smoothing it with sand or gritstone. Marbles are polished by being rubbed with the gritston then with pumice-stone, and lastly with emery powder. Rubble walls are scaffolded with single, and ashlar- Scaffold!: fronted or other gauged stone walls with double-fronted scaffolding, the former tailing one end of the putlocks in the wall, and the other having an inner row of standard poles, and ledgers parallel to the outer, making the scaffold entirely independent of the wall. In some places, however, it is the custom to dispense altogether with an external scaffold in building stone walls, particularly with gauged stones. With light and plain work this may be done without much inconvenience or retardation; but if the work be heavy or delicate, considerable delay and incor rectness result. Sometimes the finer work, such as that to mouldings, flutes, and foliate or other enrichments, is merely boasted or roughed out before the stones are set, and finished afterwards, but this can be done well only from a secure floor or scaffold on which the workman may feel he can move freely and surely. For large and elaborately decorated structures, such as a public building, a me chanical scaffolding has to be erected, by which some economy is effected through diminishing labour, or some emergencies met attendant on the works themselves. Where the face of a stone is worked in the shop and may have some weeks or months labour on it, it becomes a valuable work worth careful handling. Hence the old- fashioned kind of scaffolding, of poles and ropes, has been much superseded by the so-called whole timber or framed scaffold, with its tramway and crab engines aloft. It is usually formed by laying square timbers on the ground to receive similar uprights, which are secured by iron ties to it ; on the heads of these are placed horizontal timbers, which are also secured to the uprights, and the whole is kept from changing position by timber struts and braces. On these another range may be erected, and so on to the required height. Tramways are placed on it, and a travel ling crane, worked by hand labour or by steam, raises the neavy weights, carries them to their places, and at once deposits them in the work with great ease. By the use of a steam-lift, with a long arm to reach many feet above it, on the first stage of the frame scaffold, no other scaffold is necessary except a slight one for the use of the workmen to set the stone. The clock tower at the Houses of
Parliament was built by a scaffold formed of two timbers,