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boiled linseed oil; harder putty, the same ingredients as the last, with the addition of a small quantity of turpentine for more quickly drying it; hardest putty, composed of oil, red or white lead, and sand. The first of these putties is the most durable, because it forms an oleaginous coat on the surface, but it requires a long time for drying. The hard sorts are apt to crack if not soon well painted, and the hardest of them renders it difficult to replace a pane when broken; hence it is altogether unfit for hothouse and greenhouse work.

SECT. IX.

PLASTERING.

2232. In the finishing of our dwellings, the decoration owes much of its effect to the labours of the plasterer: it is in his department to lay the ceilings, and to give, by means of plaster, a smooth coat to the walls, so as to hide the irregularities left by the bricklayer and mason, and make them sightly and agreeable. He also, in the better sort of buildings, furnishes plain and decorated mouldings for the cornices and ceilings; and in the external parts, where stone is expensive or not to be procured, covers the exterior walls with stucco or other composition imitative of stone.

2233. The plasterer's tools are-a spade or shovel of the usual description; a rake with two or three prongs bent downwards from the line of the handle, for mixing the hair and mortar together; stopping and picking out tools; rules called straight edges; wood models; and trowels of two sorts and various sizes; namely, the laying and smoothing tool, consisting of a flat piece of hardened iron, about 10 inches long, and 24 inches wide, very thin, and ground to a semicircular shape at one end, but square at the other. Near the square

end on the back of the plate a small iron rod is riveted, with two legs, whereof one is fixed to the plate, and a round wooden handle is adapted to the other. All the first coats of plastering are laid on with this tool, as is also the last, or setting, as it is technically called. The other sorts of trowels are of three or more sizes, and are used for guaging the fine stuff and plaster for cornices, mouldings, &c. The length of these trowels is, the largest about 7 inches in length on the plate, and the smallest 2 or 3 inches: they are of polished steel, converging gradually to a point, with handles of mahogany adapted to the heel or broad end with a deep brass ferrule.

2234. The stopping and picking out tools are of polished steel, of various sizes, about 7 or 8 inches long and half an inch broad, flattened at both ends, and somewhat rounded. They are used for modelling and finishing mitres and returns to cornices, as also for filling up and finishing ornaments at their joinings. There is also used a small instrument, which is a piece of thin fir 6 or 7 inches square, called a hawk, with a handle vertical to it, for holding small quantities of plaster.

2235. The composition used by the plasterer is a groundwork of lime and hair, on which, for the finish, a coating of finer material is laid. The sorts of it are various; as, for instance, white lime and hair mortar on bare walls; the same on laths as for partitions and plain ceilings; for renewing the insides of walls, roughcasting on laths; plastering on brickwork with finishing mortar, in imitation of stone work, and the like upon laths. For cornices and the decorations of mouldings, the material is plaster of Paris, one which facilitates the giving by casts the required form and finish to the superior parts of his work. The plasterer uses it also for mixing with lime and hair, where the work is required to dry and set hard in a short time. For inside work, the lime and hair, or coarse stuff, is prepared, like common mortar, with sand; but in the mixing, hair of the bullock, obtained from the tanners' yards, is added to it, and worked in with the rake, so as to distribute it over the mass as equally as possible.

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2236. What is called fine stuff is made of pure lime, slaked with a small quantity of water, and afterwards, without the addition of any other material, saturated with water, and in a semi-fluid state placed in a tub to remain until the water has evaporated. some cases, for better binding the work, a small quantity of hair is worked into the composition. For interior work, the fine stuff is mixed with one part of very fine washed sand to three parts of fine stuff, and is then used for trowelled or bastard stucco, which makes a proper surface for receiving painting.

2237. What is called guage stuff is composed of fine stuff and plaster of Paris, in proportions according to the rapidity with which the work is wanted to be finished. About four-fifths of fine stuff to one of the last is sufficient, if time can be allowed for the setting. This composition is chiefly used for cornices and mouldings, run with a wooden mould. We may here mention that it is of the utmost importance, in plasterers' work, that the lime should be most thoroughly slaked, or the consequence will be blisters thrown out upon the work after it is finished. Many plasterers keep their stuffs a considerable

period before they are wanted to be used in the building, by which the chance of blistering is much lessened.

2238. When a wall is to be plastered, it is called rendering; in other cases the first operation, as in ceilings, partitions, &c., is lathing, nailing the laths to the joists, quarters, or battens. If the laths are oaken, wrought iron nails must be used for nailing them, but cast iron nails may be employed if the laths are of fir. The lath is made in three and four foot lengths, and, according to its thickness, is called single, something less than a quarter of an inch thick, lath and half, or double. The first is the thinnest and cheapest, the second is about one-third thicker than the single lath, and the double lath is twice the thickness. When the plasterer laths ceilings, both lengths of laths should be used, by which, in nailing, he will have the opportunity of breaking the joints, which will not only help in improving the general key, (or plastering insinuated behind the lath, which spreads there beyond the distance that the laths are apart,) but will strengthen the ceiling generally. The thinnest laths may be used in partitions, because in a vertical position the strain of the plaster upon them is not so great; but for ceilings the strongest laths should be employed. In lathing, the ends of the laths should not be lapped upon each other where they terminate upon a quarter or batten, which is often done to save a row of nails and the trouble of cutting them, for such a practice leaves only a quarter of an inch for the thickness of the plaster; and if the laths are very crooked, which is frequently the case. sufficient space will not be left to straighten the plaster.

2239. After lathing, the next operation is laying, more commonly called plastering. It is the first coat on laths, when the plaster has two coats or set work, and is not scratched with the scratcher, but the surface is roughed by sweeping it with a broom. On brickwork it is also the first coat, and is called rendering. The mere laying or rendering is the most economical sort of plastering, and does for inferior rooms or cottages.

2240. What is called pricking up is the first coat of three-coat work upon laths. The material used for it is coarse stuff, being only the preparation for a more perfect kind of work. After the coat is laid on, it is scored in diagonal directions with a scratcher (the end of a lath), to give it a key or tie for the coat that is to follow it.

2241. Lath layed or plastered and set is only two-coat work, as mentioned under laying, the setting being the guage or mixture of putty and plaster, or, in common work, of fine stuff, with which, when very dry, a little sand is used; and here it may be as well to mention, that setting may be either a second coat upon laying or rendering, or a third coat upon floating, which will be hereafter described. The term finishing is applied to the third coat when of stucco, but setting for paper. The setting is spread with the smoothing trowel, which the workman uses with his right hand, while in his left he uses a large flat-formed brush of hog's bristles. As he lays on the putty or set with the trowel, he draws the brush, full of water, backwards and forwards over its surface, thus producing a tolerably fair face for the work.

2242. Work which consists of three coats is called floated: it takes its name from an instrument called a float, which is an implement or rule moved in every direction on the plaster while it is soft, for giving a perfectly plane surface to the second coat of work. Floats are of three sorts: the hand float, which is a short rule, that a man by himself may use; the quirk float, which is used on or in angles; and the Derby, which is of such a length as to require two men to use it. Previous to floating, which is, in fact, the operation of making the surface of the work a perfect plane, such surface is subdivided in several bays, which are formed by vertical styles of plastering, (three, four, five, or even ten feet apart,) formed with great accuracy by means of the plumb rule, all in the same plane. These styles are called screeds, and being carefully set out to the coat that is applied between them, the plaster or floating laid on between them is brought to the proper surface by working the float up and down on the screeds, so as to bring the surface all to the same plane, which operation is termed filling out, and is applicable as well to ceilings as to walls. This branch of plastering requires the best sort of workmen, and great care in the

execution.

2243. Bastard stucco is of three coats, the first whereof is roughing in or rendering, the second is floating, as in trowelled stucco, which will be next described; but the finishing coat contains a small quantity of hair behind the sand. This work is not hand-floated, and the trowelling is done with less labour than what is denominated trowelled stucco.

2244. Trowelled stucco, which is the best sort of plastering for the reception of paint, is formed on a floated coat of work, and such floating should be as dry as possible before the stucco is applied. In the last process, the plasterer uses the hand float, which is made of a piece of half-inch deal, about nine inches long and three inches wide, planed smooth with its lower edges a little rounded off, and having a handle on the upper surface. The ground to be stuccoed being made as smooth as possible, the stucco is spread upon it to the extent of four or five feet square, and, moistening it continually with a brush as he proceeds, the workman trowels its surface with the float, alternately sprinkling and rubbing the face of the stucco, till the whole is reduced to a fine even surface. Thus, by small portions at a

time, he proceeds till the whole is completed. The water applied to it has the effect of hardening the face of the stucco, which, when finished, becomes as smooth as glass.

2245. From what has been said, the reader will perceive that mere laying or plastering on laths, or rendering on walls, is the most common kind of work, and consists of one coat only; that adding to this a setting coat, it is brought to a better surface, and is two-coat work; and that three-coat work undergoes the intermediate process of floating, between the rendering or pricking up and the setting.

2246. Ceilings are set in two different ways; that is the best wherein the setting coat is composed of plaster and putty, commonly called guage. Common ceilings are formed with plaster without hair, as in the finishing coat for walls set for paper.

2247. Pugging is plaster laid on boards, fitted in between the joists of a floor, to prevent the passage of sound between two stories, and is executed with coarse stuff.

2248. The following materials are required for 100 yards of render set; viz. 11 hundred of lime, 1 double load of river sand, and 4 bushels of hair; for the labour, I plasterer 3 days, 1 labourer 3 days, 1 boy 3 days; and upon this, 20 per cent. profit is usually allowed. For 130 yards of lath plaster and set-1 load of laths, 10,000 nails, 2 hundred of lime, 1 double load of river sand, 7 bushels of hair; for the labour, 1 plasterer 6 days, 1 labourer 6 days, 1 boy 6 days; and upon this, as before, 20 per cent. is usually allowed.

2249. In the country, for the exterior coating of dwellings and out-buildings, a species of plastering is used called roughcast. It is cheaper than stucco or Parker's cement, and therefore suitable to such purposes. In the process of executing it, the wall is first pricked up with a coat of lime and hair, on which, when tolerably well set, a second coat is laid on of the same materials as the first, but as smooth as possible. As fast as the workman finishes this surface, another follows him with a pailful of the roughcast, with which he bespatters the new plastering, so that the whole dries together. The roughcast is a composition of small gravel, finely washed, to free it from all earthy particles, and mixed with pure lime and water in a state of semi-fluid consistency. It is thrown from the pail upon the wall, with a wooden float, about 5 or 6 inches long, and as many wide, formed of half-inch deal, and fitted with a round deal handle. With this tool, while the plasterer throws on the rougheast with his right hand, in his left he holds a common whitewasher's brush dipped in the roughcast, with which he brushes and colours the mortar and the roughcast already spread, to give them, when finished, an uniform colour and appearance.

If

2250. In forming the coves and cornices which are applied below the ceilings of rooms, it is of the greatest importance to make them as light as possible, for the plaster whereof they are formed is heavy, and ought not to be trusted merely to its adhesion to the vertieal and horizontal surfaces to which it is attached. Hence, when cornices run of large dimension, bracketing, as has already been described in the section Joinery (2079, et seq.), must be provided, of the general form of the cornice or cove, or other work, and on this the plastering is to be formed. On this, when roughed out, the work is run with wooden moulds, having brass or copper edges, so as to give the general outline of the cornice. enrichments are used in it, they are cast in plaster of Paris, and afterwards fixed with that material in the spaces left for them to occupy. These enrichments are previously modelled, and from the model a matrix is formed, as for all other plaster casting. Great nicety is required in all the operations relative to the moulding and fixing of cornices, and most especially that the ornaments be firmly fixed, that they may not be detached from their places by partial settlements of the building, and cause accidents to the occupiers of the rooms where they are used.

2251. In the present time, the use of ornaments made of carton-pierre, a species of papier maché has been reintroduced for cornices, flowers, and other decorations. The basis of it is paper reduced to a pulp, which having other ingredients mixed with it is pressed into moulds, and thus ornaments are formed of it. Though they have not all the delicacy of the plaster cast, their lightness, and the security with which they can be fixed with screws is such, that we have no hesitation in recommending them for adoption, in preference to plaster ornaments; and, indeed, their general use at present warrants the recommendation we here give. At the same time, we must caution the architect that the thing is at present far from the perfection to which the plasterer carries his practice, and that in the fixing there is all the want of that nicety which a good cornice workman in plaster exhibits. There has been a great want of competition in this country of the manufacture of cartonpierre. Indeed of what is made here the modelling is generally very bad, inferior artists being employed upon it. That manufactured by Waillet and Huber of Paris we have found to be the best, and their modellers are able artists. We have already adverted to the cements used in plastering. Parker's, Bailey's, Atkinson's, and Chambers's are the principal ones for coating buildings, and the process of laying them on is so similar to that of other plasterer's work, that it will not be necessary to say more than that they are all good, and may be used with safety.

2252. It is scarcely within the branch of the plasterer's practice, but as we shall have no other place for adverting to it, we may as well here mention a composition which, till lately, was much in use, but will certainly now be entirely superseded by the carton-pierre, above mentioned; we mean what are called composition ornaments, which were never, however, used in cornices, but principally for the decoration of an inferior class of chimneypieces, and the like. The composition is very strong when dry, of a brownish colour, consisting of about two pounds of powdered whiting, a pound of glue in solution, and half a pound of linseed oil mixed together in a copper, heated and stirred with a spatula till the whole is incorporated. After heating it is laid upon a stone covered with powdered whiting, and beaten to a tough and firm consistence, when it is laid by for use, covered with wet cloths to keep it fresh. This composition is then put into a press, and pressed into moulds made of boxwood. It is now, however, nearly abandoned, as it ought to be, its weight being so much against its use.

SECT. X.

SMITHERY AND IRONMONGERY.

2253. Smithery is the art of uniting several lumps of iron into one lump or mass, and forming them into any desired shape. The operations necessary for this are primarily performed in the forge, and on the anvil with the hammer; but for finishing, many other implements and tools are necessary. These, however, we do not think useful to particularise, a course we have pursued in the other trades, because the expedients introduced by the engineer and machinist have of late years, except in rough work, superseded many of them. It is now, for instance, easier to plane iron to a perfect surface than it was a few years ago to file or hammer to what was then always an imperfect one. Formerly a man would be occupied as many minutes in drilling a hole as by machines it now takes seconds to perform.

2254. We have, in a previous section, given all the particulars relating to the produce of the metal from the ore; in this section we propose little more than to enumerate the different objects which the smith and ironmonger furnish in the construction of buildings; and introductory to that it will be convenient to subjoin tables of the weights of round and bar iron, and also of the weights of 1 foot of close hammered bar iron of different thicknesses; remembering that a cube foot of close hammered iron weighs about 495 lbs., of common wrought iron about 480 lbs., and of cast iron 450 lbs., whence may be derived the weight of other solids whose cubic contents are known.

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TABLE SHOWING THE WEIGHT OF close-hammered FLAT BAR IRON, FROM ONE INCH WIDE AND AN EIGHTH OF AN INCH THICK TO FOUR INCHES WIDE AND ONE INCH THICK.

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2255. For the carcass of a building the chief articles furnished by the smith are chimney bars, which are wide thin bent bars or plates of iron, to relieve the weight of brickwork over wide openings of chimneys, as in kitchens and rooms where a large area of fire is requisite. In these situations they are subject however to objection, because of their liability to constant expansion and contraction from the varying temperature, which often produces fractures about the chimney jambs. They nevertheless, on the whole, produce a security which sanctions their use. Cramps for holding together courses of stonework. These, however, are better of cast iron, being far less subject to decay by oxidisation. Balusters and railing for stairs and the areas of houses towards a public way. Shoes for piles, when that mode of obtaining a foundation is adopted. Wrought iron columns with caps and bases, for the support of great superincumbent weights. Cast iron are now preferred both for economy and stiffness; as is also that material for girders and bressumers, which have been already disposed of in a previous page. Area gratings and window bars for securing the lower stories of houses. Here, again, the founder has stept in to render the employment of wrought iron much less general than formerly. Ties of all descriptions, and for the carpenter especially the various sorts of straps, bolts, nuts and screws, plates, washers, and the like, for connecting the pieces in framing where the strain is greater than the mere fibres of the wood will resist. Casements, with their fastenings for lead lights, are also furnished by the smith. But he is now rarely employed, as heretofore, for fancy gates, sashes, and frames, such works being furnished by the founder, as well as rain-water pipes with their cistern heads, pavement gutters, air traps, scrapers, coalplates, water-closet traps, and a number of other objects which will occur to the reader.

2256. The chief articles furnished by the ironmonger are for the joiner's use, and, except in particular cases, are kept in store by that tradesman for immediate supply as required.

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