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2263. Besides the articles already mentioned, the ironmonger furnishes holdfasts, wallhooks, door springs of various sorts, door chains and barrels of brass and iron, thumbscrews, shutter fastenings, shutter bars, sash fastenings, of which there are now many varieties against burglary, adjustable silent door springs, brass turn buckles, closet knobs, brass flush rings, iron drawer handles, brass flush draw handles, brass rollers, bars with latchets, shelf brackets, sash weights, with numerous other articles.

2263a. Bolts, straps, and other exposed iron work are preserved from the action of moisture on them by the following mixture:-To two quarts of boiling oil add half a pound of litharge, putting in small quantities at a time, and cautiously. Let it simmer over the fire two or three hours; then strain it, and add a quarter of a pound of finely-pounded resin and a pound of white lead, keeping it at a gentle heat till the whole is well incorporated. It is to be used hot. A composition of oil and resin and finely levigated brickdust is found useful in preserving iron from rust. It is to be mixed, and used as a paint of the usual consistence (see par. 1779e. et seq.). Wrought iron ornamental work exposed to the weather has been cased with copper and gilt, as much for decoration as for preservation. The surface of iron may be decorated and highly vitrified, the colours being burnt in. Thus the iron can be shaped to elaborate designs and artistically treated; being easily cleaned, it is a permanent material for walls, ceilings, and other parts of a building. See the Barff-Power process, &c. for protection of iron, 1780c.

22636. Mr. T. Fletcher, of Warrington, has lately (1887), by the use of compressed oxygen and coal gas, with a 4-in. gas supply, brazed a joint of a 2-in. wrought iron pipe in about one minute. He then tried welding, a process not possible with ordinary coal gas and air, and found that a good weld was obtained on an iron wire in. diam., with a very small blowpipe, having an air jet about diam. Larger articles, as boiler plates, he thinks could be done perfectly with little trouble and no handling. By this process he fused a large hole in a plate in. thick wrought iron by an apparatus which could be carried up a ladder by one man.

GAS FITTER.

2264. The work of this artizan may be placed under the head of this section, although his trade is now kept distinct. Gas is required by the Companies' Acts of Parliament to have a lighting power of 16 sperm candles when consumed at the rate of 5 cubic feet per hour. As regards purity, the gas must be entirely free from sulphuretted hydrogen, and the maximum quantities of sulphur and ammonia allowed are fixed from time to time for London by the gas referees (1885). The pressure of gas usually during the day varies from 1 inches to about 3 inches at night. This causes the burners to flare and hiss. To regulate this pressure various contrivances have been invented. Carnaby's is for the turning off of any number of lights by working the handle of a dial in the master's room or office. The Stott, Tice, Oakley, and other gas economisers are automatic, having valves that rise and fall according as the pressure is larger or smaller; they are said to save from 20 to 40 per cent. of gas without diminution of light. A ready plan of regulating the supply is to put the tap to the meter at such a point, by trial, as will supply the lights in ordinary use. In large establishments this has been done by a man, specially instructed, who alters it according to the lighting up or putting out of the lights. A great saving has been thus effected. The various formulæ for calculating the velocity and the pressure of effluent gas are to be found in CLEGG, Treatise on Gas Lighting. The most economical working pressure is equivalent to the weight of a column of water on the outlet, of about 1 inch. The formula for calculating the quantity discharged is q = 1350a2✔ in which q=the quantity sought in cubic feet per hour; d, the diameter of the pipe; h, the working pressure in inches; l, the length of the pipe in yards; and 8, the specific gravity of the gas compared with atmospheric air as unity. TABLE OF THE DELIVERY PER HOUR THROUGH PIPES OF THE DIAMETERS NAMED.

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For cost of laying, see Lockwood's Price Book, 1887, art. Gas Fitter.

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2264a. The main distribution of gas is effected through cast iron pipes with sockets and spigot ends, whenever the diameter exceeds 2 inches. Wrought iron welded tubing for gas is made from 3 in. diameter, 1 in., and then down by each in. to in., then ,, and in. diameter, in lengths of from 4 to 12 feet, from 2 to 4 feet, and shorter pieces under 2 feet; together with all their connecting pieces, cocks, taps, screws, &c. A inch pipe is used for 2 lights, 3 inch for 6,inch for 12,3 inch for 25, 1 inch for 50, 14 inches for 70, 1 inches for 120, and 2 inches for 200 lights. In the details of house fittings, wrought iron pipes are used when the diameter is, and exceeds, half an inch; in. is the least size recommended to be used, even for supplying upper rooms. For pipes of small diameters, and for abrupt bends, block tin and composition pipes are fixed. For occasional use, flexible pipes are employed, such as those made of gutta- | percha, caoutchouc, with or without a wire coil inside, and caoutchouc coated with varnish. This list is the safest of the flexible pipes; the other, though safer when used with a wire core, is not impermeable to gas, though a coat of linseed oil may render it so. The first-named is not only permeable, but causes an unpleasant smell, and is liable to contraction at any junctions with metal work, allowing of the escape of gas. There has lately been patented one formed of two layers of rubber, with pure soft tinfoil, vulcanised, between; perfectly gas-tight under any pressure and free from smell, and very flexible. The braided or cloth-covered tube has not come into general use. Brass pipes are generally used for the gasalier.

22646. Under no circumstances whatever should either iron or composition pipes be let into the plastering, as is too constantly done, or into solid brick or stone work; for the salts in the latter are liable to affect the pipes in a serious manner, and the contraction and expansion of their materials may injure the joints; whilst it must always be difficult to trace a leakage. When placed in a partition, any gas escaping fills all the spaces between the studs, and between the joists of the floors, so that when it comes in contact with a light the whole ignites, and the force of the explosion may cause the entire destruction of the house. The police regulations of Paris require that gas-pipes in houses should be visible throughout their length, excepting when they travers floors, partitions, &c., when the pipe conveying the gas is required to be enclosed in a larger one, projecting beyond the floor or partition, so as to ensure ventilation round it. Copper pipes should never be used, on account of the action of the gas on the metal. Gas pipes should be laid with a slight fall, on account of the condensation of the gas, and a draw-off tap is required to empty it. Gas by itself will no more explode than air, and on issuing into the air it will, if at once ignited, burn quietly, as at a gas burner. When gas is previously mixed with air, the mixture, on ignition, explodes with terrific force. 2264c. The form of burner which yields the best economical results is the argand, the bat's-wing is the next best; and the fish-tail the worst. A number of small burners disperse will give a better light than collections of them. The argand burner, with 15 holes, will burn about 5 to 8 feet per hour, according to the pressure; ordinary street lamps, having the bat's-wing, burn 3 to 8 feet per hour, and are usually contracted for at the rate of 5 feet. Bronner's burners afford a steady light, and each is made to consume as many feet per hour as may be required. The number of new burners have been much increased. Bray's have a large sale; Sugg's are of various sorts for private use and in public thoroughfares and edifices. His burners for public lamps affording 20 candlepower consume 5 cubic feet per hour; 35 candles, 8 feet; 50 ca dles, 12 feet; and 60 Candles, 15 feet. The former are two burners, and the latter thr e burners. The Heron's duplex has two small burners impinging upon one another and so affording a clearer light. 34 of Bray's burners burnt 230 feet of gas, 34 of the duplex for one hour burnt 167. Hart's economising burner dates from about 1859. Peeble's needle governor burners Save 20 to 40 per cent. of gas. Many of these lights are now supplied with "noncorrosive" burners made of soapstone. One of the latest inventions (1887) is Welsbach's system of the incandescent light; it consists of a prepared "mantle" placed over a Bunsen burner. It is stated that it doubles the illuminating power of the gas; gives a steady, brilliant light; and saves 50 to 70 per cent. of gas; there is greatly diminished heat, no dirt, and no smoke; the light rivals the electric light. Another is the Clamond incandescent gas light, supplied by the Eolus Company; each gives a 40 candle-power light on a consumption of 6 feet of gas per hour. The Chandler patent regenerative gas light has no burner, the gas issuing from a free, open pipe. By the action of the air supply and the shape of the burner opening the flame assumes the form of an incandescent sphere, like a ball of fire, brilliant and white. It is adapted for burning 2 to 60 cubic feet per hour. A matchless self-lighting gas burner is in use. It is stated that 60 gas burners produce 2 gallons of water per hour by the combustion, hence part of the damage caused to the walls, works of art, &c.

2261d. The ordinary lights are stated to require 4 cubic feet of gas per hour, but this is much too large; 21 and 3 will be found to give sufficient light if the burner is fairly near the person; the high lights of a gasalier are either inefficient or wasteful for reading or working purposes, and often affect the eyesight.

2264e. For lighting large rooms the solar or sun-light arrangement is agreeable, and it is fitted to promote the ventilation of the room. It is very costly, not only in its first establishment, partly from the necessity of securing the burners and pipes from setting fire to the surrounding timbers, but also in the subsequent consumption of gas. In rooms of moderate height, the heat to the occupants is objectionable. The Wenham lamp is somewhat similar, but having a globe under, is better adapted to a small room. Benham's (formerly Rickett's) ventilating lamps are also fixtures. The reflecting and ventilating Clapton light is economical in gas and suitable for public places. The patent Albo-carbon light is said to save 30 to 50 per cent. of gas, by the gas passing through a white composition. which, on being melted by the heat obtained from the burner, gives off a vapour which is taken up by the gas, thus giving increased brilliancy to the light.

2264f. As illustrations of the mode of lighting public buildings may be cited: I. The concert room at Liverpool, designed and executed by Mr. A. King; it is effected principally by carrying a pipe in the cove of the ceiling, which pipe is pierced with numerous holes for fish-tail burners. II. St. James's Hall, London, and the great hall of the Reform Club, which are admirable illustrations of the use of the stellar and of the solar lights. III. The new theatre du Chatelet, at Paris, where the lighting is effected by 1,300 burners placed above a vault of ground glass, and under a large enamelled reflector; the glass vault forms, in fact, the ceiling of the body of the house, so that the burners themselves are entirely hid. This arrangement was also employed for a few years at the picture gallery in Suffo k Street, London. And IV. The various passages and rooms of the Houses of Parliament, which are lighted and ventilated under Faraday's principle. 2264g. TABLE OF COMPARISON OF LIGHT-PRODUCING MATERIALS, by Dr. M. Tidy, in Handbook of Modern Chemistry.

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A table, prepared by Mr. V. B. Lewes, showing the amount of oxygen removed, the carbonic acid gas and water vapour generated, by various illuminants to give a light equal to 32 candle-power, is printed in the Proceedings of the Royal Institute of British Architects, for April 12, 1888.

2264h. A notice was issued in January, 1862, from the London Fire Engine Establishment, stating that, "It appears absolutely necessary that some steps should be taken to caution owners of property, particularly in large wharves and warehouses, as to the position and protection of the dangerous gas lights. These remarks may not be considered unnecessary when it is remembered that in many of the most valuable buildings in the metropolis movable gas brackets are placed within 20 inches of the ceiling without the slightest protection whatever. It may be laid down as a rule that the jet on the outer arm of the bracket should never be less than 36 inches from the ceiling over it, and that it should be protected on the top by a hanging shade, and on the sides by stops on the swivel joints, which should prevent the brackets moving beyond a safe distance. Attention might, perhaps, also be called to the very common and dangerous practice of nailing tin or iron on the adjoining timbers. This has long proved to be no protection, and it has the disadvantage of allowing the timber to be charred completely through before it is known." In some places gas lights are used within 15 inches of the ceiling, and when the glass shade has been broken and not replaced, the heat has been known to ignite the floor timbers over the plastering.

22641. It will not be ne essary here to do more than mention the use of gas in the kitcher for boiling water, or for baking and roasting (the apparatus for each, or for such purposes, are now supplied in London by the gas companies at a rent); the baths heated by gas, so readily adaptable in places where a coal stove cannot be used; or the several gas stoves for warming buildings and rooms, &c See 2279e.

2264). The urgency of efficient ventilation when gas is burnt in a room habitually is a subject of immediate importance. It is principally to the neglect of this precaution that the bulk of the injurious effects said to attend the use of gas may indeed be attributed.

In the case of libraries, the destruction of book-bindings may be assigned more justly to the heat than to the chemical action of the products of combustion. No doubt the bisulphide of carbon, which is present in even the most carefully purified gases, must give rise to the formation of minute quantities of sulphurous acid: and this, in its turn, must be destructive to some descriptions of leather-especially Russian (as noticed in the Builder, vi. 89), but a rapid removal of the products of combustion would almost entirely obviate this effect. It seems, however, that the excessive dryness and the heat of the air in the upper part of rooms where gas is burnt may occasion the injury quite as much as the chemical reactions supposed to take place; the books which suffer most being always those placed above the level of the lamps. Under any circumstances, ventilation should take place close to the plane of the ceilings. Even when provision is made for ventilation over gas burners, a stratum of heated air is often allowed to stagnate over the openings, close under the line of the ceiling; and the area of the openings is rarely sufficient to allow the escape of the decomposed gases. Again, if any sulphurous acid should be produced, it will be found also to tarnish the colours of tapestry and hangings, and to turn imitation gold; hence none but the best leaf-gold should be employed in rooms where gas is burnt. The injury caused by the use of such gas as is supplied in London, Paris, Bruxelles, &c., is very small compared with the brilliance of the light; and the gas of Liverpool, Edinburgh, Manchester, and some other places having, bulk for bulk, a higher illuminating power than that of London, is even less injurious. Mr. Spencer has reported that the quantity of gas leaking from London gas pipes is not less than 9 per cent., or between six and seven million cubic feet per annum, which causes the stinking black earth of the London street subsoil. No such leakage occurs at Liverpool or Manchester, where the joints of the pipes are bored, turned, and fitted to each other, like ground stoppers in glass bottles; whereas in London the pipes are jointed with tow and lead, so that after expansion and contraction in summer and winter the perfection of the joints is destroyed. The gas then, acting upon the subsoil, forms sulphuretted carbon, which corrodes not only the gas pipes, but the water mains also, and converts them in ten years almost entirely into a sort of plumbago, although in pure London subsoil they last a century.

ELECTRIC APPLIANCES.

2264k. For the important subject of Lightning Conductors, reference should be made to R. Anderson, Their History, Nature, and Mode of Application, of which the third edition, revised, rearranged, and enlarged, was published in 1887: "The numerous accidents to buildings fitted with conductors sufficiently indicate the indispensable necessity for occasional inspection. The chief causes that detract from their efficacy are original defects of capacity, conductivity, and fitting, faulty earth connections, accidental injury and mechanical derangements, oxidation of joints and of earth contacts, and alterations in the conductive capacity of the ground in consequence of improved drainage.” The efficiency of a conductor is in proportion to the sectional area of the metal. Tapes are madeth of an inch thick, being inch, 11 inches, and 2 inches wide; th of an inch thick, being ths of an inch wide; 4th of an inch thick, being ths of an inch, inch, and 11⁄2 inches wide. The conductors should not be less than 4th of an inch thick and ths of an inch wide, weighing 6 oz per foot, as recommended by the Lightning Rod Conference, 1882. The upper terminal should be in the form of a sharp point, or a cluster of sharp points. As this point may become blunted, an alloy of 835 parts silver and 165 parts of copper is therefore used for it, at Paris. The earth termination should be taken some depth, and into moist ground or water, and have a large area of contact. When this is not to be obtained, a copper plate at least 9 feet square should be carefully riveted to the end of the tape and be buried in a well, packed with cinders or coke. Professor Fleming has pointed out that the ultimate safety of a conductor lies in the proper periodical testing of the earth connection of the conductor.

22647. Electricity for lighting purposes can be obtained by chemical action, as by an arrangement of a voltaic battery, and the combination of cells is termed a "primary battery." A steady light is stated to be maintained at a cost not much in excess of that from a "dynamo" machine. Such a battery may suffice for a small country house, but a large number of lamps will require a battery of great bulk; hence it is more economical to produce electricity mechanically, by couverting the energy of the prime motor into electric force by the use of the dynamo ma hine. This motive power is obtained by steam, water, or gas, according to circumstances. The engine house would contain the dynamos for generating the electric current. The current is then taken to a "switch board," which is a simple apparatus on which all connections are made with suitable arrangements, so that either one or more machines can be made to deliver into the same conductor. On this board is an instrument for measuring the strength of the current, so fixed that it can be read by the attendant by turning the handle of a switch. From this board the mains go towards the lamps, starting as a cable, which ramifies into

smaller mains and branches until each incandescent lamp is reached. It is of supreme importance in electric lighting that the current should always be uniform at all times in each individual part of the work, and be unaffected by changes in other parts. The compound shunt machine has been devised to effect this arrangement.

2264m. A source of danger to property is in the mains and branch wires conducting the current to the lamps; they must be of sufficient proportion, and of a material whose resistance is uniform. Copper wire is used because it can be obtained in a purer state than any other available metal, and next to silver it is the best conductor of electricity. Great attention is required to the connectors and joints, and the connections made with binding screws; besides causing resistance in the circuit, bad contact between a wire and a terminal will produce heat. A faulty junction may also upset the calculations made for the current to be taken by an otherwise efficient cable; solder alone must not be relied upon, as it may become softened by the current; it must be mechanically perfect. A "short circuit" is the current taking the shorter path, where, having no work to do, it causes fire. The only preventive is a "cut out" or a "safety fuse," described as “a piece of easily fusible metal, which would be melted if the current attains any undue magnitude, and would thus cause the circuit to be broken." From arc lights pieces of incandescent carbon are apt to drop; more fires have occurred from this cause than any other. Electricity, having no smell to betray a leak, shows when it is escaping by the diminished appearance of the lights, caused by the diversion of the system.

2264n. Even if the cost of electric lighting be higher than that of a private gas supply, the extra cost of it for those rooms where the preservation of works of art, books, and decorations has to be considered would be amply returned. The property of not vitiating or heating the air will be the salient one which, when fully appreciated, must banish gas and oil from the houses of those who consider sanitary excellence the principal feature of a beautiful house. (K. Hedges, in Transactions of Royal Institute of British Architects, 1883-4, p. 143). The Electric Lighting Act was passed August 18, 1882. The MaximWeston Electric Company (Limited) supply (Nov. 1887) the new "Watt" system of lighting. They claim that they can now obtain six arc lamps of 150 candle-power in place of one, as heretofore, from one electrical horse-power. The Pilsen-Joel arc lamp is of 1,000 to 10,000 candle-power; the incandescence or glow lamps are of 5, 10, 16, 20, 30, to 100 candle-power, for lighting rooms, &c. To popularise the electric light is the only way to make it pay-it must be cheap and efficient. By cheapness is to be understood, either a small first cost and a correspondingly small cost for maintenance, as in the case of a battery placed in the house, or a moderate charge for the supply of the current, as in the case of a central distributing station. The lamps must be adaptable to the present gas fittings, and the cost of the light must be but little, if at all, in excess of that of the gas of the district. Though the advantages of this light are great in a hygienic and domestic point of view, the public would, in the main, continue to use the present methods of illumination rather than adopt any new system which entailed extra cost, however satisfied they might be that positive advantages were to be gained by it. (P. F. Mersey, On Primary Batteries, Nov. 1887.) The Phoenix Fire Office rules for fixing, &c., an installation are those now generally required to be carried out by the fire offices. 22640. Although electricity has not ousted gas from the field, as it was at one time thought it would do, it has yet made more progress than many people imagine, and no architect would design a public hall without fitting it with incandescent lamps. These do not give off as much heat as gas, nor do they contaminate the atmosphere. The insertion of "storage batteries" as a sort of buffer between the machine and the lights, and as a means of avoiding the risk of a break-down of the engine, has done much to render electric lighting more generally available; and considerable improvements have been made in these "storage batteries" during the last few years. The battery of the Union Electrical Power Light Company, of fifteen cells, will run twelve ten-candle incandescent lamps, and occupies a few feet only. A small primary battery and lamp combined is invented, so that an electric lamp can be placed on the table; this can be recharged by simply pouring into the cell containing the plates the necessary liquid. These lamps will run for about three hours say a dinner time.

2264p. A method of electric lighting for small areas, where the trouble and expense of fixing up and working engines and dynamos constitute a serious objection, has been introduced by Messrs. Woodhouse and Rawson, in which no machinery is required. The whole apparatus is contained in a space of some 5 feet by 6 feet, by 8 feet in height, with a perfect absence of smell, noise, or dirt. The light is generated by an "Upward" battery. The cost for the equipment of an installation to run eleven lamps (10 candle-power each) for two hours, or six for four hours, is 567.; while fifteen lights for three hours, or eight for six hours, is 847., and so on. The House to House Electric Light Supply Co. is taking active steps to promote this means of illumination.

2264q. There is a new electric gas lighting system, by which gas is lighted, turned on, and extinguished at any distance by simply pressing a button, as in ordinary electric bells; and at the same time the battery may be used for ringing electric bells.

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