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other trades, because the expedients introduced by the engineer and machinist have of late years, except in rough work, superseded many of them.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.

These tables give a little less weight than some others now in use. To convert into weight of other metals, multiply the numbers, for cast iron by 93; for steel by 101; for copper by 1.15; for brass by 1.09; for lead by 1-48; and for zine by 92.

TABLE I. OF THE WEIGHT OF HOOP IRON, according to the customary width and thickness, by the Birmingham Wire Gauge, per 100 feet lengths (Hurst).

TABLE II. OF THE WEIGHT AND THICKNESS OF A SUPERFICIAL FOOT OF SHEET IRON, by the Birmingham Wire Gauge:

TABLE III. OF THE WEIGHT OF A SUPERFICIAL FOOT OF PLATE IRON IN POUNDS.

TABLE IV. OF THE WEIGHT OF ORDINARY ANGLE IRON IN POUNDS PER LINEAL FOOL

Breadth in inches

TABLE V. OF WEIGHT OF IRON BOLTS AND NUTS. (Mulholland, in Builder, 1v. 22.)

Diameter of Bolt, inch. 14

Weight per foot of round Iron, pounds f

2 4 7 10 15 20 27 3-4 4.2 5.0 6.0 7-0

Weight per inch of 016 033 058 083 125 166 225 283 350 416 500 589

round Iron

}

021 062 145 260 468 729 1.125 1-77 2-1872.86 3.75 4.74

2254a. Bolts are now often made with square heads, so that these being let into the timber, the stem cannot turn while the nut is being screwed up. Machinery has been brought to bear for the manufacture of bolts, rivets, spikes, and other like articles; "the motions are so arranged that no attention is required beyond entering the bars into the feed rolls and cleaning the pieces of the ends of the iron out of the dies."

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

2255. For the carcase of a building the articles furnished by the SMITH are, wrought iron columns with caps and bases for the support of great superincumbent weights. Wrought iron columns were used in England as early as 1860 by Sir W. Fairbairn, together with wrought iron girders, and brick arches for fireproof work. When columns are beyond a certain length in proportion to their diameter they fail by bending, and not by crushing; also wrought iron is much stronger to resist tension than cast iron; and as it is an undoubted fact that connections can be made to wrought iron much better than to cast, we have here a combination of advantages where long columns have to be used which cannot but be appreciated. The use of steel for constructional purposes is increasing rapidly, as it is so much more reliable than iron. Messrs. Lindsay roll many sections of steel which can very easily be formed into columns by riveting. A column made of a series of steel troughs, 16 inches diameter externally, would bear a safe load of 115 tons if 30 feet long, and the weight would be 74 lbs. per foot only. A cast iron column 16 inches in diameter, 30 feet long, with 13 inches of metal, would (roughly) in weight be 220 lbs. per foot run, and safe load 100 tons (J. Slater). Combination columns of steel can be made to 6 feet diameter; these, having a central concrete filling and outer ring of bricks in cement, can be designed to sustain a load up to 2,000 tons. They are made from 13 inches to 48 inches in diameter, and are stated to be not more expensive than cast iron columns, and far superior. Cast iron columns and stanchions were preferred both for economy and stiffness, as was also that material for girders, beams, joists, and bressummers, until the introduction of plate iron and rolled iron (all which have been treated in previous sections). Iron columns can be rendered fireproof by encasing them with fireclay blocks, grooved and secured by iron plates with claws, which fit on the rivet heads. For round columns a metal band is brought round the column, hooked together, and dropped into the groove of the blocks. In either case a heavy bed of mortar is next applied, and then another course of blucks is bedded over the band or plate. Then it is

Cast,

finished with Keene's or Parian cement, making a good surface for decoration. blister, shear, and spring steel; charcoal sheets and plates; boiler, tank, and flitch plates; galvanized and tinned sheets; chequered floor plates, buckled plates; flat bars up to 12 in. wide, round bars up to 8 in. diameter, square bars up to 5 in.; angle, Ţ, and trough trons. Ties of all descriptions, straps, bolts, nuts and screws, plates, washers, and the like, employed in connecting pieces in framing where the strain is greater than the mere fibres of the wood will resist. Half-round, bevelled, oval, octagon, hexagon, moulding, and fancy irons; hoop iron, nail rods, and sash iron; shoes for piles, when that mode of obtaining a foundation is adopted; sanitary appliances in iron; manhole covers for access to sewers and drains; The Kenon disconnecting trap and cover, hinged to manhole for outside a building, and air-tight cover for inside a building. Cramps for holding blocks of stone together; but those of cast iron are better, as less likely to be subject to oxidation, while those of copper or gun-metal are still better; area gratings and window bars for securing openings, now generally superseded for those of cast iron, especially when of an ornamental character, as are balusters and railings for stairs and balconies. Ornamental fancy gates. Rain-water pipes in 6 feet lengths, 2 to 8 in. in diameter, with their cistern heads, offsets, elbows, branch pieces, shoes, union sockets, and ears plain and ornamental. Square rain-water pipes, 2 in. square, 3 in. by 2 in., 3 in. square; 34 in. by 2 in.; 3 in. by 24 in., 3 in. by 3 in., 4 in. by 2 in., 4 in. by 3 in., 4 in. by 3 in., 4 in. square, and 5 in. by 3 in., with branch pieces, shoes, ears, &c. Rain-water gutters of all shapes and sizes, plain and moulded; patent spout irons or brackets, with a screw pin to bind the spout to the clip; roof gutters between slopes, square, angular, and square and angular. Gregson's perfectum down spouts; where the pipe is simply hung on the nails and projects an inch from the wall; it has a 7-inch socket for sliding to wall joints, and for sliding out any broken middle lengths for renewal without removing others or drawing the nails. His separate patent hanger can be bolted to the ear of any other maker's pipes; when bolted they project 1 inches, so as to be painted all round. Pavement gutters, air or stench traps, scrapers, and coal plates, for which last have lately been brought out Banner's self-fastening; Stidder's self-locking; also one self-fastening put forward by a company; Hyatt's glazed coal plates; with many, if not all, of the articles required for stable fittings, either plain, enamelled, or galvanized, as advertised by Varnel; Cottam and Hallen; the St. Pancras Iron Work Company; Musgrave, at Belfast; and others. Pavement lights, or Hayward's patent "semi-prism," are extensively used for lighting basements, cellars, and underground apartments, giving a brilliant result. Hayward's stall board lights. The former differs greatly from the prismatic or ship's deck lenses. T. Hyatt's patent ornamental tile and glass lights for pavements, semiprism gratings to light basements, &c., stall-board lights, &c.; the former have a neat appearance, and afford a better foothold than glass alone. There are also Hamilton's patent prism, and Halford's patent prism pavement. Circular iron staircases with the head, riser, and spandrel in one, and adaptable where the space is confined, or to pass from one story to another only; and among other things, chimney bars to relieve the weight of brickwork over a chimney opening (in kitchens and rooms where a large opening is required, and two bars may not be sufficiently strong, a wrought or cast iron cradling is necessary). The Metropolitan Building Act requires that under certain cases the abutments of a chimney must be tied in by an iron bar or bars, turned up and down at the ends, and built into the jambs for at least 8 in. on each side.

2255a. The advantage of now being able to procure wrought iron flitches of a good length and depth has obviated the necessity of welding two or more lengths together by the sledge hammer, which has not a sufficient impetus to reach the very core of the metal, and thus the joint became weaker than the remainder of the flitch or bar. In 1964 experiments were made at Paris, on the effect of welding by hydraulic pressure; two bars, each 11⁄2 in. square, were thus welded together with great ease, and the machine was stopped when the part welded was brought down to the thickness of the bar. After cooling, the welded part was cut through, and the inside was found perfectly compact.

2255b. Boiler plate is made of rolled or wrought iron. They are termed sheets when under inch in thickness; plates from a inch to 2 inches thick; and slabs when more than 2 inches thick. They are named according to the quality of the iron, or the locality where they are manufactured. The sizes of those most in use are from 6 feet to 9 feet long, 2 feet to 4 feet wide, and from a to of an inch n thickness. Pure charcoal Swedish galvanized flat sheet iron is imported for roofing purposes, instead of zinc or lead. It can be bent and hammered without cracking.

2255c. Corrugated iron is sheet iron which has been rolled into the form of a series of waves. It is in that state frequently used for a covering for temporary purposes; between joists to carry concrete, &c.; and for fencing, the corrugation giving a thin sheet great capability for carrying a heavy weight, or for stiffening framework. The flutes are generally about 5 or 6 inches from centre to centre. Sheets of Nos. 16, 18 and 20 wire gauge are made from 6 feet by 2 feet, to 8 feet by 3 feet; and of Nos. 22, 24, and 26,

from 6 feet by 2 feet, to 7 feet by 2 feet 6 inches. In calculating the measure for fixed roofing, add to the weight per square for lapping. The sheets should overlap each other about 6 inches, and be double riveted at the joints. About 3 lbs. of rivets are required for a square of roofing. In roofs, the iron sheets are best used in a curved form.

2255d. Wrought iron casements are still introduced into buildings. This has given rise to several improvements upon the old method of manufacture for making them wind and - water tight. Those now generally advertised are:-patent wrought iron windows, by the General Iron Foundry Company (Limited); Burt and Potts' patent wrought iron watertight window and frame; Gibbons and White's wrought iron weather-tight casements and frames for stone mullions; and casements for wood mullions, as designed by Mr. G. Devey, architect. All these are fitted with casement stays and fastenings. Connected with this purpose are Smith's (of Princes Street, Leicester Square)

B

patent weather-tight water-bar," for French casements, formed in the sill; and one of another make, by a manufacturer of the same name (formerly of Queen Street, Oxford Street). In connection with this subject is the use of iron bars and casements for forming the lights in rear of warehouses and offices in crowded localities, for the purpose of obtaining as much space and light as possible, at the same time so as not to interfere with neighbours' lights. A useful example, designed by Mr. Bassett Keeling, architect, is given in the Builder, 1880, vol. xxxix. 202, from which the following cuts forming part of the illustrations are here given. Fig. 807e. is a section of the lower part of the vertical framing and sill. Fig. 807h. is a section of one of the upFig. 807i. is a section of the other bars and of the side of casement. Fig. 807g. is a section of the horizontal bar on the curved head

WOOD

SILL

STONE SILL

Fig. 807e.

right bars, showing hinge of casement.

G

GIRDER

Fig. 807f.

Fig 8070.

W

from the vertical to the head. Fig. 807f. shows the finish of the curved head against a wrought iron girder carrying a wall above. The letters B show the iron framing; C the iron casement; G the glass; W the inside beaded wood framing.

2255e. Fire-proof ircn doors are made to shut iu a rebate, as required under the Metropolitan Building Act, or are made sliding; or sliding as carried out by Messrs. Hobbs, Hart and Co. on their new patent clutch rebate principle. A door on each side of the party wall is usually required; and for warehouse purposes in London they are specified to be made folding, and to be not larger than a definite size. The usual dimensions, outside of frames, of fireproof wrought iron doors and frames, may be usefully inserted here:-5 ft. 9 in. high by 2 ft. 3 in. wide; 6 ft. by 2 ft. 4 in.; 6 ft. 2 in. by 2 ft. 6 in.; 6 ft. 6 in. by 2 ft. 6 in.; 6 ft. 2 in. by 2 ft. 8 in.; and 6 ft. 4 in. by 3 ft.

CB

Fig. 807i.

2255f. Iron shop fronts are introduced in many towns. They are made from 12 feet by 6 feet to 14 feet by 10 feet, generally at one shilling per superficial foot. "Whole brass" and "half brass" sash bars, of nearly every form and size, are manufactured, as well as brass, copper, and zinc beads. Metal "stall-board plates" hardly come within

Fig. 807h.