reduced in one direction and increased in the other. DRAWING-IN or HITCHING. When a cutting tool cuts to a greater depth than that intended for it to cut. Usually due to the improper form of the tool; to an unsuitable cutting angle; or to the improper position of the cutting point relatively to the shank. DRAWING-ON.- Signifies the method by which wheels, pulleys, etc., are attached to their axles or shafts when they are too large to be driven on by a hammer. As commonly applied, long bolts the heads of which are held in a massive cross attached to one end of the axle, pass on the outside of the wheel, or through it between the arms, and the tightening of their nuts against a washer plate placed across the face of the wheel, pulls the wheel into the proper position on the shaft. Hydraulic presses are also used for this purpose.

DRIFTING. The shaping and enlarging of holes by the use of a drift. Also applied to the adjusting of overlapping rivet holes into alignment with each

other.

DRIVING FIT.-The fit of a bush, a spindle, or of a shaft, when it is driven by the blows of a hammer into the hole bored for its reception.

DRIVING-HOME. The driving of a wheel, shaft, or any other part of a machine to its final and permanent position.

DRYING-IN. The merging of a hollow radius with a plane surface, as distinguished from the meeting of abrupt angles.

EAR. A lug or projection upon a casting designed for the reception of a bolt or other attachment. END MEASUREMENT.- Measurements taken with a caliper or micrometer gauge. They are very much more accurate than line measurements. ERECTING. The final building-up of machines in readiness for working. The work is accomplished by the "erector, to whom all the work of the turners, planers, slotters, drillers, and fitters is brought, ready to be put together with little or no adjustment being required of them.

FEMALE. The recessed part of any piece of work designed for the reception of a dowell or stud. FILLET. A term of many meanings, and loosely applied to the hollow or to the curves given to the otherwise angular parts of the inner sides of castings; also to a great variety of moldings, beadings, flanges, chipping strips, and to any thin strips employed to give strength, or for ornamental purposes. FIN. Any thin wafer-like expansion of metal that occurs on the side or edge of a larger portion, such as those on the joints of castings, and on the edges of forgings pressed in dies.

a

FINGER. A narrow projection of metal used as guide in various kinds of metal work. FITTER. A working mechanical engineer whose duty consists of the work of putting together machine or engine parts after they have passed through the hands of the turners, planers, drillers, etc. FITTING. In a broad sense it defines the duties of the fitter, but in a limited sense it signifies the working. up and finishing by hand of the smaller pieces of metal work which cannot be accomplished by machines.

FIXED CENTRE. A centre, the position of which is localized in space, as distinguished from a movable

centre.

FLUSH. The parts of a machine are said to be flush when their surfaces are on the same level. FORGING. The making of forged or smith's work, and also applied to the work produced by a smith. FORMING. A class of work turned out on special lathes by means of broad cutting tools, the faces of which correspond exactly to the sections of the pieces to be cut. The value of the method lies in its capacity to produce irregular contours, curved and otherwise, by the use of single tools which ordinarily would require the use of several tools, thereby rendering the attainment of uniformity in many kinds of work practically impossible, or economically difficult. The method is extensively applied to the work of brass finishers and cycle makers. FRETTING. The abrasion of a cutting tool when it is sharpened on an oil stone. FROSTING. A finish put upon the exposed surfaces of machine parts for ornamental purposes only. It is effected by scraping with a scraper, or with a small piece of oil stone, a series of the lightest of cuts or scrapings upon the surface of the metal. These cuts are inflicted at different crossing angles from which the light is reflected and produce a very beautiful effect.

FULL The term signifies that a dimension is slightly larger than it ought to be, but only so slightly that the excess may be measured only by calipers rather

an

than by rule measurement. When applied to eccentric, it refers to that part of the sheave which is situated at the greatest distance from the crankshaft upon which it is fixed.

GEAR. A term widely applied to a great variety of arrangements of toothed wheels, valve motions, pump work, hoisting tackle, ropes, etc. Gearing is a synonymous term, but it is specifically applicable to gear wheels, and also to the driving in and the working of the wooden cogs of mortise wheels. GLAZING. As used in the workshop, it signifies the filling up of the interstices of the surface of a grind. stone, or of an emery wheel, with the minute particles of metal detached by the process of grinding; giving the surface a smooth and polished appearance, and reducing its cutting quality. It is primarily caused either by an insufficient supply of water; by the grinding of material unsuitable to the nature of the stone or wheel; or by the grinding of so broad a surface that the abraded particles of metal are imprisoned by it and are squeezed between the rigid particles composing the grinder. GRINDING-IN. The process of bringing the bearing surfaces of cylindrical cocks and plugs to an exact fit by the use of emery powder.

GUMMING. The tendency of lubricating oils to become thick and sticky.

HACKING. The dressing-off of the projections on the face of a grindstone which has become so uneven that the effective use of the ordinary pointed grind. ing tool is rendered very difficult. It is accomplished by means of a chisel-shaped, cross-paned hammer called a hack-hammer, the chief projections being reduced by a series of cross hatchings, or chequered

cuts.

HANDING. Making symmetrical work right and left hand respectively, and the changing of patterns from right to left hand, and from left to right hand. HOLD UP. A common term that expresses the capacity of a piece of wood or metal to finish to a given size. IRON TURNING. It is the most important branch of mechanical work, and includes all the various kinds of turning connected with the production of all circular bearing parts, and all revolving and close fitting work which has to be turned in power driven, slide rest lathes.

JACKING-UP. The elevating of masses of machinery Also the and heavy structures by means of jacks. planing of the rough outsides of boards with a jack plane.

etc.

JAG. A roughed-up or barbed projection of metal produced by nicking underneath, or in front of it, with JOINTING. The joining together of iron pipes, sockets, a cold chisel, or by casting. The jointing of iron pipes is effected with red lead and boiled oil when the flanges are brought together, while that of sockets is effected with melted lead, with a gasket, or with rubber rings. Hydraulic jointing is accomplished with sal-ammoniac and iron borings. Piston joints for hydraulic work are made of leather pressed into the shape of a cup, while piston joints for steam work are made with metal expansion rings.

JUMPING-UP. The knocking down of the end of a bar of iron upon the anvil so as to thicken the heated portion. KERF. The width of the cut produced by the teeth of a saw. It depends upon the amount of set given to the teeth.

KINK. The sharp bend or angle given to a piece of metal by a blow or a strain. It is also applied to the knotting of the links of a chain. KNOCKING. The noise caused in a pump when the motion for suction and delivery are reversed, and is due to the absence of an air vessel, or one of sufficient area.

KNOTTING. A compound, either of shellac and methy lated spirit, or of red lead and glue, used for filling. in or covering knots to prevent the absorption of oil paint. LAP. A body of lead, tin, brass, or other soft metal employed to hold or support the emery or pumice stone used in the grinding of surfaces of hardened steel, chilled iron, and other substances too hard to be attacked with ordinary tools. The character and shape of the lap depends upon the nature of the work performed. Usually the outline of the lap is made similar to that of the work. Lead is used for the commonest grades of work, tin for better grades, and brass for the finest grades. The term is also applied to the extent to which the plates pass over each other in the making of rivet joints, and to a single turn of a rope or chain around the barrel or drum of a hoisting machine.

LAPPING. The polishing and truing up of spindles and circular bearing parts in general, by the use of laps of lead or other material.

LATHE WORK. Work commonly accomplished in the lathe. It embraces practically all kinds of mechanical work accomplished by turning operations. LAYING-OUT. The marking out of work to full size. LET IN. Signifies the sinking in of one portion of wood or metal into another, as in the case of rapping plates which are let in to the patterns, and brass rings let in to sluice cock faces, etc. LINING UP. The introduction of packing pieces under bearings to compensate for wear. MACHINING. A general term applied to the operations of turning, planing, shaping, boring, etc., performed on metal work by machines.

MAGNETING. The process of separating particles of iron from those of brass and copper turnings by the use of a magnet, prior to remelting. MALE. A stud or dowell that fits into a recess formed for its reception, in a particular piece of work. MANDREL or MANDRIL. In a general sense it is ap plicable to any cylindrical rod of metal. Specifically it is applied to the revolving spindle used for chucking lathe work on; to the spindle of a circular saw; and to the round rod upon which the nuts made by a smith are finished to shape. MARKER

OUT. The workman who marks out the centres and the working lines of metal work preparatory to the operations of the machinists and the fitters.

METAL SPINNING. The process by which light articles made of malleable metal are formed into circular and other shapes by means of pressure applied to them while they are rapidly rotated in a lathe. MILLING. The method of forming metal into various shapes by means of tools or cutters slowly revolved in milling machines. A greater variety of surface contours can be produced more rapidly and accurately by milling than by the ordinary planing and shaping operations in which single cutting tools are employed. The great value of the method is its capability to produce an indefinite number of articles or machine parts exactly similar in outline, and of uni form size.

MITRE. Lines or edges which meet at an angle of 45° with each other as in the case of any two adjoining sides of a picture frame.

MORTISE. A joint in timber work formed by a recess cut in one piece, and a corresponding tenon in the other.

MOUNTING. The chucking of lathe work. MOVABLE CENTRES or MOVABLE POINTS.- The movable centres of the rods in parallel motions. NICKING. The cutting of a shallow V-shaped groove around a pipe, or across a bar of metal so that it may be broken by a blow at that particular point. OPENING-OUT. The enlarging of the diameter of hole by means of a broach or reamer.

a

OUT OF TRUTH. Signifies inaccuracy in work or materials, such as a wabbling piece of lathe work, or a winding piece of wood or metal.

Ουτ AND OUT, OR OVER-ALL. Signifies an outside dimension taken to its utmost extent. OVERHAULING. In a general sense it is loosely applied to the examination of machines and machine parts, preparatory to the making of repairs. Spe cifically, it signifies the pulling down of the slack of a hoisting chain.

PATTERN WORK. The making of patterns for purposes of casting, turning, milling, etc.

PENING. The beating over or the smoothing over of a metallic surface with the pene or smaller end of a hammer-head.

PIPE BENDING. When metal pipes are bent, any buckling or wrinkling in the inner curve is pre vented by filling the pipe with melted rosin or some fusible alloy, which tends to preserve its circular form during the process of bending, and which is subsequently melted out of the pipe at the completion of the process. When wrought iron pipes are bent hot, sand is usually employed as a filling instead of an alloy which would be melted by the

heat.

PIPE CONNECTIONS. The various parts used in making the joints of pipes, such as bends, tees, unions elbows, nipples, thimbles, etc.

PLANING. The removal of material from plane or flat surfaces by the use of cutting tools. In the case of small wood work, hand planes are employed; but, in the case of wood work in large quantities or sizes, and in metal work, the operations are performed by the use of planing machines. PLANISHING. The smoothing and polishing of metallic surfaces by hammering, or by rolling, instead of by cutting or by abrasion. Shafting is very often planished instead of turned. Planishing hammers used on sheet metal are capable of delivering blows at the rate of three hundred blows per minute.

PLAY. The freedom of movement, within definite limits, allowed in bearing or working parts, to prevent their jamming by heating, or by oscillation. PLUMB. In a vertical position, as indicated by the position of a weighted cord hanging at rest. PLY. Signifies a fold, a twist, or a single thickness of a material such as wire gauze, or cotton belting. In the latter case, the terms two-ply, three-ply, and four-ply, indicate that the belting is made up of two, three, or four single thicknesses of the material. The term also signifies to bend.

PRESS FIT. The ht of adjoining parts which is a little tighter than a sliding fit. It is provided for the purpose of allowing such parts to be pressed together by hydraulic pressure.

PRISING. The turning of a wheel around its axle with a crowbar. Sometimes called "barring." PUNCHING.- The making of holes through

metal

plates by a punching machine, as distinguished from the making of holes by drilling.

RAISED WORK. Metal work which is produced by being hammered into the required outline. RAISING. The production of raised work in curved outlines in sheet metal by hammering.

REDDLE. Red lead mixed with oil, and used in the fitting of metal surfaces by the processes of scraping and filing.

RED LEAD. The red oxide of lead. Mixed with boiled oil, or with boiled oil and white lead, it is used in making steam joints; mixed to the consistency of a thin semi-fluid paste, it is used for checking the accuracy of contact surfaces during the operations of fitting, the color being transferred from the surface that has been finished to the highest portions of the surface to which the finished surface is being fitted.

RIVET. A double-headed, solid, bolt-like fastening, used for securing metal plates together, when they are subjected to shearing and not to tensile strains. They are made of soft iron, superior in quality to that of the plates, and are pressed into form in dies while red hot. They hold partly by the grip due to contraction on cooling, and partly by the frictional resistance of the plates to slipping. RIVETING. The forming of the rivet heads in place. The rivets are first heated to a red heat, then they are placed in the rivet holes in the plates, and the tail turned over or clenched by the blows of a hammer. This operation is commonly called closingup. Large rivets are usually closed-up when red hot, and small rivets when cold; but, if the length between the heads is more than four inches, the heads formed on hot rivets are liable to be broken off by the contraction of the metal when it cools. Rivets of that length and over ought to be closed-up cold. Riveting is accomplished either by the use of hand hammers and hand riveting-sets, which close up and form the tails of the rivets, or by hydraulic pressure. In machine riveting, the closing-up and the forming of the tail are performed in one operation. ROUGHING-DOWN or ROUGHING. The removal of the outer skin or scale, and the larger bulk of the material from a piece of work preparatory to the more accurate shaping with finishing cuts.

RULE MEASUREMENTS.- The taking of all ordinary dimensions with a rule where the character of the work does not require the exactness which can be attained only by the use of calipers, trammels, gauges, and micrometer gauges. RUNNING-OUT.- In boring operations, it signifies the slipping away of the drill from the centre in which it was started. It is caused in various ways, such as the carelessness in the initial centring; the improper setting of the work; the influence of inequalities on the surface of the work; or the bad form of the drill itself.

sur

RUSTING. The coating of bright iron or steel faces, such as those of iron patterns, with rust so that they will take shellac varnish without the risk of peeling off. Rusting is accomplished very quickly by coating the iron with a solution of sal-ammoniac, or with a weak solution of hydrochloric acid, and allowing it to dry.

RYMERING OF REAMING.-The enlarging of holes, already punched or drilled, by the use of a rymer or reamer. By this method, holes which have been roughly drilled, or those in which ridges have been left by the drill, are smoothed down and made truer; holes which have been punched or drilled in plates, and which do not correspond exactly, are corrected by clamping the plates together and passing the reamer through both of them at one; and punched holes in the immediate vicinity of which local tension has been set up by the punching operations, are relieved of that strain by reaming them about 1-16 of an inch larger in diameter.

or

Also

SCALING. The taking of measurements or dimensions by means of a scale from drawings made full actual size, or from those upon which the dimensions are not given in figures. SCRAPING. A method by which approximately plane surfaces are produced by means of scrapers. used in the exact fitting of bearing surfaces, and in the removal of marks or grooves left by the cutting processes. It is a mechanical operation by which the most perfect results in the fitting of contact surfaces are obtained. See Red Lead. SCRIBING. Marking out with a scribe on rough pieces of wood or metal, the outline of the shape or pattern to which such pieces are to be worked by the subsequent operations. A timber scribe is a steel tool pointed at one end for scratching, and knifeshaped at the other end for cutting. A metal fitter's scribe is pointed at both ends, one being straight for top scribing, and the other curved for marking underneath work.

SET WORK.-Regular work or that which is repeated many times or perpetually in a workshop. It is also applied to any class of work which is made a specialty by a manufacturing concern. In such cases it is accomplished by the minute subdivision of labor and piece work, and is therefore made better and cheaper by such firms; but it tends to develop a very one-sided class of workmen, undoubtedly good in their special line though rather inferior in all other branches of shop work. SHRINKING-ON.- The fixing

together of joints in

or clasping of wheel tires; the securing of the jackets of built-up guns over the central tube, etc., by expanding the wheel or jacket, as the case may be, by means of heat, then placing it in the desired position, and allowing it to grip or tighten on the receiving part by the shrinkage caused by cooling. SHUTTING. The welding wrought iron or steel. SLACK FIT. A term usually employed to denote a bad fit, or the fit of machine parts in contact, which have more play than is sufficient or desirable for their easy movement. SLIDE PRINCIPLE. A principle of construction upon which the adjacent moving parts of a machine are So fitted to one another with guides or guiding strips, that they can slide or move over each other in one direction only. It is a principle which is applied in one way or another in the construction of all kinds of modern machine tools. SLIDING FIT. When cylindrical or plane surfaces move over each other freely, but without any per; ceptible slackness. The difference of 1-10,000th of an inch is equivalent to the difference between a sliding and a slack fit. SOLDERING. The joining of two pieces of metal by means of another metal or an alloy. Soft soldering is accomplished by means of the various alloys of lead and tin; while hard soldering or brazing is effected by the use of the alloys of copper and tin. Clean surfaces are essential to effective soldering. In soft soldering a copper bit is used to fuse the alloy; in hard soldering the metal parts are held together by means of binding wire, and the melted alloy allowed to run in between them. SPINNING. See Metal Spinning.

SQUARING-UP. A term applied to various methods by which the faces of work are brought into a square position with each other by the use of planes, files, and machine cutters; or to the setting of faces already squared, against the face of a surface plate or marking-off table, preparatory to the scribing of lines and distances. SWAGING. The drawing down of wrought metal to a definite form with or without the use of swage tools. It is the reverse of up-setting.

After

SWEATING OR SWEATING-ON. The soldering of metallic surfaces without the aid of a copper bit. being thoroughly cleaned the surfaces are heated and covered with film a of solder. Then they are brought together and heated until the solder flows and unites them. The method is often employed to hold together temporarily various kinds of work which has to be turned or shaped, and which could not be conveniently held in any other manner. The subsequent separation of the parts is easily accomplished by the aid of heat.

TAKING UP. A general term which signifies the mak ing of adjustments for wear. Specifically, it denotes the closing up of strap ends of connecting rods, the cone hearings of lathes, compensating collars, etc., and signifies the smooth working of bearing and moving parts, rather than to the tightening of parts which are either bolted or wedged together.

TRAMMELLING-OFF.- The measuring of important dimensions, lengths and centres with trammels. In shopwork, it is the only method recognized as correct, rule measurement being inadmissible. TRIAL AND ERROR. A method commonly employed in the workshop to obtain correct work in the construction of mechanisms, or in the making of tools. The most accurate results are obtained as follows: When a piece of work has been produced as accurately as possible by the use of a particular set of tools, or by a particular method of construction, some other set of tools, or some other method of construction is resorted to for the detection of the errors left un corrected by the tools or method previously employed. The production of surface plates and straight edges, and the centring of work in a lathe with chalk, are cases in point. TRYING-UP. The straight and accurate planing of wooden surfaces, out of winding and at right angles with each other.

TURNING. The fashioning of wood and metal work to circular forms in a lathe. It is accomplished either by hand tools, or by power-driven machine tools. UP-HAND OR UP-HAND SLEDGE. The delivering of light blows with a smith's sledge-hammer in light work, or the use of a light hammer for that purpose. WILLIAM MOREY, JR., C. E.

Consulting Mechanical Engineer, New York.

Work'sop, England, a town of Nottinghamshire, on the Ryton and the Chesterfield Canal; 16 miles east-southeast of Sheffield. It lies near the northern extremity of Sherwood Forest, in a district known as the "Dukery," from the number of ducal seats. Its parish church, dating from 1103, was an ancient Norman abbey church. There are manufactures of agricultural implements, mill machinery, chemicals, etc., and there are iron and brass foundries. Pop. about 18,000.

World, The. Tables showing the total area, number of inhabitants, and density of population of each of the principal divisions of the world's land surface; also the area and density of population of each of the republics and European dependencies in the Western hemisphere; based upon the important work of Alexander Supan, 'Petermann's Mittheilungen, Ergänzungsheft' (Nr. 146, Gotha: 31 March 1904).

The grand total of the earth's population, as shown in this most recent computation. is 1,503,300,000; the total area of the seven divisions or groups, which include all of its continents and islands, is 144,110,600 square kilometres; and the average density of population is 10 persons to one square kilometre. The distribution (rearranged and condensed with a view to giving prominence to the facts which are of special interest to our readers) is as follows:

The total area of the American continents and islands is 38.562,600 square kilometres, and

nary cutting tools as distinguished from the shaping of surfaces by grinding.

follows:

But compare figures in articles under these titles. + See WEST INDIES. See GUIANA,

The total population of Latin-America, if we include in that designation all countries and islands directly south or southeast of the United States, excepting parts of the British and Dutch possessions, is approximately 63,000,000. For the population of each of the foregoing LatinAmerican political divisions, and area of each in square miles, with explanation of the uncertainty that exists as to the exact figures, see separate titles; also ACRÉ.

Revised by MARRION WILCOX. World, Armament of the. See ARMAMENT OF THE WORLD.

World-English, the name given by Prof. A. Melville Bell to a proposed new phonetic system of spelling the English language, so as to render its acquirement by foreigners more easy, and to make it available for international

use.

World's Columbian Exposition, an international exposition held in Chicago, Ill., in 1893, to celebrate the 400th anniversary of the discovery of America by Columbus.

History. The fitness of some special celebration of the discovery of America had been recognized and the question agitated several years before the bill providing for a Columbian Exposition was introduced in Congress in 1889. Several cities urged their claims for the site of the exposition; chief among them were New York, Chicago, Washington, and Saint Louis; Chicago was finally chosen as the site, and the bill passed and approved 25 April 1890. The organization of the fair was placed under the charge of an Illinois corporation previously organized, and the World's Columbian Commission, a national commission consisting of delegates appointed two from each State and Territory,

two from the District of Columbia, and eight at large. Harlow N. Higginbotham was president of the former, and Thomas W. Palmer of the latter; George R. Davis was appointed director-general. Exposition headquarters were established in Chicago in January 1891. A Department of Publicity and Promotion was established, and a Board of Lady Managers with Mrs. Potter Palmer at its head, and a World's Congress Auxiliary with C. C. Bonnery as president were organized. The work of construction was placed under the charge of a Bureau of Construction of which Daniel H. Burnham was chief; work was begun on the first building in July 1891. On 23 Oct. 1892 the buildings were formally dedicated by the Vice-President of the United States; the dedication ceremony, which was attended by 130,000 people, was held in the Manufactures and Liberal Arts Building. The exposition was formally opened 1 May 1893 by President Cleveland; at the moment when he declared the fair open the flags of the various nations were unfurled, the electric fountains turned on, and the statue of "The Republic" unveiled. The attendance at the fair increased toward the close; the days showing the largest attendance were 9 October, Chicago Day, and 4 July, American Independence Day; the average daily attendance was 172,712. The exposition was formally closed 30 October; preparations had been made for elaborate closing. ceremonies, but the assassination of Mayor Harrison of Chicago two days previous prevented the carrying out of the proposed programme.

Financial.-The bill providing for the exposition required the city of Chicago to raise $10,000,000 toward the expenses; later Congress provided for the gift of a special mintage of $2,500,000 in souvenir half-dollars, the exposition authorities also issued $5,000,000 worth of debenture bonds; about $3,000,000 additional were received from other miscellaneous sources, so that about $20,000,000 was available before the opening; the total expenditures for the fair over $31,000,000, and the profits about $1,850,000. The United States Government ap$6,060,350, the foreign governments $5,830,000, propriated $2,250,000 to its exhibits, the States and over $350,000 was invested in the Midway Plaisance.

were

Buildings and Principal Exhibits.-The site chosen for the exposition was Jackson Park, a portion of the South Park system of Chicago; it covered 666 acres and extended about two miles along the shore of Lake Michigan. There were about 150 buildings erected; the more important were built of the material called "staff," a composition of plaster of Paris and jute fibre, which produced the general effect of white marble, hence the exposition grounds became generally known as the White City. One channel from the lake led into a pond in the southern part of the grounds, and north of this another channel led into a long basin; this second channel passed underneath a handsome bridge and colonnade. The basin was joined by an artificial canal to the lagoon, a small lake. containing Wooded Island. About the basin and lagoon the principal buildings were grouped. The space about the basin was known as the Court of Honor. The Manufactures and Liberal Arts Building faced the lake near the eastern end of the basin; this was the largest building ever constructed for an exposition; it cov