Locomotive

Four Cylinder, Balanced Compound. The latest development, the four cylinder, balanced compound locomotive, is built with a cranked axle, that is, one with cranks built up or forged on the axle between the wheel seats. Either the high pressure or the low pressure piston rods are connected to the cranked axle through their crossheads and main rods. Usually the high pressure cylinders are by this arrangement inside connected, and the low pressure cylinders, lying outside the high pressure, drive the same axle by means of crank pins on the outside of the driving wheels, as in a simple, non-compound locomotive. În other designs, the high pressure pistons drive the forward cranked axle, and the low pressure pistons drive the second driving axle, being outside connected. This arrangement makes it possible more nearly to balance the revolving and reciprocating masses in a locomotive engine than has ever before been accomplished. This is accomplished by placing on each side of the locomotive the high pressure and low pressure cranks, that is, those lying inside and outside of each driving wheel are set exactly opposite, or 180° from each other on their circular paths; and the two cranks on one side are set onequarter of a revolution in advance of the two on the other side, so that any one of the four cranks is 90° away from the crank next to it, thus producing a uniform turning impulse to the driving wheels. Furthermore, any one of the four pistons, when at the end of its stroke, is balanced by another moving in the opposíte direction on the same side of the engine, so that the shock of bringing to rest the masses of the piston, piston rod, and crosshead at each end of the cylinder and starting them in the opposite direction is largely absorbed by

cylinder compounds and four cylinder compounds, driving through only two crossheads. Both of these designs, while

of compounds were built and put in various kinds of service, but they were not entirely satisfactory.

the opposition arrangement of pistons just referred to. These facts being noted, an opportunity for an increase of power of loco

Locomotive

where the greatest attention has been paid to the development and operation of these engines, particularly for passenger trains; and the results obtained in those countries, as regards the hauling of heavy, fast trains, with economical fuel consumption, have attracted universal attention.

ex

In a two cylinder, compound locomotive, steam from the boiler (called live steam) enters the high-pressure steam chest and after moving the piston of the high pressure cylinder is hausted into the low pressure steam chest, whence it is admitted to the low-pressure cylinder where it also performs work, and is finally exhausted through the stack to the atmosphere. În a four cylinder compound, the action of the steam is the same, except that live steam passes through two high-pressure cylinders whence it is exhausted into two low pressure cylinders and thence to the atmosphere. Some four cylinder compounds have the high- and low-pressure cylinders on each side placed one above the other, or one ahead of the other, and actuating one crosshead; while others have the four cylinders placed alongside one another, two being inside connected, and two outside connected (Fig. 17). The theoretical advantage of a compound over a simple engine is the greater range of temperature between the live steam and the exhaust, which means the greater amount of heat energy converted into the work of moving the engine. Then, for a simple and a compound engine of equal power, the compound has smaller and lighter moving parts because the work is divided between two cylinders and their connections.

B. & O. Mallet Articulated Compound. The compound locomotive shown in Fig. 17 is called an 'articulated' locomotive, a design originated by a French engineer, M. Mallet. The locomotive is composed of two groups of engines, one carrying the highpressure cylinders which transmit power to six driving wheels supporting the rear portion, and the other group having the lowpressure cylinders turning six other driving wheels, forming a bogie or swinging truck, thus giving the locomotive great flexibility for traversing sharp curves, and making the entire weight, 167 tons, available for adhesion. The steam from the high-pressure cylinder exhaust passes to the low-pressure steam chests through a flexible joint steam pipe which swings as the forward driving truck turns. This is the largest and most powerful locomotive ever built, its tractive power,

384

when working compound, being 71,500 lbs., steam pressure 235 lbs. per square inch, and other dimensions as will be found in Table I.

Bibliography: Report of Penna. R. R.'s. Locomotive Testing Plant at St. Louis Exposition (1904;) Forney's Catechism of the Locomotive (1890); Thurston's History of the Growth of the Steam Engine (1878); Sinclair's Locomotive Engine Running and Management (1895); Meyer's Modern Locomotive Construction (1889); Master Mechanics Association's Locomotive Dictionary (1906).

Locomotive Engineers, Brotherhood of. See RAILWAY EMPLOYEES, ORGANIZATIONS OF.

Locomotor Ataxia, or TABES DORSALIS, is a nervous disease characterized by incoördination of muscular movements, and by trophic and sensory disturbances with involvement of the special senses, of which the eyes are chiefly affected. The cause of the disease is obscure; it is most common in males between thirty and forty years of age, and occurs more frequently in cities than in the country. Syphilis is a factor of the greatest importance, but does not account for all cases. Three stages are recognizedthe pre-ataxic, the ataxic, and the paralytic. The disease is frequently arrested, and may remain stationary for years.

Loco Weed. The popular Western name applied to several plants, chiefly of the papilionaceous genera Astragalus and Aragallus. They are silverywhite perennials, about a foot high, growing in tufts with a short central stem and pinnate, silky foliage. The flowers are in racemes, and are generally purple or white. They are found throughout the West on the cattle ranges, and cause many deaths among live-stock, especially horses, by inducing the loco' disease. When an animal is 'locoed' (a term which is sometimes jestingly applied to mankind), the symptoms

.

are those of cerebral origin, consisting in peculiar irregularities in gait and action, which may be compared to a drunken condition in men. Sight is frequently much impaired,' as is also hearing, and the animals tremble. A peculiar effect is the animal's inability to judge of size and distance; he will try to jump over an ordinary gate, or lower his head to avoid striking the top rail; he is also much afraid of innocent objects or imaginary ones. 'After acquiring a taste for the plant it (the animal) refuses every other kind of food,' then, 'there is a lingering period of emaciation, characterized by sunken eye-balls, lusterless hair, and feeble movements. The

Locus Delicti

animal dies as if from starvation, in periods ranging from a few months to one or two years." At one time Colorado paid out bounties for the suppression of the loco weed,' which, in that state, usually means the purpleflowered Astragalus mollissimus, the woolly loco weed, or crazy weed. The most dangerous variety in Montana, is Aragallus spicatus. This is called white loco weed or rattle weed, the single seed rattling in the dried pod, and has cream-colored flowers. See V. V. Chesnub and E. V. Wilcox's The Stock-poisoning Plants of Montana (1901), and V. V. Chesnub's Principal Poisonous Plants of the United States (1895).

Locri. (1.) Peoples of ancient Greece, the inhabitants of two districts each called Locris, of which the eastern lay south of Thessaly, along the coast of the Maliac Gulf, enclosed by Doris and Phocis on the west. It was a fertile country. The western district, the country of the Locri Ozola, lay on the northern shore of the Corinthian gulf between Phocis and Etolia, its chief town was Amphissa. (2.) L. EPIZEPHYRII was one of the most ancient Greek colonies in S. Italy. It was situated in the south-east of Bruttium (now Calabria) to the north of the promontory of Zephyrium, from which it derived its distinguishing designation, and was founded by Locrians from Greece in 683 B.C. It was renowned for the excellence of its code of laws, framed by Zaleucus in the 6th century B.C. The city figured in the wars waged by Rome with Pyrrhus and Carthage.

Locus, in mathematics, a curve or surface traced out by a point or line which has a limited freedom of motion determined by given geometric conditions. For example, all points in a plane from which a given straight line subtends a right angle lie on a circle with the given line as diameter; in space the locus similarly defined is a sphere. Again, the vertices of all triangles on a given base and with a given perimeter have for their focus à spheroid, of which the ends of the base are the foci. See CURVE.

Locus Delicti. In law, the place where a criminal offence was committed. In an indictment or information the locus delicti must be accurately set forth, both in order to show that the crime was committed within the jurisdiction of the court to which the indictment is brought and to define the offence charged so as to enable the accused to plead to the indictment. Upon the trial the proof must conform to the allegation of the indictment in this as in other respects, it

Locus Standi

being a complete defence to a charge of crime that the accused was elsewhere (alibi) than at the place alleged at the time of the commission of the crime. In general where a crime involves several acts committed in different places, as in a robbery planned in one county or state and executed in another, the goods being then taken by the robber to a third jurisdiction, the locus delicti is the county or state where the robbery was actually perpetrated. In actions for criminal conversation or for divorce on the ground of adultery the place where the alleged offence was committed must also usually be alleged and proven.

Locus Standi. In general a person's right to be represented or heard in any litigation or before a legislative body. The term is in England more commonly employed to denote the right of a person or corporation, if injuriously affected, to petition against a private bill. In the United States it is customary for legislative committees charged with the responsibility of examining into and reporting upon proposed legislation, to grant hearings to persons in lines of business which may be affected thereby, but of course they are not bound by any arguments advanced by a majority of those who appear before them. See PARTIES.

Locust, an orthopterous or straight-winged insect belonging to the family Acridiida. In the article GRASSHOPPER Some account of the general characteristics of the family will be found; it remains only to mention some of the more destructive forms of locust. The European form is Pachytylus cinerascens, found over a great part of the eastern hemisphere; but another species, P. migratorius, occurs in S.E. Europe. Other species of Pachytylus occur in Africa, and are often excessively destructive. In some of the African forms the migrations are performed not only by the winged adults, but also by the young before the development of the wings, when they are locally known as 'voetgangers.' The locust swarms show a great indifference to the nature of their food, and will eat anything green which comes in their way, and even, when pressed by hunger, attack the young of their own species. The number of individuals contained in a large swarm is almost incalculable; but it has been shown that very large swarms only visit a particular locality at intervals of several years. This has been ascribed to the action of three causes-(1) the attacks of parasitic insects; (2) the fact that the eggs may remain more than one year in the ground, VOL. VII.-25

385

and yet hatch if a favorable season occurs; and (3) the fact that the migratory instinct does not appear unless a large number of superfluous individuals are produced.

Locust (Pachytylus migratorius).

The life history is similar in all cases. The female deposits a number of eggs in hard ground in a hole made for the purpose, and surrounds the eggs with a fluid which hardens into a capsule. After a period of varying length the young hatch out, being like the parents, except that they have no wings, have shorter antennæ, and are of smaller size. After successive moults they become adult and capable of reproduction.

Destruction of Locusts.-Where locusts are abundant, they may render agriculture almost impossible, and in consequence many methods of destruction have been advocated. In Cyprus, where they were formerly a plague, what is known as the Mattei system has been adopted with remarkable success. In essence this consists in destroying the pests in the wingless stage by taking advantage of the fact that they are unable to climb up or over a smooth surface. The method adopted is to construct a canvas screen about four feet high along the line of march, and at intervals along the screen to dig pits. The locusts, on finding themselves unable to pass the screen, turn along it, and ultimately fall into one of the pits, where they are soon buried under the bodies of their fellows, until the pits are nearly full, when they are filled in with earth. It is calculated that in 1883 nearly 200,000 millions of locusts were killed in this way. So successful, indeed, was the method that of recent years locusts have become so few in the island that it is no longer necessary, and preventive measures are limited to the offering of rewards for live locusts, caught in large nets. By 1902 the cost of the focust campaign had fallen to less than $10,000 annually. In S. Africa, on the other hand, where the Mattei method

Locusta

has also been tried, it appears to have been much less successful, and parts of the country are periodically devastated by locusts. There, in addition to the Mattei method, the eggs are collected and destroyed, and attempts have also been made to inoculate the insects with disease, in the hope that this may be spread by the habit of cannibalism which prevails among locusts.

The similar occasional plagues in the western United States are referred to under GRASSHOPPER.

Locust. Various trees and shrubs of the Leguminosæ, in America. The common locust (Robinia pseud-acacia) is a tall tree, with a flat-topped head of feathery foliage, made up of pinnate leaves. It flowers profusely in May and June, being nearly covered with long pendent racemes of pa pilionaceous, white flowers, which are extremely fragrant; they are succeeded by broad, brown pods. The glandular stipules become strong thorns on second years' wood. Locust wood is very valuable for shipbuilding, turnery, tree nails, and particularly for fence-posts, as it resists decay when in contact with the ground. It is generally yellowish-green in color, very strong, hard and compact, taking a brilliant polish. Locust trees were formerly much planted, both for ornament and timber, as they grow rapidly; but are not so much cultivated nowadays, as they are ravaged by a borer.

The clammy-locust (Robinia viscosa), and the rose-acacia (R. hispida), are smaller, the latter being only a shrub, and have rosecolored flowers.

The honey-locust is Gleditschia triacanthos and becomes a large tree, with a scaling bark, and has the older branches and the trunk, armed with strong, branched thorns. The leaves are pinnate, and the flowers are greenish-yellow and rather inconspicuous, but they are followed by pendulous pods, which are flat, crooked, and filled with a pulp, which for a month after ripening is sweet, but later is very acid. It was a food of Indians, and is a favorite with children. The wood is hard and difficult to split.

Ceratonia siliqua (carob tree) is also called the locust tree,' as it has been supposed to have formed the food of John the Baptist in the wilderness. Hence it is also termed 'St. John's bread.' Its pods are the so-called 'locust beans.'

Locusta, or LUCUSTA, a notorious female poisoner in ancient Rome; employed by Agrippina to kill her husband, the Emperor Claudius, and by Nero to kill Britannicus, for which service she was rewarded with large estates

Lodes

by Nero. She was executed in the reign of his successor, Galba.

Lodes, or MINERAL VEINS, are metalliferous deposits occupying fissures in the rocks of the earth's crust. The term is somewhat loosely used even by professional miners, who do not distinguish between the beds, or contemporaneous deposits, and the veins, which are subsequent, and have been filled up at a later period than the beds they intersect. Veins, as a rule, do not coincide with bedding planes, the bedding is mostly less steeply inclined than the veins. The slope of a vein from the horizontal is known as the dip, and its inclination to the vertical is its hade; the strike, or course, is the horizontal direction; the outcrop is the surface indication of the vein. It may, if harder than the surrounding rock, stand up as a reef, and the gossan, or weathered outcrop, is carefully searched by prospectors for indications of metallic minerals and their decomposition products. On each side of the vein lies the 'country' or 'country rock'; that part which overlies the vein is the hanging wall; the underlying side is the foot wall.

The vein is occupied by 'vein stuff,' which is not all metalliferous, but consists of gangue_(or valueless minerals) and ore. Two or more ores, such as copper and gold or lead and silver, may occur in the same vein. One or both walls of the lode may be covered with a layer of clay, known as the selvage or flucan. The terms employed by miners are mostly derived from Cornwall, Saxony, and other districts where deep mining has been pursued for hundreds of years; but local usages vary in different parts of the world. Veins may be a hundred feet or more in breadth, or may be only a fraction of an inch. The broadest veins are usually most persistent both in length and in depth, but all veins pinch and swell and usually soon die out, though some have been traced for several miles. The Comstock lode has been followed to a depth of 3,000 ft., and many veins have been proved to almost equal depths; but it is probable that all fissures tend to close up in the deeper parts of the earth's crust. The upper part of the vein, however, is usually the richest, owing to 'surface enrichment." This is a consequence of the disintegration of the exposed portion continuously, as the ground is lowered by denudation. Metallic particles that are not readily washed away or dissolved out remain behind, and settle down into the loosened material of the vein. These are the sources of placer deposits. Veins that are thoroughly weathered and

386

oxidized by the action of the atmosphere and percolating waters are often excessively rich, and contain the minerals in a condition which renders extraction

especially easy. The minerals also change in character with depth; and though native metals, oxides, and carbonates are common above (in the zone of oxidation), sulphides, tellurides, and arsenides are most frequent below.

Ores that are soluble in percolating waters are leached out and often carried down farther in the same vein to be deposited again, enriching a lower zone, usually at the level of ground water. Secondary enrichment is a most important factor in the formation of most rich ore-bodies.

Metallerous veins thin out and thicken very irregularly, and the materials which form the vein are rarely uniform throughout. Parts rich in ore (known as leaders, shoots, bonanzas, etc.) alternate with poorer stone. Very rarely do metalliferous minerals Occupy the whole fissure; usually they form only a small percentage of the mass (so small in certain gold ores that they are not visible to the naked eye), and may be uniformly disseminated or collected into pockets, strings, and irregular bunches.

Veins may form parallel to the bedding planes and are often very hard to distinguish from true beds, though quite different in their origin. In the main reefs series in the Transvaal, beds of conglomerate, which have been so disturbed as to have a steep dip, have been infiltrated with gold, deposited, mostly, at any rate, from solution in circulating waters. Although truly a bedded ore, this auriferous conglomerate, the 'banket' rock, owes its richness to processes similar to those which determine the formation of veins. The famous Calumet conglomerate of Michigan is a somewhat similar case where copper is the introduced metal instead of gold. This is worked to a depth exceeding 5,000 feet. In Australia many important mines are working saddle reefs, a curious type of vein lying between beds of folded country rock. Many American veins are associated with igneous intrusions of various sorts. These are known as contact deposits.

The origin of lodes has been the subject of much controversy. One hypothesis is that of lateral secretion. Its supporters point out that most rocks and rockforming minerals contain small quantities of the useful metals, which may be dissolved out by water percolating through these rocks, and subsequently deposited in fissures. The other theory is that of 'ascension.' It is based

Lodge

on the fact that hot ascending mineral waters are known at the present day to contain metals in solution, and to deposit them on the walls of the passages through which they rise to the surface. The opinion that metalliferous veins were mostly formed in the earlier epochs of the earth's history, is now no longer generally held, as it is known that many of the richest deposits occur in the later rocks. See Kemp's Ore Deposits of the United States(1900), Phillips's Treatise on Ore Deposits (1884, 2d ed. by Professor Louis, 1896) and Tarr's Economic Geology of the United States; Reis's Economic Geology (1905).

Lodestone, a variety of magnetite, Fe3O4, which acts as a magnet, exhibiting well-defined N. and s. poles. See IRON and MAGNETISM.

Lodge, EDMUND (1756-1839), English genealogist and biographer, born in London, entered the army (1771), but resigned his commission in 1773, and held the offices of Lancaster (1793-1822), Norroy (1822-38), and Clarenceux (1838-39) herald successively. His chief work is a series of historical memoirs attached to Portraits of Illustrious Personages of Great Britain (1821-34). He also wrote historical and genealogical works, including The Genealogy of the existing British Peerage (1832), and his name still appears annually in connection with Lodge's Peerage and Baronetage.

Lodge, GONZALES (1863), American classical scholar, was born at Fort Littleton, Pa., and graduated (1883) at Johns Hopkins, taking his Ph.D. at the same university in 1886. From 1886 to 1888 he was professor of Greek at Davidson College. He was professor of Latin at Bryn Mawr from 1889 until 1900, when he accepted the classical chair at Teachers' College, Columbia University. He assisted Prof. Gildersleeɣe in recasting the latter's Greek Grammar (ed. of 1894), prepared with him their fifteenvolume Latin Series, and published separately his Lexicon Platinum (1902) and an edition of Plato's Gorgias (1890).

Lodge, HENRY CABOT (1850), American historian and public man, was born in Boston, Mass., and graduated (1871) at Harvard, and at the Harvard Law School in 1875. Meanwhile he had become assistant-editor of the North American Review and held this position until 1876. In 1875-8 he was lecturer on the history of the American colonies at Harvard. He was joint editor with John T. Morse, Jr., of the International Review from 1879 to 1882, and after serving in the Massachusetts legislature, became chairman of the state central Republican com