publications in this controversy, which were distinguished by mildness and urbanity, Locke retired from the press, and, his asthmatic complaint increasing, he resigned his post of commissioner of trade and plantations, observing that he could not, in conscience, hold a situation, to which a considerable salary was attached, without performing the duties of it. From this time, he lived wholly in retirement, where he applied himself to the study of Scripture; while the sufferings incidental to his disorders were materially alleviated by the kind attentions and agreeable conversation of lady Masham, who was the daughter of the learned doctor Cudworth, and, for many years, his intimate friend. Locke continued nearly two years in a declining state, and at length expired in a manner correspondent with his piety, equanimity and rectitude, Oct. 28, 1704. He was buried at Oates, where there is a neat monument erected to his memory, with a modest Latin inscription indited by himself. The moral, social and political character of this eminent man, is sufficiently illustrated by the foregoing brief account of his life and labors; and the effect of his writings upon the opinions and even fortunes of mankind, is the best eulogium on his mental superiority. In the opinion of doctor Reed, he gave the first example in the English language, of writing on abstract subjects with simplicity and perspicuity. No author has more successfully pointed out the danger of ambiguous words, and of having indistinct notions on subjects of judgment and reasoning; while his observations on the various powers of the human understanding, on the use and abuse of words, and on the extent and limits of human knowledge, are drawn from an attentive reflection on the operations of his own mind. In order to study the human soul, he went neither to ancient nor to modern philosophers for advice, but, like Malebranche, he turned within himself, and, after having long contemplated his own mind, he gave his reflections to the world. Locke was a very acute thinker, and his labors will always be acknowledged with gratitude, in the history of philosophy; but, at the same time, it must be remembered, that, in attempting to analyze the human soul, as an anatomist proceeds in investigating a body, piece by piece, and to derive all ideas from experience, he has unintentionally supported materialism. His declaration, that God, by his omnipotence, can make matter capable of thinking, has been considered dangerous in a religious

point of view. Locke's great work, his Essay on the Human Understanding, which he was 19 years in preparing, owes its existence to a dispute, at which he was present, and which he perceived to rest entirely on a verbal misunderstanding, and, considering this to be a common source of error, he was led to study the origin of ideas, &c. The influence of this work has rendered the empirical philosophy general, in England and France, though, in both countries, philosophers of a different school have appeared. (See Cousin.) Henry Lee and Norris (in Oxford) were among his earliest opponents. In France, Jean Leclerc (Clericus) distinguished himself particularly as a partisan of Locke; and 'sGravesande spread his philosophy, by compendiums, in Holland. Amidst the improvements in metaphysical studies, to which the Essay itself has mainly conduced, it will ever prove a valuable guide in the acquirement of the science of the human mind. His next great work, his two Treatises on Government, was opposed by the theorists of divine right and passive obedience (see Legitimacy), and by writers of Jacobitical tendencies; but it upholds the great principles, which may be deemed the constitutional doctrine of his country. It was a favorite work with the statesmen of the American revolution, by whom it is constantly appealed to in their constitutional arguments. His Reasonableness of Christianity maintains, that there is nothing contained in revealed religion inconsistent with reason, and that it is only necessary to believe that Jesus is the Messiah. His posthumous works, also, have caused him to be considered, by some, as a Socinian. Besides the works already mentioned, Locke left several MSS. behind him, from which his executors, sir Peter King and Mr. Anthony Collins, published, in 1706, his Paraphrase and Notes upon St. Paul's Epistles to the Galatians, Corinthians, Romans and Ephesians, with an Essay prefixed_for the Understanding of St. Paul's Epistles, by a reference to St. Paul himself. In 1706, the same parties published Posthumous Works of Mr. Locke (8vo.), comprising a Treatise on the Conduct of the Understanding, an Examination of Malebranche's Opinion of seeing all Things in God. His works have been collected together, and frequently printed in 3 vols., folio, 4 vols., quarto, and, more lately, in 10 vols., 8vo., with a life prefixed, by Law, bishop of Carlisle. Some unpublished MSS. yet remain in possession of lord King, who

has given to the public some valuable inaterials in his Life and Correspondence of John Locke (London, 1829).—See, also, Stewart's Philosophical Essays.

LOCKER; a kind of box, or chest, made along the side of a ship, to put or stow any thing in.-Shot lockers; strong frames of plank near the pump-well in the hold, in which the shot are put.

LOCKMAN. (See Lokman, and Fable.) LOCOMOTION. The arts of locomotion are very well described in Bigelow's Technology (Boston, 1829), and the few remarks that follow are abridged from the first part of the article. The chief obstacles which oppose locomotion, or change of place, are gravity and friction, the last of which is, in most cases, a consequence of the first. Gravity confines all terrestrial bodies against the surface of the earth, with a force proportionate to the quantity of matter which composes them. Most kinds of mechanism, both natural and artificial, which assist locomotion, are arrangements for obviating the effects of gravity and friction. Animals that walk, obviate friction by substituting points of their bodies instead of large surfaces, and upon these points they turn, as upon centres, for the length of each step, raising themselves wholly or partly from the ground in successive arcs, instead of drawing themselves along the surface. As the feet move in separate lines, the body has also a lateral, vibratory motion. A man, in walking, puts down one foot before the other is raised, but not in running. Quadrupeds, in walking, have three feet upon the ground for most of the time; in trotting, only two. Animals which walk against gravity, as the common fly, the tree-toad, &c., support themselves by suction, using cavities on the under side of their feet, which they enlarge, at pleasure, till the pressure of the atmosphere causes them to adhere. In other respects their locomotion is effected like that of other walking animals. Birds perform the motion of flying by striking the air with the broad surface of their wings in a downward and backward direction, thus propelling the body upward and forward. After each stroke, the wings are contracted, or slightly turned, to lessen their resistance to the atmosphere, then raised, and spread anew. The downward stroke also, being more sudden than the upward, is more resisted by the atmosphere. The tail of birds serves as a rudder to direct the course upward or downward. When a bird sails in the air without moving the wings, tɩ is done in some cases by the ve

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locity previously acquired, and an oblique direction of the wings upward; in others, by a gradual descent, with the wings slightly turned, in an oblique direction, downward. Fishes, in swimming forward, are propelled chiefly by strokes of the tail, the extremity of which being bent into an oblique position, propels the body forward and laterally at the same time. The lateral motion is corrected by the next stroke, in the opposite direction, while the forward course continues. The fins serve partly to assist in swimming, but chiefly to balance the body, or keep it upright; for, the centre of gravity being nearest the back, a fish turns over, when it is dead or disabled.* Some other aquatic animals, as leeches, swim with a sinuous or undulating motion of the body, in which several parts at once are made to act obliquely against the water. Serpents, in like manner, advance by means of the winding or serpentine direction which they give to their bodies, and by which a succession of oblique forces are brought to act against the ground. Sir Everard Home is of opinion that serpents use their ribs in the manner of legs, and propel the body forwards by bringing the plates on the under surface of the body to act, successively, like feet against the ground. This he deduces from the anatomy of the animal, and from the movements which he perceived in suffering a large coluber to crawl over his hand. Some worms and larvæ of slow motion, extend a part of their body forwards, and draw up the rest to overtake it, some performing this motion in a direct line, others in curves. When land animals swim in water, they are supported, because their whole weight, with the lungs expanded with air, is less than that of an equal bulk of water. The head, however, or a part of it, must be kept above water, to enable the animal to breathe; and to effect this, and also to make progress in the water, the limbs are exerted, in successive impulses, against the fluid. Quadrupeds and birds swim with less effort than man, because the weight of the head, which is carried above water, is, in them, a smaller proportional part of the whole than it is in man. All animals are provided, by nature, with organs of locomotion best

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adapted to their structure and situation; and it is probable that no animal, man not being excepted, can exert his strength more advantageously by any other than the natural mode, in moving himself over the common surface of the ground.* Thus walking cars, velocipedes, &c., although they may enable a man to increase his velocity, in favorable situations, for a short time, yet they actually require an increased expenditure of power, for the purpose of transporting the machine made use of, in addition to the weight of the body. When, however, a great additional load is to be transported with the body, a man, or animal, may derive much assistance from mechanical arrangements. For moving weights over the common ground, with its ordinary asperities and inequalities of substance and structure, no piece of inert mechanism is so favorably adapted as the wheel-carriage. It was introduced into use in very early ages. Wheels diminish friction, and also surmount obstacles or inequalities of the road, with more advantage than bodies of any other form, in their place, could do. The friction is diminished by transferring it from the surface of the ground to the centre of the wheel, or, rather, to the place of contact between the axletree and the box of the wheel; so that it is lessened by the mechanical advantage of the lever, in the proportion which the diameter of the axletree bears to the diameter of the wheel. The rubbing surfaces, also, being kept polished and smeared with some unctuous substance, are in the best possible condition to resist friction. In like manner, the common obstacles that present themselves in the public roads, are surmounted by a wheel with peculiar facility. As soon as the wheel strikes against a stone or similar hard body, it is converted into a lever for lifting the load over the resisting object. If an obstacle eight or ten inches in height were presented to the body of a carriage unprovided with w heels, it would stop its progress, or subject it to such violence as would endanger its safety. But by the action of a wheel, the load is lifted, and its centre of gravity passes over in the direction of an easy arc, the obstacle furnishing the fulcrum on which the lever acts. Rollers placed under a heavy body diminish the friction in a greater degree than wheels, provided they are true spheres or cylinders, without any axis on which they

* This remark, of course, does not apply to situations in which friction is obviated, as upon water, ice, rail-roads, &c.

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are constrained to move; but a cylindrical roller occasions friction, whenever its path deviates in the least from a straight line. The mechanical advantages of a wheel are proportionate to its size, and the larger it is, the more effectually does it diminish the ordinary resistances. large wheel will surmount stones and similar obstacles better than a small one, since the arm of the lever on which the force acts is longer, and the curve described by the centre of the load is the arc of a larger circle, and, of course, the ascent is more gradual and easy. In passing over holes, ruts or excavations, also, a large wheel sinks less than a small one, and consequently occasions less jolting and expenditure of power. The wear also of large wheels is less than that of small ones, for if we suppose a wheel to be three feet in diameter, it will turn round twice, while one of six feet in diameter turns round once; so that its tire will come twice as often in contact with the ground, and its spokes will twice as often have to support the weight of the load. In practice, however, it is found necessary to confine the size of wheels within certain limits, partly because the materials used would make wheels of great size heavy and cumbersome, since the separate parts would necessarily be of large proportions to have the requisite strength, and partly because they would be disproportioned to the size of the animals employed in draught, and compel them to pull obliquely downwards, and therefore to expend a part of their force in acting against the ground.

LOCOMOTIVE ENGINE is that which is calculated to produce locomotion,or motion from place to place. (See Steam-Engine.)

LOCRIS was a country of Middle Greece, whose inhabitants, the Locrians, were among the oldest Grecian people. There were four branches of them—the Epicnemidian, the Opuntian, Ozolian, and Epizephyrian Locrians. The last were a colony from the Ozolian stock, and lived in Lower Italy. Their capital, Locri, was one of the most powerful, splendid and wealthy cities of Magna Græcia.

LOCUST. The misapplication of popular appellations, and the mutations of entomology, have introduced some confusion in regard to the scientific names of many insects. Our American cicadœ are popularly known here both by the names of harvest-fly and locust; the latter term, however, is incorrectly applied. Under the generic name locusta is included, by several modern entomologists, the devour

ing locusts of the eastern continent, and the common grasshoppers (as they are here called) of our country. These entomologists use the term in nearly the same sense as Linnæus, who affixed it to a group of his great genus gryllus, which constitutes the genus gryllus proper of Fabricius. The grasshopper may be thus characterized. The wings and wing-cases are applied obliquely to the sides of the body in repose; the antennæ are short, and do not taper towards the ends; the feet have only three joints; and the tail is not furnished with a projecting oviduct, or piercer, for the deposition of the eggs. These insects have the hind legs formed for leaping, and the males produce a stridulous sound, by scraping these legs against their wing-cases. The female deposits her eggs in the earth, and the young survive the winter in the larvæ state, concealed among the decayed vegetation of the surface. They pass through an imperfect metamorphosis, for both larvæ and pupæ resemble, somewhat, the perfect insects in form, are active, and take food in the same way, but are destitute of wings. In all stages, they are herbivorous, and sometimes do immense injury to vegetation. Our salt marshes harbor an innumerable host, which not unfrequently strips them of every blade of grass; or, when a scanty crop is gathered into the barn, the hay is so filled with the putrescent carcasses of these grasshoppers, or locusts, as to be highly offensive, and totally unfit for forage. In some sections of our country, they occasionally appear in such numbers as to fill the air in clouds, and wherever they alight they devour every green thing in their path. It is stated, on good authority, that, more than once, when they visited some parts of New England, they not only ate up all the grass in the fields, but actually attacked clothing and fences to appease their insatiable hunger. Some workmen, employed in raising the steeple of a church, in Williamstown, Massachusetts, were, while standing near the vane, covered by them, and saw, at the same time, vast swarms flying at a great height far above their heads. These swarms are said to return after a short migration, and perish on the very grounds they have ravaged. (See Dwight's Travels.), Many of these insects are ornamented with various beautiful colors, particularly on the wings, which, however, in repose, are not visible, being folded like a fan, and covered by the long, narrow wing-cases. One of the largest and most common American spe

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cies is the locusta Carolina of Linnæus. It is about one inch and three quarters in length, and the wings are of a deep black color, surrounded with a broad ́yellow border. The most celebrated species of grasshopper is the gryllus migratorius (migratory locust). Of all animals capable of adding to the calamities of mankind, by destroying the vegetable products of the earth, the migratory locusts would seem to possess the most formidable powers of destruction. In Syria, Egypt, and almost all the south of Asia, these insects make their appearance in legions, and carry desolation with them, in a few hours changing the most fertile provinces into barren deserts, and darkening the air by their numbers. Happily for mankind, this calamity is not frequently repeated, for it is the inevitable precursor of famine, and its horrible consequences. The annals of most of the southern Asiatic climates are filled with accounts of the devastations produced by locusts. They seldom visit Europe in such swarms, though they are occasionally formidable to the agriculturist. Even when dead, they are still productive of evil consequences, since the putrefaction which arises from their inconceivable number, is so great, that it is justly regarded as the cause of some of those desolating pestilences which almost depopulate whole districts of country. When locusts thus make their appearance, they are said to have a leader, whose flight they observe, and to whose motions they pay a strict regard. We are told that nearly as much damage is occasioned by what they touch, as by what they devour. Their bite is thought to contaminate the plants, and either to destroy or greatly weaken their vegetation. Of the innumerable multitudes in which they occur, scarcely an adequate conception can be formed. Barrow (Travels, &c.) states that, in Southern Africa, the whole surface of the ground might literally be said to be covered with them for an area of 2000 square miles. The water of a very wide river was scarcely visible on account of the dead carcasses that floated on the surface When the larvæ (for these are much more voracious than the perfect insects) are on a march during the day, it is utterly impossible to turn the direction of the troop, which is generally with the wind. In some parts of the world, these insects are used for food. For this purpose, they are caught in nets, and, when a sufficient number is procured, they are roasted over a slow fire, in an earthen vessel, till the

wings and legs drop off; when thus prepared, they are said to taste like crawfish. Mr. Adanson (Voyage to Senegal) says, however, that he would willingly resign whole armies of locusts for the meanest fish. The locust constituted a common food among the Jews, and Moses has specified the different kinds which they were permitted to eat. "Even these thou mayest eat; the locust after his kind; the bald locust after his kind; the beetle after his kind; and the grasshopper after his kind." (Levit. xi, v. 22.)

The popular term grasshopper is also applied, and with more propriety, to insects in another group of the grylli-the tettigoniæ of Linnæus (locusta of Fabricius). They are distinguished from the locusts of the preceding section, by their very long, bristle-shaped, or tapering antennæ, and by having four joints to their feet, and an exserted oviduct. The latter instrument often has the form of a curved sword or sickle, and is used in preparing a hole, and conveying the eggs to their appropriate nidus beneath the soil. These insects have long, slender hind legs, formed for leaping; but the males do not play with them against their wing-cases, for the production of sounds. Their musical organs consist of a pair of frames, within each of which is stretched a transparent membrane. These tabourets are affixed to that part of the base of each wing-case which laps on the top of the back, and one lies directly over and in contact with the other; so that, whenever the wingcases are opened and shut, the frames grate together, and, as often as the shuffling motion is repeated, a grating sound is produced. These musical grasshoppers are usually of a green color, and are nocturnal in their habits. During the daytime, they conceal themselves in the grass or the foliage of trees; but at night, they quit their lurking places, and the joyous male commences the song of love with which he recreates his silent partner. It would be well to restrict the popular appellation grasshoppers to these insects, which have been distributed into several modern genera. Two only need here be mentioned, viz. conocephalus (Thunberg), [acrida, Kirby], including the species whose head terminates in front in a conical projection, and pterophylla (Kirby), whose head is obtuse, and not produced in front. The latter genus contains the well-known insect, called, from its note, katy-did, pterophylla concava (locusta concava, Say). Its large, oblong-oval, concave wing-cases, inwrap the abdomen, and

meet at their edges above and below somewhat like the two sides or valves of a pea-pod. Perched on the topmost twig of a tree, the insect begins his nocturnal call by separating, closing, and re-opening his wing-cases. The friction of the tabouret-frames upon each other, thrice, produces three distinct notes, which is the usual number; occasionally, only two are given, when the wing-cases are merely opened and shut once. The mechanism of these organs reverberates, and increases the sound to such a degree, that it may be heard, in the stillness of the night, at the distance of nearly a quarter of a mile. At intervals of three or four minutes, he repeats his obstreperous babble, while rival songsters echo the notes, and the woods resound with the call of katydid, she did, the live-long night. The tettigonia of Linnæus, or grasshoppers abovementioned, are not to be confounded with the insects referred to the modern genus tettigonia of Olivier, Lamarck and Latreille. The former, with all the grylli of Linnæus, have jaws for masticating their food, and belong to the order orthoptera; while the latter, with the cicada or harvest-fly (misnamed locust), have suctorious tubes, for puncturing plants and imbibing their juices, and belong to the order omoptera. In the genus cicada, the antennæ are six-jointed; there are three ocelli, and the legs are not adapted for leaping. In tettigonia, the antennæ are three-jointed; there are only two ocelli, the thorax is transverse, not produced behind, and the legs are formed for leaping. To the genus tettigonia (Olivier) may be referred the minute insect which attacks the grape vine, and injures it to a great extent by noxious punctures, and the exhaustion of its sap. When the leaves of this valuable plant are agitated, the little tettigonie leap or fly from them in swarms. The infested leaves soon become yellow, sickly, and, losing their vitality, give to the plant, in midsummer, the aspect it assumes, naturally, at the approach of winter. On turning up the leaves cautiously, the insects will be seen busily employed upon the under side, with their proboscis thrust into the tender epidermis. These insects pass through all their metamorphoses, which are imperfect, upon the plant; the wingless larvæ and pupæ, having a general resemblance to the perfect insects, feed together in the same manner, and their innumerable white cast skins will be found adhering to every par of the leaves. This species survives the winter in the perfect state, hybernating beneath