Diving-bell.

DIVINE SERVICE, a tenure by which the tenant was bound to do some special divine service, as to sing so many masses, to distribute a certain sum in alms, or the like. It differed from frankalmoigne (q.v.) in this, that the lord could distrain for the former, not for the latter, which, being an indefinite service, could be enforced only by a complaint to the ordinary or visitor.

DIVING. The "treasures of the deep" have at all times been the subject of much visionary exaggeration, and the accounts of the exploits of divers equally extravagant. We could name a popular school-book, still in extensive use, where children are seriously informed that the pearl-divers of the east acquire by practice the power of remaining under water from 15 to 20 minutes. Such statements are common enough in narratives of ancient date, in some of which the time is extended to two hours. It need scarcely be said that these accounts are absurd, no such endurance being possible. The more skillful divers may remain under water for two, or even three minutes; some modern accounts say four, and even six, but this is very doubtful. In a swimming and diving contest between some North American Indians and Englishmen in a London swimmingbath, one of the Indians, a renowned swimmer and diver, remained under water just one minute and a half, but a London artisan beat him by a few seconds.

In the Encyclopædia Britannica, prof. Faraday describes an interesting fact to which his attention was directed by a gentleman connected with the Asiatic society, who, according to prof. Faraday, was the first to make the observation. It was observed that by breathing hard for a short time, as a person does after violent exercise, the breath could then be held much longer than otherwise. Prof. Faraday found that he could only hold breath for three quarters of a minute, if he attempted it without preparation, but that after eight or ten of such forced inspirations, he could hold breath for two minutes. This he explained on the supposition that, ordinarily, a considerable quantity of carbonic acid remains in the involved passage of the lungs, but that it becomes completely expelled by the forced breathing, and its place supplied by atmospheric air. As regards the novelty of the observation, prof. Faraday was mistaken, as the writer of this can testify, for when a boy, he and his companion bathers in the Serpentine, in Hyde Park, commonly practiced it. The Red Indian and the artisan above referred to also did the same; it is, in fact, a sort of preparation that a practiced diver would make almost instinctively. After a few deep inspirations of this kind, a sense of giddiness is felt, and it is not prudent to carry the experiment far beyond this stage, as a fit of insensibility not unlike apoplexy is apt to result.

This giddiness, which is always produced, and the possible insensibility, indicate a different explanation from that of Faraday. The mere removal of residual carbonic acid from the lungs is not sufficient to explain these; we should rather suggest that all the phenomena result from an excessive oxygenation of the blood, and a consequently accelerated circulation similar to that produced by breathing nitrous oxide. It will be easily understood, that if the blood be forced to take an excess of oxygen, a longer time should elapse before a fresh supply would become necessary—that is, before suffocation would take place; and the giddiness, flushing of the face, and the insensibility, are results to be expected from such an excess.

Most divers suffer severely from the continual efforts in holding the breath; bloodshot eyes and spitting of blood are common among them. This rude mode of diving is now but little used except for pearl and sponge fishing; and even for these purposes, only an uncivilized people, with very little capital and knowledge, would continue to use it, as the modern applications of science afford such immense advantages for all kinds of subaqueous operations, as will be seen by the next article.

DIVING-BELL. From what has been stated in the preceding article DIVING, it will be at once understood that for all such purposes as subaqueous works upon the foundations of piers, bridges, etc., or the exploration and raising of sunken vessels, the efforts of the unaided diver would be almost valueless, and accordingly various contrivances for supplying air to the diver have been made. The cacabus aquaticus, or aquatic kettle, described by Taisnier as having been used by two Greeks in Spain, at Toledo, in 1538, in the presence of the emperor Charles V. and a multitude of spectators, is one of the earliest reliable accounts of a diving-bell. From his description, this must have been similar in principle and construction to the modern diving-bell, but of clumsy dimensions, and wanting in efficient means of renewing the supply of air. Dr. Halley's diving-bell, about 1720, was a wooden chamber of about 60 ft. internal capacity, open at the bottom, where it was loaded with lead to keep it perpendicular in its descent. Strong pieces of glass were set in the upper part to admit light. Casks filled with air, and loaded with lead, were let down with the bung-hole downwards; and from these a supply of air was drawn by means of a hose. The form of diving-bell now in use was first constructed by Smeaton for the works at Ramsgate harbor, 1788. It was of castiron, and weighed 50 cwt.; its height, 4 ft; length, the same; and width, 3 feet. It sunk by its own weight, and was lighted by stout pieces of bull's-eye glass firmly cemented by brass rings near the top. The principle of the diving-bell will be easily understood by floating a piece of lighted candle or a wax-match on a cork, and then covering it with an inverted tumbler, and pressing downwards; the candle will descend below the level of the surrounding water, and continue burning for a short time, although the tumU. K. V.-2

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bler be entirely immersed. The reason is obvious enough the air in the tumbler having no vent, remains in it, and prevents the water from occupying its place, so that the cork and candle, though apparently under water, are still floating, and surrounded by the air in the tumbler; the candle continues burning until the oxygen of the air is exhausted, and then it goes out, as would the life of a man under similar circumstances. If vessels full of air, like the barrels of Dr. Halley, were submerged, and their contents poured into the tumbler, the light might be maintained; but this could be better done if a tube passed through the tumbler, and air were pumped from above through the tube into the tumbler.

The modern diving-bell, which is made of cast-iron like Smeaton's, is supplied with air in this manner. It must be remembered that air is compressible, and diminishes in bulk in proportion to the pressure, so that at a depth of about 33 ft. in water, it would occupy half the space it filled at the surface; if the inverted tumbler were carried to this depth, it would be half filled with water. A considerable quantity of air has, therefore, to be pumped into the diving-bell, merely to keep it full as it descends; the air thus compressed exerts a corresponding pressure, and would rush up with great force if the tube were open and free. This is prevented by a valve opening downwards only. When the diving-bell has reached its full depth, the pumping is continued to supply air for respiration; and the redundant air overflows, or rather underflows, by the open mouth, and ascends to the surface in great bubbles. The diving-bell is provided with a platform or seat for the workmen, and suspended from a suitable crane or beams projecting from a barge or pier; men above are stationed to work the pumps, and attend to the signals of the bellman. These signals are simply made by striking the sides of the iron diving-bell with a hammer, and as sound is so freely communicated through water, they are easily heard above. One blow signifies “more air;" two blows, "stand fast;" three, "heave up;" four, "lower down;" five, "to eastward;" six, to westward," etc. These, of course, may be modified as agreed upon. Messages are also sent up, written on a label attached to a cord. The sensations produced in descending are rather curious. Immediately on the mouth of the diving-bell striking the water, a feeling like a slight blow on the internal ear is produced; a dull ringing in the cars and a sense of deafness follows.

The workmen accustomed to subaqueous existence do not suffer these inconveniences; novices feel pains in the head and ears, but these pass away after a short initiation. It is stated that one man who had suffered from difficulty of breathing was completely cured by "belling," and that deafness is not produced by it, but, on the contrary, is in some cases relieved.

DIVING-DRESS. In Schott's Technica Curiosa, published in 1664, is described a lorica aquatica, or aquatic armor, which consisted of a leathern dress, to protect the diver from the water, and a helmet. In 1721, Halley describes a contrivance of his own of nearly the same kind; its object was to enable the diver to go out from the bell and walk about; he was to be provided with a waterproof-dress, and a small divingbell, with glass front, as a helmet over his head, which was to be supplied with air by means of a tube from the diving-bell.

The modern diving-dress is made of india-rubber cloth; a strong metal helmet, with round pieces of plate-glass in front, rests upon a pad on the shoulders; the air is supplied to this helmet from above, in the same manner as for the diving-bell, but instead of the waste air passing out below, a second tube carries it up. Leaden weights are attached to the side of the diver, and thus he may descend a ladder and walk about below. He carries with him one end of a cord communicating with the assistants above, and by pulling this, as agreed upon, makes a series of signals.

DIVI'NING-ROD-often called the virgula divina, the baculus divinatorius, the caduceus or wand of Mercury, the rod of Aaron, etc.-is a forked branch, usually of hazel, and sometimes of iron, and even of brass and copper, by which it has been pretended that minerals and water have been discovered beneath the surface of the earth. The rod, when suspended by the two prongs, sometimes between the balls of the thumbs, will distinctly indicate, by a decided inclination, it is alleged, the spot over which the concealed mine or spring is situated. Other powers are ascribed to the divining-rod, but this is the chief. Many men, even of some pretensions to scientific knowledge, have been believers in the occult power ascribed to this magic wand. Agricola, Sperlingius, and Kirchmayer, all believed in its supernatural influence. So did Richelet, the author of the dictionary. The learned Morhoff remained in suspense, while Thouvenot and Pryce, in the latter part of the 18th c., gave ample records of its supposed power. Bayle, in his dictionary, under the word abaris, gives some ingenious arguments both for and against the divining-rod. In a work published by Dr. Herbert Mayo in 1847 and 1851, entitled On the Truth Contained in Popular Superstitions, he gave some curious illustrations of the art, supposed to be possessed by one in forty of the Cornish miners. At Weilbach, in Nassau, he likewise met with one Edward Seebold, who, he says, possessed the power, but afterwards lost it. Arthur Phippen, in 1853, published a pamphlet containing an account of two professional diviners or dowsers. One of them, named Adams, gave remarkable indications of being able to detect water under-ground.

He

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not only was able to discover the particular spot where water might be found-he could even perceive a whole line of water running under-ground.

Scientific men, who have bestowed any care on the examination of nature, regard this alleged power of the divining-rod as an unconscious delusion, ascribing the whole phenomenon to the effect of a strong impression on the mind acting through the agency of the nerves and muscles. See ANIMAL MAGNETISM.

DIVIRIGI (anc. Tephrene), a t. of the province of Sivas, Asia Minor, on the KurnerSu, a branch of the Euphrates, 28 m. n.w from Arabkir. Pop. supposed to be about 10,000.

DIVISIBILITY is that property of quantity, matter, or extension, through which it is either actually or potentially separable into parts. Whether matter is or is not indefinitely divisible, is a question which has occupied the minds of philosophers since very early times. See ATOM. There is no doubt that, abstractly speaking, it is indefinitely divisible. We cannot conceive any body or space so small but that we can subdivide it in imagination, and thus figure to ourselves bodies and spaces still smaller; and practically, we know that the subdivision of matter is carried in nature far beyond appreciation either by our senses or by calculation. The diffusion of odors through the air for long periods from odoriferous bodies without their suffering any sensible change of weight, and the tinging of great quantities of fluid by very minute portions of coloring matter, are cases commonly appealed to in proof of the extreme fineness of certain material particles; while, by experiment, it is shown that there is no practical limit to the divisibility of even the most solid substances. Thus, an ounce-weight of silver, gilt over with eight grains of gold, has been drawn out into a wire 13,000 ft. long, which was all its length covered with the gold; and a tube of glass presented to the blow-pipe has been drawn out till it became as fine as a silk fiber, or th of an inch thick, still retaining its character as a tube with a distinct interior and exterior surface. In fact, in theory, great and small are mere terms of relation; under the microscope, objects invisible to the eye appear of considerable bulk; and as sir John Herschel, in his celebrated Introduction to the Study of the Physical Scionces, has put it, there is no reason why a mote in a sunbeam should not be in itself a world. With regard to the indefinite divisibility of space, it may be demonstrated geometrically; and perhaps, after all, it is the feeling that space is infinitely divisible, which compels our minds most strongly to resist the notion of ultimate atoms with definite forms, as conceived in the corpuscular theory.

DIVISIBILITY, in the theory of numbers, means the capability of any number of being divided by another without remainder. To find the condition of divisibility of one number, N, by another, D. Let N = b+bm-1pm-1+... b1r+b. See NOTATION. Then N = bm (D+ (r = D),m+bm-1 (D + 7 − D)m¬1. +b1 (D+r− D) +bo. Expanding the different terms of the right-hand side of this equation, it will appear N that will be a whole number, if b + b1 (r− D) + .. +bm (r-D) be divisible by D. Hence, if = 10, or the number be in the denary scale, and D = 9, and therefore (r- D) = 1, any number will be divisible by 9, if b + b1 +b2+. +bm is so, or if the sum of its digits is divisible by 9.

D

...

DIVISION, one of the four principal rules of arithmetic, is that by which we find how often one quantity is contained in another. It is a compendious method of subtraction, by which we can at once take one number from another as often as it is contained in it. There are three numbers concerned in D.: the dividend, or number to be divided; the divisor, or that by which the dividend is to be divided; and the quotient, or the number expressing how often the divisor is contained in the dividend. The symbols of D. are ¿) a (, —, or or ab, where a is the dividend, and b the divisor.

There are various methods of D., such as the English, Flemish, Italian, Spanish, German, and Indian methods, which differ merely in the manner of arranging and disposing the numbers. The English method will be found explained in all the ordinary text-books of arithmetic. There are also rules of D. for the D. of integers, fractions, and algebraical quantities. The general rule for the D. of vulgar fractions is to multiply the one by the reciprocal of the other. The D. of decimal fractions is performed in the same way as the D. of integers. And, in algebra, D. is practically performed as in arithmetic, either by making a fraction of the dividend and divisor, and reducing the numerator and denominator by the parts common to both, or else by dividing the former by the latter, after the manner of long division. See any text-book on algebra. For D. by logarithms, see LOGARITHMS.

DIVISION, BENEFIT OF. By the law of Scotland, co-cautioners are each ultimately liable for the whole debt which they have guaranteed. Each, however, is liable only for his own proportion, so long as the others are solvent, provided he has not expressly renounced that privilege, or is not bound conjunctly and severally with the principal debtor, and the debt must thus be divided amongst them. The law of D. is not affected by the mercantile law amendment act; and it is therefore necessary, where there are more cautioners than one, that all should be proceeded against.

DIVISION, MILITARY, is one section of an army, indefinite in point of numbers, but established as a matter of convenience. It often comprises infantry, cavalry, and artillery, and is in effect a small army in itself, commanded by a general officer. In the Crimean war, for instance, a British D. comprised two brigades, each of three or four battalions.

DIVISION, MILITARY (DISTRICTS, MILITARY, ante). For convenience and to fix responsibility, the United States is divided into military divisions, viz.: 1. Division of the Missouri, comprehending the departments of Missouri, Dakota, Texas, and the Platte; head-quarters Chicago. 2. Division of the Pacific, including the departments of California, Columbia, and Arizona; head-quarters San Francisco. 3. Division of the Atlantic, including the departments of the east, the south, and West Point; head-quarters New York.

DIVISION, NAVAL, was a secondary group of ships in a large fleet, generally three to a squadron. In a very large and complete fleet, there might be as many as nine admirals or flag-officers commanding nine divisions, in three squadrons of three divisions each. The distinction of squadron has now been abolished, and individual ships are too gigantic to allow of large numbers being maneuvered in one fleet.

DIVISION OF LABOR, or DIVISION OF EMPLOYMENT, a term often used by political economists to express a means by which labor is economized, or, as another method of stating the same result, by which production is increased. The problem in division of labor is so to adjust matters in any given community that each member of it shall work, or be able if he pleases to work, with the greatest possible results. In practice it is, like most other arrangements, apt to be too broad or too narrow. The old term, "jack of all trades and master of none," expresses the truth, that people who try too many things are not likely to be adepts in any. On the other hand, few people can do any sort of work to great perfection, unless it is part, as it were, of a group of functions for which they are more or less prepared. A good dentist will be in some measure a surgeon; a conveyancer or a special pleader will know something of the other departments of legal practice; a shipwright will be able, on occasion, to do other kinds of carpentry, and he will be the better of a general knowledge of the mechanical powers. That division of labor, in fact, which is really productive, is where a man who can do several things selects one as that which he can do best, or has most opportunity of doing. By constant practice at that one thing, and the withdrawal of his attention from other matters, he achieves perfection and rapidity of execution. There is an important difference between this selection of a special pursuit, and the inability to do anything more than one thing, which is often confounded with it. In the former case, the worker, whether with head or hand, has great resources, for his adopted pursuit is the best out of several others, on which he can fall back. The man who can do only one thing is in a precarious condition, because that one thing may be superseded. Indeed, as the one thing which can be so done is generally a very simple thing, it is almost a law in political economy that it will come to be superseded by machinery. Such was the fate of the hand-loom weavers, whose function, especially in the plainer and lighter fabrics, was too easy to last. Of the division of unskilled and easy labor, there is an excellent illustration in Adam Smith's description of pin-making: One man draws out the wire, another straights it, a third cuts it, a fourth points it, a fifth grinds it at the top for receiving the head; to make the head requires two or three distinct operations; to put it on is a peculiar business; to whiten the pin is another; it is even a trade by itself to put them into a paper; and the important business of making a pin is in this manner divided into above eighteen distinct operations, which in some manufactories are all performed by distinct hands." This division was doubtless useful, so long as pins were made entirely by human hands. It prompted serious inquiries, however, how far such functions were of an improving or a deteriorating character, and essays were written to prove that in manufacturing countries human beings were deteriorating, as no one of them had the faculty of self-support in separation from his fellows, and none could even make one single article by himself, all being dependent for their bread on a complex co-operation, which might break down any day. The answer to such fears may be found in the pin-making of the present day, where one man tends a machine, feeding it with wire at one end, while the pins drop out at the other. This, too, is the fruit of division of labor, for many skillful heads and hands have been occupied in bringing to perfection the different parts of the machinery. It is of the highest importance to the working-classes of a country, to keep in view that though the division of labor does sometimes create functions which, while they are extremely simple and easy, are of value as helping other functions to go on, yet this kind of easy and uniform work has no stability in it, and the possession of the facility for doing it acquired by practice is no permanent industrial endowment, since it is pretty sure some day to be superseded by machinery.

DIVI'SOR. See DIVISION. See also PRIME NUMBERS.

DIVORCE is defined by a Scottish writer to be "the disruption, by the act of the law, of the conjugal tie, made by a competent court on due cause shown."-Fraser, Pers. and Domestic Relations, i. 645. This definition correctly expresses the law of D. as it

Divorce.

pow stands in the United Kingdom. There are some differences of detail in the working of the law in England and Scotland, which will be noticed below.

The desire to obtain a release from the matrimonial bond has existed at all times and under all legal systems. In heathen nations this release was often granted on the slightest grounds. Even among the Romans, marriage was regarded as little more than a conventional union, to be observed so long only as it suited the mutual convenience of the spouses. Christian nations, on the other hand, adopting as the basis of their . systems the Scriptural law as declared Matt. xix. 9, Mark x. 9-11, Luke xvi. 18, and 1st Cor. vii. 10, 11, are agreed in considering marriage a sacred tie, not to be dissolved except on the ground of unfaithfulness to the marriage vow. Even this limited ground for dissolution of marriage is denied by a large portion of the Christian world. By the civil law, as it existed for some centuries after Christianity, a greater laxity was allowed in regard to divorce. The emperor Constantine was the first to prohibit dissolution of marriage by simple consent of the parties. This practice was again revived under the emperors Theodosius and Valentinian; and though those emperors subsequently rescinded this edict, yet the rule as to the grounds on which marriage might be dissolved continued to fluctuate. By the canon law, marriage was regarded as a sacrament; and though marriages contracted in disobedience to certain rules might be declared null ab initio, a marriage validly contracted would not be dissolved except by papal. dispensation. But the rule of the canon law was not uniformly adopted by the states of Europe, and it was not till the famous council of Trent issued a decree, in its 24th session, in 1562, declaring marriage indissoluble even after the adultery of one or both of the parties, that a uniform rule on the subject was established. But before this decree was issued, the reformation had made progress throughout Europe, and thus a change again took place in regard to the law of divorce. It should be observed, that though by the canon law D. a vinculo matrimonii was unattainable, parties might obtain a separation a mensa et thoro. The nature of this remedy will be explained below.

Roman Catholic countries adopted the principle laid down by the council of Trent, and this rule continues to be in force in most countries which are in the Roman Catholic communion. But by the code civile of France, D. is allowable on the ground of adultery and certain other causes. Countries which adopted the reformed religion, have varied greatly in the rules established in regard to the question of divorce. In Holland D. is permitted on the ground of adultery and desertion. In America, the practice varies in different states. "In several of them no D. is granted but by special act of the legislature, according to the English practice; and in others, the legislature itself is restricted from granting them, but it may confer the power on courts of justice. So strict and scrupulous has been the policy of South Carolina, that until recently there was no means of obtaining a D. of any kind, either by sentence of a court of justice or by act of the legislature. In all other states, D. a vinculo may be granted by courts of justice for adultery. In New York, the jurisdiction of the courts as to absolute D. for causes subsequent to marriage is confined to the single cause of adultery; but in most of the other states, in addition to adultery, intolerable ill-usage or willful desertion, or unheard-of absence, or habitual drunkenness, or some of them, will authorize a decree for D. a vinculo under different modifications and restrictions."-Kent, Comm. iv. 105. In England, previous to the passing of the late divorce and matrimonial act, marriage was by the common law indissoluble. It was, indeed, competent to obtain a declaration of nullity of marriage on the ground of relationship, previous marriage of one of the parties, mental or physical incapacity, or coercion. But the judgment so obtained was not a decree of D., but a declaration that the marriage tie between the parties had never really been contracted. A wife may now obtain a D. on the ground of the husband's incestuous adultery; or of his bigamy with adultery; or of rape; or of sodomy; or of adultery coupled with gross cruelty; or of adultery coupled with desertion without reasonable excuse for two years. The husband may obtain a D. on the ground of the wife's adultery. But neither party can obtain a Ď. on the ground of mere desertion alone, however long continued. The court may order the husband to pay a divorced wife a certain sum for her maintenance during their joint lives. A decree of D. does not come into full force until six months after it is pronounced. The bars to a D. are condonation, connivance, or collusion. When divorced, the parties are at liberty to marry with third parties. When the D. is on the ground of adultery, both parties may be examined as witnesses, 32 and 33 Vict. c. 68.

In Scotland, D. may be obtained on the ground of adultery or willful desertion. Immediately after the reformation, the courts in Scotland recognized the right of either spouse to obtain a D. on the ground of adultery. And in the year 1573, a statute was passed declaring that, in case either husband or wife should desert without due cause for four years, the injured party might raise an action of adherence, and, in case redress was not obtained, a decree of D. might be pronounced. In Scotland, it is not permitted that a marriage should take place between the offending parties. The effect of a decree of D. on the pecuniary interests of the parties, is to cause the offender to forfeit all benefit which might accrue to him or her from the marriage. Separation a mensa et thoro may also be obtained in Scotland on the ground of ill usage, and perhaps desertion (q. v.). Condonation and collusion, but not recrimination, are, in Scotland, a bar to obtaining a dissolution of marriage on the ground of adultery.