tinual wars with the states of Italy, with the Hungarians, and their own rebellious subjects, kept the Venetians employed, so that they had no leisure to oppose the Turks, whose rapid advances ought to have alarmed all Europe. After the destruction of the eastern empire, the Turks came more immediately to interfere with the republic. The consequences are related under the article TURKEY. Whatever valor might be shown by the Venetians, or whatever successes they might boast of, it is certain that the Turks ultimately prevailed; so that for some time it seemed scarcely possible to resist them. What contributed also greatly to the decline of the republic was the discovery of a passage to the East Indies by the Cape of Good Hope, in 1497. To this time the greatest part of the East India goods imported into Europe passed through the hands of the Venetians; but, as soon as the above-mentioned discovery took place, the carriage by the way of Alexandria almost entirely ceased. Still, however, the Venetian power was strong; and in the beginning of the sixteenth century they maintained a war against almost the whole power of France, Germany, and Italy; but soon after we find them entering into an alliance with some Italian states and Henry IV. of France, against the emperor. These wars, however, produced no consequences of any great moment; and in 1573 tranquillity was restored by the conclusion of a peace with the Turks. Nothing of consequence happened in the affairs of the Venetian republic till 1645, when the Turks made a sudden and unexpected descent on the island of Candia. The senate of Venice did not display their usual vigilance on this occasion. They had seen the immense warlike preparations going forward, and yet allowed themselves to be amused by the grand seignior's declaring war against Malta, and pretending that the armament was intended against that island. The troops landed without opposition; and the town of Canea was taken, after an obstinate defence. This news, being brought to Venice, excited a universal indignation against the Turks; and the senate resolved to defend to the utmost this valuable part of the empire. Extraordinary ways and means of raising money were fallen upon; among others it was proposed to sell the rank of nobility. Four citizens offered 100,000 ducats each for this honor; and, notwithstanding some opposition, this measure was at last carried. Eighty families were admitted into the grand council, and to the honor and privileges of the nobility. The siege of Candia, the capital of the island of that name, is, in some respects, more memorable than that of any town which history has recorded. It lasted twenty-four years. The amazing efforts made by the republic of Venice astonished all Europe; their courage interested the gallant spirits of every nation: volunteers from every country came to Candia to exercise their valor, to acquire knowledge in the military art, and assist a brave people whom they admired. During this famous siege the Venetians gained many important victories over the Turkish fleet. Sometimes they were driven from the walls of Candia, and the Turkish garrison of Canea was even besieged by the Venetian fleets. Great slaughter was made of the Turkish armies ; but new armies were soon found to supply their place. Mahomet IV., impatient at the length of this siege, came to Negropont, that he might have more frequent opportunities of hearing from the vizier, who carried on the siege. This war cost the lives of 200,000 Turks. Candia capitulated in 1668. The conditions were honorably fulfilled. Morsini, the Venetian general, marched out of the rubbish of this well-disputed city with the honors of war. The expense of such a tedious war greatly exhausted the resources of Venice, which could not now repair them so quickly as formerly, when she enjoyed the rich monopoly of the Asiatic trade. This republic remained in a state of tranquillity, endeavouring, by the arts, of peace, and cultivation of that commerce which she still retained, to fill her empty exchequer, till she was drawn into a new war, in 1683, by the insolence of the Ottoman court. The Venetians had for some time endeavoured, by negociation and many conciliatory representations, to accommodate matters with the Turks; and, though the haughty conduct of their enemies afforded small hopes of success, yet such was their aversion to war that they still balanced, whether to bear those insults or repel them by arms; when they were brought to decision by an event which gave the greatest joy to Venice, and astonished all Europe. This was the great victory gained over the Turkish army before the walls of Vienna, by Sobieski, king of Poland. In this new war their late general Morsini again had the command of the fleets and armies of the republic, and sustained the great reputation he had acquired in Candia. He conquered the Morea, which was ceded formally to Venice, with some other acquisitions, at the peace of Carlowitz, in 1699. During the war of the succession the state of Venice observed a strict neutrality. They considered that dispute as unconnected with their interests, taking care, however, to keep on foot an army on their frontiers in Italy, of sufficient force to make them respected by the contending powers. But, soon after the peace of Utrecht, the Venetians were again attacked by their old enemies the Turks; who, beholding the great European powers exhausted by their late efforts, and unable to assist the republic, thought this the favorable moment for recovering the Morea, which had been so lately taken from them. The Turks obtained their object; and at the peace of Passarowitz, which terminated this unsuccessful war, the Venetian state yielded up the Morea; the grand seignior, on his part, restoring to them the small islands of Cerigo and Cerigotto, with some places which his troops had taken during the course of the war in Dalmatia. In the storms which followed the French revolution, and which brought Buonaparte with his army into the Venetian territory, the republic observed a cautious neutrality, and allowed its continental provinces to be overrun without resistance, at one time by the French, at another by the Austrians: but this caution could not secure the independence of the state; it was overturned in 1797, when it suited France to throw the city and territory of Venice into the scale in the treaty of Campio Formio. They remained subject to Austria till 1805, when, after the disaster of Austerlitz, they were annexed to the French kingdom of Italy; but in 1814 returned definitively under the power of Austria. 150 miles east of Milan, and 246 north of Rome. VENIRE FACIAS, in law, is a judicial writ lying where two parties plead and come to issue, directed to the sheriff, to cause twelve men of the same neighbourhood, to meet and try the same, and to say the truth upon the issue taken. VENISON, n. s. French venaison. Game; beast of chase; the flesh of deer. Chapman writes it venzon. To our venson's store We added wine, till we could wish no more. Chapman. In the records of Ireland, no mention is made of any park, though there be vert and venison within this land. Davies's History of Ireland. He for the feast prepared In equal portions with the venison shared. Dryden. VENIUS (Otho), a celebrated Dutch painter, was born at Leyden, in 1556. He was the first, after Polydore Caravaggio, who reduced the claro-obscura to a principle of the art of painting. He died at Brussels 1634. He had also the honor of breeding up the famous Rubens in his art. Fr. venin. Poison: VEN'OM, n. s. > The barbarians saw the venomous beast hang on his Have lost their quality. Shakspeare. Henry V. A posterity not unlike their majority of mischievous progenitors; a venomous and destructive progeny. Browne. Like some tall tree, the monster of the wood, O'ershadowing all that under him would grow, He sheds his venom on the plants below. His praise of foes is venomously nice; Dryden. So touched, it turns a virtue to a vice. Id. This falsity was broached by Cochleus, a venomous writer; one careless of truth or falsehood. Addison. VENT, n.s. & v. a. Fr. fente. A small aperture; hole; spiracle; passage at which any thing is let out; the act of opening; emission; discharge; also (Fr. vente) sale: to vent is to let out; give way to; utter; emit; report; sell. On her breast There is a vent of blood, and something blown ; Shakspeare. Antony and Cleopatra. Or, whilst I can vent clamour from my throat, Raleigh. Without the vent of words. Denham. Milton. They at once their reeds Put forth, and to a narrow vent applied With nicest touch. Id. Paradise Lost. By this war there is no vent for any commodity but of wool. Temple's Miscellany. Lab'ring still, with endless discontent, The queen of heaven did thus her fury vent. Dryden. Land-floods are a great improvement of land, where a vent can be had. Mortimer's Husbandry. The farmer's cades mature, T' indulge a-while. Philips. The smothered fondness burns within him: When most it swells and labours for a vent, The sense of honour and desire of fame Drive the big passion back into his heart. Addison's Cato. Scarce any countries that are much annoyed with earthquakes, that have not one of these fiery vents, disgorging that fire, whereby it gains an exit. Woodward. He drew off a thousand copies of a treatise, which not one in threescore can understand, can hardly exceed the vent of that number. Pope's Letters. a vent; or, if you take out the vent, stay not to put it To draw any drink, be not at the trouble of opening Swift. in. VENTA ICENORUM, an ancient city of South Britain, now called Castor. The ruins of its walls contain a square of thirty acres, and exhibit four gates and towns. Urns, coins, &c., are dug up in it. dow. VENTAN'NA, n.s. Span. ventanna. A win What after passed Was far from the ventanna, where I sate; But you were near, and can the truth relate. Dryden. VEN'TER, n. s. Lat. venter. Any cavity of the body, applied to the head, breast, and abdomen, which are called by anatomists the three venters a wonb; mother. A has issue B a son, and C a daughter, by one venter; and D a son by another venter. If B purto the sister, and not to the brother of the half blood. chases in fee, and dies without issue, it shall descend metaphorically, to examine; discuss: ventilation It is well known, indeed, to all who are practi is the act of ventilating, or state of being ventilated; vent; utterance: ventilator, an instrument of ventilation. To his secretary, Doctor Mason, whom he let lie in a pallet near him, for natural ventilation of his thoughts, he would break out into bitter eruptions. Wotton's Buckingham. Procure the blood a free course, ventilation, and transpiration, by suitable and ecphractic purges. Harvey. The soil, worn with too frequent culture, must lie fallow till it has recruited its exhausted salts, and again enriched itself by the ventillations of the air. Addison. Nor is the right of the party, nor the judicial process in right of that party, so far perempted, but that he same may be begun again, and ventilated de novo. Ayliffe. Miners, by perflations with large bellows, letting down tubes, and sinking new shafts, give free passage to the air, which ventilates and cools the mines. Woodward. VENTILATOR, a machine by which the noxious air of any close place, as an hospital, gaol, ship, chamber, &c., may be discharged and changed for fresh. The noxious qualities of bad air have been long known; and no one has taken greater pains to set the mischief arising from foul air in a proper light than Dr. Hales; who also proposed an easy and effectual remedy by the use of his ventilators; his account of which was read to the Royal Society in May 1741. In the November following M. Triewald, military architect to the king of Sweden, informed Dr. Mortimer, secretary to the Royal Society, that he had in the preceding spring invented a machine for the use of the king's men of war, to draw out the bad air from under the decks, the least of which exhausted 36,172 cubic feet of air in an hour, or at the rate of 21,732 tons in twenty-four hours. In 1742 he sent one of them, formed for a sixty gun ship to France; which was approved of by the Royal Academy of Sciences at Paris; and the king of France ordered all the men of war to be furnished with these ventilators. VENTILATION. The purity of the atmosphere is a subject of considerable importance, and one that should form a part of the medical police of a commercial country. In the crowded manufacturing cities of Great Britain we find steam engine furnaces continually pouring forth their deleterious vapors so as to darken and pollute the surrounding atmosphere. The process of ventilation that is going on naturally in the higher regions of the air, as well as the forced ventilation in common buildings, has been fully examined under the articles PNEUMATICS and SPECIFIC GRAVITY, and it remains for us now to illustrate the most perfect species of under-ground ventilation that has yet been suggested. It was originally proposed by Mr. John Taylor of mining celebrity. Next in importance to the means employed for draining underground works for water may be reckoned those which are intended to afford a supply of pure air, sufficient to enable the workmen to continue their operations with ease and safety to themselves, and to keep up undiminished the artificial light upon which they depend. cally engaged in concerns of this kind, that men are frequently obliged to persevere in their labor where a candle will scarcely burn, and where not only their own health materially suffers in the end, but their employers are put to considerable additional expense by the unavoidable hinderance and the waste of candles and other materials. We mean to confine the following remarks to such mines as are worked upon metalliferous veins. We find, then, that a single shaft, not communicating by levels to another, can hardly be sunk to any considerable depth, nor can a level (or, as the foreign miners call it, a gallery) be driven horizontally to any great distance without some contrivance being had recourse to for procuring currents of air to make up the deficiency of oxigen, which is so rapidly consumed by respiration and combustion in situations like these, where otherwise the whole remains in nearly a stagnant condition. We are here unacquainted with the rapid production of those gases, which occasionally in the collieries are the cause of such dreadful effects; such as hydrogen gas, or the fire-damp, carbonic acid, or the choke-damp; the inconvenience we experience takes place gradually as we recede from the openings to the atmosphere, and seems to arise solely from the causes before assigned, though it is found to come on more rapidly in certain situations than in others. The most obvious remedy, and that which is most frequently resorted to, is the opening a communication either to some other part of the mine, or to the surface itself, and as soon as this is done the ventilation is found to be complete, by the currents which immediately take place, often with considerable force, from the different degrees of temperature in the subterranean and upper atmospheres; and these currents may be observed to change their directions as the temperatures alternate. The great objection to this mode of curing the evil is the enormous expense with which it is most commonly attended. In driving a long level, or tunnel, for instance, it may happen to be at a great depth under the surface, and the intervening rock of great hardness; in such a case every shaft which must be sunk upon it for air alone, where not required (as often they might not) to draw up the waste, would cost several hundred pounds; or in sinking a shaft it may be necessary, at an expense not much less, to drive a level to it from some other for this purpose alone. To avoid this, recourse has been had to dividing the shaft or level into two distinct parts, communicating near the part intended to be ventilated, so that a current may be produced in opposite directions on each side the partition; and this, where room is to be spared for it, is often effectual to a certain extent. It is found however to have its limits at no very great distance, and the current at best is but a feeble one, from the nearly equal states of heat in the air on each side. The only scheme beside these has hitherto been to force down a volume of purer air, through a system of pipes placed for the purpose, and a variety of contrivances have been devised for effecting this; most of them are so old that they may be found described in Agricola's work De Re Metallicâ. The most common are by bellows worked by hand; by boxes or cylinders of various forms placed on the surface with a large opening against the wind, and a smaller one communicating with the air-pipes by a cylinder and piston working in it, which, when driven by a sufficient force, has great power; but the cheapest and most effectual scheme for this purpose, where circumstances will admit of its being applied, is one adopted some time since in the tunnel of the Tavistock canal. It is by applying the fall of a stream of water for this purpose, and it has been long known that a blast of considerable strength may be obtained in this manner, which has the advantage of being constant and self-acting. The stream being turned down a perpendicular column of pipes, and dashing in at a vessel so contrived as to let off the water one way, with an opening at another part for the air, which, being pressed into it by the falling water, may be conveyed in any direction, and will pass through air-pipes with a strong current, which will be found efficacious in ventilating mines in many instances, as it has likewise, in some cases, been sufficient for urging the intensity of fires for the purposes of the forge. It is easily procured where a sufficient fall is to be had, and the perpendicular column can be so fixed as that the water from the bottom may pass off, while the air is forced into a pipe branching from the air-vessel, and which is to be continued to the part of the mine where the supply of fresh air is required. We have found, however, that the forcing into vitiated air a mixture of. that which is purer, even when the best means are used, though a measure which affords relief, is not in bad cases a complete remedy; and where the operation depends on manual labor, or any means that are not unremitted in their action, it becomes quite ineffectual. The foul air, charged with the smoke of gunpowder used in blasting, and which it strongly retains, is certainly meliorated by the mixture of pure air, but is not removed. While the blast continues, some of it is driven into the other parts of the mine; but when the influx of pure air ceases it returns again, or if during the influx of pure air a fresh volume of smoke be produced by explosions, which are constantly taking place, it is not until some time afterward that it becomes sufficiently attenuated for the workmen to resume their stations with comfort. A consideration of these circumstances led an ingenious engineer to think that the usual operation of all ventilating engines ought to be reversed, to afford all the advantages that could be desired; that, instead of using the machines which serve as condensers, exhausters should be adopted; and thus, instead of forcing pure air into that in a vitiated state, a complete remedy could only be had by pumping out all that was impure as fast as it became so. Many modes of doing this suggested themselves to Mr. Taylor by the alteration of the machines commonly applied, and by producing an ascending stream of air through pipes by a furnace constructed for the purpose. The latter mode would however have been here expensive in fuel, as well as in attendance; and the others required power to overcome the friction of pistons, and so on, or considerable accuracy in construction. Mr. Taylor at last erected a machine which, while it is so simple in construction, and requires so small an expense of power, is so complete in its operation, and its parts are so little liable to be injured by wear, that nothing more can be desired, where such a one is applied. This engine bears a considerable resemblance to Mr. Pepys's gazometer; and the machine may be as well placed at the bottom of the shaft as at the top, and that in either case it is proper to fix it upon a floor, which may prevent the return of the foul air into the mine, after being discharged from the exhauster; this floor may be furnished with a trap door to be opened occasionally for the passage of buckets through it. The exhausting-cylinder is made of cast-iron, open at the bottom and suspended over the air-pipe, immersed some way in the water. It is furnished with a wooden top, in which is an opening fitted with a valve likewise opening upwards. The exhausting cylinder has its motion up and down given to it by a bob connected to any engine by an horizontal rod, and the weight of the cylinder is balanced, if necessary, by a counterpoise. The action is obvious.-When the exhausting cylinder is raised, a vacuum would be produced, or rather the water would likewise be raised in it, were it not for the stream of air from the mine rushing through the pipe and valve. As soon as the cylinder begins to descend, this valve closes and prevents the return of the air which is discharged through the upper valve. The quantity of air exhausted is calculated of course from the area of the bore of the cylinder, and the length of the stroke. The dimensions which Mr. Taylor has found sufficient for large works are as follows:-The bore of the exhausting cylinder two feet. The length six feet, so as to afford a stroke of four feet. The pipes which conduct the air to such an engine ought not to be less than six-inch bore. The best rate of working is from two to three strokes a minute; but, if required to go much faster, it will be proper to adapt a capacious air-vessel to the pipes near the machine, which will equalise the current pressing through them. A small engine to pump out two gallons at a stroke, which would be sufficient in many cases, could be worked by a power equal to raising a very few pounds weight, as the whole machine may be put into complete equilibrium before it begins to work, and there is hardly any other friction to overcome but that of the air passing through the pipes. The end of the tunnel of the Tavistock canal, which it was Mr. Taylor's object to ventilate, was driven into the hill to a distance of nearly 300 yards from any opening to the surface, and being at a depth of 120 yards, and all in hard schistus rock, air-shafts would have been attended with an enormous expense; so that the tun nel being a long one, it was most desirable to sink as few as possible, and of course at considerable distances from each other. Within a very short time after the engine began to work, the superiority of its action over those formerly employed was abundantly evident. The whole extent of the tunnel, which had been uninterruptedly clouded with smoke for some months before, and which the air that was forced in never could drive out, now became speedily so clear that the day light and even objects at its mouth were distinctly seen from its farthest end. After blowing up the rock, the miners could instantly return to the place where they were employed, unimpeded by the smoke, of which no appearance would remain underground in a very few minutes, while it might be seen to be discharged in gusts from the valve at the top of the shaft. The constant current into the pipe at the same time effectually prevented the accumulation of air unfit for respiration. The influx of air, from the level into the mouth of the pipe, rushes with such force as instantly to extinguish the flame of a large candle; and any substance, applied so as to stop the orifice, is held tight by the outward pressure. Two similar engines have been since constructed for other parts of the same tunnel, and have in every respect answered the purpose for which they were designed. The original one is worked by the small stream of water, by means of a light overshot wheel twelve feet in diameter, and about six inches in breast. The two others are attached to the great overshot-wheel, which pumps the water from the shafts which are sinking upon the line, and, as their friction is comparatively nothing, this may be done in any case, with so little waste of power for this purpose as not to be an object of consideration, even if the power be derived from more expensive means. The size of the exhauster may always be proportioned to the demand for air, and, by a due consideration of this circumstance, this engine may be effectually adapted not only to mines and collieries, but also to manufactories, workhouses, hospitals, prisons, ships, and so on. Thus, if it were required to ventilate a shaft of a mine, or a single level, which is most frequently the case, where three men are at work at one time, and we allow that those three men vitiate each twenty-seven cubic inches and a half of air per minute (as determined by the experiments of Messrs. Allen and Pepys); and allowing, farther, that their candles vitiate as much as the men, there will be six times twenty-seven cubic inches and a half of air to be drawn out in a minute, equal to 165. Now a cylinder five inches in diameter, working with a stroke of nine inches, will effect this by one stroke in a minute, though it would certainly be advisable to make it larger. Mr. Vallance's late patent for ventilating houses, is entitled to a place in our present article. The specification of this patent, after expatiating at considerable length upon the dangerous consequences to the health of individuals, as well as the unpleasant sensations produced by the extreme heat of crowded rooms, and also upon the present ineffectual modes of ventilating places intended for public assemblage, proposes the following methods to be resorted to under existing circumstances, viz. in the first instance, simply for the supply of pure air, to inject it in its natural state, by means of a pump from the atmosphere into the crowded room; secondly, for alleviating the extreme heat by cooling the air, before it is conveyed into the room; and, thirdly, when it may be necessary for warming the place, to heat the air previously to its being injected. For this purpose it is designed to erect a condensing or injecting air pump, or large bellows, in some convenient part of an adjacent building, from which a pipe is laid, conducting the air round the room, behind the skirting board; which pipe is to have minute openings to allow the passage of air in small streams, so as not to annoy the company. In the event of the natural state of the atmosphere being too warm to afford the necessary cool refreshment, it is proposed that the air, thus injected, should be condensed in pipes or other vessels, and deprived of part of its caloric (matter of heat): Several modes are proposed to effect this, one of which is to force it through cold water, or through pipes surrounded with cold water. When the temperature of the atmosphere is too cold, the air is proposed to be passed through hot water or heated pipes. The The pump or bellows to be employed for this purpose must be large, as the quantity of air required to be injected is calculated at one entire foot for each person present per minute. The piston of the pump is proposed to be worked by a contrivance similar to the pile driving machinery, with a weight of about 1000 lbs. windows and all other parts are intended to be rendered air-tight by luting; the only exit passage, or ventilator, is to be an aperture in the ceiling, from which a pipe is to lead to a cistern or reservoir without the building, making a water-valve, through which the air is to make its escape when sufficiently condensed by the pumping before mentioned; so that the room at all times is, as the patentee expresses it than full of air. In order to exclude as much as possible the atmospheric air, it is proposed to place on the outside of the door-way a cylindrical porch having two openings opposite each other, of about four feet wide; and in the middle of this cylinder to erect an upright revolving shaft, with four fans, as the fans of a winnowing machine; the edges of these fans are to fit as close as may be to the interior of the cylinder; and each person, on entering the room, is to pass between these fans as they revolve like a turnstile, by which the rushing in of air, when the door opens, will be prevented, and the interior contain an artificial atmosphere produced and maintained by the means before described. more VENTRICLE, n. s. Fr. ventricule; Lat. ventriculus. The stomach; a small cavity in the body, and particularly of the heart. Knowest thou how blood, which to the heart doth flow, Doth from one ventricle to the other go? Donne. Whether I will or not, while I live, my heart beats, and my ventricle digests what is in it. Hale. |