Chapter XI: Front Matter (11)

Again, the object of the law of G.A. is to put one whose property is sacrificed upon an equal footing with the rest, not upon a better footing. Thus, if goods to the value of L100 have been thrown overboard for the general safety, the owner of those goods must not receive the full L100 in contribution. He himself must bear a part of it, for those goods formed part of the adventure for whose safety the jettison was made; and it is owing to the partial safety of the adventure that any contribution at all is received by him. He, therefore, is made to contribute with the other saved interests towards his own loss, in respect of the amount "made good" to him for that. The full L100 is treated as the amount to be made good, but the owner of the goods is made to contribute towards that upon the sum of L100 thus saved to him.

The same principle has a further consequence. The amount to be made good will not necessarily be the value of the goods or other property in their condition at the time they were sacrificed; so to calculate it would in effect be to withdraw those goods from the subsequent risks of the voyage, and thus to put them in a better position than those which were not sacrificed. Hence, in estimating the amount to be made good, the value of the goods or property sacrificed must be estimated _as on arrival_, with reference to the condition in which they would probably have arrived had they remained on board throughout the voyage.

The liability to pay G.A. contributions falls primarily upon the owner of the contributing interest, ship, goods or freight. But in practice the contributions are paid by the insurers of the several interests. Merchants seldom have to concern themselves with the subject. And yet in an ordinary policy of insurance there is no express provision requiring the underwriter to indemnify the assured against this liability. The policy commonly contains clauses which recognize such an obligation, _e.g._ a warranty against average "unless general," or an agreement that G.A. shall be payable "as per foreign statement," or "according to York-Antwerp Rules"; but it does not directly state the obligation. It assumes that. The explanation seems to be that the practice of the underwriter to pay the contribution has been so uniform, and his liability has been so fully recognized, that express provisions were needless. But one result has been that very differing views of the ground of the obligation have been held. One view has been that it is covered by the sue and labour clause of an ordinary policy, by which the insurer agrees to bear his proportion of expenses voluntarily incurred "in and about the defence, safeguard and recovery" of the insured subject. But that has been held to be mistaken by the House of Lords (_Aitchison_ v. _Lohre_, 1879, 4 A.C. 755). Another view is that the underwriter impliedly undertakes to repay sums which the law may require the assured to pay towards averting losses which would, by the contract, fall upon the underwriter. Expenses voluntarily incurred by the assured with that object are expressly made repayable by the sue and labour clause of the policy. It might well be implied that payments compulsorily required from the assured by law for contributions to G.A., or as salvage for services by salvors, will be undertaken or repaid by the underwriter, the service being for his benefit. But the decision in _Aitchison_ v. _Lohre_ negatives this ground also. The claim was against underwriters on a ship which had been so damaged that the cost of repairs had exceeded her insured value. A claim for the ship's contribution to certain salvage and G.A. expenses which had been incurred, over and above the cost of repairs, was disallowed. The view seems to have been that the insurer is liable for salvage and G.A. payments as losses of the subject insured, and therefore included in the sum insured, not as collateral payments made on his behalf. This bases the claim against the insurer upon a fiction, for there has been no loss of [v.03 p.0058] the subject insured; in fact, the payment has been for averting such a loss. And it suggests that the insurer is not liable for salvage where the policy is free of particular average, which does not accord with practice.

An important question as to an insurer's liability for G.A. arose in the case of the _Brigella_ (1893, P. 189), where a shipowner had incurred expenses which would have been the subject of G.A. contributions, but that he alone was interested in the voyage. There were no contributories. He claimed from the insurers of the ship what would have been the ship's G.A. contribution had there been other persons to contribute in respect of freight or cargo. The claim was disallowed on the ground that there could be no G.A. in such circumstances, and therefore no basis for a claim against the insurer. The liability of the insurer was thus made to depend, not upon the character of the loss, but upon the fact or possibility of contribution. But this was not followed in _Montgomery_ v. _Indemnity Mutual M. I. Co._ (1901, 1 K.B. 147). There ship, freight and cargo all belonged to the same person. He had insured the cargo but not the ship. The cargo underwriters were held liable to pay a contribution to damage done to the ship by cutting away masts for the general safety. The loss was in theory spread over all the interests at risk, and they had undertaken to bear the cargo's share of such losses. Their liability did not depend upon the accident of whether the interests all belonged to one person or not. This agrees with the view taken in the United States.

As to _Particular Average_, see under INSURANCE: _Marine_.

AUTHORITIES.--Lowndes on _General Average_ (4th ed., London, 1888); Abbott's _Merchant Ships and Seamen_ (14th ed., London, 1901); Arnould's _Marine Insurance_ (7th ed., London, 1901); Carver's _Carriage by Sea_ (4th ed., London, 1905).

(T. G. C.)

[1] Per Bowen, L.J., in _Svensden_ v. _Wallace_, 1883, 13 Q.B.D. at p. 84.

AVERNUS, a lake of Campania, Italy, about 1 1/2 m. N. of Baiae. It is an old volcanic crater, nearly 2 m. in circumference, now, as in Roman times, filled with water. Its depth is 213 ft., and its height above sea-level 3 1/2 ft.; it has no natural outlet. In ancient times it was surrounded by dense forests, and was the centre of many legends. It was represented as the entrance by which both Odysseus and Aeneas descended to the infernal regions, and as the abode of the Cimmerii. Its Greek name, [Greek: Aornos], was explained to mean that no bird could fly across it. Hannibal made a pilgrimage to it in 214 B.C. Agrippa in 37 B.C. converted it into a naval harbour, the _Portus Iulius_; joining it to the Lacus Lucrinus by a canal, and connecting the latter with the sea, he reduced the distance to Cumae by boring a tunnel over 1/2 m. in length, now called Grotta della Pace, through the hill on the north-west side of Lake Avernus. After Sextus Pompeius had been subdued, the chief naval harbour was transferred to Misenum. Nero's works for his proposed canal from Baiae to the Tiber (A.D. 64) seem to have begun near Lake Avernus; indeed, according to one theory, the Grotta della Pace would be a portion of this canal. On the east side of the lake are remains of baths, including a great octagonal hall known as the Temple of Apollo, built of brickwork, and belonging to the 1st century. The so-called Grotto of the Cumaean Sibyl, on the south side, is a rock-cut passage, ventilated by vertical apertures, possibly a part of the works connected with the naval harbour. To the south-east of the lake is the Monte Nuovo, a volcanic hill upheaved in 1538, with a deep extinct crater in the centre. To the south is the Lacus Lucrinus.

See J. Beloch, _Campanien_ (2nd ed., Breslau, 1890), pp. 168 seq.

(T. AS.)

AVERROES [Ab[=u]l-Wal[=i]d Mu[h.]ammad ibn-A[h.]mad Ibn-Mu[h.]ammad ibn-Rushd] (1126-1198), Arabian philosopher, was born at Cordova. His early life was occupied in mastering the curriculum of theology, jurisprudence, mathematics, medicine and philosophy, under the approved teachers of the time. The years of his prime fell during the last period of Mahommedan rule in Spain under the Almohades (_q.v._). It was Ibn-Tufail (Abubacer), the philosophic vizier of Yusef, who introduced Averroes to that prince, and Avenzoar (Ibn-Zuhr), the greatest of Moslem physicians, was his friend. Averroes, who was versed in the Malekite system of law, was made cadi of Seville (1169), and in similar appointments the next twenty-five years of his life were passed. We find him at different periods in Seville, Cordova and Morocco, probably as physician to Yusef al-Mansur, who took pleasure in engaging him in discussions on the theories of philosophy and their bearings on the faith of Islam. But science and free thought then, as now, in Islam, depended almost solely on the tastes of the wealthy and the favour of the monarch. The ignorant fanaticism of the multitude viewed speculative studies with deep dislike and distrust, and deemed any one a Zendik (infidel) who did not rest content with the natural science of the Koran. These smouldering hatreds burst into open flame about the year 1195. Averroes was accused of heretical opinions and pursuits, stripped of his honours, and banished to a place near Cordova, where his actions were closely watched. At the same time efforts were made to stamp out all liberal culture in Andalusia, so far as it went beyond the little medicine, arithmetic and astronomy required for practical life. But the storm soon passed. Averroes was recalled to Morocco when the transient passion of the people had been satisfied, and for a brief period survived his restoration to honour. He died in the year before his patron, al-Mansur, with whom (in 1199) the political power of the Moslems came to an end, as did the culture of liberal science with Averroes. The philosopher left several sons, some of whom became jurists like his own grandfather. One of them has left an essay, expounding his father's theory of the intellect. The personal character of Averroes is known to us only in a general way, and as we can gather it from his writings. His clear, exhaustive and dignified style of treatment evidences the rectitude and nobility of the man. In the histories of his own nation he has little place; the renown which spread in his lifetime to the East ceased with his death, and he left no school. Yet, from a note in a manuscript, we know that he had intelligent readers in Spain more than a century afterwards. His historic fame came from the Christian Schoolmen, whom he almost initiated into the system of Aristotle, and who, but vaguely discerning the expositors who preceded, admired in his commentaries the accumulated results of two centuries of labours.

The literary works of Averroes include treatises on jurisprudence, grammar, astronomy, medicine and philosophy. In 1859 a work of Averroes was for the first time published in Arabic by the Bavarian Academy, and a German translation appeared in 1873 by the editor, J. Mueller. It is a treatise entitled _Philosophy and Theology_, and, with the exception of a German version of the essay on the conjunction of the intellect with man, is the first translation which enables the non-Semitic scholar to form any adequate idea of Averroes. The Latin translations of most of his works are barbarous and obscure. A great part of his writings, particularly on jurisprudence and astronomy, as well as essays on special logical subjects, prolegomena to philosophy, criticisms on Avicenna and Alfarabius (F[=a]r[=a]b[=i]), remain in manuscript in the Escorial and other libraries. The Latin editions of his medical works include the _Colliget_ (_i.e._ _Kulliyyat_, or summary), a _resume_ of medical science, and a commentary on Avicenna's poem on medicine; but Averroes, in medical renown, always stood far below Avicenna. The Latin editions of his philosophical works comprise the _Commentaries on Aristotle_, the _Destructio Destructionis_ (against Ghaz[=a]li), the _De Substantia Orbis_ and a double treatise _De Animae Beatitudine_. The Commentaries of Averroes fall under three heads:--the larger commentaries, in which a paragraph is quoted at large, and its clauses expounded one by one; the medium commentaries, which cite only the first words of a section; and the paraphrases or analyses, treatises on the subjects of the Aristotelian books. The larger commentary was an innovation of Averroes; for Avicenna, copied by Albertus Magnus, gave under the rubrics furnished by Aristotle works in which, though the materials were borrowed, the grouping was his own. The great commentaries exist only for the _Posterior Analytics_, _Physics_, _De Caelo_, _De Anima_ and _Metaphysics_. On the _History of Animals_ no commentary at all exists, and Plato's _Republic_ is substituted for the then inaccessible _Politics_. The Latin editions of these works between 1480 and 1580 number about 100. The first [v.03 p.0059] appeared at Padua (1472); about fifty were published at Venice, the best-known being that by the Juntas (1552-1553) in ten volumes folio.

See E. Renan, _Averroes et l'Averroisme_ (2nd ed., Paris, 1861); S. Munk, _Melanges_, 418-458; G. Stoeckl, _Phil. d. Mittelalters_, ii. 67-124; _Averroes (Vater und Sohn), Drei Abhandl. ueber d. Conjunction d. separaten Intellects mit d. Menschen_, trans. into German from the Arabic version of Sam. Ben-Tibbon, by Dr J. Hercz (Berlin, 1869); T. J. de Boer, _History of Philosophy in Islam_ (London, 1903), ch. vi.; A. F. M. Mehren in _Museon_, vii. 613-627; viii. 1-20; Carl Brockelmann, _Geschichte der arabischen Litteratur_ (Weimar, 1898), vol. i. pp. 461 f. See also ARABIAN PHILOSOPHY.

(W. W.; G. W. T.)

AVERRUNCATOR, a form of long shears used in arboriculture for "averruncating" or pruning off the higher branches of trees, &c. The word "averruncate" (from Lat. _averruncare_, to ward off, remove mischief) glided into meaning to "weed the ground," "prune vines," &c., by a supposed derivation from the Lat. _ab_, off, and _eruncare_, to weed out, and it was spelt "aberuncate" to suit this; but the _New English Dictionary_ regards such a derivation as impossible.

AVERSA, a town and episcopal see of Campania, Italy, in the province of Caserta, 15-1/2 m. S.S.W. by rail from Caserta, and 12-1/2 m. N. by rail from Naples, from which there is also an electric tramway. Pop. (1901) 23,477. Aversa was the first place in which the Normans settled, it being granted to them in 1027 for the help which they had given to Duke Sergius of Naples against Pandulf IV. of Capua. The Benedictine abbey of S. Lorenzo preserves a portal of the 11th century. There is also a large lunatic asylum, founded by Joachim Murat in 1813.

AVESNES, a town of northern France, capital of an arrondissement in the department of Nord, on the Helpe, 28 m. S.E. of Valenciennes by rail. Pop. (1906) 5076. The town is the seat of a sub-prefect, and has a tribunal of first instance, a chamber of commerce and a communal college. Its church of St Nicholas (16th century) has a tower 200 ft. high, with a fine chime of bells. The chief industry of the town is wool-spinning, and there is trade in wood. Avesnes was founded in the 11th century, and formed a countship which in the 15th century passed to the house of Burgundy and afterwards to that of Habsburg. In 1477 it was destroyed by Louis XI. By the treaty of the Pyrenees (1659) it came into the possession of the French, and was fortified by Vauban. It was captured by the Prussians in 1815.

AVEYRON, a department of southern France, bounded N. by Cantal, E. by Lozere and Card, S.W. by Tarn and W. by Tarn-et-Garonne and Lot. Area, 3386 sq. m. Pop. (1906) 377,299. It corresponds nearly to the old district of Rouergue, which gave its name to a countship established early in the 9th century, and united with that of Toulouse towards the end of the 11th century. The earliest known natives of this region were the Celtic Rutheni, to whom the numerous megalithic monuments found in the department are attributed. Aveyron lies on the southern border of the central plateau of France. Its chief rivers are the Lot in the north, the Aveyron in the centre and the Tarn in the south, all tributaries of the Garonne. They flow from east to west, following the general slope of the department, and divide it into four zones. In the north-east, between the Lot and its tributary the Truyere, lies the lonely pastoral plateau of the Viadene, dominated by the volcanic mountains of Aubrac, which form the north-eastern limit of the department and include its highest summit (4760 ft.). Entraygues, at the confluence of the Lot and the Truyere, is one of the many picturesque towns of the department. Between the Lot and the Aveyron is a belt of _causses_ or monotonous limestone table-lands, broken here and there by profound and beautiful gorges--a type of scenery characteristic of Aveyron. This zone is also watered by the Dourdou du Nord, a tributary of the Lot. The salient feature of the region between the Tarn and the Aveyron is the plateau of the Segala, bordered on the east by the heights of Levezou and Palanges and traversed from east to west by the deep valley of the Viaur, a tributary of the Aveyron. The country south of the Tarn is occupied in great part by the huge plateau of Larzac, which lies between the Causse Noir and the Causse St Affrique, the three forming the south-western termination of the Cevennes. On the Causse Noir is found the fantastic chaos of rocks and precipices known as Montpellier-le-Vieux, resembling the ruins of a huge city. The climate of Aveyron varies from extreme rigour in the mountains to mildness in the sheltered valleys; the south wind is sometimes of great violence. Wheat, rye and oats are the chief cereals cultivated, the soil of Aveyron being naturally poor. Other crops are potatoes, colza, hemp and flax. The mainstay of the agriculture of the department is the raising of live-stock, especially of cattle of the Aubrac breed, for which Laguiole is an important market. The wines of Entraygues, St Georges, Bouillac and Najac have some reputation; in the Segala chestnuts form an important element in the food of the peasants, and the walnut, cider-apple, mulberry (for the silk-worm industry), and plum are among the fruit trees grown. The production of Roquefort cheeses is prominent among the agricultural industries. They are made from the milk of the large flocks of the plateau of Larzac, and the choicest are ripened in the even temperature of the caves in the cliff which overhangs Roquefort. The minerals found in the department include the coal of the basins of Aubin and Rodez as well as iron, zinc and lead. Quarries of various kinds of stone are also worked. The chief industrial centres are Decazeville, which has metallurgical works, and Millau, where leather-dressing and the manufacture of gloves have attained considerable importance. Wool-weaving and the manufacture of woollen goods, machinery, chemicals and bricks are among the other industries.

There are five arrondissements, of which the chief towns are Rodez, capital of the department, Espalion, Millau, St Affrique and Villefranche, with 43 cantons and 304 communes. Rodez is the seat of a bishopric, the diocese of which comprises the department. Aveyron belongs to the 16th military region, and to the _academie_ or educational circumscription of Toulouse. Its court of appeal is at Montpellier. The department is traversed by the lines both of the Orleans and Southern railways. The more important towns are Rodez, Millau, St Affrique, Villefranche-de-Rouergue and Decazeville. The following are also of interest:--Sauveterre, founded in 1281, a striking example of the bastide (_q.v._) of that period; Conques, which has a remarkable abbey-church of the 11th century like St Sernin of Toulouse in plan and possessing a rich treasury of reliquaries, &c.; Espalion, where amongst other old buildings there are the remains of a feudal stronghold and a church of the Romanesque period; Najac, which has the ruins of a magnificent chateau of the 13th century; and Sylvanes, with a church of the 12th century, once attached to a Cistercian abbey.

AVEZZANO, a town of the Abruzzi, Italy, in the province of Aquila, 67 m. E. of Rome by rail and 38 m. S. of Aquila by road. Pop. (1901) 9442. It has a fine and well-preserved castle, built in 1490 by Gentile Virginio Orsini; it is square, with round towers at the angles. Avezzano is on the main line from Rome to Castellammare Adriatico; a branch railway diverges to Roccasecca, on the line from Naples to Rome. The Lago Fucino lies 1-1/2 m. to the east.

AVIANUS, a Latin writer of fables, placed by some critics in the age of the Antonines, by others as late as the 6th century A.D. He appears to have lived at Rome and to have been a heathen. The 42 fables which bear his name are dedicated to a certain Theodosius, whose learning is spoken of in most flattering terms. He may possibly be Macrobius Theodosius, the author of the _Saturnalia_; some think he may be the emperor of that name. Nearly all the fables are to be found in Babrius, who was probably Avianus's source of inspiration, but as Babrius wrote in Greek, and Avianus speaks of having made an elegiac version from a rough Latin copy, probably a prose paraphrase, he was not indebted to the original. The language and metre are on the whole correct, in spite of deviations from classical usage, chiefly in the management of the pentameter. The fables soon became popular as a school-book. Promythia and epimythia (introductions and morals) and paraphrases, and imitations were frequent, such as the _Novus Avianus_ of Alexander Neckam (12th century).

EDITIONS.--Cannegieter (1731), Lachmann (1845), Froehner (1862), [v.03 p.0060] Bahrens in _Poetae Latini Minores_, Ellis (1887). See Mueller, _De Phaedri et Aviani Fabulis_ (1875); Unrein, _De Aviani Aetate_ (1885); Hervieux, _Les Fabulistes latins_ (1894); _The Fables of Avian translated into Englyshe ... by William Caxton at Westmynstre_ (1483).

AVIARY (from Lat. _avis_, a bird), called by older writers "volary," a structure in which birds are kept in a state of captivity. While the habit of keeping birds in cages dates from a very remote period, it is probable that structures worthy of being termed aviaries were first used by the ancient Romans, chiefly for the process of fattening birds for the table. In Varro's time, 116-127 B.C., aviaries or "ornithones" (from Gr. [Greek: ornis, ornithos], bird) were common. These consisted of two kinds, those constructed for pleasure, in which were kept nightingales and other song-birds, and those used entirely for keeping and fattening birds for market or for the tables of their owners. Varro himself had an aviary for song-birds exclusively, while Lucullus combined the two classes, keeping birds both for pleasure and as delicacies for his table. The keeping of birds for pleasure, however, was very rarely indulged in, while it was a common practice with poulterers and others to have large ornithones either in the city or at Sabinum for the fattening of thrushes and other birds for food.

Ornithones consisted merely of four high walls and a roof, and were lighted with a few very small windows, as the birds were considered to pine less if they could not see their free companions outside. Water was introduced by means of pipes, and conducted in narrow channels, and the birds were fed chiefly upon dried figs, carefully peeled, and chewed into a pulp by persons hired to perform this operation.

Turtle-doves were fattened in large numbers for the market on wheat and millet, the latter being moistened with sweet wine; but thrushes were chiefly in request, and Varro mentions one ornithon from which no less than five thousand of these birds were sold for the table in one season.

The habit of keeping birds in aviaries, as we understand the term, for the sake of the pleasure they afford their owners and for studying their habits is, however, of comparatively recent date. The beginning of geographical research in the 15th century brought with it the desire to keep and study at home some of the beautiful forms of bird-life which the explorers came across, and hence it became the custom to erect aviaries for the reception of these creatures. In the 16th century, in the early part of which the canary-bird was introduced into Europe, aviaries were not uncommon features of the gardens of the wealthy, and Bacon refers to them in his essay on gardening (1597). Elizabeth of Bohemia, the daughter of James I. of England, when a child, had an outdoor aviary at Coombe Abbey near Coventry, the back and roof of which were formed of natural rock, in which were kept birds of many species from many countries.

Within recent years the method of keeping birds in large aviaries has received considerable attention, and it is fully recognized that by so doing, not only do we derive great pleasure, but our knowledge of avian habits and mode of living can thereby be very considerably increased.

An aviary may be of almost any size, from the large cage known, on account of its shape, as the "Crystal Palace aviary," to a structure as large as a church; and the term is sometimes applied to the room of a house with the windows covered with wire-netting; but as a rule it is used for outdoor structures, composed principally of wire-netting supported on a framework of either iron or woodwork. For quite hardy birds little more than this is necessary, providing that protection is given in the form of growing trees and shrubs, rock-work or rough wooden shelters. For many of the delicate species, however, which hail from tropical countries, warmth must be provided during the inclement months of the year, and thus a part at least of an aviary designed for these birds must be in the form of a wooden or brick house which can be shut up in cold weather and artificially warmed.

The ideal aviary, probably, is that which is constructed in two parts, viz. a well-built house for the winter, opening out into a large wire enclosure for use in the summer months. The doors between the two portions may be of wood or glazed. The part intended as the winter home of the birds is best built in brick or stone, as these materials are practically vermin-proof and the temperature in such a building is less variable than that in a thin wooden structure. The floor should be of concrete or brick, and the house should be fitted with an efficient heating apparatus from which the heat is distributed by means of hot-water pipes. Any arrangement which would permit the escape into the aviary of smoke or noxious fumes is to be strongly condemned. Such a house must be well lighted, preferably by means of skylights; but it is a mistake to have the whole roof glazed, at least half of it should be of wood, covered with slates or tiles. Perches consisting of branches of trees with the bark adhering should be fixed up, and, if small birds are to be kept, bundles of bushy twigs should be securely fixed up in corners under the roofs.

The outer part, which will principally be used during the summer, though it will do most birds good to be let out for a few hours on mild winter days also, should be as large as possible, and constructed entirely of wire-netting stretched on a framework of wood or iron. If the latter material is selected, stout gas-piping is both stronger and more easily fitted together than solid iron rods.

If the framework be of wood, this should be creosoted, preferably under pressure, or painted with three coats of good lead paint, the latter preservative also being used if iron is the material selected.

The wire-netting used may be of almost any sized mesh, according to the sized birds to be kept, but as a general rule the smallest mesh, such as half or five-eighths of an inch, should be used, as it is practically vermin-proof, and allows of birds of any size being kept. Wire-netting for aviaries should be of the best quality, and well galvanized. The new interlinked type is less durable than the old mesh type, though perhaps it looks somewhat neater when fixed.

Provision must be made for the entire exclusion of such vermin as rats, stoats and weasels, which, if they were to gain access, would commit great havoc amongst the birds. The simplest and most effectual method of doing this is by sinking the wire-netting some 2 ft. into the ground all round the aviary, and then turning it outwards for a distance of another foot as shown in the annexed cut (fig. 1).

The outer part of the aviary should be turfed and planted with evergreen and deciduous shrubs, and be provided with some means of supplying an abundance of pure water for the birds to drink and bathe in; a gravel path should not be forgotten.

Perhaps the most useful type of aviary is that built as above described, but with several compartments, and a passage at the back by which any compartment may be visited without the necessity of passing through and disturbing the birds in other compartments. Fig. 2 represents a ground plan of an aviary of this type divided into four compartments, each with an inner house 10 ft. square, and an outer flight of double that area. The outer flights are intended to be turfed, and planted with shrubs, and the gravel path has a glazed roof above it by which it is kept dry in wet weather. Shallow water-basins are shown, which should be supplied by means of an underground pipe and a cock which can be turned on from outside the aviary; and they must be connected with a properly laid drain by means of a waste plug and an overflow pipe.

An aviary should always be built with a southern or southeastern aspect, and, where possible, should be sheltered from the north, north-east and north-west by a belt of fir-trees, high wall or bank, to protect the birds from the biting winds from these quarters.

When parrots of any kind are to be kept it is useless to try [v.03 p.0061] to grow any kind of vegetation except grass, and even this will be demolished unless the aviary is of considerable size. The larger parrots will, in fact, bite to pieces not only living trees but also the woodwork of their abode, and the only really suitable materials for the construction of an aviary for these birds are brick or stone and iron; and the wire-netting used must be of the stoutest gauge or it will be torn to pieces by their strong bills.

The feeding of birds in aviaries is, obviously, a matter of the utmost importance, and, in order that they may have what is most suitable, the aviculturist should find out as much as possible of the wild life of the species he wishes to keep, or if little or nothing is known about their mode of living, as is often the case with rare forms, of nearly related species whose habits and food are probably much the same, and he should endeavour to provide food as nearly as possible resembling that which would be obtained by the birds when wild. It is often, however, impossible to supply precisely the same food as would be obtained by the birds had they their liberty, but a substitute which suits them well can generally be obtained. The majority of the parrot tribe subsist principally upon various nuts, seed and fruit, while some of the smaller parrakeets or paroquets appear to feed almost exclusively upon the seeds of various grasses. Almost all of these are comparatively easy to treat in captivity, the larger ones being fed on maize, sunflower-seed, hemp, dari, oats, canary-seed, nuts and various ripe fruits, while the grass-parrakeets thrive remarkably well on little besides canary-seed and green food, the most suitable of which is grass in flower, chickweed, groundsel and various seed-bearing weeds. But there is another large group of parrots, the _Loriidae_ or brush-tongued parrots, some of the most interesting and brightly coloured of the tribe, which, when wild, subsist principally upon the pollen and nectar of flowers, notably the various species of _Eucalyptus_, the filamented tongues of these parrots being peculiarly adapted for obtaining this. In captivity these birds have been found to live well upon sweetened milk-sop, which is made by pouring boiling milk upon crumbled bread or biscuit. They frequently learn to eat seed like other parrots, but, if fed exclusively upon this, are apt, especially if deprived of abundance of exercise, to suffer from fits which are usually fatal. Fruit is also readily eaten by the lories and lorikeets, and should always be supplied.

The foreign doves and pigeons form a numerous and beautiful group which are mostly hardy and easily kept and bred in captivity. They are for the most part grain-feeders and require only small corn and seeds, though a certain group, known as the fruit-pigeons, are fed in captivity upon soft fruits, berries, boiled potato and soaked grain.

The various finches and finch-like birds form an exceedingly large group and comprise perhaps the most popular of foreign aviary birds. The weaver-birds of Africa are mostly quite hardy and very easily kept, their food consisting, for the most part, of canary-seed. The males of these birds are, as a rule, gorgeously attired in brilliant colours, some having long flowing tail-feathers during the nuptial season, while in the winter their showy dress is replaced by one of sparrow-like sombreness. The grass-finches of Australasia contain some of the most brilliantly coloured birds, the beautiful grass-finch (_Poephila mirabilis_) being resplendent in crimson, green, mauve, blue and yellow. Most of these birds build their nests, and many rear their young, successfully in outdoor aviaries, their food consisting of canary and millet seeds, while flowering grasses provide them with an endless source of pleasure and wholesome food. The same treatment suits the African waxbills, many of which are extremely beautiful, the crimson-eared waxbill or "cordon-bleu" being one of the most lovely and frequently imported. These little birds are somewhat delicate, especially when first imported, and during the winter months require artificial warmth.

There is a very large group of insectivorous and fruit-eating birds very suitable for aviculture, but their mode of living necessarily involves considerable care on the part of the aviculturist in the preparation of their food. Many birds are partially insectivorous, feeding upon insects when these are plentiful, and upon various seeds at other times. Numbers of species again which, when adult, feed almost entirely upon grain, feed their young, especially during the early stages of their existence, upon insects; while others are exclusively insect-eaters at all times of their lives. All of these points must be considered by those who would succeed in keeping and breeding birds in aviaries.

It would be almost an impossibility to keep the purely insectivorous species, were it not for the fact that they can be gradually accustomed to feed on what is known as "insectivorous" or "insectile" food, a composition of which the principal ingredients generally consist of dried ants' cocoons, dried flies, dried powdered meat, preserved yolk of egg,[1] and crumb of bread or biscuit. This is moistened with water or mixed with mashed boiled potato, and forms a diet upon which most of the insectivorous birds thrive. The various ingredients, or the food ready made, can be obtained at almost any bird-fancier's shop. Although it is a good staple diet for these birds, the addition of mealworms, caterpillars, grubs, spiders and so forth is often a necessity, especially for purely insectivorous species.

The fruit-eating species, such as the tanagers and sugar-birds of the New World, require ripe fruit in abundance in addition to a staple diet such as that above described, while for such birds as feed largely upon earth-worms, shredded raw meat is added with advantage.

Many of the waders make very interesting aviary birds, and require a diet similar to that above recommended, with the addition of chopped raw meat, mealworms and any insects that can be obtained.

Birds of prey naturally require a meat diet, which is best given in the form of small, freshly killed mammals and birds, the fur or feathers of which should not be removed, as they aid digestion.

The majority of wild birds, from whatever part of the world they may come, will breed successfully in suitable aviaries providing proper nesting sites are available. Large bundles of brushwood, fixed up in sheltered spots, will afford accommodation for many kinds of birds, while some will readily build in evergreen shrubs if these are grown in their enclosure. Small boxes and baskets, securely fastened to the wall or roof of the [v.03 p.0062] sheltered part of an aviary, will be appropriated by such species as naturally build in holes and crevices. Parrots, when wild, lay their eggs in hollow trees, and occasionally in holes in rocks, making no nest,[2] but merely scraping out a slight hollow in which to deposit the eggs. For these birds hollow logs, with small entrance holes near the top, or boxes, varying in size according to the size of the parrots which they are intended for, should be supplied. In providing nesting accommodation for his birds the aviculturist must endeavour to imitate their natural surroundings and supply sites as nearly as possible similar to those which the birds, to whatever order they may belong, would naturally select.

Aviculture is a delightful pastime, but it is also far more than this; it is of considerable scientific importance, for it admits of the living birds being studied in a way that would be quite impossible otherwise. There are hundreds of species of birds, from all parts of the world, the habits of which are almost unknown, but which may be kept without difficulty in suitable aviaries. Many of these birds cannot be studied satisfactorily in a wild state by reason of their shy nature and retiring habits, not to mention their rarity and the impossibility, so far as most people are concerned, of visiting their native haunts. In suitable large aviaries, however, their nesting habits, courtship, display, incubation, moult and so forth can be accurately observed and recorded. The keeping of birds in aviaries is therefore a practice worthy of every encouragement, so long as the aviaries are of sufficient size and suitable design to allow of the birds exhibiting their natural habits; for in a large aviary they will reveal the secrets of their nature as they never would do in a cage or small aviary.

(D. S.-S.)

[1] It has recently been stated by certain medical men that egg-food in any form is an undesirable diet for birds, owing to its being peculiarly adapted to the multiplication of the bacillus of septicaemia, a disease which is responsible for the death of many newly imported birds. It is a significant fact, however, that insectivorous species, which are those principally fed upon this substance, are not nearly so susceptible to this disease as seed-eating birds which rarely taste egg; and in spite of what has been written concerning its harmfulness, the large majority of aviculturists use it, in both the fresh and the preserved state, with no apparent ill effects, but rather the reverse.

[2] There is, however, one true nest-building parrot, the grey-breasted parrakeet (_Myopsittacus monachus_), which constructs a huge nest of twigs. The true love-birds (_Agapornis_) may also be said to build nests, for they line their nest-hole with strips of pliant bark.

AVICENNA [Ab[=u] 'Al[=i] al-Husain ibn 'Abdall[=a]h ibn S[=i]n[=a]] (980-1037), Arabian philosopher, was born at Afshena in the district of Bokhara. His mother was a native of the place; his father, a Persian from Balkh, filled the post of tax-collector in the neighbouring town of Harmaitin, under N[=u]h II. ibn Mansur, the Samanid amir of Bokhara. On the birth of Avicenna's younger brother the family migrated to Bokhara, then one of the chief cities of the Moslem world, and famous for a culture which was older than its conquest by the Saracens. Avicenna was put in charge of a tutor, and his precocity soon made him the marvel of his neighbours,--as a boy of ten who knew by rote the Koran and much Arabic poetry besides. From a greengrocer he learnt arithmetic; and higher branches were begun under one of those wandering scholars who gained a livelihood by cures for the sick and lessons for the young. Under him Avicenna read the _Isagoge_ of Porphyry and the first propositions of Euclid. But the pupil soon found his teacher to be but a charlatan, and betook himself, aided by commentaries, to master logic, geometry and the Almagest. Before he was sixteen he not merely knew medical theory, but by gratuitous attendance on the sick had, according to his own account, discovered new methods of treatment. For the next year and a half he worked at the higher philosophy, in which he encountered greater obstacles. In such moments of baffled inquiry he would leave his books, perform the requisite ablutions, then hie to the mosque, and continue in prayer till light broke on his difficulties. Deep into the night he would continue his studies, stimulating his senses by occasional cups of wine, and even in his dreams problems would pursue him and work out their solution. Forty times, it is said, he read through the _Metaphysics_ of Aristotle, till the words were imprinted on his memory; but their meaning was hopelessly obscure, until one day they found illumination from the little commentary by F[=a]r[=a]b[=i] (_q.v._), which he bought at a bookstall for the small sum of three dirhems. So great was his joy at the discovery, thus made by help of a work from which he had expected only mystery, that he hastened to return thanks to God, and bestowed an alms upon the poor. Thus, by the end of his seventeenth year his apprenticeship of study was concluded, and he went forth to find a market for his accomplishments.

His first appointment was that of physician to the amir, who owed him his recovery from a dangerous illness (997). Avicenna's chief reward for this service was access to the royal library of the Samanids (_q.v._), well-known patrons of scholarship and scholars. When the library was destroyed by fire not long after, the enemies of Avicenna accused him of burning it, in order for ever to conceal the sources of his knowledge. Meanwhile, he assisted his father in his financial labours, but still found time to write some of his earliest works.

At the age of twenty-two Avicenna lost his father. The Samanid dynasty came to its end in December 1004. Avicenna seems to have declined the offers of Mahm[=u]d the Ghaznevid, and proceeded westwards to Urjensh in the modern Khiva, where the vizier, regarded as a friend of scholars, gave him a small monthly stipend. But the pay was small, and Avicenna wandered from place to place through the districts of Nishapur and Merv to the borders of Khorasan, seeking an opening for his talents. Shams al-Ma'[=a]l[=i] Q[=a]b[=u]s, the generous ruler of Dailam, himself a poet and a scholar, with whom he had expected to find an asylum, was about that date (1012) starved to death by his own revolted soldiery. Avicenna himself was at this season stricken down by a severe illness. Finally, at Jorj[=a]n, near the Caspian, he met with a friend, who bought near his own house a dwelling in which Avicenna lectured on logic and astronomy. For this patron several of his treatises were written; and the commencement of his _Canon of Medicine_ also dates from his stay in Hyrcania.

He subsequently settled at Rai, in the vicinity of the modern Teheran, where a son of the last amir, Majd Addaula, was nominal ruler, under the regency of his mother. At Rai about thirty of his shorter works are said to have been composed. But the constant feuds which raged between the regent and her second son, Shams Addaula, compelled the scholar to quit the place, and after a brief sojourn at Kazw[=i]n, he passed southwards to Hamad[=a]n, where that prince had established himself. At first he entered into the service of a high-born lady; but ere long the amir, hearing of his arrival, called him in as medical attendant, and sent him back with presents to his dwelling. Avicenna was even raised to the office of vizier; but the turbulent soldiery, composed of Kurds and Turks, mutinied against their nominal sovereign, and demanded that the new vizier should be put to death. Shams Addaula consented that he should be banished from the country. Avicenna, however, remained hidden for forty days in a sheik's house, till a fresh attack of illness induced the amir to restore him to his post. Even during this perturbed time he prosecuted his studies and teaching. Every evening extracts from his great works, the _Canon_ and the _Sanatio_, were dictated and explained to his pupils; among whom, when the lesson was over, he spent the rest of the night in festive enjoyment with a band of singers and players. On the death of the amir Avicenna ceased to be vizier, and hid himself in the house of an apothecary, where, with intense assiduity, he continued the composition of his works. Meanwhile, he had written to Abu Ya'far, the prefect of Isfahan, offering his services; but the new amir of Hamad[=a]n getting to hear of this correspondence, and discovering the place of Avicenna's concealment, incarcerated him in a fortress. War meanwhile continued between the rulers of Isfahan and Hamad[=a]n; in 1024 the former captured Hamad[=a]n and its towns, and expelled the Turkish mercenaries. When the storm had passed Avicenna returned with the amir to Hamad[=a]n, and carried on his literary labours; but at length, accompanied by his brother, a favourite pupil, and two slaves, made his escape out of the city in the dress of a Sufite ascetic. After a perilous journey they reached Isfahan, and received an honourable welcome from the prince. The remaining ten or twelve years of Avicenna's life were spent in the service of Abu Ya'far 'Al[=a] Addaula, whom he accompanied as physician and general literary and scientific adviser, even in his numerous campaigns. During these years he began to study literary matters and philology, instigated, it is asserted, by [v.03 p.0063] criticisms on his style. But amid his restless study Avicenna never forgot his love of enjoyment. Unusual bodily vigour enabled him to combine severe devotion to work with facile indulgence in sensual pleasures. His passion for wine and women was almost as well known as his learning. Versatile, light-hearted, boastful and pleasure-loving, he contrasts with the nobler and more intellectual character of Averroes. His bouts of pleasure gradually weakened his constitution; a severe colic, which seized him on the march of the army against Hamad[=a]n, was checked by remedies so violent that Avicenna could scarcely stand. On a similar occasion the disease returned; with difficulty he reached Hamad[=a]n, where, finding the disease gaining ground, he refused to keep up the regimen imposed, and resigned himself to his fate. On his deathbed remorse seized him; he bestowed his goods on the poor, restored unjust gains, freed his slaves, and every third day till his death listened to the reading of the Koran. He died in June 1037, in his fifty-eighth year, and was buried in Hamad[=a]n.

It was mainly accident which determined that from the 12th to the 17th century Avicenna should be the guide of medical study in European universities, and eclipse the names of Rhazes, Ali ibn al-Abbas and Avenzoar. His work is not essentially different from that of his predecessors Rhazes and Ali; all present the doctrine of Galen, and through Galen the doctrine of Hippocrates, modified by the system of Aristotle. But the _Canon_ of Avicenna is distinguished from the _Al-Hawi_ (_Continens_) or _Summary_ of Rhazes by its greater method, due perhaps to the logical studies of the former, and entitling him to his surname of Prince of the Physicians. The work has been variously appreciated in subsequent ages, some regarding it as a treasury of wisdom, and others, like Avenzoar, holding it useful only as waste paper. In modern times it has been more criticized than read. The vice of the book is excessive classification of bodily faculties, and over-subtlety in the discrimination of diseases. It includes five books; of which the first and second treat of physiology, pathology and hygiene, the third and fourth deal with the methods of treating disease, and the fifth describes the composition and preparation of remedies. This last part contains some contingent of personal observation. He is, like all his countrymen, ample in the enumeration of symptoms, and is said to be inferior to Ali in practical medicine and surgery. He introduced into medical theory the four causes of the Peripatetic system. Of natural history and botany he pretends to no special knowledge. Up to the year 1650, or thereabouts, the _Canon_ was still used as a text-book in the universities of Louvain and Montpellier.

About 100 treatises are ascribed to Avicenna. Some of them are tracts of a few pages, others are works extending through several volumes. The best-known amongst them, and that to which Avicenna owed his European reputation, is the _Canon of Medicine_; an Arabic edition of it appeared at Rome in 1593, and a Hebrew version at Naples in 1491. Of the Latin version there were about thirty editions, founded on the original translation by Gerard of Cremona. The 15th century has the honour of composing the great commentary on the text of the _Canon_, grouping around it all that theory had imagined, and all that practice had observed. Other medical works translated into Latin are the _Medicamenta Cordialia_, _Canticum de Medicina_, _Tractatus de Syrupo Acetoso_. Scarcely any member of the Arabian circle of the sciences, including theology, philology, mathematics, astronomy, physics and music, was left untouched by the treatises of Avicenna, many of which probably varied little, except in being commissioned by a different patron and having a different form or extent. He wrote at least one treatise on alchemy, but several others have been falsely attributed to him. His book on animals was translated by Michael Scot. His _Logic_, _Metaphysics_, _Physics_, _De Caelo_, are treatises giving a synoptic view of Aristotelian doctrine. The _Logic_ and _Metaphysics_ have been printed more than once, the latter, _e.g._, at Venice in 1493, 1495 and 1546. Some of his shorter essays on medicine, logic, &c., take a poetical form (the poem on logic was published by Schmoelders in 1836). Two encyclopaedic treatises, dealing with philosophy, are often mentioned. The larger, _Al-Shif[=a]'_ (_Sanatio_), exists nearly complete in manuscript in the Bodleian library and elsewhere; part of it on the _De Anima_ appeared at Pavia (1490) as the _Liber Sextus Naturalium_, and the long account of Avicenna's philosophy given by Shahrastani seems to be mainly an analysis, and in many places a reproduction, of the _Al-Shif[=a]'_, A shorter form of the work is known as the _An-naj[=a]t_ (_Liberatio_). The Latin editions of part of these works have been modified by the corrections which the monkish editors confess that they applied. There is also a _Philosophia Orientalis_, mentioned by Roger Bacon, and now lost, which according to Averroes was pantheistic in tone.

For Avicenna's life, see Ibn Khallikan's _Biographical Dictionary_, translated by McG. de Slane (1842); F. Wuestenfeld's _Geschichte der arabischen Aerzte und Naturforscher_ (Goettingen, 1840). For his medicine, see Sprengel, _Histoire de la Medecine_; and for his philosophy, see Shahrastani, German trans. vol. ii. 213-332; K. Prantl, _Geschichte der Logik_, ii. 318-361; A. Stoeckl, _Phil. d. Mittelalters_, ii. 23-58; S. Munk, _Melanges_, 352-366; B. Haneberg in the _Abhandlungen der philos.-philolog. Class. der bayerischen Academie_ (1867); and Carra de Vaux, _Avicenne_ (Paris, 1900). For list of extant works see C. Brockelmann's _Geschichte der arabischen Litteratur_ (Weimar, 1898), vol. i. pp. 452-458.

(W. W.; G. W. T.)

AVIENUS, RUFIUS FESTUS, a Roman aristocrat and poet, of Vulsinii in Etruria, who flourished during the second half of the 4th century A.D. He was probably proconsul of Africa (366) and of Achaia (372). Avienus was a pagan and a staunch supporter of the old religion. He translated the [Greek: Phainomena] of Aratus and paraphrased the [Greek: Periegesis] of Dionysius under the title of _Descriptio Orbis Terrarum_, both in hexameters. He also compiled a description, in iambic trimeters, of the coasts of the Mediterranean, Caspian and Black Seas in several books, of which only a fragment of the first is extant. He also epitomized Livy and Virgil's _Aeneid_ in the same metre, but these works are lost. Some minor poems are found under his name in anthologies, _e.g._ a humorous request to one Favianus for some pomegranates for medicinal purposes.

AVIGLIANA, a town of Piedmont, Italy, in the province of Turin, 14 m. W. by rail from the town of Turin. Pop. (1901) 4629. It has medieval buildings of some interest, but is mainly remarkable for its large dynamite factory, employing over 500 workman.