the subject insured; in fact, the payment has been for averting of his life were passed. We find him at different periods in such a loss. And it suggests that the insurer is not liable for Seville, Cordova and Morocco, probably as physician to Yusef salvage where the policy is free of particular average, which al-Mansur, who took pleasure in engaging him in discussions on does not accord with practice.

the theories of philosophy and their bearings on the faith of An important question as to an insurer's liability for G.A. Islam. But science and free thought then, as now, in Islam, arose in the case of the Brigella (1893, P. 189), where a shipowner depended almost solely on the tastes of the wealthy and the had incurred expenses which would have been the subject of favour of the monarch. The ignorant fanaticism of the multitude G.A. contributions, but that he alone was interested in the viewed speculative studies with deep dislike and distrust, and voyage. There were no contributories. He claimed from the deemed any one a Zendik (infidel) who did not rest content with insurers of the ship what would have been the ship's G.A. the natural science of the Koran. These smouldering hatreds contribution had there been other persons to contribute in respect burst into open flame about the year 1195. Averroes was of freight or cargo. The claim was disallowed on the ground accused of heretical opinions and pursuits, stripped of his that there could be no G.A. in such circumstances, and therefore honours, and banished to a place near Cordova, where his no basis for a claim against the insurer. The liability of the actions were closely watched. At the same time efforts were insurer was thus made to depend, not upon the character of the made to stamp out all liberal culture in Andalusia, so far as loss, but upon the fact or possibility of contribution. But this it went beyond the little medicine, arithmetic and astronomy was not followed in Montgomery v. Indemnity Mutual M. I. Co. required for practical life. But the storm soon passed. Averroes (1901, I K.B. 147). There ship, freight and cargo all belonged was recalled to Morocco when the transient passion of the to the same person. He had insured the cargo but not the ship. people had been satisfied, and for a brief period survived his The cargo underwriters were held liable to pay a contribution restoration to honour. He died in the year before his patron, to damage done to the ship by cutting away masts for the al-Mansur, with whom (in 1199) the political power of the general safety. The loss was in theory spread over all the Moslems came to an end, as did the culture of liberal science interests at risk, and they had undertaken to bear the cargo's with Averroes. The philosopher left several sons, some of whom share of such losses. Their liability did not depend upon the became jurists like his own grandfather. One of them has left accident of whether the interests all belonged to one person or an essay, expounding his father's theory of the intellect The not. This agrecs with the view taken in the United States. personal character of Averroes is known to us only in a general

As to Particular Average, see under INSURANCE: Marine. way, and as we can gather it from his writings. His clear, AUTHORITIES.-Lowndes on General Average (4th ed., London, exhaustive and dignified style of treatment evidences the 1888); Abbott's Merchant Ships and Seamen (14th ed., London: rectitude and nobility of the man. In the histories of his own 1901): Arnould's Marine Insurance (7th ed., London, 1991); nation he has little place; the renown which spread in his Carver's Carriage by Sea (4th ed., London, 1905).

AVERNUS, a lake of Campania, Italy, about 11 m. N. of lifetime to the East ceased with his death, and he left no school. Baiae. It is an old volcanic crater, nearly 2 m. in circumference, Yet, from a note in a manuscript, we know that he had intelligent now, as in Roman times, filled with water. Its depth is 213 ft., readers in Spain more than a century afterwards. His historic and its height above sea-level 31 ft.; it has no natural outlet. fame came from the Christian Schoolmen, whom he almost In ancient times it was surrounded by dense forests, and was the initiated into the system of Aristotle, and who, but vaguely centre of many legends. It was represented as the entrance discerning the expositors who preceded, admired in his commenby which both Odysseus and Aeneas descended to the infernal taries the accumulated results of two centuries of labours. regions, and as the abode of the Cimmerii. Its Greek name, The literary works of Averroes include treatises on juris"Aopvos, was explained to mean that no bird could fly across it. prudence, grammar, astronomy, medicine and philosophy, Hannibal made a pilgrimage to it in 214 B.C. Agrippa in 37 B.C. In 1859 a work of Averroes was for the first time published converted it into a naval harbour, the Portus Iulius; joining in Arabic by the Bavarian Academy, and a German translation it to the Lacus Lucrinus by a canal, and connecting the latter appeared in 1875 by the editor, J. Müller. It is a treatise enwith the sea, he reduced the distance to Cumae by boring a tunnel titled Philosophy and Theology, and, with the exception of a over 1 m. in length, now called Grotta della Pace, through the hill German version of the essay on the conjunction of the intellect on the north-west side of Lake Avernus. After Sextus Pompeius with man, is the first translation which enables the non-Semitic had been subdued, the chicf naval harbour was transferred to scholar to form any adequate idea of Averroes. The Latin Misenum. Nero's works for his proposed canal from Baiae to translations of most of his works are barbarous and obscure. the Tiber (A.D. 64) seem to have begun near Lake Avernus; A great part of his writings, particularly on jurisprudence and indeed, according to one theory, the Grotta della Pace would astronomy, as well as essays on special logical subjects, prolegobe a portion of this canal. On the east side of the lake are mena to philosophy, criticisms on Avicenna and Alfarabius remains of baths,

including a great octagonal hall known as the (Färābi),remain in manuscript in the Escorial and other libraries. Temple of Apollo, built of brickwork, and belonging to the The Latin editions of his medical works include the Colliget (i.e. Ist century. The so-called Grotto of the Cumacan Sibyl, on Kulliyyat, or summary), a résumé of medical science, and a the south side, is a rock-cut passage, ventilated by vertical commentary on Avicenna's poem on medicine; but Averroes, apertures, possibly a part of the works connected with the naval in medical renown, always stood far below Avicenna. The harbour. To the south-east of the lake is the Monte Nuovo, a Latin editions of his philosophical works comprise the Commenvolcanic hill upheaved in 1538, with a deep extinct crater in the taries on Aristotle, the Destructio Destructionis (against Ghazali), Centre. To the south is the Lacus Lucrinus.

the De Substantia Orbis and a double treatise De Animae BeatiSee J. Beloch, Campanien (2nd ed., Breslau, 1890), pp. 168 tudine. The Commentaries of Averrocs fall under three heads:Seq.

(T. As.) the larger commentaries, in which a paragraph is quoted at large, AVERROES [Abül - Walid Muḥammad ibn-Ahmad Ibn- and its clauses expounded one by one; the medium commentaries, Muhammad ibn-Rushd) (1126–1198), Arabian philosopher, was which cite only the first words of a section; and the paraphrases born at Cordova. His early life was occupied in mastering the or analyses, treatises on the subjects of the Aristotelian books. curriculum of theology, jurisprudence, mathematics, medicine The larger commentary was an innovation of Averroes; for and philosophy, under the approved teachers of the time. The Avicenna, copied by Albertus Magnus, gave under the rubrics years of his prime fell during the last period of Mahommedan furnished by Aristotle works in which, though the materials rule in Spain under the Almohades (9.0.). It was Ibn-Tufail were borrowed, the grouping was his own. The great com(Abubacer), the philosophic vizier of Yusef, who introduced mentaries exist only for the posterior Analytics, Physics, De Averroes to that prince, and Avenzoar (Ibn-Zuhr), the greatest Caelo, De Anima and Metaphysics. On the History of Animals of Moslem physicians, was his friend. Averroes, who was no commentary at all exists, and Plato's Republic is substituted versed in the Malekite system of law, was made cadi of Seville for the then inaccessible

Politics. The Latin editions of these (1169), and in similar appointments the next twenty-five years I works between 1480 and 1580 number about 100. The first

appeared at Padua (1472); about fifty were published at Venice, | Cévennes. On the Causse Noir is found the fantastic chaos of the best-known being that by the Juntas (1552-1553) in ten volumes folio.

Bährens in Poetae Latini Minores, Ellis (1887). See Müller, 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. öрvis öриlos, bird) were common. These consisted of two kinds, those constructed for pleasure, in which were kept nightin-glazed, at least half of it should be of wood, covered with slates gales 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.

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 hotwater 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

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

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 ft. into the ground all round the aviary, and then turning it outwards for a surface of distance of another foot as shown in the annexed cut (fig. 1).

Wire-1

Surface of ground

+

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, and a gravel path should not be forgotten.

FIG. 1.

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 to 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

sheltered part of an aviary, will be appropriated by such species concluded, and he went forth to find a market for his accomplishas naturally build in holes and crevices. Parrots, when wild, ments. lay their eggs. in hollow trees, and occasionally in holes in rocks, His first appointment was that of physician to the amir, making no nest," but merely scraping out a slight hollow in which who owed him his recovery from a dangerous illness (997). to deposit the eggs. For these birds hollow logs, with small Avicenna's chief reward for this service was access to the royal entrance holes near the top, or boxes, varying in size according library of the Samanids (9.0.), well-known patrons of scholarship to the size of the parrots which they are intended for, should and scholars. When the library was destroyed by fire not long be supplied. In providing nesting accommodation for his after, the enemies of Avicenna accused him of burning it, in birds the aviculturist must endeavour to imitate their natural order for ever to conceal the sources of his knowledge. Meansurroundings and supply sites as nearly as possible similar to while, he assisted his father in his financial labours, but still those which the birds, to whatever order they may belong, found time to write some of his earliest works. would naturally select.

At the age of twenty-two Avicenna lost his father. The Aviculture is a delightful pastime, but it is also far more than Samanid dynasty came to its end in December 1004. Avicenna this; it is of considerable scientific importance, for it admits of seems to have declined the offers of Mahmūd the Ghaznevid, the living birds being studied in a way that would be quite and proceeded westwards to Urjensh in the modern Khiva, impossible otherwise. There are hundreds of species of birds, where the vizier, regarded as a friend of scholars, gave him a from all parts of the world, the habits of which are almost un- small monthly stipend. But the pay was small, and Avicenna known, but which may be kept without difficulty in suitable wandered from place to place through the districts of Nishapur aviaries. Many of these birds cannot be studied satisfactorily and Merv to the borders of Khorasan, seeking an opening for in a wild state by reason of their shy nature and retiring habits, his talents. Shams al-Ma'āli Qābūs, the generous ruler of not to mention their rarity and the impossibility, so far as most Dailam, himself a poet and a scholar, with whom he had people are concerned, of visiting their native haunts. In suitable expected to find an asylum, was about that date (1012) starved large aviaries, however, their nesting habits, courtship, display, to death by his own revolted soldiery. Avicenna himself was incubation, moult and so forth can be accurately observed and at this season stricken down by a severe illness. Finally, at recorded. The keeping of birds in aviaries is therefore a practice Jorjān, near the Caspian, he met with a friend, who bought near worthy of every encouragement, so long as the aviaries are of his own house a dwelling in which Avicenna lectured on logic sufficient size and suitable design to allow of the birds exhibiting and astronomy. For this patron several of his treatises were their natural habits; for in a large aviary they will reveal the written; and the commencement of his Canon of Medicine also secrets of their nature as they neyer would do in a cage or small dates from his stay in Hyrcania. aviary.

(D. S.-S.) He subsequently settled at Rai, in the vicinity of the modern AVICENNA (Abū 'Ali al-Husain ibn 'Abdallah ibn Sinā] | Teheran, where a son of the last amir, Majd Addaula, was (980-1037), Arabian philosopher, was born at Afshena in the nominal ruler, under the regency of his mother. At Rai about district of Bokhara. His mother was a native of the place; his thirty of his shorter works are said to have been composed. But father, a Persian from Balkh, filled the post of tax-collector in the constant feuds which raged between the regent and her the neighbouring town of Harmaitin, under Nūh II. ibn Mansur, second son, Shams Addaula, compelled the scholar to quit the the Samanid amir of Bokhara. On the birth of Avicenna's place, and after a brief sojourn at Kazwin, he passed southwards younger brother the family migrated to Bokhara, then one of to Hamadān, where that prince had established himself

. At the chief cities of the Moslem world, and famous for a culture first he entered into the service of a high-born lady; but ere which was older than its conquest by the Saracens. Avicenna long the amir, hearing of his arrival, called him in as medical was put in charge of a tutor, and his precocity soon made him attendant, and sent him back with presents to his dwelling. the marvel of his neighbours, -as a boy of ten who knew by rote Avicenna was even raised to the office of vizier; but the turbulent the Koran and much Arabic poetry besides. From a green- soldiery, composed of Kurds and Turks, mutinied against their grocer he learnt arithmetic; and higher branches were begun nominal sovereign, and demanded that the new vizier should be under one of those wandering scholars who gained a livelihood put to death. Shams Addaula consented that he should be by cures for the sick and lessons for the young. 'Under him banished from the country. Avicenna, however, remained Avicenna read the Isagoge of Porphyry and the first propositions hidden for forty days in a sheik's house, till a fresh attack of of Euclid. But the pupil soon found his teacher to be but a illness induced the amir to restore him to his post. Even during charlatan, and betook himself, aided by commentaries, to master this perturbed time he prosecuted his studies and teaching. logic, geometry and the Almagest. Before he was sixteen he Every evening extracts from his great works, the Canon and the not merely knew medical theory, but by gratuitous attendance Sanatio, were dictated and explained to his pupils; among on the sick had, according to his own account, discovered new whom, when the lesson was over, he spent the rest of the night methods of treatment. For the next year and a half he worked in festive enjoyment with a band of singers and players. On the at the higher philosophy, in which he encountered greater death of the amir Avicenna ceased to be vizier, and hid himself obstacles. In such moments of baffled inquiry he would leave in the house of an apothecary, where, with intense assiduity, he his books, perform the requisite ablutions, then hie to the continued the composition of his works. Meanwhile, he had mosque, and continue in prayer till light broke on his difficulties. written to Abu Ya'far, the prefect of Isfahan, offering his Decp into the night he would continue his studies, stimulating services; but the new amir of Hamadān getting to hear of this his senses by occasional cups of wine, and even in his dreams correspondence, and discovering the place of Avicenna's conproblems would pursue him and work out their solution. Forty cealment, incarcerated him in a fortress. War meanwhile contimes, it is said, he read through the Metaphysics of Aristotle, tinued between the rulers of Isfahan and Hamadän; in 1024 till the words were imprinted

on his memory; but their meaning the former captured Hamadan and its towns, and expelled the was hopelessly obscure, until one day they found illumination Turkish mercenaries. When the storm had passed Avicenna from the little commentary by Farabi (9.0.), which he bought returned with the amir to Hamadān, and carried on his literary at a bookstall for the small sum of three dirhems. So great was labours; but at length, accompanied by his brother, a favourite his joy at the discovery, thus made by help of a work from which pupil, and two slaves, .made his escape out of the city in the he had expected only mystery, that he hastened to return thanks dress of a Sufite ascetic. After a perilous journey they reached to Gol, and bestowel an alms upon the poor. Thus, by the Isfahan, and received an honourable welcome from the prince, end of his seventeenth year his apprenticeship of study was The remaining ten or twelve years of Avicenna's life were spent 1 There is, however, one true nest-building parrot,

the grey- in the service of Abu Ya'far 'Ala Addaula, whom he accompanied huge nest of twigs. The true love birds (Agapornis) may also be as physician and general literary and scientific adviser, even in said to build nests, for they line their nest-hole with strips of pliant his numerous campaigns. During these years he began to study bark.

literary matters and philology, instigated, it is asserted, by