[1] The migration was made compulsory by Alphonso I. in 1442, and
remained so until 1865. Since that time the _tratturi_ have been to
some extent absorbed by private proprietors.
APURE, a river of western Venezuela, formed by the confluence of the
Sarare and Uribante at 6 deg. 45' N. lat. and 71 deg. W. long., and
flowing eastward across the Venezuelan _llanos_ to a junction with the
Orinoco at about 7 deg. 40' N. lat. and 66 deg. 45' W. long. Its
drainage area includes the slopes of both the Colombian and Venezuelan
Andes. It has a sluggish course across the _llanos_ for about 300 m.,
and is navigable throughout its length. Its principal tributaries are
the Caparro, Portuguesa and Guarico on the north, and the Caucagua on
the south. Its lateral channels on the south mingle with those of the
Arauca for many miles, forming an extensive district subject to annual
inundations.
APURIMAC, a river of central Peru, rising in the Laguna de Villafra in
the western Cordilleras, 7 m. from Caylloma, a village in the department
of Arequipa, and less than 100 m. from the Pacific coast. It flows first
north-easterly, then north-westerly past Cuzco to the mouth of the
Perene tributary, thence east and north to its junction with the Ucayali
at 10 deg. 41' S. lat., and 73 deg. 34' W. long. It is known as the
Apurimac only down to the mouth of the Mantaro tributary, 11 deg. 45' S.
lat. and 1325 ft. above sea-level. Thence to the mouth of the Perene
(984 ft.) it is known as the Ene, and from that point to its junction
with the Ucayali (859 ft.) as the Tambo.
APURIMAC, an interior department of southern Peru, bounded N. by the
department of Ayacucho, E. by Cuzco, S. and W. by Cuzco and Ayacucho.
Area, 8187 sq. m.; pop. (1896) 177,387. The department was created in
1873 and comprises five provinces. Its physical features and productions
are very similar to those of Ayacucho (q.v.), with the exception that
sugar-cane is cultivated with noteworthy success in the low valley of
the province of Abancay. The capital, Abancay, 110 m. south-west of
Cuzco, which is only a village in size but is rich in historical
associations and Andahuaylas, in the north-west part of the department,
are its principal towns.
APYREXIA (Gr. [Greek: apyrexia], from [Greek: a-], privative, [Greek:
pyressein], to be in a fever, [Greek: pyr], fire, fever), in pathology,
the normal interval or period of intermission in a fever.
'AQIBA BEN JOSEPH (c. 50-132), Jewish Palestinian rabbi, of the circle
known as _tana_ (q.v.). It is almost impossible to separate the true
from the false in the numerous traditions respecting his life. He became
the chief teacher in the rabbinical school of Jaffa, where, it is said,
he had 24,000 scholars. Whatever their number, it seems certain that
among them was the celebrated Rabbi Meir, and that through him and
others 'Aqiba exerted a great influence on the development of the
doctrines embodied in the Mishnah. He sided with Bar Cochebas in the
last Jewish revolt against Rome, recognized him as the Messiah, and
acted as his sword-bearer. Being taken prisoner by the Romans under
Julius Severus, he was flayed alive with circumstances of great cruelty,
and met his fate, according to tradition, with marvellous steadfastness
and composure. He is said by some to have been a hundred and twenty
years old at the time of his death. He is one of the ten Jewish martyrs
whose names occur in a penitential prayer still used in the synagogue
service. 'Aqiba was among the first to systematize the Jewish tradition,
and he paved the way for the compilation of the Mishnah. From his school
emanated the Greek translation of the scriptures by Aquila.
AQUAE (Lat. for "waters"), a name given by the Romans to sites where
mineral springs issued from the earth. Over a hundred can be identified,
some declaring by their modern names their ancient use: Aix-les-Bains in
Savoy (_Aquae Sabaudicae_), Aix-en-Provence (_Aquae Sextiae_),
Aix-la-Chapelle or Aachen (_Aquae Grani_), &c. Only two occur in
Britain: _Aquae Sulis_--less correctly _Aquae Solis_--at Bath in
Somerset, which was famous, and Buxton (called _Aquae_ simply), which
seems to have been far less important. Aquae Sulis was occupied by the
Romans almost as soon as they entered the island in A.D. 43, and
flourished till the end of the Roman period. It was frequented by
soldiers quartered in Britain, by the Britons, and by visitors from
north Gaul, and its name was known in Italy, though patients probably
seldom travelled so far. Like most mineral springs known to the
ancients, it was under the protection of a local deity, the Celtic Sul,
whom the Romans equated with their Minerva. Stately remains of its baths
and temple have been found at various times, especially in 1790 and
1878-1895, and may still be seen there.
AQUAE CUTILIAE, a mineral spring in Italy, near the modern Cittaducale,
9 m. E. of Rieti. The lake near it was supposed by classical writers to
be the central point of Italy, and was renowned for its floating
islands, which, as in other cases, were formed from the partial
petrification of plants by the mineral substances contained in the
water. Considerable remains of baths may still be seen there--they were
apparently resorted to by both Vespasian and Titus in their last
illnesses, for both died there.
AQUAMARINE (Lat. _aqua marina_, "water of the sea"), a transparent
variety of beryl (q.v.), having a delicate blue or bluish-green colour,
suggestive of the tint of sea-water. It occurs at most localities which
yield ordinary beryl, some of the finest coming from Russia. The
gem-gravels of Ceylon contain aquamarine. Clear yellow beryl, such as
occurs in Brazil, is sometimes called aquamarine chrysolite. When
corundum presents the bluish tint of typical aquamarine, it is often
termed Oriental aquamarine.
AQUARELLE (from Ital. _acquarella_, water-colour), a form of painting
with thin water-colour or ink.
AQUARII, a name given to the Christians who substituted water for wine
in the Eucharist. They were not a sect, for we find the practice widely
in vogue at an early time, even among the orthodox. In Greek they were
called _Hydroparastatae_, or those who offer water. Theodosius, in his
persecuting edict of 382, classes them as a special sect with the
Manicheans, who also eschewed wine. See EUCHARIST.
AQUARIUM (plural _aquaria_), the name given to a receptacle for a marine
flora and fauna. Until comparatively recently, aquaria were little more
than domestic toys, or show-places of a popular character, but they have
now not only assumed a profound scientific importance for the convenient
study of anatomical and physiological problems in marine botany and
zoology, but have also attained an economic value, as offering the best
opportunities for that study of the habits and environment of marketable
food-fish without which no steps for the improvement of sea-fisheries
can be safely taken. The numerous "zoological stations" which have
sprung up, chiefly in Europe and the United States, but also in the
British colonies and Japan, often endeavour to unite these two aims, and
have in many cases become centres of experimental work in problems
relating to fisheries, as well as in less directly practical subjects.
Of these stations, the oldest and the most important is that at Naples,
which, though designed for purely scientific objects, also encourages
popular study by means of a public aquarium. The following account
(1902) of this station by Dr W. Giesbrecht, a member of the staff, will
serve to show the methods and aims, and the complex and expensive
equipment, of a modern aquarium:--
"The zoological station at Naples is an institution for the advancement
of biological science--that is, of comparative anatomy, zoology, botany,
physiology. It serves this end by providing the biologist with the
various objects of his study and the necessary appliances; it is not a
teaching institution. The station was founded by Dr Anton Dohrn, and
opened in the spring of 1874; it is the oldest and largest of all
biological stations, of which there are now about thirty in existence.
Its two buildings are situated near the seashore in the western town
park (Villa Nazionale) of Naples. The older and larger one, 33 metres
long, 24 m. deep, 16 m. high, contains on the ground floor the aquarium,
which is open to the public. On the first floor there is, facing south,
the principal library, ornamented with fresco paintings, and, facing
north, a large hall containing twelve working tables, several smaller
rooms and the secretarial offices. On the second floor is the
physiological laboratory, and on the third floor the small library, a
hall with several working tables, and the dark rooms used in developing
photographs. The ground floor of the smaller building, which was
finished in 1887, contains the rooms in which the animals are delivered,
sorted and preserved, and the fishing tackle kept, together with the
workshop of the engineer; on the first and second floors are workrooms,
amongst others the botanical laboratory; on the third floor are
store-rooms. In the basement of both buildings, which is continued
underneath the court, there are sea-water cisterns and filters, engines
and store-rooms. The materials for study which the station offers to the
biologist are specimens of marine animals and plants which abound in the
western part of the Mediterranean, and especially in the Gulf of Naples.
To obtain these, two screw-steamers and several rowing boats are
required, which are moored in the harbour of Mergellina, situated close
by. The larger steamer, 'Johannes Muller' (15 m. long, 2-1/2 m. wide, 1
m. draught), which can steam eight to ten English miles per hour, is
provided with a steam dredge working to a depth of eighty fathoms. From
the small steamer, 'Frank Balfour,' and the rowing boats, the fishing is
done by means of tow-nets. Besides these there are fishermen and others
who daily supply living material for study. The plankton (small floating
animals) is distributed in the morning, other animals as required. The
animals brought in by the fishermen are at once distributed amongst the
biologists, whereas the material brought up by the dredges is placed in
flat revolving wooden vessels, so as to give the smaller animals time to
come out of their hiding-places. The students who work in the station
have the first claim on specimens of plants and animals; but specimens
are also supplied to museums, laboratories and schools, and to
individuals engaged in original research elsewhere. Up to the present
time about 4000 such parcels have been despatched, and not infrequently
live specimens of animals are sent to distant places. This side of the
work has been of very great value to science. The principal appliances
for study with which the station provides the biologist are workrooms
furnished with the apparatus and chemicals necessary for anatomical
research and physiological experiments and tanks. Every student receives
a tank for his own special use. The large tanks of the principal
aquarium are also at his disposal for purposes of observation and
experiment if necessary.
"The water in the tanks is kept fresh by continual circulation, and is
thus charged with the oxygen necessary to the life of the organisms. It
is not pumped into the tanks directly from the sea, but from three large
cisterns (containing 300 cubic metres), to which it again returns from
the tanks. The water wasted or evaporated during this process is
replaced by new water pumped into the cisterns directly from the sea.
The water flows from the large cisterns into a smaller cistern, from
which it is distributed by means of an electric pump through vulcanite
or lead pipes to the various tanks. The water with which the tanks on
the upper floors are filled is first pumped into large wooden tanks
placed beneath the roof, thence it flows, under almost constant
pressure, into the tanks. The water circulated in this manner contains
by far the largest number of such animals as are capable of living in
captivity in good condition. Some of them even increase at an
undesirable rate, and it sometimes happens that young Mytilus or Ciona
stop up the pipes; in laying these, therefore, due regard must be had to
the arrangements for cleaning. For the cultivation of very delicate
animals it is necessary to keep the water absolutely free from harmful
bacteria; for this purpose large sand-filters have lately been placed in
the system, through which the water passes after leaving the cisterns.
Each of the smaller cisterns, which are fixed in the workrooms, consist
of two water-tanks, placed one above the other; their frames are of
wrought iron and the walls generally of glass. Vessels containing minute
animals can be placed between these two tanks, receiving their water
through a siphon from the upper tank; the water afterwards flows away
into the lower tank.
"The twenty-six tanks of the public aquarium (the largest of which
contains 112 cubic metres of water) have stone walls, the front portion
alone being made of glass. As the tanks hold a very large number of
animals in proportion to the quantity of water, they require to be well
aerated. The pipes through which the water is conducted are therefore
placed above the surface of the water, and the fresh supply is driven
through them under strong pressure. A large quantity of air in the form
of fine bubbles is thus taken to the bottom of the tank and distributed
through the entire mass of water. Should the organisms which it is
desired to keep alive be very minute, there is a danger of their being
washed away by the circulating water. To obviate this, either the water
which flows away is passed through a strainer, or the water is not
changed at all, air being driven through it by means of an apparatus put
into motion by the drinking-water supply.
"The library contains about 9000 volumes, which students use with the
help of a slip catalogue, arranged according to authors. The station has
published at intervals since 1879 two periodicals treating of the
organisms of the Mediterranean. One is _Fauna und Flora des Golfes van
Neapel_, the other _Mittheilungen aus der zoologischen Station zu
Neapel_. The former consists of monographs in which special groups of
animals and plants are most exhaustively treated and the Mediterranean
species portrayed according to life in natural colours; up to the
present time twenty-one zoological and five botanical monographs have
appeared, making altogether 1200 4to sheets with about 400 plates. Of
the Mittheilungen, which contain smaller articles on organisms of the
Mediterranean, fourteen volumes in 8vo have been published. The station
also publishes a _Zoologischer Jahresbericht_, which at first treated of
the entire field of zoology, but since 1886 has been confined
principally to comparative anatomy and ontogeny; it appears eight to
nine months after the end of the year reported. The _Guide to the
Aquarium_, with its descriptions and numerous pictures, is meant to give
the lay visitor an idea of the marine animal world.
"There are about forty officials, amongst them six zoologists, one
physiologist, one secretary, two draughtsmen, one engineer. The station
is a private institution, open to biologists of all nations under the
following conditions: there are agreements with the governments of
Austria, Baden, Bavaria, Belgium, Hamburg, Holland, Hesse, Italy,
Prussia, Russia, Saxony, Switzerland, Hungary, Wurttemberg, the province
of Naples, and the universities of Cambridge, Oxford, Strassburg,
Columbia College (New York), and the British Association for the
Advancement of Science, the Smithsonian Institution, and a society of
women in the United States of North America (formerly also with
Bulgaria, Rumania, Spain, the Academy of Sciences in Berlin, Williams
College, University of Pennsylvania), by virtue of which the governments
and corporate bodies named have the right, on payment of L100 per annum,
to send a worker to the station; this places at his disposal a 'table'
or workplace, furnished with all the necessary appliances and materials
as set down in the agreement. At present there are agreements for
thirty-three tables, and since the foundation of the station nearly 1200
biologists have worked there. The current expenses are paid out of the
table-rents, the entrance fees to the public aquarium, and an annual
subvention paid by the German empire."
In England a station on similar lines, but on a smaller scale, is
maintained at Plymouth by the Marine Biological Association of the
United Kingdom, with the help of subsidies from the government and the
Fishmongers' Company.
Little difficulty is experienced in maintaining, breeding and rearing
fresh-water animals in captivity, but for many various reasons it is
only by unremitting attention and foresight that most marine animals can
be kept even alive in aquaria, and very few indeed can be maintained in
a condition healthy enough to breed. Much experience, however, has been
gained of late years at considerable expense, both in England and
abroad. In starting a marine aquarium of whatever size, it should be
obvious that the first consideration must be a supply of the purest
possible water, as free as may be, not only from land-drainage and
sewage, but also from such suspended matters as chalk, fine sand or mud.
This is most ideally and economically secured by placing the station a
few feet above high-water mark, in as sheltered a position as possible,
on a rocky coast, pumping from the sea to a large reservoir above the
station, and allowing the water to circulate gently thence through the
tanks by gravity (Banyuls). At an inland aquarium (Berlin, Hamburg),
given pure water in the first instance, excellent if less complete
results may nevertheless, be obtained. The next consideration is the
method by which oxygen is to be supplied to the organisms in the
aquarium. Of the two methods hitherto in use, that of pumping a jet of
air into tanks otherwise stagnant or nearly so (Brighton), while
supplying sufficient oxygen, has so many other disadvantages, that it
has not been employed regularly in any of the more modern aquaria. It
is, however, still useful in aerating quite small bodies of water in
which hardy and minute organisms can be isolated and kept under control.
In the other method, now in general use, a fine jet of water under
pressure falls on to the surface of the tank; this carries down with it
a more than sufficient air-supply, analysis showing in some cases a
higher percentage of oxygen in aquarium water than in the open sea.
The water supply is best effected by gravity from reservoirs placed
above the tanks, but may be also achieved by direct pumping from low
reservoirs or from the sea to the tanks. Provided that an unlimited
supply of pure water can be obtained cheaply, the overflow from the
tanks is best run to waste; but in aquaria less fortunately placed, it
returns to a storage low-level reservoir, from which it is again pumped,
thus circulating round and round (Naples, Plymouth). The storage
reservoirs should be in all cases very large in comparison with the bulk
of water in circulation; if practicable, they should be excavated in
rock, and lined with the best cement. Thera is no reason why they should
not be shallow, exposed to light and air, and cultivated as rock-pools
by the introduction of seaweeds and small animals, but they must then be
screened from rain, cold and dust. The pumps used in circulation will be
less likely to kill minute animals if of the plunger or ram type, rather
than rotary, and should be of gun-metal or one of the new bronze-alloys
which take a patina in salt water. For the circulating pipes many
materials have been tried. Vulcanite is not only expensive and brittle,
but has other disadvantages; common iron pipes, coated internally with
cement or asphalt or glazed internally, with all unions and joints
cemented, have been used with more or less success. Probably best of all
is common lead piping, the joints being served with red-lead; water
should be circulated through such pipes till they become coated with
insoluble carbonate, for some time before animals are put into the
tanks. For small installations glass may be used, the joints being made
with marine glue or other suitable cement.
In building the tanks themselves, regard must be had to their special
purposes. If intended for show-tanks for popular admiration, or for the
study of large animals, they must be large with a plate-glass front; for
ordinary scientific work small tanks with all sides opaque are
preferable from every point of view. According to their character, size
and position, fixed tanks may be of brickwork, masonry or rock, coated
in each case with cement; asphalting the sides offers no particular
advantages, and often gives rise to great trouble and expense. All
materials, and especially the cements, must be of the finest quality
procurable. For smaller and movable tanks, slate slabs bolted or screwed
together have some disadvantages, notably those of expense, weight and
brittleness, but are often used. Better, cheaper and lighter, if less
permanent, are tanks of wood bolted together, pitched internally. Glass
bell-jars, useful in particular cases, should generally have their sides
darkened, except when required for observation. Provision should always
be made for cleaning every part of the tanks, pipes and reservoirs; all
rock-work in tanks should therefore be removable. As regards the
lighting of fixed tanks, it should always be directly from above. In all
tanks with glass sides, whether large or small, as much light as
possible should be kept from entering through the glass; otherwise, with
a side-light, many animals become restless, and wear themselves out
against the glass, affected by even so little light as comes through an
opposite tank.
In cases where distance from the sea or other causes make it
impracticable to allow the overflow from the tanks to run to waste,
special precautions must be taken to keep the water pure. Chemically
speaking, the chief character of the water in an aquarium circulation,
when compared with that of the open sea, lies in the excessive quantity
of nitrogen present in various forms, and the reduced alkalinity; these
two being probably connected. The excess of nitrogen is referable to
dead animals, to waste food and to the excreta of the living organisms.
The first two of these sources of contamination may be reduced by care
and cleanliness, and by the maintenance of a flow of water sufficient to
prevent the excessive accumulation of sediment in the tanks. The
following experiment shows the rapid rise of nitrogen if unchecked. A
tank with a considerable fauna was isolated from the general circulation
and aerated by four air-jets, except during hours 124-166 of the
experiment; column I. shows per 100,000 the nitrogen estimated as
ammonia, column II. the total inorganic nitrogen:--
I. II.
Sea-water at source of original
supply 0.001 0.003
Aquarium water in tank at
commencement of experiment 0.012 0.400
After 22-1/2 hours 0.020 ..
" 75 " 0.025 1.200
" 93 " 0.019 ..
" 121-1/2 " 0.012 ..
" 141 " 0.015 2.200
" 165 " 0.025 ..
" 169 " 0.025 ..
" 189 " 0.012 ..
During this time the alkalinity was reduced to the equivalent of 30 mg.
CaCO3 per litre, ocean water having an alkalinity equivalent to 50-55
mg. per litre. It has been suggested that the organic nitrogen becomes
oxidized into nitrous, then into nitric acid, which lowers the carbonate
values. A great deal of reduction of this nitrogenous contamination can
be effected by filtration, a method first introduced successfully at
Hamburg, where a most thriving aquarium has been maintained by the local
Zoological Society for many years on the circulation principle, new
water being added only to compensate for waste and evaporation. The
filters consist of open double boxes, the inner having a bottom of
perforated slate on which rests rough gravel; on the latter is fine
gravel, then coarse, and finally fine sand. Filtration may be either
upwards or downwards through the inner box to the outer. Such filters,
intercalated between tanks and reservoir, have been shown by analysis to
stop a very large proportion of nitrogenous matter. It is doubtful
whether aquarium water will not always show an excess of nitrogenous
compounds, but they must be kept down in every way possible. In small
tanks, well lighted, seaweeds can be got to flourish in a way that has
not been found practicable in large tanks with a circulation; these,
with Lamellibranchs and small Crustacea as scavengers, will be found
useful in this connexion. Slight or occasional circulation should be
employed here also, to remove the film of dust and other matters, which
otherwise covers the surface of the water and prevents due oxygenation.
In such small tanks for domestic use the fauna must be practically
limited to bottom-living animals, but for purposes of research it is
often desired to keep alive larval and other surface-swimming animals
(plankton). In this case a further difficulty is presented, that of
helping to suspend the animals in the water, and thus to avoid the
exhaustion and death which soon follow their unaided efforts to keep off
the bottom; this duty is effected in nature by specific gravity, tide
and surface current. In order to deal with this difficulty a simple but
efficient apparatus has been devised by Mr E.T. Browne; a "plunger,"
generally a glass plate or filter funnel, moves slowly up and down in a
bell-jar or other small tank, with a period of rest between each stroke;
the motive power is obtained through a simple bucket-and-siphon
arrangement worked by the overflow from other tanks. This apparatus
(first used at the Plymouth Laboratory of the Marine Biological
Association in 1897, and since introduced into similar institutions), by
causing slight eddies in the water, keeps the floating fauna in
suspension, and has proved very successful in rearing larvae and in
similar work. (G. H. Fo.)
AQUARIUS (the "Water-bearer" or "Cup-bearer"), in astronomy, the
eleventh sign of the zodiac (q.v.), situated between Capricornus and
Pisces. Its symbol is [symbol], representing part of a stream of water,
probably in allusion to the fact that when the sun is in this part of
the heavens (January, February) the weather is rainy. It is also a
constellation mentioned by Eudoxus (4th century B.C.) and Aratus (3rd
century B.C.); Ptolemy catalogued forty-five stars, Tycho Brahe
forty-one, Hevelius forty-seven. [Zeta] _Aquarii_ is a well-defined
binary, having both components of the fourth magnitude; it is probably
of long period.
AQUATINT (Lat. _aqua_, water, and _tincta_, dyed), a kind of etching
(q.v.) which imitates washes with a brush. There are many ways of
preparing a plate for aquatint, the following being recommended by P.G.
Hamerton. Have three different solutions of rosin in rectified alcohol,
making them of various degrees of strength, but always thin enough to be
quite fluid, the weakest solution being almost colourless. First pour
the strongest solution on the plate. When it dries it will produce a
granulation; and you may now bite as in ordinary etching for your darker
tones, stopping out what the acid is not to operate upon, or you may use
a brush charged with acid, perchloride of iron being a very good mordant
for the purpose. After cleaning the plate, you proceed with the weaker
solutions in the same way, the weakest giving the finest granulation for
skies, distances, &c. The process requires a good deal of stopping-out,
and some burnishing, scraping, &c., at last. Aquatint may be effectively
used in combination with line etching, and still more harmoniously with
soft ground etching in which the line imitates that of the lead pencil.
AQUAVIVA, CLAUDIO (1542-1615), fifth general of the Jesuits, the
youngest son of the duke d'Altri, was born at Naples. He joined the
Jesuits at Rome in 1567, and his high administrative gifts marked him
out for the highest posts. He was soon nominated provincial of Naples
and then of Rome; and during this office he offered to join the Jesuit
mission to England that set out under Robert Parsons (q.v.) in the
spring of 1580. The following year, being then only thirty-seven years
old, he was elected, by a large majority, general of the society in
succession to Mercurian, to the great surprise of Gregory XIII.; but the
extraordinary political ability he displayed, and the vast increase that
came to the Society during his long generalate, abundantly justified the
votes of the electors. He, together with Lainez, may be regarded as the
real founder of the Society as it is known to history. A born ruler, he
secured all authority in his own hands, and insisted that those who
prided themselves on their obedience should act up to the profession. In
his first letter "On the happy increase of the Society" (25th of July
1581), he treats of the necessary qualifications for superiors, and
points out that government should be directed not by the maxims of human
wisdom but by those of supernatural prudence. He successfully quelled a
revolt among the Spanish Jesuits, which was supported by Philip II., and
he made use in this matter of Parsons. A more difficult task was the
management of Sixtus V., who was hostile to the Society. By consummate
tact and boldness Aquaviva succeeded in playing the king against the
pope, and Sixtus against Philip. For prudential reasons, he silenced
Mariana, whose doctrine on tyrannicide had produced deep indignation in
France; and he also appears to have discountenanced the action of the
French Jesuits in favour of the League, and was thus able to secure
solid advantages when Henry IV. overcame the confederacy. To him is due
the Jesuit system of education in the book _Ratio atque institutio
studiorum_ (Rome, 1586). But the Dominicans denounced it to the
Inquisition, and it was condemned both in Spain and in Rome, on account
of some opinions concerning the Thomist doctrines of the divine physical
premotion in secondary causes and predestination. The incriminated
chapters were withdrawn in the edition of 1591. In the fierce disputes
that arose between the Jesuit theologians and the Dominicans on the
subject of grace, Aquaviva managed, under Clement VIII. and Paul V., to
save his party from a condemnation that at one time seemed probable. He
died at Rome on the 31st of January 1615, leaving the Society numbering
13,000 members in 550 houses and 15 provinces. The subsequent influence
exercised by the Jesuits, in their golden age, was largely due to the
far-seeing policy of Aquaviva, who is undoubtedly the greatest general
that has governed the Society. (E. Tn.)
AQUEDUCT (Lat. _aqua_, water, and _ducere_, to lead; Gr. [Greek:
hydragogeion], [Greek: hydragogion], [Greek: hyponomos]), a term
properly including artificial works of every kind by means of which
water is conveyed from one place to another, but generally used in a
more limited sense. It is, in fact, rarely employed except in cases
where the work is of considerable magnitude and importance, and where
the water flows naturally by gravitation. The most important purpose for
which aqueducts are constructed is that of conveying pure water, from
sources more or less distant, to large masses of population. Aqueducts
are either below ground, on the surface, or raised on walls either solid
or pierced with arches; to the last the term is often confined in
popular language. The choice of method naturally depends on the contour
of the country.
Phoenician.
I. _Ancient Aqueducts._--In Egypt, Babylonia and Assyria--flat countries
traversed by big rivers and subject to floods--water was supplied by
means of open canals with large basins. In Persia devices of all kinds
were adopted according to the nature of the country. In relation to the
achievements of Greece and Rome, the Phoenicians are the most important
among pre-classical engineers. In Cyprus water was supplied to temples
by rock-cut subterranean conduits carried across intervening valleys in
siphons. Such conduits have been found near Citium, Amathus, &c.
(Cesnola, _Cyprus_, pp. 187, 341). In Syria the most striking of
Phoenician waterworks is the well of Ras-el-Ain near Tyre, which
consisted of four strong octagonal towers through which rises to a
height of 18 to 20 ft. the water from four deep artesian wells. The
water thus accumulated was carried off in conduits to reservoirs near
the shore, and thence in vessels or skins to the island. The aqueduct
across to the island is, of course, of Roman work.
Jerusalem.
It is not possible in all cases to find a satisfactory date for the
numerous conduits which have supplied Jerusalem; some probably go back
to the times of the kings of Judah. The principal reservoir consists of
the three Pools of Solomon which supplied the old aqueduct; the highest
is about 20 ft. above the middle one and 40 above the lowest. These
pools collected the water from Ain Saleh and other springs, and sent it
to the city by two conduits. The higher of these--probably the
older--was partly a rock-cut canal, partly carried on masonry; the
siphon-pipe system was adopted across the lower ground near Rachel's
Tomb, where the pipe (15 in. wide) is formed of large pierced stones
embedded in rubble masonry. The lower conduit is still complete; it
winds so much as to be altogether some 20 m. long. Near the
Birket-es-Sultan it passes over the valley of Hinnom on nine low arches
and reaches the city on the hill above the Tyropeon valley. It enters
the Haram enclosure at the Gate of the Chain (Bab es-Silsila), outside
which is a basin 84 ft. by 42 by 24 deep. It is interesting to note in
the case of the underground tunnel which brought water from the Virgin's
Fountain to the pool of Siloam, that the two boring parties had no
certain means of keeping the line; there is evidence that they had to
make shafts to discover their position, and that ultimately the parties
almost passed one another. Though the direct distance is 1100 ft., the
length of the conduit is over 1700 ft. Perrot and Chipiez incline to
attribute the Pools of Solomon to the Asmonaeans, followed by Roman
governors, whereas the earlier tunnels of the Kedron and Tyropeon valley
may be Punic-Jewish (see also _Palest. Explor. Fund Mem._, "Jerusalem,"
pp. 346-365). Besides these conduits excavation has discovered traces of
many other cisterns, tunnels and conduits of various kinds. Many of them
point to periods of great prosperity and engineering enterprise which
gave to the city a water-supply far superior to that which exists at
present.
See the publications of the Palestine Exploration Fund; A.S. Murray's
_Handbook to Syria and Palestine_ (1903), pp. 63-67; Perrot and
Chipiez, _History of Art in Sardinia, Judaea, &c._ (Eng. trans.,
1890), pp. 321 ff.; other authorities quoted under JERUSALEM.