Encyclopaedia Britannica > Volume 3, Anatomy-Astronomy

APE
ipennines. unite ; the road going southwards by Pettorano, passing
—the upper Sangro, over Monte Janipro and the Iserina, and
then dividing itself into two roads, the one southwards to
Capua, the other eastwards by Campobasso towards Lucera
and Foggia. The passes above Castel Franco and Ariano
are the highest points of the road over the mountain ridge
from Benevento to Troja, and from Avellino to Foggia.
The eastern branch of the southern Apennines begins at the
Lake of Pesole, and proceeds in an easterly, and afterwards
in a southern direction to its termination at Cape Leuca.
At Monte Albano it approaches very near the coast of the
Adriatic. The best passages here are on the road from
Taranto to Canosa, and from Ofanto and Bari to Ostani,
Mesagna, and Lecca, which often contract into narrow de¬
files. The western branch extends in a southern direction
from the Lake of Pesole to Capo dell’ Armi. The principal
passes here are in Calabria on the road from Naples to
Sicily, and from Naples to Otranto passing by Taranto.
Connected with this main chain of the Apennines are
three distinct groups of mountains, which usually take the
distinguishing prefix of “ Sub.” These are the sub-Tuscan,
the sub-Roman, and the sub-Vesuvian Apennines.
The Sub- Tuscan Apennines are a distinct group of moun¬
tains, extending over Tuscany. They are separated from
the main range by the valleys of the Arno and Tiber, as
well as by the Chiana, whence they diverge in the form of
an obtuse angle towards the Mediterranean, covering with
their ramifications all the country between the Arno and
Po. On the top of the mountain range separating the Tiber
from the Arno is the Lake of Perugia, which has no visible
outlet. This range afterwards divides itself into several
branches, between the two principal of which lies the district
of the Maremma of Siena. The two principal passes here
are those from Florence to Rome; the eastern going by
Arezzo, thence above the Lake of Perugia to Foligno, &c.;
the other from Siena over the two highest points of the two
principal branches mentioned above, the one beyond Cas-
tiglioncello, the other on this side of Radicofani. From
Siena there are also communications to Leghorn, Piombino,
and Civita Vecchia.
The Sub-Roman Apennines detach themselves from the
main chain near Monte Velino. They commence in the
upper valleys of the Liri, Salto, Turano, and Sacco, where
they contain the mountains of Cantaro, Corglio, Acuto,
Carbonara, Ceraso, and Campatri, and afterwards lose them¬
selves below the Lake of Albano. From the extremity a
branch goes off almost in a straight line from Narni on the
Nera to Sora on the Liri, and forms the valley of Velino.
A second branch incloses the valley of the Anieno, the
upper part of the Teverone, and divides the Liri from the
Sacco. In the vicinity of Palestrina a third branch runs off
between the Sacco and the Garegliano on the east, and the
Pontine Marshes on the west, and terminates in a steep rocky
tongue of land, on which the Fort of Gaeta stands. The
extreme declivity forms the seven hills on which Rome is
built. Over the main branch of this group there are three
passes; the first, between the sources of the Liri and the
Sacco, is the means of communication between Lora and
lagiiacozzo, and hence it sends forth three branches to
Aquila, Rieti, and Rome; the second extends from Zaga-
iol° to Palestrina, on the direct route from Rome to Lora;
t ie third passes above the lake, and is the great road from
Rome to Naples by Terracina. Besides these there are
ot lei passes, as those from Rieti and Leonessa, the first
pint ceding to Viterbo and Rome, the other to Spoleto and
.,liul f. ’ ^ ^ fr°m Celano to Carsoli on the road from
i ivoh to Salmona; a by-way also goes from Carsoli in a
noi th-western direction to Rieti through the valley of
I urano.
APE 293
The Sub- Vesuvian Apennines derive their name from the Apenrade
volcano Vesuvius which, with Somma, are the principal II
mountains of this group, and from which ramifications pro- APex-
ceed in several directions. The only passage is that of
rorchia or Claudma, near Monte Sarchio, north-east of
Naples, and on the road to Benevento. See Vesuvius.
Fhe Apennines consist in part of white compact lime¬
stone containing no petrifactions or other heterogeneous sub¬
stances. This rock does not, however, prevail through the
whole range. From its junction with the Alps to Florence
the chain is composed of calcareous or slaty masses, and of
a serpentine rock called gabbro or granitello. This last
principally composes the summits of the Mountains of Genoa
rising from the Gulf of Spezzia. This part of the northern
Apennines is generally considered to belong to the primitive
formation, but some geologists contend that it belongs to
the transition class with a large quantity of graywacke. The
mountains extending from Florence to the Abruzzi and
hence to Calabria, are composed of limestone analogous to
that of the Jura range. In the last-mentioned province the
central part of the chain is formed of granite, gneiss, and
mica-schist, on which here and there repose some secondary
deposits.
The Sub-Apennines belong to the tertiary formation,
and are composed of marl, shale, gravel, sand, and conglo¬
merate. Gypsum and calcareous and volcanic tufa are also
seen here, but less frequently. Travertin, a limestone of
recent formation, is found abundantly in the vicinity of
Rome, and of it most of the edifices of that city are con¬
structed. The volcanic mountains are all on the south¬
western side of the chain, with only one exception (Monte
Voltore, near Melfi). The principal groups are those of
Santa Fiora and Viterbo; that of Latium; those of Sant’
Agatha and Rocca Monfina towards Sessa; and finally that
of Naples. There is no active volcano except Vesuvius.
Volcanic tufa forms a great part of the soil about Rome, and
the Capitoline, Quirinal, Esquiline, Aventine, &c., are princi¬
pally composed of it. Most of the lakes that surround Rome,
as the Albano, Nemi, &c., occupy ancient craters. The
environs of Modena abound in those small mud volcanoes
called Salzes. They sometimes disengage carburetted hy¬
drogen gas, and often this is inflamed, as may be seen at
Villeia, Pietra Mala, and Barigazza. The Apennines con¬
tain few metals; the principal is iron, found in Tuscany, and
particularly in the island of Elba. The coal mines are very
unimportant, but there are extensive saliferous depots near
Cosenza. The marbles of the Apennines, however, are
justly celebrated for their beauty, as those of Carrara, the
ancient Luni, Seravazza, and Sienna.
APENRADE, a city in the duchy of Schleswig, the capi¬
tal of the bailiwick of the same name. It contains 4200 in¬
habitants, chiefly occupied in agriculture, ship-building, and
the transit trade. The harbour is shallow, and vessels must
discharge below the town. The roadstead at the entrance
is without shelter. Long. 9. 25. E. Lat. 55. 2. N.
APER, the wild boar. See Sus Aper, Mammalia.
APERIENT, a term applied to those medicines which
act as deobstruents, and promote the secretions. See Cath¬
artics.
APERTURE, in Geometry, the space between two right
lines which meet in a point and form an angle.
Aperture, in Optics, a round hole in a turned bit of
wood or plate of tin, placed within the side of a telescope or
microscope, near to the object glass, by means of which
fewer rays are admitted, and a more distinct appearance of
the object is obtained.
APETALOSE, or Apetalous, among Botanists, an ap¬
pellation given to such plants as have no flower-leaves.
APEX, the vertex or summit of any thing.