from the elbow-joint instead of from the wrist. The family is represented by two flying genera, Anomalurus and Idiurus; the latter containing only one very minute species (shown in the cut) characterized by its small ears and elongated tail. Most of the species are West African. In habits these rodents appear to be very similar to the true flying-squirrels. The species without a parachute constitutes the genus Zenkerella, and looks very like an ordinary squirrel (see Rodentia).
In Australia and Papua the name flying-squirrel is applied to such marsupials as are provided with parachutes; animals which naturalists prefer to designate flying-phalangers (see Marsupialia) (R. L.*)
FLYSCH, in geology, a remarkable formation, composed
mainly of sandstones, soft marls and sandy shales found extending
from S.W. Switzerland eastward along the northern Alpine zone
to the Vienna basin, whence it may be followed round the
northern flanks of the Carpathians into the Balkan peninsula.
It is represented in the Pyrenees, the Apennines, the Caucasus
and extends into Asia; similar flysch-like deposits are related
to the Himalayas as the European formations are to the Alps.
The Flysch is not of the same age in every place; thus in the
western parts of Switzerland the oldest portions probably belong
to the Eocene period, but the principal development is of
Oligocene age; as it is traced eastward we find in the east Alps
that it descends into the upper Cretaceous, and in the Vienna
region and the Carpathians it contains intercalations which clearly
indicate a lower Cretaceous horizon for the lower parts. It
appears indeed that this type of formation was in progress of
deposition at one point or another in the regions enumerated
above from Jurassic to late Tertiary times. The absence of
fossils from enormous thicknesses of Flysch makes the correlation
with other formations difficult; often the only indications
of organisms are the abundant markings supposed to represent
Algae (Chondrites, &c.), which have given rise to the term
“Hieroglyphic-sandstone.” The most noteworthy exceptions
are perhaps the Oligocene fish-bed of Glarus, the Eocene nummulitic
beds in Calabria, and the Aptychus beds of Waidhofen.
Local phases of the Flysch have received special names; it is
the “Vienna” or “Carpathian” sandstone of those regions;
the “macigno” (a soft sandstone with calcareous cement) of
the Maritime Alps and Apennines; the “scagliose” (scaly clays)
and “alberese” (limestones) of the same places are portions of
this formation. The gris de Menton, the gris d’Annot of the
Basses Alps, and the gris d’Embrun of Chaillot appear in Switzerland
as the gris de Taveyannaz. At several places the upper
layers of the Flysch are iron-stained, as in the region of Léman
and at the foot of the Dent du Midi; it is then styled the “Red-Flysch.”
Lenticular intercalations of gabbro, diabase, &c., occur
in the Flysch in Calabria on the Pyrenees. Large exotic blocks of
granite, gneiss and other crystalline rocks in coarse conglomerates
are found near Vienna, near Sonthofen in Bavaria, near Lake Thun
(Wild Flysch) and at other points, which have been variously
regarded as indications of glaciation or of coastal conditions.
FOČA (pronounced Fáwtcha), a town of Bosnia, situated at
the confluence of the Drina and Čehotina rivers, and encircled
by wooded mountains. Pop. (1895) 4217. The town is the headquarters
of a thriving industry in silver filigree-work and inlaid
weapons, for which it was famous. With its territories enclosed
by the frontiers of Montenegro and Novi Bazar, Foča, then
known as Chocha, was the scene of almost incessant border
warfare during the middle ages. No monuments of this period
are left except the Bogomil cemeteries, and the beautiful mosques,
which are the most ancient in Bosnia. The three adjoining
towns of Foča, Goražda and Ustikolina were trading-stations
of the Ragusans in the 14th century, if not earlier. In the 16th
century, Benedetto Ramberti, ambassador from Venice to the
Porte, described the town, in his Libri Tre delle Cose dei Turchi,
as Cozza, “a large settlement, with good houses in Turkish style,
and many shops and merchants. Here dwells the governor of
Herzegovina, whose authority extends over the whole of Servia.
Through this place all goods must pass, both going and returning,
between Ragusa and Constantinople.”
FOCHABERS, a burgh of barony and village of Elginshire,
Scotland. Pop. (1901) 981. It is delightfully situated on the
Spey, about 9 m. E. by S. of Elgin, the terminus of a branch of
the Highland railway connecting at Orbliston Junction with the
main line from Elgin to Keith. The town was rebuilt in its
present situation at the end of the 18th century, when its earlier
site was required for alterations in the grounds of Gordon Castle,
in which the old town cross still stands. The streets all lead at
right angles to the central square, where fairs and markets are
held. The public buildings include a library and reading-room,
the court-house and the Milne school, named after Alexander
Milne, who endowed it with a legacy of £20,000. Adjoining the
town, surrounded by a park containing many magnificent old
trees, stands Gordon Castle, the chief seat of the duke of
Richmond and Gordon, erected in the 18th century. The antiquary
George Chalmers (1742–1825) and the composer William
Marshall (1748–1833) were natives of the burgh.
FOCSHANI (Rumanian Focșani, sometimes incorrectly written
Fokshani or Fokshan), the capital of the department of Putna,
Rumania; on the river Milcov, which formed the ancient frontier
of the former principalities of Moldavia and Walachia. Pop.
(1900) 23,783; of whom 6000 were Jews. The chief buildings
are the prefecture, schools, synagogues, and many churches,
including those of the Armenians and Protestants. Focshani
is a commercial centre of some importance, the chief industries
being oil and soap manufacture and tannery. A large wine trade
is also carried on, and corn is shipped in lighters to Galatz. The
annual fair is held on the 29th of April. Government explorations
in the vicinity of this town show it to be rich in minerals,
such as iron, copper, coal and petroleum. The line Focshani-Galatz
is covered by a very strong line of fortifications, known
as the Sereth Line. A congress between Russian and Turkish
diplomatists was held near the town in 1772. In the neighbourhood
the Turks suffered a severe defeat from the Austrians and
Russians in 1789.
FOCUS (Latin for “hearth” or “fireplace”), a point at which
converging rays meet, toward which they are directed, or from
which diverging rays are directed; in the latter case called
the virtual focus (see Microscope; Telescope; Lens). In
geometry the word is used to denote certain points (see
Geometry; Conic Section; and Perspective).
FOG, the name given to any distribution of solid or liquid
particles in the surface layers of the atmosphere which renders
surrounding objects notably indistinct or altogether invisible
according to their distance. In its more intense forms it hinders
and delays travellers of all kinds, by sea or land, by railway, road
or river, or by the mountain path. It is sometimes so thick as
to paralyse traffic altogether. According to the New English
Dictionary the word “appears to be” a back formation from
the adjective “foggy,” a derivative of “fog” used with its old
meaning of aftermath or coarse grass, or, in the north of Britain,
of “moss.” Such a formation would be reasonable, because
wreaths of fog in the atmospheric sense are specially characteristic
of meadows and marshes where fog, in the more ancient
sense, grows.
Two other words, mist and haze, are also in common use with reference to the deterioration of transparency of the surface layers of the atmosphere caused by solid or liquid particles, and in ordinary literature the three words are used almost according to the fancy of the writer. It seems possible to draw a distinction between mist and haze that would be fairly well supported by usage. Mist may be defined as a cloud of water particles at the surface of land or sea, and would only occur when the air is nearly or actually saturated, that is, when there is little or no difference between the readings of the dry and wet bulbs; the word haze, on the other hand, may be reserved for the obscuration of the surface layers of the atmosphere when the air is dry.
It would not be difficult to quote instances in which even this distinction is disregarded in practice. Indeed, the telegraphic code of the British Meteorological Office uses the same figure for mist and haze, and formerly the Beaufort weather notation had no separate letter for haze (now indicated by z), though it
