Encyclopaedia Britannica, 11th Edition, "Fleury, Claude" to "Foraker"

Chapter XIV: Part 14

Text size

The flying gurnards are much less numerous than the _Exocoeti_ with regard to individuals as well as species, there being only three or four species known of the former, whilst more than fifty have been described of the latter, which, besides, are found in numerous shoals of thousands. The _Dactylopteri_ may be readily distinguished by a large bony head armed with spines, hard keeled scales, two dorsal fins, &c. The _Exocoeti_ have thin, deciduous scales, only one dorsal fin, and the ventrals placed far backwards, below the middle of the body; some have long barbels at the chin. In both kinds the pectoral fins are greatly prolonged and enlarged, modified into an organ of flight, and in many species of _Exocoetus_ the ventral fins are similarly enlarged, and evidently assist in the aerial evolutions of these fishes. Flying-fishes are found in the tropical and sub-tropical seas only, and it is a singular fact that the geographical distribution of the two kinds is nearly identical. Flying-fish are more frequently observed in rough weather and in a disturbed sea than during calms; they dart out of the water when pursued by their enemies or frightened by an approaching vessel, but frequently also without any apparent cause, as is also observed in many other fishes; and they rise without regard to the direction of the wind or waves. The fins are kept quietly distended, without any motion, except an occasional vibration caused by the air whenever the surface of the wing is parallel with the current of the wind. Their flight is rapid, greatly exceeding that of a ship going 10 m. an hour, but gradually decreasing in velocity and not extending beyond a distance of 500 ft. Generally it is longer when the fishes fly against, than with or at an angle to, the wind. Any vertical or horizontal deviation from a straight line is not caused at the will of the fish, but by currents of the air; thus they retain a horizontally straight course when flying with or against the wind, but are carried towards the right or left whenever the direction of the wind is at an angle with that of their flight. However, it sometimes happens that the fish during its flight immerses its caudal fin in the water, and by a stroke of its tail turns towards the right or left. In a calm the line of their flight is always also vertically straight or rather parabolic, like the course of a projectile, but it may become undulated in a rough sea, when they are flying against the course of the waves; they then frequently overtop each wave, being carried over it by the pressure of the disturbed air. Flying-fish often fall on board of vessels, but this never happens during a calm or from the lee side, but during a breeze only and from the weather side. In day time they avoid a ship, flying away from it, but during the night when they are unable to see, they frequently fly against the weather board, where they are caught by the current of the air, and carried upwards to a height of 20 ft. above the surface of the water, whilst under ordinary circumstances they keep close to it. All these observations point clearly to the fact that any deflection from a straight course is due to external circumstances, and not to voluntary action on the part of the fish.

A little Malacopterygian fish about 4 in. long has recently been discovered in West Africa which has the habits of a fresh-water flying-fish. It has been named _Pantodon buchholzi_. It has very large pectoral fins with a remarkable muscular process attached to the inner ray. It lives in fresh-water lakes and rivers in the Congo region, and has been caught in its flight above the water in a butterfly-net.

FLYING-FOX, or, more correctly, FOX-BAT. The first name is applied by Europeans in India to the fruit-eating bats of the genus _Pteropus_, which contains more than half the family (_Pteropidae_). This genus is confined to the tropical regions of the Eastern hemisphere and Australia. It comprises numerous species, a considerable proportion of which occur in the islands of the Malay Archipelago. The flying-foxes are the largest of the bats, the kalong of Java (_Pteropus edulis_) measuring about a foot in length, and having an expanse of wing-membrane measuring 5 ft. across. Flying-foxes are gregarious, nocturnal bats, suspending themselves during the day head-downwards by thousands from the branches of trees, where with their wings gathered about them, they bear some resemblance to huge shrivelled-up leaves or to clusters of some peculiar fruit. In Batchian, according to Wallace, they suspend themselves chiefly from the branches of dead trees, where they are easily caught or knocked down by sticks, the natives carrying them home in basketfuls. They are then cooked with abundance of spices, and "are really very good eating, something like hare." Towards evening these bats bestir themselves, and fly off in companies to the village plantations, where they feed on all kinds of fruit, and so numerous and voracious are they that no garden crop has much chance of being gathered which is not specially protected from their attacks. The flying-fox of India (_Pteropus medius_) is a smaller species, but is found in great numbers wherever fruit is to be had in the Indian peninsula.

FLYING-SQUIRREL, properly the name of such members of the squirrel-group of rodent mammals as have a parachute-like expansion of the skin of the flanks, with attachments to the limbs, by means of which they are able to take long flying-leaps from tree to tree. The parachute is supported by a cartilage attached to the wrist or carpus; in addition to the lateral membrane, there is a narrow one from the cheek along the front of each shoulder to the wrist, and in the larger species a third (interfemoral) connecting the hind-limbs with the base of the long tail. Of the two widely distributed genera, _Pteromys_ includes the larger and _Sciuropterus_ the smaller species. The two differ in certain details of dentition, and in the greater development in the former of the parachute, especially the interfemoral portion, which in the latter is almost absent. In _Pteromys_ the tail is cylindrical and comparatively thin, while in _Sciuropterus_ it is broad, flat and laterally expanded, so as to compensate for the absence of the interfemoral membrane by acting as a supplementary parachute.

In general appearance flying-squirrels resemble ordinary squirrels, although they are even more beautifully coloured. Their habits, food, &c., are also very similar to those of the true squirrels, except that they are more nocturnal, and are therefore less often seen. The Indian flying-squirrel (_P. oral_) leaps with its parachute extended from the higher branches of a tree, and descends first directly and then more and more obliquely, until the flight, gradually becoming slower, assumes a horizontal direction, and finally terminates in an ascent to the branch or trunk of the tree to which it was directed. The presence of these rodents at night is made known by their screaming cries. _Sciuropterus_ is represented by _S. velucella_ in eastern Europe and northern Asia, and by a second species in North America, but the other species of this genus and all those of _Pteromys_ are Indo-Malayan. A third genus, _Eupetaurus_, typified by a very large, long-haired, dark-grey species from the mountains to the north-west of Kashmir (_Eu. cinereus_), differs from all other members of the squirrel-family by its tall-crowned molar teeth. It has a total length of 37 in., of which 22 are taken up by the tail.

In Africa the name of flying-squirrel is applied to the members of a very different family of rodents, the _Anomaluridae_, which are provided with a parachute. Since, however, this parachute is absent in some members of the family, the most distinctive character is the presence of a double row of spiny scales on the under surface of the tail, which apparently aid in climbing. The flying species are also distinguished from ordinary flying-squirrels by the circumstance that the additional bone serving for the support of the fore part of the flying-membrane rises 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 Leman 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.

FOCA (pronounced _Fawtcha_), a town of Bosnia, situated at the confluence of the Drina and Cehotina 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, Foca, 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 Foca, Gorazda 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 L20,000. 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 _Focsani_, 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 distinguished between f, fog, and m, mist. It is possible, however, that these practices may arise, not from confusion of idea, but from economy of symbols, when the meaning can be made out from a knowledge of the associated observations.

As regards the distinction between mist and fog, careful consideration of a number of examples leads to the conclusion that the word "fog" is used to indicate not so much the origin or meteorological nature of the obscurity as its effect upon traffic and travellers whether on land or sea. It is, generally speaking, "in a fog" that a traveller loses himself, and indeed the phrase has become proverbial in that sense. A "fog-bell" or "fog-horn" is sounded when the atmosphere is so thick that the aid of sound is required for navigation. A vessel is "fog-logged" or "fog-bound" when it is stopped or detained on account of thick atmosphere. A "fog-signal" is employed on railways when the ordinary signals are obliterated within working distances. A "fog-bow" is the accompaniment of conditions when a mountain traveller is apt to lose his way.

These words are used quite irrespective of the nature of the cloud which interferes with effective vision and necessitates the special provision; the word "mist" is seldom used in similar connexion. We may thus define a fog as a surface cloud sufficiently thick to cause hindrance to traffic. It will be a _thick mist_ if the cloud consists of water particles, a _thick haze_ if it consists of smoke or dust particles which would be persistent even in a dry atmosphere.

It is probable that sailors would be inclined to restrict the use of the word to the surface clouds met with in comparatively calm weather, and that the obscurity of the atmosphere when it is blowing hard and perhaps raining hard as well should be indicated by the terms "thick weather" or "very thick weather" and not by "fog"; but the term "fog" would be quite correctly used on such occasions from the point of view of cautious navigation. If cloud, drizzling rain, or heavy rain cause such obscurity that passing ships are not visible within working distances the sounding of a fog-horn becomes a duty.

The number of occasions upon which fog and mist may be noted as occurring with winds of different strengths may be exemplified by the following results of thirty years for St Mary's, Scilly Isles, where the observations have always been made by men of nautical experience.

+----------------------------+-----+---+---+---+---+---+----+----+-------+
| Wind Force. |0 & 1| 2 | 3 | 4 | 5 | 6 | 7 |8-12| All |
| | | | | | | | | | Winds.|
+----------------------------+-----+---+---+---+---+---+----+----+-------+
|Number of occasions of fog | | | | | | | | | |
| per 1000 observations | 8 | 7 | 9 |14 | 6 | 3 | <1 | <1 | 47 |
|Number of occasions of mist | | | | | | | | | |
| per 1000 observations | 5 | 6 |11 |22 |20 |12 | 6 | 2 | 84 |
+----------------------------+-----+---+---+---+---+---+----+----+-------+

The use of the word "fog" in the connexion "high fog," to describe the almost total darkness in the daytime occasionally noted in London and other large cities due to the persistent opaque cloud in the upper air without serious obscuration of the surface layers, is convenient but incorrect.

Regarding "fog" as a word used to indicate the state of the atmosphere as regards transparency considered with reference to its effect upon traffic, a scale of fog intensity has been introduced for use on land or at sea, whereby the intensity of obscurity is indicated by the numbers 1 to 5 in the table following. At sea or in the country a fog, as a rule, is white and consists of a cloud of minute water globules, of no great vertical thickness, which disperses the sunlight by repeated reflection but is fully translucent. In dust-storms and sand-storms dark or coloured fog clouds are produced such as those which are met with in the Harmattan winds off the west coast of Africa. In large towns the fog cloud is darkened and intensified by smoke, and in some cases may be regarded as due entirely to the smoke.

_Description of Effects._

The physical processes which produce fogs of water particles are complicated and difficult to unravel. We have to account for the formation and maintenance of a cloud at the earth's surface; and the process of cloud-formation which is probably most usual in nature, namely, the cooling of air by rarefaction due to the reduction of pressure on ascent, cannot be invoked, except in the case of the fogs forming the cloud-caps of hills, which are perhaps not fairly included. We have to fall back upon the only other process hitherto recognized as causing cloudy condensation in the atmosphere, that is to say, the mixing of masses of mist air of different temperatures. The mixing is brought about by the slow motion of air masses, and this slow motion is probably essential to the phenomenon.

TABLE I.--_Air travelling from Northern Africa to Northern Russia,
round by the Azores._

+------------------------------------+---------+---------+---------+---------+-----------+
| Successive Temperatures of sea | 68 deg. | 68 deg. | 67 deg. | 59 deg. | 54 deg. F.|
| " " " air | 68 deg. | 70 deg. | 67 deg. | 60 deg. | 56 deg. F.|
| " States of the atmosphere | clear | clear | clear | shower | mist |
+------------------------------------+---------+---------+---------+---------+-----------+

TABLE II.--_Air travelling from N.W. Africa to Scotland._

+-------------------------------+---------+---------+-----------------+
|Successive Temperatures of sea | 67 deg. | 63 deg. | 54 deg. F. |
| " " " air | 66 deg. | 64 deg. | 53 deg. F. |
| " State of atmosphere | fair | shower | mist with shower|
+-------------------------------+---------+---------+-----------------+

Over the sea fog is most frequently due to the cooling of a surface layer of warm air by the underlying cold water. The amount of motion of the air must be sufficient to prevent the condensation taking place at the sea surface without showing itself as a cloud. In a research on the Life History of Surface Air Currents the changes incidental to the movement of the air over the north Atlantic Ocean were traced with great care, and the above examples (Tables I, II) taken from page 72 of the work referred to are typical of the formation of sea fog by the cooling of a relatively warm current passing over cold water.

In conformity with this suggestion we find that fog is most liable to occur over the open ocean in those regions where, as off the Newfoundland banks, cold-water currents underlie warm air, and that it is most frequent at the season of the year when the air temperature is increasing faster than the water temperature. But it is difficult to bring this hypothesis always to bear upon actual practice, because the fog is representative of a temperature difference which has ceased to exist. One cannot therefore observe under ordinary circumstances both the temperature difference and the fog. Doubtless one requires not only the initial temperature difference but also the slow drift of air which favours cooling of the lower layers without too much mixing and consequently a layer of fog close to the surface. Such a fog, the characteristic sea fog, may be called a cold surface fog. From the conditions of its formation it is likely to be less dense at the mast-head than it is on deck.

One would expect that a cold-air current passing over a warm sea surface would give rise to an ascending current of warmed air and hence cause cumulus cloud and possibly thunder showers rather than surface fog, but one cannot resist the conclusion that sea fog is sometimes formed by slow transference of cold air over relatively warm water, giving rise to what may be called a "steaming-pot" fog. In such a case the actual surface layer in contact with the warm water would be clear, and the fog would be thicker aloft where the mixing of cold air and water vapour is more complete. Such fogs are, however, probably rare in comparison with the cold-water fogs. If the existence of a cold current over warm water were a sufficient cause of fog, as a current of warm air over cold water appears to be, the geographical distribution of notable fog would be much more widespread than it actually is, and the seasonal distribution of fog would also be other than it is.

The formation of fog over land seems to be an even more complicated process than over the sea. Certainly in some cases mistiness amounting to fog arises from the replacement of cold surface air which has chilled the earth and the objects thereon by a warm current. But this process can hardly give rise to detached masses or banks of fog. The ordinary land or valley fog of the autumn evening or winter morning is due to the combination of three causes, first the cooling of the surface layer of air at or after sunset by the radiation of the earth, or more particularly of blades of grass, secondly the slow downward flow (in the absence of wind) of the air thus cooled towards lower levels following roughly the course of the natural water drainage of the land, and thirdly the supply of moisture by evaporation from warm moist soil or from the relatively warm water surface of river or lake. In this way steaming-pot fog gradually forms and is carried downward by the natural though slow descent of the cooled air. It thus forms in wreaths and banks in the lowest parts, until perhaps the whole valley becomes filled with a cloud of mist or fog. A case of this kind in the Lake District is minutely described by J.B. Cohen (_Q.J. Roy. Met. Soc._ vol. 30, p. 211, 1904).

It will be noticed that upon this hypothesis the circumstances favourable for fog formation are (1) a site near the bottom level of the drainage area, (2) cold surface air and no wind, (3) an evening or night of vigorous radiation, (4) warm soil, and (5) abundant moisture in the surface-soil. These conditions define with reasonable accuracy the circumstances in which fog is actually observed.

The persistence of these fog wreaths is always remarkable when one considers that the particles of a fog cloud, however small they may be, must be continually sinking through the air which holds them, and that unless some upward motion of the air keeps at least a balance against this downward fall, the particles of the cloud must reach the earth or water and to that extent the cloud must disappear. In sheltered valleys it is easy to suppose that the constant downward drainage of fresh and colder fog-laden material at the surface supplies to the layers displaced from the bottom the necessary upward motion, and the result of the gradual falling of drops is only that the surface cloud gets thicker; but there are occasions when the extent and persistence of land fog seems too great to be accounted for by persistent radiation cooling. For example, in the week before Christmas of 1904 the whole of England south of the Humber was covered with fog for several days. It is of course possible that so much fog-laden air was poured down from the sides of mountains and hills that did project above the surface of the fog, as to keep the lower reaches supplied for the whole time, but without more particulars such a statement seems almost incredible. Moreover, the drifting of fog banks over the sea seems capricious and unrelated to any known circumstances of fog-formation, so that one is tempted to invoke the aid of electrification of the particles or some other abnormal condition to account for the persistence of fog. The observations at Kew observatory show that the electrical potential is abnormally high during fog, but whether that is the cause or the result of the presence of the water particles, we are not yet in a position to say. It must be remembered that a fog cloud ought to be regarded as being, generally speaking, _in process of formation_ by mixing. Observations upon clouds formed experimentally in globes tend to show that if a mass of fog-bearing air could be enclosed and kept still for only a short while the fog would settle and leave the air clear. The apparently capricious behaviour of fog banks may be due to the fact that mixing is still going on in the persistent ones, but is completed in the disappearing ones.

One remarkable characteristic of a persistent fog is the coldness of the foggy air at the surface in spite of the heat of the sun's rays falling upon the upper surface of the fog. A remarkable example may be quoted from the case of London, which was under fog all day on 28th January 1909. The maximum temperature only reached 31 deg. F., whereas at Warlingham in Surrey from which the fog lifted it was as high as 46 deg. F.

_A priori_ we might suppose that the formation of fog would arrest cooling by radiation, and that fog would thus act as a protection of plants against frost. The condensation of water evaporated from wet ground, which affords the material for making fog, does apparently act as a protection, and heavy watering is sometimes used to protect plants from frost, but the same cannot be said of fog itself--cooling appears to go on in spite of the formation of fog.

A third process of fog-formation, namely, the descent of a cloud from above in the form of light drizzling rain, hardly calls for remark. In so far as it is subject to rules, they are the rules of clouds and rain and are therefore independent of surface conditions.

These various causes of fog-formation maybe considered with advantage in relation to the geographical distribution of fog. Statistics on this subject are not very satisfactory on account of the uncertainty of the distinction between fog and mist, but a good deal may be learned from the distribution of fog over the north Atlantic Ocean and its various coasts as shown in the Monthly Meteorological Charts of the north Atlantic issued by the Meteorological Office, and the Pilot charts of the North Atlantic of the United States Hydrographic Office. Coast fog, which is probably of the same nature as land fog, is most frequent in the winter months, whereas sea fog and ocean fog is most extensive and frequent in the spring and summer. By June the fog area has extended from the Great Banks over the ocean to the British Isles, in July it is most intense, and by August it has notably diminished, while in November, which is proverbially a foggy month on land, there is hardly any fog shown over the ocean.

The various meteorological aspects of fog and its incidence in London were the subject of reports to the Meteorological Council by Captain A. Carpenter and Mr R.G.K. Lempfert, based upon special observations made in the winters of 1901-1902 and 1902-1903 in order to examine the possibility of more precise forecasts of fog.

The study of the properties and behaviour of fog is especially important for large towns in consequence of the economic and hygienic results which follow the incidence of dense fogs. The fogs of London in particular have long been a subject of inquiry. It is difficult to get trustworthy statistics on the subject in consequence of the vagueness of the practice as regards the classification of fog. For large towns there is great advantage in using a fog scale such as that given above, in which one deals only with the practical range of vision irrespective of the meteorological cause.

Accepting the classification which distinguishes between fog and haze or mist, but not between the two latter terms, as equivalent to specifying fog when the thickness amounts to the figure 2 or more on the fog scale, we are enabled to compare the frequency of fog in London by the comparison of the results at the London observing stations. The comparison was made by Mr Brodie in a paper read before the Royal Meteorological Society (_Quarterly Journal_, vol. 31, p. 15), and it appears therefrom that in recent years there has been a notable diminution of fog frequency, as indicated in the following table of the total number of days of fog in the years from 1871:--

+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
| 1871.| 1872.| 1873.| 1874.| 1875.| 1876.| 1877.| 1878.| 1879.| 1880.| 1881.| 1882.| 1883.| 1884.| 1885.| 1886.| 1887.| 1888.| 1889.|
+-------------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
| 42 | 35 | 75 | 53 | 49 | 40 | 46 | 63 | 69 | 74 | 59 | 69 | 61 | 53 | 69 | 86 | 83 | 62 | 75 |
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
| 1890.| 1891.| 1892.| 1893.| 1894.| 1895.| 1896.| 1897.| 1898.| 1899.| 1900.| 1901.| 1902.| 1903.| 1904.| 1905.| 1906.| 1907.| 1908.|
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
| 65 | 69 | 68 | 31 | 51 | 48 | 43 | 48 | 47 | 56 | 13 | 45 | 42 | 26 | 44 | 19 | 16 | 37 | 19 |
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+

But from any statistics of the frequency occurrence of fog it must not be understood that the atmosphere of London is approaching that of the surrounding districts as regards transparency. Judged by the autographic records it is still almost opaque to sunshine strong enough to burn the card of the recorder during the winter months.

The bibliography of fog is very extensive. The titles referring to
fog, mist and haze in the _Bibliography of Meteorology_ (part ii.) of
the U.S. Signal Office, published in 1889, number 306. Among more
recent authors on the subject, besides those referred to in the text,
may be mentioned:--Koppen, "Bodennebel," _Met. Zeit._ (1885); Trabert,
_Met. Zeit._ (1901), p. 522; Elias in _Ergebnisse des aeronautischen
Observatoriums bei Berlin_, ii. (Berlin, 1904); Scott, _Q.J.R. Met.
Soc._ xix. p. 229; A.G. McAdie, "Fog Studies," _Amer. Inv._ ix.
(Washington, D.C., 1902), p. 209; Buchan, "Fogs on the Coasts of
Scotland," _Journ. Scot. Met. Soc._ xii. p. 3. (W. N. S.)

FOGAZZARO, ANTONIO (1842- ), Italian novelist and poet, was born at Vicenza in 1842. He was a pupil of the Abate Zanella, one of the best of the modern Italian poets, whose tender, thoughtful and deeply religious spirit continued to animate his literary productions. He began his literary career with _Miranda_, a poetical romance (1874), followed in 1876 by _Valsolda_, which, republished in 1886 with considerable additions, constitutes perhaps his principal claim as a poet, which is not inconsiderable. To the classic grandeur of Carducci and D'Annunzio's impetuous torrent of melody Fogazzaro opposes a Wordsworthian simplicity and pathos, contributing to modern Italian literature wholesome elements of which it would otherwise be nearly destitute. His novels, _Malombra_ (1882), _Daniele Cortis_ (1887), _Misterio del Poeta_ (1888), obtained considerable literary success upon their first publication, but did not gain universal popularity until they were discovered and taken up by French critics in 1896. The demand then became prodigious, and a new work, _Piccolo Mondo antico_ (1896), which critics far from friendly to Fogazzaro's religious and philosophical ideas pronounced the best Italian novel since _I Promessi Sposi_, went through numerous editions. Even greater sensation was caused by his novel _Il Santo_ (_The Saint_, 1906), on account of its being treated as unorthodox by the Vatican; and Fogazzaro's sympathy with the Liberal Catholic movement--his own Catholicism being well known--made this novel a centre of discussion in the Roman Catholic world.

See the biography by Molmenti (1900).

FOGELBERG, BENEDICT (or BENGT) ERLAND (1786-1854), Swedish sculptor, was born at Gothenburg on the 8th of August 1786. His father, a copper-founder, encouraging an early-exhibited taste for design, sent him in 1801 to Stockholm, where he studied at the school of art. There he came much under the influence of the sculptor Sergell, who communicated to him his own enthusiasm for antique art and natural grace. Fogelberg worked hard at Stockholm for many years, although his instinct for severe beauty rebelled against the somewhat rococo quality of the art then prevalent in the city. In 1818 the grant of a government pension enabled him to travel. He studied from one to two years in Paris, first under Pierre Guerin, and afterwards under the sculptor Bosio, for the technical practice of sculpture. In 1820 Fogelberg realized a dream of his life in visiting Rome, where the greater part of his remaining years were spent in the assiduous practice of his art, and the careful study and analysis of the works of the past. Visiting his native country by royal command in 1854, he was received with great enthusiasm, but nothing could compensate him for the absence of those remains of antiquity and surroundings of free natural beauty to which he had been so long accustomed. Returning to Italy, he died suddenly of apoplexy at Trieste on the 22nd of December 1854. The subjects of Fogelberg's earlier works are mostly taken from classic mythology. Of these, "Cupid and Psyche," "Venus entering the Bath," "A Bather" (1838), "Apollo Citharede," "Venus and Cupid" (1839) and "Psyche" (1854) may be mentioned. In his representations of Scandinavian mythology Fogelberg showed, perhaps for the first time, that he had powers above those of intelligent assimilation and imitation. His "Odin" (1831), "Thor" (1842), and "Balder" (1842), though influenced by Greek art, display considerable power of independent imagination. His portraits and historical figures, as those of Gustavus Adolphus (1849), of Charles XII. (1851), of Charles XIII. (1852), and of Birger Jarl, the founder of Stockholm (1853), are faithful and dignified works.

See Casimir Leconte, _L'Oeuvre de Fogelberg_ (Paris, 1856).

FOGGIA, a town and episcopal see (since 1855) of Apulia, Italy, the capital of the province of Foggia, situated 243 ft. above sea-level, in the centre of the great Apulian plain, 201 m. by rail S.E. of Ancona and 123 m. N.E. by E. of Naples. Pop. (1901) town, 49,031; commune, 53,134. The name is probably derived from the pits or cellars (_foveae_) in which the inhabitants store their grain. The town is the medieval successor of the ancient Arpi, 3 m. to the N.; the Normans, after conquering the district from the Eastern empire, gave it its first importance. The date of the erection of the cathedral is probably about 1179; it retains some traces of Norman architecture, and the facade has a fine figured cornice by Bartolommeo da Foggia; the crypt has capitals of the 11th (?) century. The whole church was, however, much altered after the earthquake of 1731. A gateway of the palace of the emperor Frederick II. (1223, by Bartolommeo da Foggia) is also preserved. Here died his third wife, Isabella, daughter of King John of England. Charles of Anjou died here in 1284. After his son's death, it was a prey to internal dissensions and finally came under Alphonso I. of Aragon, who converted the pastures of the Apulian plain into a royal domain in 1445, and made Foggia the place at which the tax on the sheep was to be paid and the wool to be sold. The other buildings of the town are modern. Foggia is a commercial centre of some importance for the produce of the surrounding country, and is also a considerable railway centre, being situated on the main line from Bologna to Brindisi, at the point where this is joined by the line from Benevento and Caserta. There are also branches to Rocchetta S. Antonio (and thence to either Avellino, Potenza, or Gioia del Colle), to Manfredonia, and to Lucera.

FOHN (Ger., probably derived through Romansch _favongn_, _favoign_, from Lat. _favonius_), a warm dry wind blowing down the valleys of the Alps from high central regions, most frequently in winter. The Fohn wind often blows with great violence. It is caused by the indraft of air from the elevated region to areas of low barometric pressure in the neighbourhood, and the warmth and dryness are due to dynamical compression of the air as it descends to lower levels. Similar local winds occur in many parts of the world, as Greenland, and on the slopes of the Rocky Mountains. In the southern Alpine valleys the Fohn wind is often called sirocco, but its nature and cause are different from the true sirocco. The belief that the warm dry wind comes from the Sahara dies hard; and still finds expression in some textbooks.

For a full account of these winds see Hann, _Lehrbuch der
Meteorologie_, p. 594.

FOHR, a German island in the North Sea, belonging to the province of Schleswig-Holstein, and situated off its coast. Pop. 4500. It comprises an area of 32 sq. m., and is reached by a regular steamboat service from Husum and Dagebull on the mainland to Wyk, the principal bathing resort on the E. coast of the island. The chief attraction of Wyk is the Sandwall, a promenade which is shaded by trees and skirts the beach. Fohr, the most fertile of the North Frisian islands, is principally marshland, and comparatively well wooded. There are numerous pleasantly-situated villages and hamlets scattered over it, of which the most frequented are Boldixum, Nieblum and Alkersum. The inhabitants are mainly engaged in the fishing industry, and are known as excellent sailors.

FOIL. 1. (Through O. Fr. from Lat. _folium_, a leaf, modern Fr. _feuille_), a leaf, and so used in heraldry and in plant names, such as the "trefoil" clover; and hence applied to anything resembling a leaf. In architecture, the word appears for the small leaf-like spaces formed by the cusps of tracery in windows or panels, and known, according to the number of such spaces, as "quatrefoil," "cinquefoil," &c. The word is also found in "counterfoil," a leaf of a receipt or cheque book, containing memoranda or a duplicate of the receipt or draft, kept by the receiver or drawer as a "counter" or check. "Foil" is particularly used of thin plates of metal, resembling a leaf, not in shape as much as in thinness. In thickness foil comes between "leaf" and "sheet" metal. In jewelry, a foil of silvered sheet copper, sometimes known as Dutch foil, is used as a backing for paste gems, or stones of inferior lustre or colour. This is coated with a mixture of isinglass and translucent colour, varying with the stones to be backed, or, if only brilliancy is required, left uncoloured, but highly polished. From this use of "foil," the word comes to mean, in a figurative sense, something which by contrast, or by its own brightness, serves to heighten the attractive qualities of something else placed in juxtaposition. The commonest "foil" is that generally known as "tinfoil." The ordinary commercial "tinfoil" usually consists chiefly of lead, and is used for the wrapping of chocolate or other sweetmeats, tobacco or cigarettes. A Japanese variegated foil gives the effect of "damaskeening." A large number of thin plates of various metals, gold, silver, copper, together with alloys of different metals are soldered together in a particular order, a pattern is hammered into the soldered edges, and the whole is hammered or rolled into a single thin plate, the pattern then appearing in the order in which the various metals were placed.

2. (From an O. Fr. _fuler_ or _foler_, modern _fouler_, to tread or trample, to "full" cloth, Lat. _fullo_, a fuller), an old hunting term, used of the running back of an animal over its own tracks, to confuse the scent and baffle the hounds. It is also used in wrestling, of a "throw." Thus comes the common use of the word, in a figurative sense, with reference to both these meanings, of baffling or defeating an adversary, or of parrying an attack.

3. As the name of the weapon used in fencing (see FOIL-FENCING) the word is of doubtful origin. One suggestion, based on a supposed similar use of Fr. _fleuret_, literally a "little flower," for the weapon, is that foil means a leaf, and must be referred in origin to Lat. _folium_. A second suggestion is that it means "blunted," and is the same as (2). A third is that it is an adaptation of an expression "at foils," i.e. "parrying." Of these suggestions, according to the _New English Dictionary_, the first has nothing to support it, the second is not supported by any evidence that in sense (2) the word ever meant to blunt. The third has some support. Finally a suggestion is made that the word is an alteration of an old word "foin," meaning a thrust with a pointed weapon. The origin of this word is probably an O. Fr. _foisne_, from the Lat. _fuscina_, a three-pronged fork.

FOIL-FENCING, the art of attack and defence with the fencing-foil. The word is used in several spellings (foyle, file, &c.) by the English writers of the last half of the 16th century, but less in the sense of a weapon of defence than merely as an imitation of a real weapon. Blunt swords for practice in fencing have been used in all ages. For the most part these were of wood and flat in general form, but when, towards the close of the 17th century, all cutting action with the small-sword was discarded (see FENCING), foil-blades were usually made of steel, and either round, three-cornered or four-cornered in form, with a button covering the point. The foil is called in French _fleuret_, and in Italian _fioretto_ (literally "bud") from this button. The classic small-sword play of the 17th and 18th centuries is represented at the present time by fencing with the _epee de combat_ (fighting-rapier), which is merely the modern duelling-sword furnished with a button (see EPEE-DE-COMBAT), and by foil-fencing. Foil-fencing is a conventional art, its characteristic limitation lying in the rule that no hits except those on the body shall be considered good, and not even those unless they be given in strict accordance with certain standard precepts. In epee-fencing on the contrary, a touch on any part of the person, however given, is valid. Foil-fencing is considered the basis, so far as practice is concerned, of all sword-play, whether with foil, epee or sabre.

There are two recognized schools of foil-fencing, the French and the Italian. The French method, which is now generally adopted everywhere except in Italy, is described in this article, reference being made to the important differences between the two schools.

_The Foil._--The foil consists of the "blade" and the "handle." The blade, which is of steel and has a quadrangular section, consists of two parts: the blade proper, extending from the guard to the button, and the "tongue," which runs through the handle and is joined to the pommel. The blade proper is divided into the "forte," or thicker half (next the handle), and the "foible" or thinner half. Some authorities divide the blade proper into three parts, the "forte," "middle" and "foible." The handle is comprised of the "guard," the "grip" and the "pommel." The guard is a light piece of metal shaped like the figure 8 (Fr. _lunettes_, spectacles) and backed with a piece of stiff leather of the same shape. The grip, which is grasped by the hand, is a hollow piece of wood, usually wound with twine, through which the tongue of the blade passes. The pommel is a piece of metal, usually pear-shaped, to which the end of the tongue is joined and which forms the extremity of the handle. The blade from guard to button is about 33 in. long (No. 5), though a somewhat shorter and lighter blade is generally used by ladies. The handle is about 8 in. long and slightly curved downwards.

The genuine Italian foil differs from the French in having the blade a trifle longer and more whippy, and in the form of the handle, which consists of a thin, solid, bell-shaped guard from 4 to 5 in. in diameter, a straight grip and a light metal bar joining the grip with the guard, beyond the edge of which it extends slightly on each side. Of late years many Italian masters use French blades and even discard the cross-bar, retaining, however, the bell-guard.

In holding the foil, the thumb is placed on the top or convex surface of the grip (the sides of which are a trifle narrower than the top and bottom), while the palm and fingers grasp the other three sides. This is the position of "supination," or thumb-up. "Pronation" is the reverse position, with the knuckles up. The French lay stress upon holding the foil lightly, the necessary pressure being exerted mostly by the thumb and forefinger, the other fingers being used more to guide the direction of the executed movements. This is in order to give free scope to the _doigte_ (fingering), or the faculty of directing the point of the foil by the action of the fingers alone, and includes the possibility of changing the position of the hand on the grip. Thus, in parrying, the end of the thumb is placed within half an inch, or even less, of the guard, while in making a lunge, the foil is held as near the pommel as possible, in order to gain additional length. It will be seen that _doigte_ is impossible with the Italian foil, in holding which the forefinger is firmly interlaced with the cross-bar, preventing any movement of the hand. The lightness of grasp inculcated by the French is illustrated by the rule of the celebrated master Lafaugere: "Hold your sword as if you had a little bird in your hand, firmly enough to prevent its escape, yet not so firmly as to crush it." This lightness has for a consequence that a disarmament is not considered of any value in the French school.

_To Come on Guard._--The position of "on guard" is that in which the fencer is best prepared both for attack and defence. It is taken from the position of "attention"; the feet together and at right angles with each other, head and body erect, facing forward in the same direction as the right foot, left arm and hand hanging in touch with the body, and the right arm and foil forming a straight line so that the button is about 1 yd. in front of the feet and 4 in. from the floor. From this position the movements to come "on guard" are seven in number:--

1. Raise the arm and foil and extend them towards the adversary (or
master) in a straight line, the hand being opposite the eye.

2. Drop the arm and foil again until the point is about 4 in. from the
floor.

3. Swing the button round so that it shall point horizontally
backwards, and hold the hilt against the left thigh, the open fingers
of the left hand being held, knuckles down, against the guard and
along the blade.

4. Carry the foil, without altering the position of the hands, above
the head until the arms are fully extended, the foil being kept
horizontal and close to the body as it is lifted.

5. Let the left arm fall back behind the head to a curved position,
the hand being opposite the top of the head; at the same time bring
the right hand down opposite the right breast and about 8 in. from it;
keeping the elbow well in and the point of the foil directed towards
the opponent's eye.

6. Bend the legs by separating them at the knees but without moving
the feet.

7. Shift the weight of the body on to the left leg and advance the
right foot a short distance (from 14 to 18 in., according to the
height of the fencer).

Previous Next

Comments

Encyclopaedia Britannica, 11th Edition, "Fleury, Claude" to "Foraker"Chapter XIV: Part 14

0%37 min left in chapter