Geography

GEOGRAPHY. - It is in general the science that studies the different parts of the earth's surface.

I. DEFINITION, CONCEPT AND METHODS

The etymology of the words γῆ (earth) and γράφειν (to describe), according to which the Greeks designated this science as a description of the earth's surface, does not correspond perfectly to the current scientific concept of geography, which seeks instead causes and effects of phenomena on the earth's surface. While, as a scientific organism, geography was constituted only at the end of the 19th century, considered as the science of the earth, it represents one of the most ancient branches of knowledge, because it goes back to the work of Ionian philosophers in the 7th and 6th centuries B.C., when it had to determine theoretically the shape and dimensions of the earth, and to the 1st and 2nd centuries B.C. and A.D., when with practical aims it sought to illustrate the different parts of the earth and to establish a descriptive design of it (Polybius, 2nd century B.C., Strabo, 1st century A.D., Claudius Ptolemy, 2nd century A.D.).

Geography, which by its methods and aims has distinguished itself among the other disciplines relating to the earth and which has had to restrict the field reserved to itself with a unique and synthetic system, and which several times has changed the limits of its field, can be defined as the science that studies the regional distribution and the spatial coordination of physical and human facts manifesting on the earth's surface and in marine spaces, considered in their causes, in their effects and in the relationships of interdependence and connection, and delineating in particular typical aspects of the landscape.

It has been said to be a unique and synthetic system because with the method proper to geography there are coordinated the results of those other disciplines which, although they do not have a geographical character, are considered useful for their points of contact, their relations, their common fields of research.

The task of geography is not so much that of systematically coordinating facts and phenomena that manifest on the earth's surface, as that of localizing these manifestations in relation to their extension, that is, to the space occupied by them, and to the correlation with all the constituent elements of the landscape and of the environment. Landscape and environment which, objectively described, result from the combination of natural and artificial elements, from the terrain as nature presents it for a given period of time and in a certain space, and with all the transformations brought to it by man.

Taking into account the ever-changing aspect of the earth's surface, geography, as a scientific description of it, refers to the current geological period and therefore takes into account only the variations that the cortical part may have undergone in historical times.

Geographical investigation can be carried out essentially by availing itself of various methods of research: the principle of extension, that is, the search for the area in which a phenomenon extends over the earth's surface; the principle of coordination, by which «the geographical study of a phenomenon presupposes the constant concern with analogous phenomena that may manifest in other points of the globe» (E. De Martonne) and consequently creates for geography the tendency to classify scientifically the facts that it studies; the principle of causality, the search for the causes that determined the extension and distribution of a phenomenon on the earth's surface, whereby the historical consideration of facts constitutes precisely an original character of modern geographical science; the principle of correlation, according to which the various parts of the earth's surface are to be considered in continuous and constant relations among themselves, as if belonging to a single organic body.

Geography is thus a synthetic science because the results acquired by other disciplines, which nevertheless do not have a geographical character, are coordinated by it with methods which, by the principles described above, ensure for this science a marked individuality with respect to the others.

II. THE EARTH'S SURFACE

By direct observation only a very limited thickness of the earth's crust, or rather of the rocky shell that forms the solid outer part of the earth, is accessible. The meaning of "earth's surface" therefore is not to be understood in the literal or geometric sense, but rather in that of a thickness existing and accessible to man's experience and daring, as well as to organic life. The difference between the greatest altitudes and the greatest depths is a small thing in comparison with the mean radius of the geoid (6,371 km). Nevertheless, since this solid, superficial thickness, among whose hollows lie the ocean waters, constitutes the field of geography's investigations, vertical and horizontal forms are a fundamental element of our study. Forms that are both subject to a variability that generally does not appear because, during a historical epoch — an infinitesimal fraction of a geological era — no essential changes occur, or at least these escape man, who is "briefly alive." And if the investigation of the processes of transformation interests the geologist for the interpretation of past phenomena and for the history of the globe's evolution, it likewise interests the geographer because it is precisely from endogenic and exogenic actions and energies that the present forms of the earth's surface result. The outward description of forms, however, is not satisfying unless it is completed by the investigation of the physical vicissitudes through which one recognizes that the earth's surface is in perpetual becoming.

As regards the horizontal division of the earth's crust, continental masses are generally distinguished from oceanic basins. The former constitute the more stable zones of the earth, having been subjected for long geological periods only to general and uniform movements of uplift. The latter are areas covered by water, with a relief much simpler than the subaerial one, and they are held to be such perhaps also because of the incompleteness of our knowledge of marine bathymetry. The lowlands that have emerged, and those lying between the edge of the continental masses and the oceanic basins, constitute the continental platforms, while those zones of the earth's crust endowed with particular vertical and horizontal mobility which modify the original arrangement of deposits, brought to emerge by raising the great corrugations of the lithosphere to considerable altitudes, are called geosynclines; characteristic of them are unstable equilibrium, strong gravity anomalies and high seismicity. The continental masses would be composed of rocks on the whole lighter than those composing the oceanic basins, which are, moreover, more plastic than the former. On the basis of gravity measurements, geophysics admits that the earth's crust floats, in a state of equilibrium, above a very dense fluid substratum. Isostatic equilibrium (Sial in secular hydrostatic equilibrium on the Sima) by which, according to Archimedes' principle, the weight of the body that is immersed is equal to the weight of the liquid displaced. Hence A. Wegener's theory (1880-1930) of continental drift: the continental masses, once united among themselves in a single block (Pangaea), surrounded by a single ocean (Panthalassa), during the Jurassic would have undergone fractures and consequently splits into several parts, gradually moved away from their primitive position. Besides the geological and paleontological arguments that would prove this theory, what remains astonishing is the concordance of opposing continents but above all the parallelism of the Atlantic shores. Geographical homologies, that is, similarities of forms, were already noted by Francis Bacon (d. 1626) in the Novum Organum, where he alludes to the "similitudines physicae in configuratione mundi," then by R. Forster, who noted how the continents taper and end in a point toward the south, then by L. Agassiz and by O. Peschel, by A. Penck and by Olinto Marinelli.

The emerged lands can be estimated at 140 million sq km, while the seas occupy 361 million, for a total of about 310 million, corresponding to the entire earth's surface, according to the calculations of geodesists. An important geographical fact is that in the present distribution of lands and waters any regular arrangement is lacking; lands and seas are therefore unequally divided (one notes a kind of opposition between continents and oceans, the former grouped in the northern hemisphere, the latter in the southern) and the singular antipodal arrangement by which, at the antipodes of a continent, there is as a rule an oceanic basin, and vice versa.

III. GEOGRAPHICAL MAPS

Geographical science is a science of observation, but its object is such that it cannot be studied either directly or by resorting to a means that reproduces what is the peculiar object of study. A completely autonomous art in its scientific and technical organization, cartography aims to represent on a plane all or part of the earth's surface, creating not only ideal graphic expressions, but true and proper metric expressions, from which most of the measurements of the territory that is the object of the representation can be deduced. A symbolic expression of phenomena as localized and distributed on the earth's surface, it avails itself of the help that geodesy, topography, mathematics, statistics and other sciences can give it.

The geographical map is, according to G. Caraci, «the representation on a plane of all or part of the earth's surface, a representation obtained by means of points, lines and symbols, which are linked to one another, and all together in relation to the area represented, by relations of position, direction and distance determining it as exactly as possible».

Maps, an instrument and source not only of research but also of description, are indispensable for any geographical study, and without them it would not be possible to order the facts acquired. Flat, reduced and approximate images of the earth's surface, their construction implies the solution of a geometric problem that seeks to reproduce, with the least deformation, geometric constructions devised by mathematicians with various procedures and called geographical projections. The grid of coordinates, the foundation of the drawing, assigns to every point of the earth's surface a corresponding point on the map. Because of the alterations that reality brings, the projection will therefore be conformal (isogonic or orthomorphic) if the meridians and parallels come to be cut perpendicularly as on the sphere, keeping the angles equal, keeping a «shape» equal to that on the sphere, though presenting the drawback of not being able to maintain the same scale in every corner of the map. The projection will be equivalent when the areas of the map are proportional to the corresponding actual area, the individual figures represented undergoing notable deformations, particularly toward the peripheral part of the map. It will be an equidistant projection if along certain lines the map preserves lengths proportional to the real distances. Since it is not possible to construct maps that combine the three aforementioned conditions, means have been studied for constructing, by means of projections, conventional systems for which the approximate coexistence of two of the conditions set out is possible. Thus a distinction is made between projections made directly on the plane and those obtained instead by means of an auxiliary surface (cylinder, cone); the former are azimuthal (horizontal) projections, the latter are development projections (conical and cylindrical).

The projection is chosen taking into account not only the content and purpose of the map but also, and above all, the extent of the region to be represented and its position with respect to the geographical coordinates. According to the scale of proportion, that is, the ratio between graphic lengths and natural ones, maps are topographic, chorographic and geographic. According to the nature of the phenomena they represent, maps are physical, orographic, hydrographic, political, ethnographic, demographic, economic, zoo-and phytogeographic, geological, etc.

Of particular importance are the maps that aim to illustrate the distribution in the world of the followers of the various religions, as well as the atlases that have been constructed for this purpose.

An important problem of cartographic technique is that of devising and using the graphic signs and those colors most appropriate for representing with effectiveness and clarity the reality of the earth's surface: hatching, shading, contour lines (isopises) do not exist on the ground, just as the difficulties to be overcome in finding those conventional signs that in the smallest space can give an immediate idea of the phenomenon are well known.

The chromoplastic procedure, moreover, is linked to the established habit of giving the overall image of the terrain with certain surface tints, which are blue for the sea, lakes and rivers, green for the lowlands, brown for the elevations.

Representability is different depending on whether it is a matter of isolated objects or phenomena, or of phenomena having surface diffusion, of representations of a quantitative or qualitative character, variable in time, describing phenomena in movement, etc. Depending on whether it is a matter of point-like objects, of linear character or extended over a surface, the methods of representation vary. In the quantitative representation of facts with surface extension, reference is often made to isometric or isarithmic curves, lines passing through the points of the earth's surface at which the intensity of a given phenomenon is the same. When these are not applicable, other widely used methods are mosaic cartograms (each division receives a color or hatching corresponding to the average value of the intensity that the phenomenon in question reaches in that region) and the system of points (in a number proportional to that which measures the absolute magnitude of the phenomenon to be represented). All maps are evidently approximate; the main causes of their imperfection are due to the deformations originating in the projection, to the inaccuracies due to draughtsmanship, to deficiencies in surveying and to the insufficiency of data. For surveys in vast and poorly accessible zones, aerophotogrammetry has had a growing development in recent years. Even though it thus has the value of a synthetic representation of a great number of factual data, the map cannot be considered as the final result of scientific research.

IV. GEOGRAPHY IN ITS HISTORICAL DEVELOPMENT

1. In ancient times

The very etymology of the word shows that this science was born among the Greeks, where, however, it was at first meant to signify the representation of the earth by means of a map. Later it was used to indicate a description not only on a map, but also in words, of the whole world then known, while the description of a limited region was called chorography, a term still in use.

Traces of primitive stages of knowledge appear in the Iliad and the Odyssey (2nd millennium B.C.), while the merits of the first explorations of the Mediterranean basin belong to the Cretans (15th century B.C.) and to their heirs: the Mycenaeans and the Phoenicians. The Greek expansion into the Mediterranean countries (7th-6th centuries B.C.) subsequently widened the known horizon still further, with results that for that time may be considered grandiose.

It was Anaximander of Miletus, a disciple of Thales, who outlined the first map of the world and coordinated the views concerning the earth. He created the image of the ecumene (inhabited earth) in the island surrounded on every side by the Ocean, from which it had emerged through the reduction of the water following the absorption of the sun's rays. Toward the end of the 6th century Anaximander's map was perfected by Hecataeus, who accompanied the work with a commentary describing a territory vaster than those previously studied, thanks to the knowledge that had meanwhile been acquired of other regions: Scythians and Ethiopians, Celts and Indians were in fact the peoples placed by Hecataeus at the extreme limits of the ecumene. While Anaximander considered the making of maps the fundamental object of geography, Hecataeus began to consider geography with a scientific and at the same time practical intent, that is, as a description of countries and peoples. Herodotus (485-430 B.C.) was more a chorographer than a geographer, more an exact describer of particular countries than an elaborator of general syntheses, while Aristotle (second half of the 4th century) was dominated by excessively general and speculative tendencies, often at odds with the true reality of the observed facts. Nevertheless he pointed out new and brilliant paths in the astronomical and cosmological field, based on the sphericity of the earth.

The conception of the earth as a flat disk (of Anaximander, of Hecataeus and of their successors) fell in the course of the 5th century with the school of Pythagoras, which arrived at that of sphericity. Parmenides (513-440 B.C.) laid the first foundations of climatology, and the mathematician Eudoxus (or Eudoxus) attempted to measure the dimensions of the terrestrial globe.

Meanwhile the horizon of the world continued to expand: the Gulf of Guinea and the present-day Canary Islands had already been reached by the middle of the 5th century; the coasts of Gaul, of Frisia and the British Isles, in the second half of the 4th century. Hanno and Pytheas were the most famous navigators of those times. The unsuspected extent of Asia was then revealed by Alexander the Great, who pushed on from Asia Minor to Egypt and the Libyan desert, crossed the Persian Empire, reached the gigantic mountain rampart of central Asia, Turkestan, India. Dicaearchus of Messina, around 300 B.C., outlined a new map of the whole ecumene, having as its reference base the famous diaphragma, which can in substance be reduced to a central parallel running from W. to E., assisted by other secondary ones. Eratosthenes of Cyrene (ca. 284-203 B.C.) wrote the first true and proper treatise on geography, already containing the elements of mathematical and general physical geography, of regional descriptive geography with anthropic references, elements based on observations and factual reports and set forth with acute scientific discernment. The Eratosthenian approach drew into the field of geography's investigation the study of all phenomena of the terrestrial globe. The age of Eratosthenes marks the culmination of ancient geographical science which, with Aristarchus of Samos, precursor of Copernicus in the construction of the heliocentric system, also reached very bold conceptions regarding the solar system. The Eratosthenic work was subsequently continued by Posidonius of Apamea (ca. 140-65), who learnedly wrote on the Ocean and its phenomena and devoted himself to physical geography, to meteorology, and could moreover be considered the precursor of the most modern of the geographical sciences: anthropogeography. He nevertheless did not attempt, as Eratosthenes did, a general work of synthesis of geographical knowledge. Among the opponents of Eratosthenes are found one of the greatest Greek astronomers, Hipparchus of Nicaea (ca. 190-125), and the Stoic Crates of Mallus.

While the Greek spirit was more inclined to pure scientific inquiry, the Roman spirit had more practical aims. The Roman conquests between the second half of the 2nd century B.C. and the first centuries A.D. procured reliable knowledge about Gaul, Germany, part of Iberia, Britannia, etc. Africa and Asia were traversed by Roman legionaries and the extent of the ecumene was thus gradually widened through their efforts. In the age of Augustus and immediately afterward, new conceptions of geographical synthesis were elaborated. By the will of Augustus the administrative reorganization of the Empire was fixed (comprising itinerary works, cadastral records, official descriptions of the provinces, etc.), which favored the elaboration of geographical works. Agrippa meanwhile, the great collaborator of Augustus, had a map of the whole known world, and of the Roman Empire in particular, engraved in a portico of Rome. Strabo, Pomponius Mela and Pliny the Elder wrote powerful geographical works in the following years and set among other things as the supreme aim of geographical science the relations between the natural characteristics of each country and the ethnic, social and cultural conditions of individual peoples. From the descriptive point of view, and as a general synthesis of the knowledge acquired at the end of the Augustan age, the geography of Strabo is truly complete, even if its approach is more limited, descriptive and practical than the Greek Eratosthenic one.

At the beginning of the 2nd century A.D. we find Marinus of Tyre, whose principal work is known only through Ptolemy: a new map of the world. Ptolemy was instead first of all an astronomer, who consolidated the geocentric cosmic system and disseminated the value of the measurement of the earth's circumference (180,000 stadia), already accepted by Posidonius, a measurement corresponding to a terrestrial globe much smaller than reality.

To sum up, it can be said that, while Greek geography expressed itself above all in graphic form (maps), in the Roman age the expository form prevailed. At the foundation of both approaches one can in any case place the elaboration of observational data and experiences.

2. In the Middle Ages and the Renaissance

Geographical science underwent a broad interruption in the Middle Ages owing to the fact that, once the unity of the Roman State was broken, relations between peoples were much more limited and new knowledge had no way of spreading. Culture, almost entirely in the hands of the Church, was marked even in the geographical field by a symbolism at times far from reality: the circular mappae mundi, for example, often had Jerusalem as their center. The descriptions in this period are arid, often reduced to mere lists of countries, peoples and cities. St. Isidore of Seville (336), St. Bede the Venerable (733?), Rabanus Maurus (9th century) wrote geographical works of no excessive value. On the contrary, among the Arabs a rich geographical literature flourished, predominantly descriptive, which however remained almost entirely unknown to Westerners, who knew only the astronomical work of Ptolemy. The scholastic period was based precisely on the physical principles of Aristotle and on the cosmic system of Ptolemy when studies on the terrestrial globe were resumed. Gervase of Tilbury (beginning of the 13th century), Alexander Neckam (1157-1217), Albertus Magnus (1206-80), Vincent of Beauvais (ca. mid-13th century), Roger Bacon (1214-94) and Restoro d'Arezzo, all without distinction based themselves on the Aristotelian-Ptolemaic doctrines, harmonizing with the principles of Christian theology. Observation in the geographical field still did not exist and the new knowledge brought to geographical science through the work of Giovanni di Pian del Carpine, Rubruk, Odoric of Pordenone and Marco Polo was met with incredulity.

A renewal can be found at the beginning of the 14th century in the cartographic field: nautical charts, regional maps, new circular world maps make their appearance, while descriptive geography remains unchanged until the 15th century. In this period Enea Silvio Piccolomini, who was later Pope Pius II (1458), compiled a geographical work (Historia rerum ubique gestarum locorumque descriptio), one of the many examples in which one encounters the then current use of the name cosmography. Between the mid-15th century and the mid-16th century Bartolomeu Dias, Vasco da Gama, Christopher Columbus and Ferdinand Magellan brought about a revolution in the world of geography through their enterprises: the sphericity of the earth was universally recognized, the globe appeared enormously vaster than could have been suspected, the extent of the oceanic areas proved unthought-of. The study of and interest in nature were rekindled and in the Humanism the forgotten works of Strabo and Ptolemy saw the light again; cartography returned to vogue and names such as Leonardo da Vinci, Fineo, Gastaldi, Apianus and Mercator gave life during the 16th century to a great number of systems for representing the entire globe.

The resurrection of descriptive geography occurred with Sebastian Münster (1544). With the end of the 1500s the Aristotelian system crumbles and the cosmic system of Ptolemy suffers the same fate with Kepler, Copernicus and Galileo, who lay the foundations of the new heliocentric system. Geography then appears as a well-defined science, with its own aims and methods, particularly in a work by Varenius (1650): it was the first of the modern age, geographical phenomena being therein clearly subdivided into celestial, terrestrial and human phenomena, a division that has remained until our own days.

3. From the 17th century to modern times

Mathematical geography was set on new paths and Sanson, Cassini, Delisle and d'Anville kept cartography in high regard for France with the new planispheres and the maps of Europe and Africa. In the 17th century geology begins, through the work of N. Steno, founder of stratigraphy. In the 18th century, on the other hand, geography becomes an auxiliary discipline of the new economic, social and statistical sciences and loses the character of a science of observation, remaining in part even deprived of its content. With the 19th century geographical science is once again in the foreground, with the resumption of the geographical explorations of Cook, Niebuhr, Pallas and Bruce.

Alexander Humboldt was the first true and great traveler-geographer, who dealt with terrestrial morphology, climatology, botanical and political geography. His "comparative investigations of phenomena" constituted from then on the basis of geography. His contemporary was that Carl Ritter, a methodical scholar, who gave great importance to geography in teaching. But physical geography, greatly deepened by Humboldt, rose to great importance after 1870, a period in which one sees the rise of countless geographical societies. Scientific explorations meanwhile continued with Nansen (1893), Peary (1909), Ross (1842), Amundsen (1911). All branches of geographical science were being deepened, and modern oceanography finds its starting point in the Challenger expedition. From the middle of the 19th century onward the states of Europe understood the importance of possessing cartographic representations of their own territories, based on topographic surveys. Central meteorological offices from then on multiplied their studies. The German Oscar Peschel (1826-75) remains one of the major exponents of physical geography, because he sought to bring geographical science back to its naturalistic foundations: biogeography sees its own position clarified with him. Geology had meanwhile made very notable progress in many countries, and terrestrial morphology became a new branch of physical geography. Giuseppe Dalla Vedova (1834-1919) specified the true and proper tasks of geography, consisting in the investigation of distribution and of the causal correlations among forms, phenomena and living beings. Anthropogeography had in Friedrich Ratzel (1844-1904) its principal exponent. It considered man and the manifestations of his activity or, more precisely, the influences of the environment on man.

At the beginning of the present century geography was therefore divided into two great branches: physical and human geography, while astronomy and geodesy assumed the appearance of autonomous sciences. In very recent times explorations have continued at an increasing pace in the two polar caps, in desert regions, equatorial forests, mountain systems, in the depths of the sea and in the highest atmosphere. Extensive exploration has, however, given way, in the present day, to more circumscribed and thorough exploration.

Geography, which is based exclusively on facts of interdependence and mutual correlations, has become very complex today. The description and classification of the various aspects of the earth's surface lead today to defining geography as the science that studies and scientifically describes the landscape understood in the geographical sense (an abstract synthesis of the visible one), which is constituted by a small number of, or by a few groups of, characteristic elements which, as a result of facts determined by climate, morphology, hydrography, vegetation, etc., outline the great physiognomic forms of the earth's surface.

The classification scheme proposed by Hassinger in 1933 into 43 landscape types (Landschaftstypen) dates from that year, a simplification of an earlier essay by Passarge. Recently, in Italy, R. Biasutti (1947) described the principal types of the earth's landscape with reference to the life and activity of man. Today geographical research is in many states directed by special national bodies linked in the Union géographique internationale, a promoter of studies, research and congresses. The major collaborative geographical works are: La géographie universelle (formerly directed by P. Vidal de la Blache); the Handbuch der geogr. Wissenschaft (directed by R. Klute) and the G. universale (directed by R. Almagià).

The bodies in Italy that concern themselves with geography are: the Società Geografica Italiana (Rome), the Società di Studi Geografici (Florence), the Istituto Geografico Militare (Florence), the Comitato Nazionale per la g. within the Consiglio Nazionale delle Ricerche (Rome), the Istituto Idrografico della Marina (Genoa), the Touring Club Italiano (Milan), etc., all of which have periodical publications of scientific interest.

V. GEOGRAPHY AND ITS SUBDIVISIONS

Geography, in the present organic scientific field, can be divided into a few large sections.

1. Physical geography (physiogeography)

Physical geography could be defined as the science that studies the physical facts and phenomena that manifest themselves on the surface of the terrestrial globe (understood as including the marine spaces), examined from the point of view of their extent and their mutual relations. Knowledge of the shape, dimensions, position and movements of the terrestrial sphere are indispensable general notions. The geographical consequences of these facts are many, and while one of Humboldt's essential merits is that of having, in the practice of observation, brought geography back to the study of reality, the first element of the success of E. Reclus and of his fortunate influence on the spread of a taste for geography was his profound sense of that activity which animates the surface of the terrestrial globe with a kind of physical life.

It is only from the 19th century that the definitive constitution of terrestrial morphology on scientific bases dates. This, vivified by the historical conception developed by the American geographer W. M. Davis and his school, would rest on the continuous transformation of the forms of the surface, transformations that would determine the distinction of relief into morphological cycles, classifiable according to the terrain and the modelling agent. The American morphological school has been combated, especially in Germany, where emphasis has been given to the scientific, and therefore rational and comparative, description of the "landscape" (Landschaft), in its physical and anthropic aspects.

Physical geography, in describing the forms of the earth's surface, also aims to explain the origin and the effects of the action of the energy proper to the earth and of the transformations of solar energy; for knowledge of the climates in the various regions it deals with the atmosphere and with the consequences of the phenomena that manifest themselves in it, seeking likewise the extent and the distribution of the phenomena connected with the hydrosphere in its many aspects. One is thus led to distinguish in physical geography the following branches: a) Terrestrial morphology (geomorphology). - It deals with the great features of the earth (geochemical constitution of the globe, distribution of lands and waters), investigates the genesis of the reliefs on the emerged lands in relation to their localization and to the determining causes, traces the effects of exogenous dynamics on shaping, studies coastal topography, the influence of rocks and the tectonic influence on relief, and therefore all the factors that bear upon the essential features of the geographical aspect.

b) Oceanography. - It pursues in depth the investigation of the physical characteristics of the sea, the composition of its waters and the distribution of salinity, temperature and transparency of the waters, deals with currents, sub-oceanic relief, sea level and bathymetric research; it studies the sea from the physico-chemical point of view (thalassography), and the nature and development of living beings (thalassobiology). The first studies are by the Bolognese scientist Luigi Ferdinando Marsili (1658-1730), a member of the Academy of Sciences of Paris, who in 1725 published his Histoire physique de la mer. Since then this branch of study has had a notable development both in Italy and abroad.

c) Meteorology. - It studies the properties of the atmosphere and the phenomena that take place in it; it investigates the general laws general laws of atmospheric movements, as well as the formation and path of disturbances (dynamic meteorology). It studies the localization of the various meteorological facts, their mutual relations, the influence of geographical conditions, and the relations of these phenomena to the life and development of animals and plants, as well as to hygiene and public health of man (climatology). It deals with studies relating to the free atmosphere, that is, to the layers of air not in contact with the ground (aerology). Meteorology thus covers the vast field of study of the entire aeriform mass surrounding the earth, of the pressure exerted by it, of isobaric types, of temperature, of solar radiation, of hydrometeors; and of these in particular it traces the functions and geographical distributions.

d) Seismology. - It deals with the rapid and violent movements of the earth's crust (earthquakes), produced by the passage of elastic waves transmitted from regions where a mechanical disturbance has occurred, with their effects, their distribution over the earth's surface, the precursor and concomitant signs, seismic periods, microseismic movements and epeirogenic movements in general.

e) Volcanology. - It seeks to investigate the causes and effects of the superficial layers (subaerial and submarine) of the globe, from which rocky materials from the deep layers (volcanoes) emanate continuously or intermittently. It identifies the points of volcanicity, recognizes in some of them secondary or pseudovolcanic phenomena, in others postvolcanic phenomena, and studies their distribution in the various regions of the earth.

f) Glaciology. - It concerns itself with glaciers, their structure, oscillations, cycles, movements, and their geographical distribution; these studies, which began with scientific aims only at the end of the 18th century (the Swiss geologist and physicist Horace

Benedict de Saussure [1740-99] was the pioneer of scientific alpinism), later aimed to classify glaciers into types, to mark their characteristics, to study their parts, the collector and ablator basins, recording, etc.

g) Potamology. - It studies the action of surface waters, rivers in particular, their elements, the phenomena of erosion, deposition, etc., and the cycles of hydrographic basins.

h) Limnology. - It aims to study the nature, origin, and life of lake basins, their relief, hydrology, soundings, bathymetric charts, movements, temperature, transparency, composition of the waters, climatic and topographic influences, oscillations, etc. An accessory branch of oceanography, limnology has the same problems, which it solves with the same methods. Systematic studies in this branch have greatly developed in recent times.

All branches of physical g., while forming an integral part of it, aim at a certain autonomy, which, however, cannot disregard the basic consistency of physiogeography, the first part of g. proper, and which, while abstracting from the work of man, forms the basis of human g., a branch, in turn, of organic or biological g.

2. Anthropic g

It studies the distribution of men over the earth's surface and their activities, investigates their characteristics and quantitative variations (density, distribution of population) and qualitative variations (differentiation into races [types] constituting all indices of series of facts of a physical, biological, and economic order interconnected among themselves).

Anthropic g. has subgroups: a) Ecological g. - It applies the principle of correlation, whereby man is influenced by the surrounding environment. It is here that g. makes use of ecology, dealing properly with the study of the relations of living organisms with the surrounding world and of the peoples composing present humanity, basing itself on linguistic, cultural, and social data of man as a modifier of the environment (so that from a natural or unmodified landscape one passes to a human or modified landscape), making use of mineral, animal, or vegetable resources.

b) Economic g. - Availing itself of commodity science and economics, autonomous sciences that deal particularly with the distribution of products, their commercial value, etc., it studies the utilization of terrestrial resources by man. Parts of economic g. may be considered: commercial g., which studies economic phenomena in relation to the soil (and which can be subdivided into g. of production and g. of consumption); and industrial g., which concerns itself with the distribution of raw materials and the possibilities of transformation into pro-

(from Images de Grande-Bretagne, British Council s. a.)
GEOGRAPHY - Flow of basaltic lava cleaved into columnar prisms, Northern Ireland.

useful products, with the exploitation of those natural forces that depend on climatic and geomorphological factors.

c) Political geography. - It examines the modifications that man makes on the earth's surface by virtue of living grouped in complex societies (States), determining frontiers, and protective, developmental and conservation works.

d) Ethnographic geography. - It investigates the causes and formative processes of peoples and their languages, the ways of human life, natural increase, and migrations.

A particular study of ethnographic geography is that of the distribution of religions, which, because of their complexity and their influence on other human activities, have given grounds for the formation of the geography of religions.

e) Geography of civilization. - It concerns all the manifestations of human activity that modified the natural state of the earth's surface, shaping the artificial landscape of civilization in the distribution of major types: geography of settlements, geography of communications, geography of traffic. The geographical study of the city is given the name of urban geography.

3. Aesthetic geography

There is also talk of aesthetic geography, of which A. von Humboldt, F. Ratzel and G. Pennesi may be considered exemplars, when, in describing the works of man in their regional coexistence, geographical subjects are treated synthetically and artistically, but at the same time with absolutely scientific rigor.

4. Tourist geography

A chapter unto itself could be constituted by tourist geography, which coordinates the geographical elements that represent the dominant factor of the problem of tourism understood internationally and socially.

5. Historical geography

Its purpose is to bring to light the changes that have occurred in past epochs. It also makes use of toponymy, which is the glottological elaboration of the proper names of places and of historical regions that denote particular natural and human conditions.

It is necessary, however, to draw on these sciences with discretion, without losing sight of the principle of localization and extension, proper to geography — a principle which, if unobserved, would make it lose part of its character as an autonomous science.

To feed, grow, reproduce, pass through phases of existence and die is common to living individuals. That part of geography which claims the task of seeking the causes of the processes of transformation of plants and animals and their influence in the modifying work on the earth's surface constitutes biogeography.

6. Botanical geography

By botanical geography is meant the classification and distribution of plant formations on the globe.

For one to be able to speak of botanical geography properly so called, it was necessary to wait for the definition of the plant species given by Linnaeus toward the middle of the 18th century. From the ancients, notions were known regarding the origin and the cultivation requirements of useful plants; but with Linnaeus come the first floras compiled according to scientific criteria, flower, which prompted C. Willdenow to compile a phyto-geographical sketch and Alexander von Humboldt to draw up a scheme of the distribution of vegetation across the globe.

Humboldt thus created the preconditions for more detailed research; A. P. de Candolle (1826) divided the surface of the globe into natural floristic regions; J. Schouw described the relations between vegetation forms and habitat.

New aspects of botanical g. were then discovered, such as the physical structure and chemical composition of the soil, the concept of plant formation, and the reconstruction of vegetation in geological periods preceding the present one. A. Engler therefore formulated the systematic-genetic method, making use of data and information from all parts of the globe. A. W. Schimper, on the other hand, upheld a more detailed method based on the biological reactions of plant species, classifying the plant formations of the most varied climates and making use of advances in systematics, physical g., and Quaternary paleontology — a method that has provided knowledge about the processes of transformation of vegetal landscapes.

From the concept of flora, which is the complex of plant families in relation to their ecological or environmental characteristics — a relation from which the floristic regions take their name (the Holarctic Eurasian or American, the Mediterranean, the North-Tropical desertic of the Old World, the Intertropical, the Austral) — one passes to the concept of the formation of vegetal zones. An association of plants with common biological characteristics constitutes formations (forests, steppes, tundras), which may be aquatic or terrestrial. Among the vegetation zones are to be counted that of hot climates, with the equatorial virgin forest (an almost continuous mantle of impenetrable arboreal vegetation) and the savanna; that of subtropical climates, with the Mediterranean forest and scrubland (with its twofold period of vegetative rest), the steppe, the Chinese forest; that of temperate climates, with the boreal forest of broad-leaved trees and conifers, with the prairie and the prairie-steppe; that of cold climates, with the characteristic tundras.

Among the geographical factors in the distribution of plants, climatic ones must be considered: light, heat, moisture, wind, variously distributed; physical ones, on account of the physical-chemical conditions of the soil on which the plants live; organic ones, on account of those conditions of life of saprophytism, commensalism or symbiosis of plants to the advantage or disadvantage of others with which they live.

7. Zoological G

It examines in particular the characteristics of the fauna presented by the various regions of the earth, divides the earth into regions and subregions, noting the zoogeographical affinities.

Among the divisions that have a scientific character, that made by Ph. L. Sclater (1857) is remembered. The attempts at classifying zoogeographical regions were numerous. Among the most successful was that of A. R. Wallace (1876), who recognized the following regions: Palaearctic (with the European, Mediterranean, Siberian and Manchurian subregions), Ethiopian, Oriental (Indian, Ceylonese, Indochinese, Indomalayan), Australian (Austro-Malayan-Polynesian, New Zealand), Neotropical (Chilean, Brazilian, Mexican, Antillean), Nearctic (Californian, Canadian, Rocky Mountain).

Among the other classifiers of zoogeographical regions, F. E. Beddar (1895) and L. Trouessart (1922) distinguished themselves; G. Colosi, H. Woodnard and A. Günther delimited the marine zoogeographical regions.

Considering the animals that populate the surface of the globe, three great ecological domains are distinguished: the alabious or marine, the limnobious or freshwater, and the aerobious or terrestrial. In the first, where life is held to have originated, since the environmental conditions found there are the least distant from those that would have confirmed this opinion, live the representatives of all the types of the animal kingdom.

The other two domains possess genera and families exclusive to themselves; the systematics of their faunas makes a notable contribution to the marine genesis of the elements that constitute them. With regard to the areas of distribution, there are groupings that occupy vast expanses, just as there are others confined to very restricted areas.

VI. SCIENTIFIC GEOGRAPHY AND AS A SCIENCE OF COORDINATION

The name scientific geography has been used to designate the whole speculative and theoretical part of this science, in order to distinguish it from what might be called exploratory geography, which, being experimental, retains its empirical character. A group of English geographers called it "the study of local correlations," while in Italy G. Dalla Vedova asserted that "the distributive and chorological moment of the sciences belongs to geography." Between the end of the 18th century and the first half of the 19th, the dualism between the two distinct approaches, naturalistic and historical, had delayed the establishment of scientific geography; the conflict between general physical geography and the chorography concerning man (in which regional history and States form the central part) disappears, or at least shows signs of disappearing, with the new evolution of geographical science, in which causal investigation dominates; the unity of the geographical point of view requires that Geography be thus recognized as a unitary science, a "monistic" science.

Thus the merit remains with geography, unlike the other sciences which do not contemplate the material and ideal unity of the earth, of recognizing in it a new office of reference, control and correlation among the various sciences, which, until then separate and autonomous, had remained without any possibility of synthesis.

A science of coordination, geography is not geology; it is not statistics, not history, not topography, not biology. It must have its place among the unifying sciences, and to geology, statistics, history, topography and biology it provides the spatial element, the seat of man and the theater of his activities: the earth's surface. The universality of geography allows it to penetrate into the search for the ultimate causes of nature, just as philosophy intends to reach the ultimate causes of the idea, without however becoming confused with it but remaining the former in the speculative-practical field, in more immediate contact with the experimental, social and historical sciences.

VII. GEOGRAPHY, THE RELATED AND AUXILIARY SCIENCES

Geography is in itself a complete science: it studies at the same time history, physics, chemistry, zoology, botany, meteorology, etc., embracing a vast field that extends from the ethical sciences (history, politics, etc.) to the strictly scientific and natural ones (geology, chemistry, botany, etc.). There is no other science that, like geography, synthesizes so many and has need of so many auxiliary sciences.

In modern geography as a scientific organism, cosmography and cartography no longer have a place, since these now belong to the group of physical or mathematical disciplines, both by their purpose and by their methods of study: they deal with matters that once, and still in part today, were the object of mathematical geography or astronomical geography; the latter considers the earth as a celestial body having a determinate shape, dimensions and motions, studies its position in the cosmos and above all its relations with the solar system. Geography understood in the modern sense avails itself of the preliminary notions of what constitutes astronomical geography and of knowledge of the procedures directed to the construction of geographical maps (v. above, III).

But the geographer must be in possession of notions from other sciences kindred and auxiliary to geography.

Statistics, a mathematical and social discipline, collects, examines, elaborates and classifies the numerical data of populations and their activities, marking the course of demographic phenomena and furnishing material for the work of geography, which studies, among other things, the distribution of living beings on the earth.

Terrestrial physics studies the constitution, the characters and the physical properties (shape, dimensions, measurement of gravity of the earth, etc.) of the basins of the sea (suboceanic relief, motions of the sea, oceanic circuits, etc.), of the atmosphere (thermal conditions, movements, circulation, regimes, etc.), above all in function of the geode, as a body in itself and on bases of research of an essentially physical order.

Geology (v.) investigates the constitution and the structure of the earth's crust, in which phenomena are at work fi-

physical and human; it, subject to continuous evolution, constitutes a true and proper history of the earth.

Lithology studies the origin and nature of the rocks that form the earth's crust.

Paleontology concerns itself with the study of fossil organisms contained in the cortical surface, determining, through a comparative process, the era to which they belong.

Tectonics and stratigraphy are peculiar in the study of the arrangements of materials, for the correlation of the principles of action and reaction.

Anthropology describes the racial characteristics of the various human groups distributed over the earth's surface.

Paleontology and ethnology concern themselves with the cultural characteristics, the customs and the habits of life of the various peoples; of these the former studies prehistoric chronology, giving the pictures of the different forms through which human civilization developed.

In the retinue of the auxiliary sciences are to be numbered history, politics, ethics, law, economics, philology, linguistics, archaeology, psychology, mineralogy, zoology, botany, mathematics, chemistry, commodity science, medicine etc., which, although they do not have a direct and immediate relation with geography, nevertheless have with it a necessary logical and practical connection. - See plates IV-V.

Gastone Imbrighi