GEOGRAPHY (Gr. ye, the earth, to write or describe) is, as its name implies, -a description of the earth. This science is best considered under the three distinct heads of Mathematical or Astronomical geography, Physical geography, and Political geography, which all admit of further subdivision into numerous subsidiary branches.
Mathematical or Astronomical geography describes the earth in its planetary relations as a member of the solar system, influencing and influenced by other cosmical bodies. It treats of the figure, magnitude, and density of the earth; its motion, and the laws by which that motion is governed; together with the phenomena of the movements of other cosmical bodies, on which depend the alternation of day and night, and of the seasons of the year, and the eclipses and occultations of the sun, moon, and planets; it deter mines position and estimates distances on the earth's surface, and teaches methods for the solution of astronomical problems, and the construction of the instruments neces sary for such operations, together with the modes of representing the surface of the earth by means of globes, charts, and maps. The numerous subjects comprised in this portion of geographical science will be found in other parts of the present work, and we therefore refer our readers for further particulars to the several articles in which they are more fully treated, as, for instance, ASTRONOMY, LATITUDE AND LONGITUDE, MATIIEMATICAL INSTRUMENTS, OBSERVATORIES, CIC.
Physical geography, as the name indicates, considers the earth in its relation to nature and natural or physical laws only. It describes the earth, air, and water, and the organized beings, whether animal or vegetable, by which those elements are occu pied, and considers the history, extent, mode, and causes of the distribution of these beings. This may be regarded as the most important branch of geographical science, since it involves the consideration and study of phenomena, which not only tend to further the material interests of man, by teaching him how best to promote the develop ment of the products of nature, but also conduce in no inconsiderable degree to 'intellectual advance, by stimulating the faculties of observation, and exercising the powers of thought. The vast sphere o' inquiry included in physical geography neces
sarily embraces the consideration of al, the natural sciences generally, and we can here, therefore, merely refer our readers fri more special information regarding the details of the subject to such articles as CLIMATE, HEAT, DARES, RIVERS, MOUNTAINS, OCEAN, WINDS, RAIN, CLOUDS; ETHNOLOGY, GEOGRAPHICAL DISTRIBUTION OF ANDIALS AND PLANTS, etc.
Political geography has been well defined as "including all those facts which are the immediate consequences of the operations of man, exercised either on the raw materials of the earth, or on the means of his intercourse with his fellow-creatures." Thus con sidered, it embraces, primarily, the description of the political or arbitrary divisions and limits of empires, kingdoms, and states; and, secondarily, that of the laws, modes of government, and social organization which prevail in the several countries. The details of this branch of geography will be found under the names of countries, cities, etc., while more general information in regard to the subject must be sought from historical, political, and statistical sources.
Before proceeding to sketch the progress and history of geographical discovery, we will indicate a few of the leading works that afford the best aid in studying the three main branches of geography to which we have referred. Thus, for instance, in mathe matical geography, we would specially instance: Manual of Geographical Science (Part L Mathematical Geography, by Mr. O'Brien); Herschel's Outlines of Astronomy; KlOden's Erdkuncle (Part I.): in physical geography, Ritter's Erdlouncle; Kloden's; A. Maury's La Terre et l'Homme; Mrs. Somerville's Physical Geography; Mr. F. Maury's Physical Geography of the Sea, etc.: while in regard to political geography, information may be sought from the great works of Ritter, Berghaus, Stein, Wappans, and Kltiden, and from the ordinary geographical manual and maps.