The Student's Manual of Modern Geography. Mathematical, physical, and descriptive

Front matter

THE ROCK OF GIBRALTAR, THE STUDENTS MANUAL OF MODERN GEOGRAPHY. MATHEMATICAL, PHYSICAL, AND DESCRIPTIVE. By W. L. BEVAN, M.A.. CANON OF ST. DAVIDS AND VICAR OF HAY, AUTHOR OF THF. 'STUDENT'S MANUAJ. OF ANCIENT GKOORA PHY.' XlM Iinnubo below rrc*t/m SfXTS EDI TH)y. LONDON: JOHN MURRAY, ALBEMAKLE STJiEET. 187ft. Tlie right nf 'jyanllatum it MM «"' BY THE SAME AUTHOR, TOE STUDENT'S MANUAL OF ANCIENT GEOGRAPHY. With Woodcuts. Post 8vo. 7s. Gd, i '-■:-•!" in: rniHTED hi William clowes a si. sods, eiaufobd btseet, AKD CllABIVC CKOBS. preface to the sixth edition. Extensive alterations have been made in the present edition in order to bring the work up to the level of the day. Among the more important matters thus dealt with, the following may be specified : — (1.) The political changes consequent on the recent Russo-Turkish war and the Treaty of Berlin.

(2.) The advance of the Russian Empire in Central Asia and the present condition of Turkestan. (3.) The extension of the Egyptian Empire to the equatorial region. (4.) The progress of geographical discovery in Central Africa. In addition to these more prominent topics, the statistical statements as to area and population have been corrected throughout the whole of the work, and the figures now given are in accordance with the latest returns. July, 1879. MOD. GEO. b

Preface

. The Author of the present manual has proposed as his primary object to draw a sketch, complete and comprehen sive in outline without being overloaded with detail, of the whole province of geographical science together with its various points of contact with other branches of science and knowledge. The student will, it is hoped, derive from a perusal of the work a fair idea of the general scope and range of the subject, however imperfect may be his acquaintance with its details. The Author has further endeavoured, by the selection and treatment of his materials, and by the numerous illustrations intro duced into the pages, to redeem the study of elementary geography from the imputation of tediousness currently attached to it. The introductory chapters are devoted to the moro scientific portions of the subject, — Mathematical and Physical Geography.

These are treated in a simple and elementary manner ; and the various topics thus intro duced are illustrated by maps and diagrams. Consider able attention is paid in this portion of the work to Geographical Terminology ; and a brief exposition of the leading principles of Cartography will be found under tho head of Mathematical Geography. The body of the work is occupied with Descriptive Geography, and here the following features may bo noticed : — Z>2 PREFACE, VIII (1) The History of Geographical Discovery is carried on from the point where it is left in the 'Student's Manual of Ancient Geography ' down to the present day. (2) The progressive steps by which the great states of the world have arrived at their present position are sum marized under the head of Historical Geography, prefixed to the description of each state.

(3) The influence of Geographical Position on the political and commercial fortunes of a country is occasionally brought prominently before the student's notice. (4) Under the head of Military Geography will be found notices of the various points of attack and defence on the frontiers of the great military nations of Europe. The events of military history are noticed among other topics under tho head of Historical Associations. (5) The Coast-lines and Harbours are described at some length, inasmuch as they form a most important element in the commercial capabilities of a country. (6) Attention is drawn to the significance of names in cases where they illustrate points of historical or geographical interest. (7; Maps are occasionally introduced in illustration of Physical and Military Geography.

These are designed to supplement, not to supersede, the use of the ordinary atlas in the study of the book. The other Hlustrations have been selected with care, as characteristic either of the physical features of the globe, or of its great political and commercial centres, and are not to be looked upon as mere pictures. (8) General rules are given for the pronunciation of foreign names, and accents are affixed to the individual names wherever they have been deemed necessary. In regard to the style and composition of the work, tho Author has endeavoured to consult the taste and con-

PREFACE.

. IX venience of his readers by separating, in each of the more important countries, the general description from the de tailed one ; gathering together in the latter, under spe cified heads, such particulars as may be useful either for fuller information or for reference. The distinction above noticed is marked by a change in the type. Bare lists of names are avoided as much as possible in the descriptive paragraphs, and are thrown into a tabulated form for the purpose of reference. In respect to the proportionate space assigned to the various countries, the only noticeable point is that the United States are described at greater length than has hitherto been customary in works of this size. The lively interest aroused by the late Civil War, and the numerous links that bind us to that great country, appear to justify this departure from previous custom. An ample Index is apponded. CONTENTS.

Introduction

. Chap. Page 1. Geography. — Definition and Divisions 1 Mathematical Geography 2 II. Physical Geography. — Land and Water 16 III. Physical Geography, continued. — Climate and Organic Life 37 DESCRIPTIVE GEOGRAPHY,

Book I. Europe

I. Europe. — General Description 53 H. The British Isles. — Position — Historical Geography — Seas — Climate and Productions — Colonial Empire . . 76 III. England and Wales. — Natural Features — Productive Industry — Political Divisions, &c 90 IV. England and Wales, continued. — Counties and Towns . . 110 V. Scotland 133 VI. Ireland 152 VII. The Iberian Peninsula 167 Spain 175 Portugal 185 VID. France 189 IX. Switzerland 212 X. Belgium 224 The Netherlands 231 XI. Germany. — Extent and Natural Divisions— Climate and Vegetation — Inhabitants 239 North Germany. — Natural Features — Political Divisions 243 Prussia 247 Saxony and the Minor States CONTENTS. Chap. Pao» XII. South Germany. — Extent and Divisions 263 Bavaria and the Minor States 265 Austria-Hungary 269 XIII. Italy 286 Malta 309 XIV.

Greece 310 Turkey 319 The Suzerain Provinces 330 XV. Denmark 332 Iceland 337 The Scandinavian Peninsula 338 Sweden , 342 Norway 345 XVI. The Bcssian Empire. — Extent and Divisions^Historical Geography 348 Bussia, Poland, and Finland 350 Caucasia 368 BOOK n. ASIA. XVII. Asia. — History of Discovery — General Description . . . . 372 SmERiA ., .. ., 384 Turkestan (Independent) , ,, .. .. 388 XVIH. Turkey.— Extent and Divisions 392 Asia Minor 393 Armenia and Kurdistan 397 Mesopotamia 398 Syria 400 Arabia 404 Persia 406 Beloochistan 409 Afghanistan 411 XLX. India. — British India — Anglo-Indian Empire .. .. 413 Hindostan 415 British Burmah and Straits Settlements 436 Ceylon 438 Indo-Chinese States. — Burmah, Siam, Laos, Cambodia, and Anam or Cochin-China 441 XX. The Chinese Empire. — Extent and Divisions 444 China 445 Mantchooria .. ..

CONTENTS. XIII Chap. Pagr Chinese Empire — continued. Corea 452 Mongolia 453 Turkestan and Dzungaria 453 Tibet 455 Japan 456 Malaysia or the Indian Archipelago 459 BOOK IH. AFRICA. XXI. Africa. — Position, Boundaries, &c. — History of Discovery — General Description 462 Egypt, Ncbia, and Kordofan 472 Egyptian Soudan 476 Abyssinia 478 Adal and East Africa 480 XXII. Barbary. — Extent and Divisions 482 Tripoli 483 Tunis 484 Algeria 485 Marocco 487 The Sahara 488 Senegambia and Sierra Leone 489 Guinea 490 Soudan or Nigritia 491 Lower Guinea 493 Cimbebasia and Hottentotia 494 South Africa. — General Description 495 Political Divisions 498 Sofala, Mozambique, and South Central Africa . . 499 Madagascar 500 Mauritius, Bourbon, &c 501

BOOK IV. AMERICA.

XXIII. America. — Position, Extent, &c. — History of Discovery — Continental Divisions 504 North America. — General Description 508 British North America. — Extent — Historical Geography 518 Dominion of Canada CONTENTS. Paob Chap. British North America — continued. Newfoundland, Labrador, Prince Edward Isle, &c. 525 British Columbia, Vancouver Island, &c 527 North-West Territory — Ked Kiver Settlement — Arctic Archipelago and North-West Passage- Greenland 529 XXIV. The United States 532 XXV. Mexico 560 Central America 565 The West Indies 570 XXVI. South America. — General Description 578 Colombia or New Granada 593 Venezuela 595 Ecuador 597 XXVII. Peru 599 Bolivia 601 Chili 603 Patagonia 605 Tierra del Fuego 606 Argentine Republic 606 Paraguay 610 Uruguay 611 Brazil 611 Guiana .. 616 Falkland Isles 618

BOOK V. OCEANIA.

XXVIII. Oceania. — Extent and Divisions 619 British Australasia 620 Australia 620 Tasmania 629 New Zealand 630 Auckland, Chatham, and Norfolk Isles 634 Melanesia 635 Polynesia 637 Antarctic Regions , 641 Index ) LIST OF ILLUSTRATIONS The Rock of Gibraltar Frontispiece. The Danube below Presburg Title Page, * Kishtymsk and its Lake, Siberia . . . . Page xvi. Page Rheinfels Castle and the Rhine 239 The Town-hall, Danzig . . 255 The Japanese Palace, Dresden 259 Temple of Fame, Munich 263 The Austrian Alps from Gosau, S. of Ischl . . . . 269 Dolomite Mountain in the Grodnerthal, Austria ..276 The Danube below Presburg 281 Puszta, treeless plain, Hungary 282 Fort Bard, Italy . . . . 286 Page Diagrams relating to Mathematical Geography 3-15 Chart of Ocean Currents . . 19 Comparative Heights of Mountains 29 Map of Mean Annual Temperature 37 Map of the Winds .. . . 40 Map of Distribution of Rain 43 Map of Varieties of the Human Race . . . . . . 49 Mont Blanc, from the Lake of Geneva 63 Sketch Map of Europe . . 55 Summit of Mont Blanc . . 60 Mount Ætna, from Reggio 65 Defile of the Danube below Belgrade 69 Sketch Map of the British Isles 76 Merton College, __c, Oxford 86 Plymouth Sound . . . . 90 The Bristol Avon, with Clifton Suspension Bridge . . 97 London, with new Bridge at Blackfriars . , . . 106 Page Volcano of Fusi-yama, Japan 457 Victoria Fails of the Zambesi.

South Africa . . . . 462 Sketch Map of Africa . . 465 Hippopotamus carrying her Young 470 Cairo 473 The shadoof, for raising water from the Nile . . 475 Algiers 482 Cape of Good Hope .. .. 494 Entrance to Christmas Harbour, Kerguelen Land . . 502 American Prairie, with Sketch Map of Northern Italy, illustrating lit) Military Geography . . 288 Rome 299 bisons 504 Sketch Map of North America 509 Beaver lodge and trench . . 515 Great dam made by beavers, Grass Laku, North America 616 Florence 304 Temple of Theseus, Athens 310 Modern Greeks 316 The Dardanelles . . . - 319 Chaudiere Falls of the Ottawa, Canada . . . . 521 Moonlight in Arctic Regions 630 Red River Canon, United States 532 Joanina, Epirus 328 Elsinore, Denmark . . . . 332 The Exchange, Copenhagen 336 Nœroen's Fiord, Norway . . 340 Statue of Peter the Great, St Petersburg . . . . 348 Kit's Coty House, Kent .. 108 Westminster, with the Thames Embankment . . 110 Girard College, Philadelphia 554 Map of the Battle-fields of •View in the Steppes, Russia 353 The Albert Bridge, South Devon Railway . . . . 117 Birmingham 121 Map of Russian Canal System 358 Virginia and Maryland . . 553 Ruins of Uxmal, Mexico . . 560 Menai Suspension Bridge 131 The Kyles of Bute . . . . 133 Loch Katrine 139 The Alexander Column, St. Petersburg 365 Agave Americana . . . . 563 Pyramid at Uxmal . . . . 565 Sketch Map of Inter-oceanic Routes, Central America 567 Chimborazo and the Andes, South America . . . . 578 Bashkir Camp 372 Forres Pillar, Morayshire 143 Giant's Causeway, Antrim 152 Round Tower, Ireland . . 161 Gibraltar 167 Sketch Map of Asia . . . . 377 Saddling a Camel . . . . 382 Baghdad 392 Kurd3 397 Sketch Map of South America 580 Interior of Cordova Cathedral 181 Raft on the Tigris . . . . 399 Jerusalem 402 Mules in the Andes . . . . 589 The Peak of Teneriffe . . 184 The Falls of Gavarniee .. 189 Arab Women grinding Corn 404 Indians of the Pampas, South America . . . . 591 Sketch Map of N.E.

Frontier of France .. ..191 The Bolan Pass, Beloochistan 410 Towers of Sillustani, Peru 599 Cape Horn 605 The Landes, in the South of France 198 Tope at Bimeran .. ..411 Gaucho lassoing Cattle . . 608 Tussack Grass of the Falk- Kunchinjunga, Sikkim .. 413 Sketch Map of India . . 416 Temple at Tanjore . . . . 423 Tiger Cave at Cuttack . . 435 Adam's Peak, Ceylon . . 439 Scene on the Meinam, Place de la Concorde, Paris 206 Via Mala, Gorge of the Rhine 212 land Islands . . . . . . 618 Hobart Town, Tasmania . . 619 Native Village, New Zealand 634 Sketch Map of Switzerland 214 Lausanne 221 Whitsunday Isle, Melanesia 637 Cape Crozier and Mount Town Hall, Louvain . . 224 Map of Battle-fields of Belgium 230 Amsterdam 232 Siam 442 The Great Wall of China 444 Sha-sze on the Yang-tze 447 Chinese Bridge near Poking 450 Terror, Antarctic Re gions 642 * These cuts are copied from Sir Roderick Murchison's valuable work, and the Oural Mountains.' 'The Geology of Russia Kiflhtymat and its lake (Siberia), as seen from the Ural ran je MODERN GEOGRAPHY.

INTKODUCTION.

Chapter I. Mathematical Geography

y 1. Definition and Divisions of Geography. y 2. Definitions of terms connected with Mathematical Geography. y 3. Earth's position in the Universe. y 4. Figure and dimensions of the Earth. y 5. Motions of the Earth. y 6. Correspondence between the terrestrial and celestial spheres. y 1. Meridians and parallels. y 8. Methods of ascertaining latitude and longitude. y 9. Ecliptic, Tropics, Zones. $ 10. Globes and Maps. y 11. Perspective projections. y 12. Orthographic projection. y 13. Stereographic projection. y 14. Globular projection. y 15. Projection of two-thirds of the globe. $ 16. Conical projection. $ 17. Mercator's projection. § 1, Definition and Divisions of Geography. — The term Geography is derived from a Greek word (yeayparpia), which was applied both to verbal and pictorial descriptions of the earth, in other words, to trea tises and maps.

The modern term is restricted to the former of these senses as being the most important, and maps are regarded merely as auxiliary to Geography. The classical definition of the term is hardly precise enough for the requirements of modern science, inasmuch as a "description of the earth," iu its widest sense, would include almost the whole range of the physical sciences. Geography regards the earth as the platform on which man lives and moves, and, without entering into the theory of such scieuces as Astronomy, Botany, Zoology, &c, it culls from them such facts as bear on the interests or sustenance of man. Geography may therefore be defined to be a description of the earth as the abode of man. The topics which form its subject-matter may be conveniently classified under the three heads of Mathematical, Physical, and Descriptive Geography.

I. Mathematical Geography includes all such matters as are derived from the Mathematical sciences, and particularly from Astronomy and Geometry. It deals (1) with the planetary relations of the earth, such as its position in the Universe, its size, form, and movements ; and (2) with the methods by which its surface may be represented. This branch of Geography might otherwise be described as Cosmography. II. Physical Geography deals with the natural history of the earth's surface. It discusses such phenomena as the distribution of land and water, climate, volcanic agency, the animal and vegetable kingdoms, &c, and it examines into the causes and effects of each. III. Descriptive Geography takes as its basis the political divisions of the earth, and gives a general survey of the various countries — their physical features, productions, climate, inhabitants, towns, &c. It MOD.

GEO. B MATHEMATICAL GEOGRAPHY. iNTsiOC. includes what is termed Political Geography, but goes beyond iti; inas~ much as it interweaves the purely political with the physical aspect of each country. I— MATHEMATICAL GEOGRAPHY. § 2. Definition of Terms.— Mathematical Geography involves the use of certain terms of a scientific character, borrowed chiefly from Astro nomy and Geometry. The following need explanation : — Sphere, a body terminated by a curved surface, every point of which is equidistant from a point inside it, named its centre. Spheroid, a body approximating to a sphere, but not a perfect sphere. Axis of a sphere, an imaginary line, passing through its centre, upon which it rotates or may rotate. Poles, the extremities ofthe axis. Diameter, a straight line passing through the centre of a curved figure, and terminated at both ends by the sides of the figure.

Plane (in Astronomy), an imaginary level surface, bounded by a circle described on a sphere. Ellipse, a figure of an oval shape, formed by the intersection of a cone by a plane passing obliquely through both sides of it. Horizon., in the ordinary sense of the term, the circle which bounds the view of the earth's surface to a spectator on a level surface, such an a plain or the sea. This is termed the sensible horizon. The rational horizon is a circle parallel to the visible horizon, with a plane passing through the earth's centre, and extended to the celestial sphere, which 13 thus divided into hemispheres, one of which is upper and visible, the other lower and invisible. In the expression " plane of the horizon " the rational horizon is understood. Apparent Motion, the change of position which an object assumes to the eye of a spectator, who, being himself in motion, transfers the idea of that motion from himself to the object.

It is distinguished from real motion, where a change of position actually takes place in the object. Gravity, the reciprocal attraction of matter to matter. Centrifugal force, the tendency that a revolving body has to fly from the centre of motion. Mean distance (of a revolving body from the centre of the body round which it revolves), the moiety of the sum of the greatest and least distances. Mass, the quantity of matter in a given bulk. Satellite, a body revolving about a planet. § 3. Tlie Earth's position in the Universe. — The Earth is a member of the Solar system, which consists of the sun, eight planets, twenty-one satellites, a number of planetoids, or small planet-like bodies, of which above 170 have been already discovered; and, lastly, an indefinite number of comets. The solar system itself is one of a vast number of .similar systems, with which it is united in a single universal system.

It is supposed that the solar system is performing a movement, in con nexion with the other systems, in the wide fields of space ; but the effects of this movement on the earth are a mere matter of theory. The sun is the centre of the solar system ; it dispenses light, and heat throughout the whole, and its preponderating mass keeps the various members of the system in their places by the force of attraction. The Planets revolve about the sun in elliptical orbits at various distances. The earth holds the third place among them in point of proximity to Chai'. I. FIGURE AND DIMENSIONS OF THE EARTH. 3 the sun, at a mean distance of 92,300,000 m. ; and the fifth place in point of size, being larger than Venus, Mars, and Mercury, and smaller than Jupiter, Saturn, Neptune, and Uranus. The earth has one satellite, the Moon, which revolves about it at a mean distance of 237,600 miles, and exercises, from its proximity, a powerful attracting influence on the waters of the earth, which we shall presently notice under the head of Tides.

The moon effects its revolution round the earth in 27 d. 7 h. 43 m. 4-7 s., and so gives rise to the period of a lunar month. In the course of its revolution it occasionally comes between the earth and the sun, and occasionally has the earth between itself and the sun : in the former case an eclipse of the sun is caused by the passage of the'moou across its disc, in the latter case an eclipse of the moon by the shadow of the earth falling on it. § 4. Figure and dimensions of the Earth. — -That the earth is of a spherical, or, at all events, of a spheroidal form, is patent to the observation eve'n of unscientific persons. The gradual appearance of a vessel above the horizon as she approaches the land — the possibility of a traveller returning to the spot whence he started by pursuing an undeviating course in one direction — the circular shadow which the earth throws upon the moon at the time of an eclipse — these phenomena furnish indications which tend to show that the earth must either be a sphere, or very nearly a sphere.

Its exact form can only be ascer tained" by ineasui-emeuts and calculations of great precision, and is a subject which still engages the attention of scientific mell. Assuming that the earth rotates on its axis, and that its materials are, or once were, of a plastic or fluid character, it might be inferred a priori that the earth would bulge towards the equator, because the centrifugal force would naturally be greater there than elsewhere. And this is proved by observation to be the case : the oscillations of a pendulum of a given length become more rapid as it is conveyed from the equator towards either pole, proving that the force of gravity iB increased, and consequently that the poles are nearer the earth's centre than tlie equator is. The measurement of the arcs of a meridian under different parallels furnishes another proof of the same fact : for it is found that the length of a degree of a meridian increases as the poles are approached, and consequently that the earth's surface must be Hatter in that direction than elsewhere.

The earth may there fore be defined to be a spheroid of revolution, as the depression or flattening occurs at the polos, just as in an orange, it would be described in mathe- O. tical language as an oblate Fig. 1. spheroid, in contradistinction to a prolate spheroid, or one which resembles an egg in being drawn out in the direction of the axis. The accompanying figure represents such a spheroid, A A' being the axis upon which the body revolves in the direction indicated by the dotted lines, and E E' a line intersecting it midway at right angles, I! Introd. MATHEMATICAL GEOGRAPHY. and having a greater length than A A'. The two lines A A' and E E' represent in the earth the Polar and the Equatorial diameters respectively, but the proportionate difference in length of these is less than is represented in the figure, the Polar diameter having a length of about 7899-142 m.,1 and the Equatorial diameter of 7925-62G m., the difference being only 26J m., and the degree of ellipticity consequently about 2J3.

The circumference at the equator is 24,899 m., and at the poles 24,815 m., giving as the mean 24,857 m. The total area is estimated at 196,663,000 sq. m., and the solid contents at 260,000 millions of cubic miles. Whether the earth is a perfect sphere at the equator is perhaps doubtful : from the measurements of arcs of meridians it has been surmised that the equatorial diameters are not equal at all points. § 5. Motions ofthe Earth. — The earth has a double motion — a motion of rotation upon its axis, and a motion of translation about the sun. Both of these motions are in the direction of W. to E. The earth completes a revolution of the former kind in a day of 24 hours, and of the latter kind in a year of 365 d. 5 h. 48 m. 49-7 s. The rate of its daily motion varies in different parts of its surface from a maximum of about 1000 miles an hour at the equator to nil at the poles : for as the earth is 24,899 m. round at the former point, and makes a complete revolution in 24 hours, its velocity exceeds 1000 m. per hour ; from thence its circumference, and consequently its rate of motion, diminishes with each succeeding parallel, until the poles are reached where the circumference resolves itself into a point.

The rate of its annual motion round the sun may be put roughly at 1 140 m. per minute ; for it completes its orbit of nearly 600 millions of miles in 365 days, from which the above result may be ob tained : the rate varies at different periods of its revolution, being greatest when the earth approximates nearest to the sun. The effects of this yearly revolution cannot be estimated without taking into considera tion the position, or rather the posture, of the earth in reference to the sun. The axis of the earth is not perpendicular to the plane of its orbit, but in clined towards it at an angle of about 23^ degrees (exactly 23° 27' 28-75"), as shown in Fig. 2, where A A' represents its axis, B C D E the equator, F C G E the plane* of the earth's Fig. a. orbit, or the ecliptic, and H I a line perpendicular to that plane.

A A' 1 'she figures here given are the mean ofthe amounts as calculated byBeasel and Airy viz.: — Besscl. Airy Equatorial diam .925-604 7925-64S Polar diam. .899-114 7899 -170 The difference between the two amounts to 234 ft. in the equatorial, and 296 ft. in the polar diam. Chap. I. MOTIONS OF THE EARTH. 5 forms an angle of 23J° with H I, and B C D E does the same with F C G E. As the earth never varies its posture, its axis always retaining the same direction, the result is that different parts of the earth's surface are brought more directly under the sun's influence at different periods of the earth's revolution : in other words, the variations of the seasons are produced by the combined effects of the inclination of the earth's axis and its revolution round the sun. This will be made clearer by reference to Fig. 3, where S represents the sun, and E the earth at four different Fig. 3. stages of its revolution, with A A in each case for its axis.

Nos. 1 and 3 represent the position of the earth about the 21st of March and 23rd of September, when the northern and southern hemispheres have an equal share of the sun's presence, and day and night are of the same length throughout the world. No 2 exhibits the earth's position on or about June 21, when the northern hemisphere has an excess and the southern a deficiency of the sun's presence : in the former it is summer, in the latter winter. No. 4 represents the position on or about December 21, when the cases are reversed ; the southern has an excess, and the northern a deficiency : it is summer in the former and winter in the latter. § 6. Correspondence between the Terrestrial and Celestial Spheres. — The movements of tbe earth are faithfully represented in the aspect of the heavenly bodies.

The terrestrial sphere is to all appearance en cased in a celestial sphere, and each spot on the former has, at a given moment, its corresponding position on the latter. The earth's diurnal revolution from west to east produces the apparent movement of the sun from east to west, and of the stars about the point which answers to the earth's axis : and its annual revolution, combined with the incli nation of its axis, produces the apparent movement of the sun to the north and south of the equator in the path of the ecliptic. It is evident that the apparent movements of the celestial bodies of which we are conscious may be used as an index of the real movements of the earth of which we are not otherwise conscious, and that the conditions of time and space which belong to the one may be transferred to the other.

If, for instance, the sun or a certain star appear at one spot to be higher in the heavens than at another (in other words to have a different altitude), it is an indication of a proportionate difference of position between those spots: and a measurement of the difference MATHEMATICAL GEOGRAPHY. lN'TKOD. of altitude supplies a basis for calculating the difference of position on the earth's surface. If, again, an observer were to take a point in the heavens, representing a certain point on the earth, — such, for instance, as the point which stands opposite to the earth's axis, — and were to ob serve the position in the heavens corresponding to the spot on which he stands, he might ascertain what portion of the celestial sphere, and consequently what portion of the terrestrial sphere intervenes between those points : this portion he may further express in miles, from his knowledge of the dimensions of the sphere with which he is dealing.

Again, as the sun appears to revolve round the earth in 24 hours, it is easily ascertained how much of the earth's circle it traverses in each hour and each minute : time and space thus become convertible into each other, so that if we know the interval of time occupied by the sun in its passage from spot to spot we may calculate the space on the earth's sphere: vice x-ersd, if we know the space, we may calculate the time. § 7. Meridians and Parallels. — As the earth is of a spherical form, the most obvious method of dividing and subdividing its surface is by imaginary lines draw-n round it in different directions. As suming as the basis of our operations the axis of the earth, we may draw circles from any point on it with a radius re volving in a plane at right angles to it. Thus, in Fig. 4, from the points B and C in the axis A A' the circles E G H I aud D K L M are drawn with the radii B E and C D. Or, again, from a single point in the axis, viz. the. centre, circles may be drawn in the plane of the axis ; as from C with the radii C F and C N are drawn the circles F A L K and NA'OA.