Page images
PDF
EPUB

Strathclyde Briton; and Geoffrey is responsible for the blunder of transferring him to South Wales. So intimately is Geoffrey connected with Arthur's celebrity, that he is often called Galfridus Arturus. Although the wondrous cycle of Arthurian romances scarcely originated with Geoffrey, be made the existing legends radiant with poetic colouring. They thus became the common property of Europe; and, after being modified by the trouvères in France, the minnesingers in Germany, and by such writers as Gaimar, Wace, Mapes, Robert de Borron, Luces de Gast, and Hélie de Borron, they were converted into a magnificent prose poem by Sir Thomas Malory, in 1461. Malory's Morte Darthur, printed by Caxton in 1485, is as truly the epic of the English mind as the Iliad is the epic of the Greek mind.

The first English tragedy, Gorboduc, or Ferrex and Porrex (1565), which was written mainly by Sackville, is founded on the Historia Britonum. John Higgins, in The Mirror for Magistrates (1587), borrows largely from the old legends. This work was extremely popular in the Elizabethan period, and furnished dramatists with plots for their plays. Spenser's Faërie Queene is saturated with the ancient myths; and, in his Arthur, the poet gives us a noble spiritual conception of the character. In the tenth canto of Book ii. there is

"A chronicle of Briton kings, From Brut to Uther's rayne.

lit up with his sunny humour. Alexander Smith has a poem treating of Edwin of Deira, who figures towards the close of Geoffrey's history. And Tennyson's Idylls of the King furnish the most illustrious example of Geoffrey's influence, although the poet takes his stories, in the first instance, from Malory's Morte Darthur. The influence tha legends have had in causing other legends to spring up, and in creating a love for narrative, is simply incalculable. In this way Geoffrey was really, for Englishmen, the inventor of a new literary form, which is represented by the romances and novels of later times.

There are several MSS. of Geoffrey's work in the old Royal Library of the British Museum, of which one formerly belonging to Margan Abbey is considered the best. The titles of the various editions of Geoffrey are given in Wright's Biog. Brit. Lit., in the volume devoted to the Anglo-Norman period, which also contains an excellent notice of Geoffrey. The work compiled by Balo and Pits gives a mythical literary history, corresponding to Geoffrey's mythical political history. Of the Life and Prophecies of Merlin, falsely attributed to Geoffrey, 42 copies were printed for the Roxburghe Club in 1830. The Historia was translated into English by Aaron Thompson (London, 1718); and a revised edition was issued by Dr Giles (London, 1842), which is to be found in the volume entitled Six Old English Chronicles in Bohn's Antiquarian Library. A discussion of Geoffrey's literary influence is given in "Legends of Pre-Roman Britain," an article in the Dublin University Magazine for April 1876. The latest instance of the interest in Geoffrey is the publication of the following work:-Der Münchener Brut Gottfried von Monmouth in französ. Versen des zwölflen Jahrhunderts, herausgeg. von R. Hofmann und K. Vollmöller, Halle, 1877. For further information about Geoffrey, consult Warton's English (1586),Poetry; Morley's English Writers; Skene's Four Ancient Books of Wales; and a valuable paper on Geoffrey of Monmouth's History of the Britons," in the 1st vol. of Mr Thomas Wright's Essays on (T. GI.) Archaeological Subjects (London, 1861).

Warners lengthy poem entitled Albion's England is full of legendary British history. Drayton's Polyolbion (1613) is largely made up of stories from Geoffrey, beginning with Britain-founding Brute. Geoffrey's good faith and historic accuracy are warmly contended for by Drayton, in Song x. of his work.

In Shakespeare's time Geoffrey's legends were still implicitly believed by the great mass of the people, and were appealed to as historical documents by so great a lawyer as Sir Edward Coke. They had also figured largely in the disputes between the Edwards and Scotland. William Camden was the first to prove satisfactorily that the Historia was a romance. Shakespeare's King Lear was preceded by an earlier play entitled The Chronicle History of King Lear and his Three Daughters, Gonorill, Ragan, and Cordelia, as it hath been divers and sundry times lately acted. Shakespeare's immediate authority was Holinshed; but the later chronicles, in so far as they were legendary, were derived from Geoffrey. The story of Cymbeline is another illustration of the fascination these legends exercised over Shakespeare. An early play, ascribed by some to Shakespeare, on Locrine, Brutus's eldest son, is a further example of how the dramatists ransacked Geoffrey's stores. The Historia was a favourite book with Milton; and he once thought of writing a long poem on King Arthur, whose qualities he would probably have idealized, as Spenser has done, but with still greater moral grandeur. In addition to the evidence afforded by the introduction to his History of England, Milton shows in many ways that he was profoundly indebted to early legendary history. His exquisite conception of Sabrina, in Comus, is an instance of how the original legends were not only appropriated but ennobled by many of our writers. In his Latin poems, too, there are some interesting passages pertinent to the subject.

Dryden once intended to write an epic on Arthur's exploits; and Pope planned an epic on Brutus. Mason's Caractacus bears witness to Geoffrey's charm for poetic minds, Wordsworth has embalmed the beautiful legend of Pious Elidure in his own magic verse. In chapter xxxvi. of the Pickwick Papers Dickens gives what he calls "The True Legend of Prince Bladud," which is stamped throughout with the impress of the author's peculiar genius, and

[ocr errors]

He

GEOFFROY SAINT-HILAIRE, ÉTIENNE (1772-1844), a celebrated French naturalist, was the son of Jean Gérard Geoffroy, procurator and magistrate of Étampes, Seine-etOise, where he was born, April 15, 1772. His early education was carefully superintended by his mother and paternal grandmother, and when still a boy he had already become acquainted with the masterpieces of the literature of the ancients, and of the age of Louis XIV: Destined by his friends for the church, he entered, as an exhibitioner, the college of Navarre, in Paris, where he studied natural philosophy under Brisson; and in 1788 he obtained one of the canonicates of the chapter of Sainte Croix at Étampes, and also a benefice. Science, however, offered to him a career more congenial to his tastes than that of an ecclesiastic, and, after some persuasion, he gained from his father permission to remain in Paris, and to attend the lectures at the Collège de France and the Jardin des Plantes, on the condition that he should likewise read law. accordingly took up his residence at Cardinal Lemoine's college, and there became the pupil and soon the esteemed associate of Brisson's friend, Haüy, the eminent mineralogist, under whose guiding influence his passion for the natural sciences daily deepened. Having, before the close of the year 1790, taken the degree of bachelor in law, he became a student of medicine, but the lectures of Fourcroy at the Jardin des Plantes, and of Daubenton at the Collégo de France, and his favourite scientific pursuits gradually came to occupy his almost exclusive attention. His studies at Paris were at length suddenly interrupted, for, on the 12th or 13th of August 1792, Hauy and the other profes sors of Lemoine's college, as also those of the college of Navarre, were arrested by the revolutionists as priests, and confined in the prison of St Firmin. Through Daubenton and other persons of distinction with whom he was acquainted, Geoffroy on the 14th August obtained an order for the release of Haüy in the name of the Academy; still the other professors of the two colleges, save Lhomond, who had been rescued by his pupil Tallien, remained in confinement. Geoffrey, foreseeing their certain destruction

devoted himself more exclusively than before to the study of anatomical philosophy. In 1815 he was elected political representative for his native town. Three years later he gave to the world the first part of his celebrated Philosophie Anatomique, the second volume of which, published in 1822, aud memoirs subsequently written account for the forma tion of monstrosities on the principle of arrest of develop ment, and of the attraction of similar parts. When, in 1830, Geoffroy proceeded to apply to the invertebrata his views as to the unity of animal composition, he found a vigorous opponent in Georges Cuvier, and the discussion between them, continued up to the time of the death of the latter, soon attracted the attention of the scientific throughout Europe. Geoffroy, a synthesist, contended, in accordance with his theory of unity of plan in organic composition, that all animals are formed of the same elements, in the same number, and with the same connexions: homologous parts, however they differ in form and size, must remain associated in the same invariable order. With Goethe he held that there is in nature a law of compensation or balancing of growth, so that if one organ take on an excess of development, it is at the expense of some other part (cf. Darwin, Origin of Species, 5th ed., p. 182); and he maintained that, since nature takes no sudden leaps, even organs which are superfluous in any given species, if they have played an important part in other species of the same family, are retained as rudiments, which testify to the per manence of the general plan of creation. It was his conviction that, owing to the conditions of life, the same forms had not been perpetuated since the origin of all things, although it was not his belief that existing species are becoming modified (see Darwin, op. cit., p. xvi.). Cuvier, who was an analytical observer of facts, admitted only the prevalence of "laws of coexistence" or "harmony" in animal organs, and maintained the absolute invariability of species, which he declared had been created with a regard to the circumstances in which they were placed, each organ contrived with a view to the function it had to fulfil, thus putting, in Geoffroy's consideration, the effect for the cause. In July 1840 Geoffroy became blind, and some months later he had a paralytic attack. From that time his strength gradually failed him. He resigned his chair at the museum in 1841, and on the 19th June 1844, at the age of 72, he died.

if they remained in the hands of the revolutionists, determined if possible to secure their liberty by stratagem. By bribing one of the officials at St Firmin, and disguising himself as a commissioner of prisons, he gained admission to his friends, and entreated them to effect their escape by following him. All, however, dreading lest their deliverance should render the doom of their fellow-captives the more certain, refused the offer, and one priest only, who was unknown to Geoffroy, left the prison. Already on the night of the 2d of September the massacre of the proscribed had begun, when Geoffroy, yet intent on saving the life of his friends and teachers, repaired to St Firmin. At 4 o'clock on the morning of the 3d Sept., after 8 hours' waiting, he by means of a ladder assisted the escape of twelve ecclesiastics, not of the number of his acquaintance, and then the approach of dawn and the discharge of a gun directed at him warned him, his chief purpose unaccomplished, to return to his lodgings. Leaving Paris he retired to Étampes, where, in consequence of the anxieties of which he had lately been the prey, and the horrors which he had witnessed, he was for some time seriously ill. At the beginning of the winter of 1792 he returned to his studies in Paris, and in March of the following year Daubenton, through the interest of Bernardin de Saint Pierre, procured him the office of sub-keeper and assistant demonstrator of the cabinet of natural history, vacant by the resignation of Lacepède. By a law passed June 10th, 1793, Geoffroy was appointed one of the twelve professors of the newly constituted museum of natural history, being assigned the chair of zoology. In the same year he busied himself with the formation of a menagerie at that institution. On the 6th May 1794 commenced his opening course of lectures, and on December 1st he read to the society of natural history his first paper, on the subject of the Aye-aye. It was in 1794, also, that through the introduction of Tessier he entered into correspondence with Georges Cuvier, to whom, after the perusal of some of his manuscripts, he wrote: "Venez jouer parmi nous le rôle de Linné, d'un autre législateur de l'histoire naturelle." Shortly after the appointment of Cuvier as Mertrud's assistant (see vol. vi. p. 740), Geoffroy received him into his house. The two friends wrote together five memoirs on natural history, one of which, on the classification of mammals, puts forward the idea of the subordination of characters upon which Cuvier based his zoological system. It was in a paper entitled "Histoire des Makis, ou singes de Madagascar," written in 1795, that Geoffroy first gave expression to his views on "the unitymique, -t. i., Des organes respiratoires, 1818, & t. ii., Des Monstruo

of organic composition," the influence of which is perceptible in all his subsequent writings: nature, he observes, presents us with only one plan of construction. the same in principle, but varied in its accessory parts.

In 1798 Geoffroy was chosen a member of the great scientific expedition to Egypt. With Delile and Larrey, on the capitulation of Alexandria in August 1801, he resisted the claim made by the British general Hutchinson to the collections of the expedition, sending him word that, were his demand persisted in, history would have to record of him that he also had burnt a library in Alexandria. Early in January 1802 Geoffroy returned to his accustomed labours in Paris. He was elected a member of the academy of sciences of that city in September 1807. In March of the following year the emperor, who had already recognized. his national services by the award of the cross of the legion of honour, selected him to visit the museums of Portugal, for the purpose of procuring from them collections, and these, though in the face of considerable opposition from the British, he eventually was successful in retaining as a permanent possession for his country. In 1809, the year after his return to France, he was made professor of zoology of the faculty of sciences at Paris, and from that period he

Geoffroy wrote-Catalogue des Mammifères du Muséum national d'Histoire naturelle, 1813, not quite completed; Philosophie anato

sités humaines, 1822; Système dentaire des Mammifères et des
Oiscaux, 1st pt., 1824; Sur le Principe de l'Unité de Composition
organique, 1828; Cours de l'Histoire naturelle des Mammiferes,
1829; Principes de Philosophie zoologique, 1830; Études progressives
d'un Naturaliste, 1835; Fragments biographiques, 1832; Notions
synthétiques, historiques, et physiologiques de Philosophic naturelle,
1838; and other works; also part of the Description de l'Égypte par
la Commission des Sciences, 1821-30; and, with F. Cuvier, Histoire
naturelle des Mammiferes, 4 vols., 1820-42; besides very numerous
papers published in the Annales du Muséum, the Ann. des Sci.
nat., the Bulletin philomatique, La Décade égyptienne, La Décade
philosophique, the Rev. encyclopédique, Mém. de l'Acad. des Sciences,
and elsewhere, among the subjects of which are the anatomy of
marsupials, ruminants, and electrical fishes, the vertebrate theory
of the skull, the opercula of fishes, teratology, paleontology, and
the influence of surrounding conditions in modifying animal forms.
Seo Vie, Travaux, et Doctrine Scientifique d'Étienne Geoffroy Saint-Hilaire,
par son fils M. Isidore Geoffroy Saint-Hilaire, Paris and Strasburg, 1847, to
which is appended a list of Geoffroy's works; and Joly, in Biog. Universelle
xvi, 1856.
(F. H. B.)

GEOFFROY SAINT-HILAIRE, ISIDORE (1805-61); a French zoologist, son of the preceding, was born at the Jardin des Plantes, Paris, December 16, 1805. In his earlier years he showed an aptitude for mathematics, but eventually he devoted himself to the study of natural history and of medicine, and in 1824 he was appointed assistant naturalist to his father. On the occasion of his taking the degree of doctor of medicine, September 8, 1829, he

[ocr errors]

road a thesis entitled Propositions sur la monstruosité, considérée chez l'homme et les animaux; and in 1832-37 was published his great teratological work, Histoire générale et particulière des anomalies de l'organisation chez l'homme et les animaux, 3 vols. 8vo, with 20 plates. In 1829 he delivered for his father the second part of a course of lectures on ornithology, and during the three following years he taught zoology at the Athénée, and teratology at the École pratique. He was elected a member of the academy of sciences at Paris on April 15, 1833, was in 1837 appointed to act as deputy for his father at the faculty of sciences in Paris, and in the following year was sent to Bordeaux to organize a similar faculty there. He became successively inspector of the academy of Paris (1840), professor of the museum on the retirement of his

INTRODUCTION.

[ocr errors]

father, inspector general of the university (1844), a member of the royal council for public instruction (1845), and, on the death of Blainville, professor of zoology at the faculty of sciences (1850). In 1854 he founded the Acclimatization Society of Paris, of which he was president. He died at Paris, November 10, 1861.

Besides the above-mentioned works, he wrote-Essais de Zoologie générale, 1841; Vie....d Etienne Geoffroy Saint-Hilaire, 1847; Acclimatation et Domestication des Animaux utiles, 1849, 4th ed., 1861; Lettres sur les substances alimentaires et particulièrement sur la viande de cheval, 1856; and Histoire naturelle générale des règnes organiques, 3 vols., 1854-62, which was not completed, chap. xx. of tome iii. being unfinished. He was the author also of various papers on zoology, comparative anatomy, and paleontology, published for the most part in the Annales du Muséum, the Mémoires des Savants étrangers, the Comptes rendus, and the Dict. des Sciences naturelles.

GEOGRAPHY

GEOGRAPHY is the science which describes the earth, the term being derived from two Greek words y, the earth, and ypάow, to write. By means of geography the surface of the earth is delineated and described, boundaries are defined, areas are exactly measured, and the relative positions of places are determined. Geography thus embraces a wide range of subjects, and it has been found necessary to divide its study into several distinct sections. 1. Comparative Geography traces the history of discovery, and records the changes which have taken place in land and

sea in historic times.

II. Mathematical Geography explains the figure, magnitude, and motion of the earth, teaches how to determine the positions of places on its surface, and shows how the whole or any portion of the earth may, on the principles of projection, be delineated on a map or chart.

IIL Physical Geography is the description of the actual state of the earth's surface in its three great divisions-land, sea, and air.

IV. Political Geography describes the earth as divided into countries, occupied by various nations, and improved by human art and industry.

The following article is limited to a view of the progress of geographical discovery, an explanation of the principles of mathematical geography, and a synopsis of physical geography. For details relating to political geography the reader must consult the descriptive articles under their particular headings.

L. VIEW OF THE PROGRESS OF GEOGRAPHICAL DISCOVERY. Four main causes have led to geographical discovery and exploration, namely, commercial intercourse between different countries, the operations of war, pilgrimages and missionary zeal, and in later times the pursuit of knowledge for its own sake, which is the highest of all motives.

The Phoenicians are the earliest commercial people of whose discoveries we have any correct accounts. They first explored the shores of the Mediterranean, and eventually extended their voyages through the Straits of Gibraltar, and visited the western shores of Spain and Africa, planting colonies and opening wider fields for their commerce by instructing the natives in their arts and improvements. They also monopolized the trade with India; and their chief emporium, the rich city of Tyre, was the centre whence the products of the East and West were distributed. The trade of the West was brought from the port called Tarshish in Scripture, which is probably identical with Carthage, where the ships arrived from Spain, Africa, and distant Britain. Concerning the far eastern land reached by the Phoenicians,

called Ophir in Scripture, there has been much dispute. and homopard, and thold, occupied three years thither and homeard, and the cargo consisted of gold, ivory, apes, peacocks, and "algum" wood (1 Kings ix. 26, and x. 11). The following reasons lead to the conclusion that Ophir was the Malabar coast of India. In the Hebrew the word for apes is koph (without any etymology in Semitic tongues), in Sanskrit kafi. Ivory in Hebrew is shen-habbim; in Sanskrit ibha is an elephant. Peacocks is in Hebrew tokki-im from togei, the name still used on the Malabar coast, derived from the Sanskrit. Algum wood, or almug, is corrupted from valgu (ka), sandal wood from Malabar. Thus the Phoenicians were the first great carriers of the ancient world, extending their commercial operations from their central mart of Tyre on the Syrian coast to the tinyielding isles of the Cassiterides in the far west, and to the ports of India in the east.

The great Phoenician colony of Carthage retained in full Carthage The vigour the commercial spirit of the parent state. Carthaginians traded on the coasts of Spain and Gaul, and extended their discoveries southwards along the coast of Africa, and to the Fortunate Islands, now known as the Canaries. Herodotus relates how the Phoenicians, setting sail from the Red Sea, made their way to the south, and sowed a crop, and waited till it was grown, when they when autumn approached they drew their vessels to land, reaped it and again put to sea. Having spent two years in this manner, in the third year they reached the pillars of Hercules and returned to Egypt. But the most celebrated voyage of antiquity, undertaken for the purpose of discovery, was the expedition under Hanno, fitted out by the senate of Carthage with the view of attempting the complete survey of the western coast of Africa. Hanno is said, in the Periplus Hannonis, to have set sail with a fleet of 60 vessels, and the extent of his voyage has been variously estimated as reaching to the river Nun, to a little beyond Sierra Leone, and even as far as the Gulf of Benin. Another famous navigator, who sailed from the Carthaginian colony of Massilia (Marseilles) in about 320 B.C., was Pytheas. He steered northwards along the coasts of Spain and Gaul, sailed round the island of Albion, and stretching still further to the north, he discovered an island known to the ancients as Ultima Thule, which may possibly have been the Shetland Isles.

Great.

The conquests of Alexander the Great, by making known Alexanthe vast empire of Persia, materially enlarged the bounds der the of geographical knowledge. Although the course of his expedition was mainly by land, the mind of the conqueror was also intent on commerce and maritime discovery. In 327 B.C. Alexander led an army of Greeks down the valley of the Cabul river into the Punjab, and his expedition

Ptolom

ics.

Romans.

resulted in a voyage of discovery from the mouth of the Indus to that of the Tigris, and in opening direct intercourse between Grecian and Hindu civilization. The Greeks who accompanied Alexander were accurate observers, and described the towns and villages, the products and the aspect of the country, with care. The conqueror resolved to return through Gedrosia (the modern Baluchistan), but he also intended to open the trade by sea between Europe and India, and his general Nearchus, a native of Crete, volunteered to lead this famous voyage of discovery. His fleet consisted of 30 galleys containing 2000 men. On October 2, 326 B.C., the fleet of Nearchus left the Indus, and the anchorages each night are carefully recorded. On the 17th of December Cape Jask was doubled and the fleet entered the Persian Gulf, and on the 9th of February it was at the mouth of the Karún. Nearchus rejoined Alexander at Susa; and the conqueror himself embarked in the fleet and ascended the Tigris to Opis, above Baghdad. He then ordered his successful admiral to prepare another expedition for the circumnavigation of Arabia; but unfortunately the great conqueror died at Babylon in 324 B.C., and the fleet was dispersed.

The dynasties founded by Alexander's generals, Seleucus, Antiochus, and Ptolemy, encouraged the same spirit of enterprise which their master had so carefully fostered, and extended geographical knowledge in several directions. Seleucus Nicator established the Greco-Bactrian empire, and continued the intercourse with India. The most authentic information respecting the Gangetic valley was supplied by Megasthenes, an ambassador sent by Seleucus, who reached the remote city of Patali-putra, the modern Patna, on the Ganges.

The Ptolemies of Egypt showed equal anxiety to extend the bounds of geographical knowledge. Ptolemy Euergetes sent an expedition which discovered Abyssinia, and fitted out a fleet under Eudoxus to explore the Arabian Sea. After two successful voyages, Eudoxus left the Egyptian service, and proceeded to Cadiz with the object of fitting out an expedition for the purpose of African discovery; and we learn from Strabo that the veteran explorer made at least two voyages southward along the coast of Africa. The Ptolemies sent fleets annually from their Red Sea ports of Berenice and Myos Hormus to Arabia, as well as to ports on the coasts of Africa and India.

The Romans did not encourage navigation and commerce with the same ardour as their predecessors; still the luxury of Rome, which gave rise to demands for the varied products of all the countries of the known world, led to an active trade both by ships and caravans. But it was the military genius of Rome, and the ambition for universal empire, which led not only to the discovery but also to the survey of nearly all Europe, and of large tracts in Asia and Africa. Every new war produced a new survey and itinerary of the countries which were conquered. In the height of their power the Romans had surveyed and explored all the coasts of the Mediterranean, Italy, Greece, the Balkan peninsula, Spain, Gaul, western Germany, and Britain; but the eastern parts of Germany, Denmark, Sweden, and Russia were still unknown regions. In Africa their empire included Egypt, Carthage, Numidia, and Mauritania In Asia they held Asia Minor and Syria, had sent expeditions into Arabia, and were acquainted with the more distant countries formerly overrun by Alexander, namely, Persia, Scythia, Bactria, and India. Roman intercourse with India especially led to the extension of geographical knowledge.

The first Roman who undertook a journey to India was solely influenced by the desire to acquire a knowledge of the people and their doctrines. This was Apollonius, a resident at Antioch, who set out towards the close of the

He and his attendants,

first half century of our era. Damis and Philostratus, reached the Indus, and journeying across the Punjab, came to a bronze pillar with the inscription "Here Alexander halted"; but it is doubtful whether the party advanced as far the Ganges. It was, however, in the reigns of Severus and his immediate successors that Roman intercourse with India was at its height.

atiz

In all time, while warriors and explorers extended the Atte area of geographical knowledge, there have been students at sy who have striven to systematize and put into due form the accumulated information. From the first it was perceived that a knowledge of localities could not be attained without some notion of their relative positions, and their distances from each other. Consequently the attempts to establish fixed principles on which the surface of the earth, or any portion of it, could be delineated, were almost coeval with the earliest voyages of discovery.

The first attempt made to determine the position of places appears to have depended on the division of the earth into "climates," distinguished by the species of animals and plants produced in each. This method, however, was soon abandoned for another, which consisted in observing at places the length of the longest and shortest days by means of a "gnomon." An upright pillar of a known height being erected on a level pavement, by observing the lengths of the meridian shadows the progress of the sun from tropic to tropic was traced. The most ancient observation with the gromon is that of Pytheas, in the days of Alexander the Great, who observed at the summer solstice at Massilia that the length of the meridian shadow was to the height of the gnomon as 2131 to 600, an observation which makes the meridian altitude of the sun at Marseilles on that day 70° 27'. The merit of the invention of the gnomon in Greece is ascribed to the astronomical school of Miletus; but there is reason to believe that this method of observation was invented in Egypt, and that Thales carried the knowledge of it into Greece. This was the first step towards connecting geography with astronomy; and .ttle further advance was made until the establishment of the famous astronomical school of Alexandria.

Eratosthenes (276-196 B.C.) was the first who reduced Era geography to a regular system, and laid its foundations on the clear and solid principles. Under the patronage of the Ptolemies he had access to all the materials collected by Alexander and his generals. The doctrine of the sphericity of the earth had by this time been adopted, and the aim of his labours was to delineate, in conformity with this principle, the known parts of the earth's surface. Founding his system on the use of the gnomon, he supposed a line to be traced through certain places, in all of which the longest day was known to be exactly of the same length. Such a line would evidently be a parallel to the equator. This first parallel passed through Rhodes, and was ever afterwards adopted as the basis of ancient maps. Eratosthenes continued his work by tracing other parallels at certain intervals from the first, one through Alexandria, another through Syene, a third through Meroe. He also traced, at right angles to these, a meridian passing through Rhodes and Alexandria, southwards to Syene and Meroe. As the progress which he thus made towards the completion of what he had so skilfully conceived naturally tended to enlarge his ideas concerning geographical science, he attempted next to determine the circumference of the globe by the actual measurement of a segment of one of its great circles. Posidonius made another measurement of an arc of the Pos meridian between Rhodes and Alexandria about 170 years afterwards; but the amount of error in the calculations of Eratosthenes and Posidonius is uncertain, for want of a knowledge of the true length of the stadium in which their results are expressed. The ancients made their first meri

don

« EelmineJätka »