FIGURE OF THE EARTH.

BY SR. MIGUEL MERINO.

Anuario del Real Observatorio de Madrid; cuarto año; 1863.

TRANSLATED FOR THE SMITHSONIAN INSTITUTION BY C. A. ALEXANDER

IN an article inserted in our Annual for 1862, under the same title with the present, we proposed, as our nearly exclusive object, to present, in an elementary manner, the result of the investigations heretofore made to determine the form and volume of the earth, apart from historical notices, numerical details, and, in a word, whatever might embarrass the course of the reasoning, or distract the attention of our readers. Thus conceived and compiled, that first article was for the most part dry, as regards results, and incomplete under various aspects. Dry, inasmuch as the mind takes less pleasure in the final solution of a problem than in the survey of the means and computations employed to overcome, one after another, the difficulties which beset it; and incomplete, because without numbers there is in the physical sciences no precise solution, such as shall leave the mind tranquil and satisfied. To supply our intentional omission is the design of the present pages, in which, assuming the substance of our former article to be known, we shall consider, successively, and under the new point of view just indicated, the three following points:

First. In what manner the human understanding, acted upon by the immediate testimony of the senses, acquired, after a long uncertainty, a clear idea of the roundness and rotation of the earth.

Second. By what means that first idea, founded on a somewhat superficial examination, became confirmed, and, at the same time, modified in some of the details by the actual and direct measurement of our globe.

Third. The present state of the question, briefly summed up in certain numerical tables.

I.

In considering the progress of astronomy we must distinguish two epochs of quite different character-one very remote, and only known to us by vague and confused tradition, which has often undergone a strained interpretation; the other nearer to our own times, whose history has been consigned to unequivocal and imperishable monuments. In the opinion of certain authors possessed of erudition and talent, and doubtless sincere in their belief, but led astray possibly by the excess of their imagination, the ancient people of central Asia, the Chinese, Indians, Assyrians, and Chaldeans, as well as the Egyptians, enjoyed a civilization superior to the modern, cultivated the sciences, and possessed, particularly, a knowledge of celestial phenomena, to which our present astronomers cannot yet pretend. In the possible case that this were so, although the mind instinctively revolts from believing it; that astronomy flourished at a period of which history preserves no distinct traces, and that all which we know to

day respecting the form of the earth and its relations with the other bodies of our system was known many ages before that in which we live; granting, moreover, that in view of the constant and great vicissitudes to which the world is subject, where the events of to-day so readily and radically efface the most momentous memories of yesterday, we are left without any positive grounds for roundly denying the above assertions, yet what imports it to us whether the primitive people of Asia were more enlightened than those of modern Europe, if there remain only incomplete traces of their knowledge-if their science has disappeared or been transmitted only when the modern had secured new foundations, assuredly not less solid than the ancient? If we concede at once that those people had ascertained the roundness of the earth, whether from the experience acquired in their emigrations and their warlike and commercial expeditions, or else from a species of intuition; that from the demonstrated fact they ascended to the producing cause, and that, not content with a knowledge of the form, they had sought and succeeded in determining the dimensions of the globe, what advantage have the moderns derived from all this? In what respect have these problematical antecedents served to enlighten us with reference to the questions with which we are engaged? This is to us the point of interest, and it is this which we should first of all endeavor to make plain.

In his heroic poems Homer brings together all the cosmographic and geographic ideas of his age and of the people to whom he belonged-a people fitted, beyond all then known, for the cultivation of the sciences, distinguished by their lively and penetrating imagination, and inhabiting a country in all respects the most favorably situated for observation. And yet Homer, minute and exact as he is in the description of the scene on which his heroes moved, supposes the earth to be a plane, and bounded in all directions by the waters of the ocean; places in the middle of it Greece, and particularly the Thessalian Olympus; establishes, on the mysterious limits of the horizon, pillows which serve as a support for the skies; pictures Tartarus, the abode of the enemies of the gods, at a great depth beneath the surface; and beyond the dim confines of carth imagines chaos, or immensity, a confused mixture of life and vacuity, an abyss where exist, without order, all the elements of Tartarus, earth, and heaven. Here we have the point of departure for our existing knowledge respecting the form of the earth and the constitution of the celestial vault; and is there here anything which reveals the profound research, whether certain or problematical, of the pristine races? Have we here, indeed, anything more than the primitive ideas, which the spectacle of nature wakens in the breast of every one moderately endowed with an inquiring spirit, dressed in the colors of a glowing imagination, but betraying the incapacity to discover the truth through the mists which envelope it?

The voyages of the Phenicians, though conducted with less timidity than those of the cotemporary Greeks, yet with a prudence and caution indicative of no transmitted knowledge, open the door to wider investigation, to juster ideas of the figure of the earth, and lead, by a more certain, at least more expeditious path, to the discovery of the truth. Till this epoch history presents to us each people shut up within the narrow limits which nature had marked for it, here separated from the rest by mountain chains, there by tempestuous seas. The dwellers of Tyre and Sidon are the first to venture habitually on distant voyages in search of new lands, of foreign productions, of the objects of luxury and affluence, which were wanting at home. They visit, one by one, all the islands of the Mediterranean, coast along the north of Africa, founding colonies wherever suitable; and, without recoiling before the dreaded straits of Gades, launch into the ocean and establish the principal seats of their com merce on the smiling shores of Betica. And while advancing on the west to points never before reached, this commercial people unite the fleets of their King Hiram with those of Solomon to explore the coasts of the Red and of the

Erythrean or Indian seas; while still later, as some historians maintain, their boldness reaches such a point that they navigate the shores of Africa by the east, double the Cape of Good Hope, afterwards long forgotten, and regain their country at the end of three years by the before-mentioned straits of Gades, or Gibraltar.*

The Carthaginians, possessing the same enterprising and mercantile genius with their ancestors of Phenicia, and benefiting by the experience of the latter, projected still more important, if not more daring, expeditions. Hanno, with a numerous fleet, traces the western coast of Africa and attains the mouth of the river Senegal, while Himilco, sailing in the opposite direction, stops not short of England, where he loads his vessels with the coveted metal stored in that region.

Similar expeditions, made with ever-increasing frequency and boldness, such as the voyage of Colous of Samos, which extended to the entrance of the Atlantic, and so strongly excited the curiosity of the Greeks, and the much later one of Pytheast of Marseilles, who advanced as far as the Feroe islands, and even entered the Baltic, although they might be undertaken solely with the views of adventure or cupidity, could not but be conducive to the progress of astronomy and its kindred sciences, as well in regard to the preliminaries they required, as the observations and notices collected in these protracted wanderings. However closely attracted to the land by necessity or interest, can we suppose that these early navigators did not often lift their eyes to contemplate the celestial vault, induced as well by the requirements of safety as by the curiosity inherent in man of seeing and learning something new? In this way the old impressions that the earth was plane and undefined, that the stars, quenched in the sea, were again kindled at their rising, and others of the same kind, would necessarily give way, not alone in the conceptions of the thoughtful, but in the opinion of the vulgar, and be replaced by ideas more creditable to human sagacity, and conformable to the truth and simplicity of nature. To this result would conduce, indirectly but still effectually, the travels undertaken by land, whether towards the north in search of amber, furs and materials of construction, towards the east for ivory and spices, or towards the west for metals. The wars among nations would also promote this result, as necessarily tending to a mixture of races, and a comparison of conflicting ideas. Among influences of this kind we may especially distinguish the expedition of Alexander, at once enlarging beyond example the limits of the known world, and bringing into propitious coincidence a vast material and a most favorable conjuncture of circumstances for new and fruitful meditation; the conquests of the Romans, extend into one almost all the nations of the known world, and attracting to the common centre whatever that world contained which could minister to an unbounded love of ostentation and luxury; the Gothic irruption, covering the world with ruins from which the germs of knowledge might spring with a new and more vigorous life; and the subsequent appearance of the Saracens,

*This voyage of circumnavigation, of which Herodotus speaks as having been undertaken about the beginning of the sixth century before our era, and at the instance and direction of Necos, King of Egypt, has always met with warm asserters and oppugners. To us the arguments of the latter seem to have the most weight, though amongst the former appears the learned and judicious Cesar Cantu. In so disputable a matter, doubtless, the reader need not resign himself blindly to the opinion of any one; but, for our present purpose, it is sufficient to know, that if such a voyage was really performed, it led to no results worthy, from their curiosity or importance, to be transmitted to modern times. As regards other ancient voyages around Africa, there are still stronger reasons for discrediting them than that attributed to the Phenicians.

The reality of the voyage of Pytheas, to the west and north of Europe, is generally ad mitted, but the descriptions given by him of the lands and scas he visited are regarded as exaggerated, as they are certainly in many points obscure, even when we concede their foundation in fact.

endowed with a special culture and heirs of the ancient civilization of the East, upon the theatre where modern civilization was undergoing its definite development. This series of momentous events, we repeat, in proportion as it conveyed to each people the traditions and impressions of the rest, as it brought into contact, beneath another climate and sky, under natural conditions essentially different from those in which they had before lived, the natives of regions most widely remote from one another, could not but prompt human reason to discard the trivial ideas which it had cherished and insensibly adopt others more in harmony with the truth of nature. And this, be it observed, without the intervention of ancient science, lost or at least forgotten amidst the convulsions which had swept away its cultivators, and solely by an immediate effect of the events which, at the epoch of regeneration referred to, constantly modified the state of societies.

The incursions of the northern hordes having at last ceased, the present nationalities began to take shape; and if the systematic cultivation of the sciences was not yet to be expected, at least a delight in their study began to dawn. Nor did eventual circumstances, and such as might have appeared extraneous, cease to stimulate the taste for voyages and discoveries. As the occupation of the south and west of Europe by their warlike predecessors opposed an insuperable barrier to the progress, in that direction, of the Scandinavians or Normans who brought up the rear of the Asiatic migration, these established themselves permanently on the shores of the Baltic, and from thence, impelled by their roving and hardy genius, explored the northern islands and continents, the archipelagoes of Shetland and Feroe, Iceland, and, in the tenth and two succeeding centuries, the inhospitable coasts of Greenland, and those, somewhat more fertile, of Vineland, the present Labrador. * Meanwhile there arises in Asia a formidable empire, whose limits expand with astonishing rapidity from the seas of India to the frontiers of Europe, giving rise to the dread of a new invasion of destructive races; yet its service as a counterpoise to the Saracenic power, not less formidable on another side, is appreciated, and pontiffs and kings send embassies, sometimes to propitiate the redoubtable successors of Genghis Khan, sometimes to solicit help from Tartar and Mogul princes, at times simply in sign of admiration and respect. At their return from these distant scenes, observers like Ascelin, Carpini, Rubruquis, Polo, Sotomayor, and Clavijo, whether sent as ambassadors or led thither by inclination, communicate their impressions and adventures without reserve, and awaken in all

The following is a recapitulation of the later discoveries referred to in the text. They may be found more particularly described in the eighteenth book of Malte Brun's Geography, and in the notes to the fourteenth book of Cesar Cantu's Universal History.

About the middle of the ninth century Iceland was discovered, and before the end of the century a numerous colony of northmen was established in that island. In 986, among other colonists, one called Eric the Red, having been banished from Iceland, takes refuge in Greenland. Biörn, son of Eriulph, one of the companions of Eric, desirous of joining his father, freighted a ship and directed his course towards Greenland, but wandering for some time in those seas, got a sight of new coasts other than that which he was seeking. In the same ship with Biörn, Leif Ericson, son of Eric the Red, set sail from Greenland in the year 1000, and visited in succession a sterile, rocky and snow-covered coast, (Helluland;) another level, hoar with frost and well wooded, (Markland;) and a third, which abounded in vines, (Vineland.) Thorwald and Thorstein, brothers of Leif, prosecuted, with no successful result, the exploration of these lands, as did others of the same race. And though commerce and communication between Iceland, Greenland and the parts last mentioned, continued for a considerable length of time, they underwent many alternations, and proved of no real importance to geography. Judging from the descriptions given, as well of the lands as of the celestial phenomena which were observed, Markland seems to correspond to Nova Scotia, and Vineland to the region about Cape Cod, as far south as latitude 41. If the documeuts published by the Society of Northern Antiquaries may be relied on-and it is not our province to controvert them-Columbus made no true discovery; but how the Icelandic adventurers came to stop midway, and allowed the intrepid Genoese to snatch from them the domain of a world, is a phenomenon difficult to explain, and, in our opinion, more discreditable than otherwise to those in whose honor it is cited.

minds more competent conceptions of the form and size of the earth, and of the diversity of climates, than could otherwise have been attained. Thus, by means the most indirect, the limits of the world were extended, many obscure spaces of the earth brought to light, and the minds of men prepared for greater and more decisive discoveries.

We have now arrived at the first half of the fifteenth century. Portugal is a prosperous kingdom, without near enemies to combat, and possessed of a vitality which refuses to confine itself within the territorial frontier; it claims a wider field, and enterprises more worthy of the national spirit. With this spirit the geographical position of Portugal at one of the extremities of the ancient world, in front of that world which now awaits discovery, concurs to make it the point of departure for the great maritime expeditions of the age. Its princes, too, second opportunely the impulse, as well by their patronage of science and its cultivators as by a steady faith and interest in all enterprises calculated to enhance the name and importance of their country. Under the protection of Prince Henry, the Portuguese navigators explore and take possession of the archipelagoes of Azores, Madeira, and Cape Verde, and double Cape Bojador, so long the terminus of the African coast, thus penetrating into the vast Gulf of Guinea. Still later, in 1486, Bartholomew Diaz reaches the southernmost extremity of Africa, to which he gives the name of the Cape of Storms, a name soon changed by King John II into the more propitious one of Good Hope; and, finally, Vasco de Gama, passing, in 1497, beyond this formidable promontory, and turning his prow in an opposite direction to that of the supposed Phenician navigators of a remote age, points out to his adventu rous cotemporaries the marit me route to India and China, immense regions till then only known through vague and inexact tradition.

It seemed impossible that the ardor of the Portuguese for distant and hazardous exploration could be surpassed by any other country, and that still more important successes were in reserve for a different people. And yet this seeming impossibility was realized in a manner the most simple and natural, and with means the most limited imaginable. The genius and perseverance of an obscure and ill-understood mariner having met, though after long struggles, with support and countenance in the faith and enthusiasm of a queen, Columbus was enabled to launch his three frail caravels, manned by a handful of Spaniards, upon the broad Atlantic; there, leaving the Portuguese to contend with the dangers of the African coasts, and disregarding the circuitous and unprofitable track pursued by the Scandinavian adventurers, he directed the course of his vessels first south, and then constantly west, until he reached the archipelago of the Antilles, the gate of a new world resplendent with beauty, which seemed at that moment to ascend from the bosom of the seas.

Among the multitude of daring navigators who followed Columbus in the work of western exploration we may distinguish Magallanes, a Portuguese in the service of Spain, for the importance of the results attending his enterprise. After the discoveries of Columbus and De Gama, it still remained to be ascertained what separated, and at how wide an interval, the two continents to which they had led the way. There existed, as Balboa had descried, in 1513, from the Isthmus of Darien, a vast sea, but of its extent no conception had been formed, and yet Magallanes, not more enlightened on this point than previous explorers, proposed to traverse it. He sailed from Spain in September, 1519, passed the next year through the difficult straits which bear his name, and perished in the Philippine islands, after having overcome the chief difficulty of his undertaking. His second in command, Elcano, a Biscayan by birth, and not less resolute than the chief he had lost, still continued his course westwardly, and finally regained his country in a direction opposite to that by which he had departed. The sphericity of the earth, already recognized by reflecting minds, and gradually revealed by the discoveries which have been here briefly re