COLUMBUS' DISCOVERY OF VARIATION. 199 have sufficed. Columbus also believed that the lodestone was influenced by the different parts of the heavens, so that if the needle were touched with one part of the stone it would point east, with another west, and so on; and in fact he says that those who rub the needles cover the stone with a cloth so that the north part only is exposed, and the needle being touched with this possesses the virtue of turning to the north.' Whatever interpretation Columbus may have given to the phenomenon in order to quiet the fears of his men, or whatever his own ideas may have been as to the cause of it, there is certainly no disputing the fact that he did then fully observe and recognize the variation of the compass. Moreover, he saw the needle vary at other times on other voyages, and the net result of his observation is given in his letter to the King and Queen on his third voyage, in his own words, as follows: "When I sailed from Spain to the West Indies I found that as soon as I had passed 100 leagues west of the Azores, there was a very great change in the sky and the stars, in the temperature of the air and in the water of the sea: and I remarked that from North to South in traversing these hundred leagues from the said islands, the needle of the compass, which hitherto had turned toward the northeast, turned a full quarter of the wind to the northwest, and this took place from the time when we reached that line.' 992 He even drew a deduction from his observations which is curious, and characteristic of both the man and the time: "I have come," he says, "to the conclusion that the earth is not round, but of the form of a pear, or of a ball with a protrusion-being highest and nearest the sky situated under the equinoctial line. . . . In confirmation 1 Hist. del Almirante, C. 66. Muñoz.: Hist. N. Mundo, lib., vi., 8 32. Also authorities before cited. 2 Major: Select Letters, cit. sup. of my opinion, I revert to the arguments which I have detailed respecting the line which passes from north to south one hundred leagues west of the Azores; for, in sailing thence, westward, the ships went on rising smoothly towards the sky, and then the weather was felt to be milder, on account of which mildness the needle shifted one point of the compass; the further we went the more the needle moved to the northwest, this elevation producing the variation of the circle which the North star described with its satellites." The denial of credit to Columbus for the actual discovery of variation depends chiefly upon the supposed indications of the 1436 chart of Andrea Blanco or Bianco (see note, page 197) and in a general way upon inferences that earlier navigators may have observed the same behavior of the needle. Humboldt' states that three places in the Atlantic line of no variation for September 13th, 1492, May 21, 1496, and August 16th, 1498, can be certainly determined, and that the line at that time ran from northeast to southwest, touching the South American coast a little east of Cape Cordova. That distinguished scientist, however, summed up the achievement of Columbus in the words: "The rediscoverer of the New World found a line of no variation 3° west of the meridian of the Island of Flores, one of the Azores," and elsewhere explicitly says that he has no right to the title of discoverer of the variation itself. But then, Humboldt, who as the foregoing quotation shows, was equally averse to according to Columbus the greater honors which the world's opinion now freely bestows upon him, appears to have based his conclusion upon the show 1Examen. Critique de l'Hist. de la Géog., vol. iii., p 44-48. Cosmos, i., 169-197; v., 49–60. 2 He also says (Cosmos, v. 54) that Columbus “had the great merit of determining astronomically the position of a line of no variation 21⁄2° east of the Island of Corvo in the Azores on the 13th of September, COLUMBUS' DISCOVERY OF VARIATION. 201 ing of the Blanco chart, which modern research has since proved to have been misinterpreted. The fact that a similar dictum to that of Humboldt is advanced by Washington Irving in his fascinating life of the Admiral has done. much to place the matter apparently beyond dispute; but an impartial study of the history of the rise and progress of magnetic knowledge up to the time of Columbus, and of the condition of it during his life, and a recognition of the fact that much important data underlying such history has been made known since both Humboldt and Irving wrote, indicate the need for a revision of their verdict. Little weight can be given to the argument that the first freely suspended magnetic needle certainly showed variation, as did all later ones when influenced by the earth's field, and that therefore the phenomenon was always open to observation. Unfortunately many a physical effect has thus presented itself for ages to the perception of mankind-nay, forced itself under the very eyes of the keenest investigators—without gaining recognition, or adding in the slightest to the world's stock of knowledge, until suddenly hailed as a great discovery. Moreover there were cogent reasons why, even if navigators had noted an aberration of the needle, they would have been likely to ascribe it to other causes than the true one, and so have failed to recognize the real variation at all. Thus, in May, 1496, when the Genoese and the Flemish compasses on the ships of Columbus were found to disagree, one varying to the northwest and the other indicating the star, Columbus himself concludes the reason to be the difference in the magnets with which the needles were rubbed. In such rudely constructed instruments as then existed, it was equally possible to have assigned the errors to difference in shape of the needles, or weakness of magnetization, while it is not at all unlikely that both their form and treatment resulted in the production of consequent poles, which imported into them still further error. There was much better reason, therefore, for the European pilots before Columbus to have regarded any deviation of the needle as due to faulty construction or faulty magnetization, than to have assumed that it varied because of some external influence. Because Columbus laid most stress upon his observation of the variation of the variation and of a line of no variation, is no more reason for disputing his right to be known as the discoverer of the variation itself, than is his notion that he had visited a part of India one for denying him. his title as the discoverer of the New World. Mankind has long since decided that the forgotten voyages of the 9th century Icelanders detract nothing from his renown: equally immaterial is the hidden knowledge of the Chinese. The planets moved in accordance with definite law before the eyes of millions before Newton or Kepler lived; but the originality of the conceptions of these men is unimpaired. Moving planets and moving compass needles merely produced images on retinas: it was inconsequent whether of men or of sea-gulls. But to discover meant the establishment of connection between retina and a thinking, intelligent brain, and the application of the result of thought to the world's benefit. That is what Newton and Kepler did and Columbus did likewise. He was the first discoverer of the New World who made his discovery known to the Old World. He was the first discoverer of the variation of the compass needle who made that fact known to the rest of mankind. And the true discoverer is not only he who has eyes to see and ears to hear, but he who has a tongue and uses it to tell to others what his keener senses have told to him. The variation of the compass needle having been discovered, the importance of it was soon perceived by the sailors, for such a vagary of the needle would lead ships far astray if not known and allowed for in laying the course. But the philosophers, who cared little about nau THE MAGNETIC ROCKS. 203 tical matters, and knew less, were more interested in speculating upon it and evolving new causes. Despite the light shed upon the problems of navigation by Prince Henry and his wise men, the myth of the magnetic rocks still survived among sailors the world over. With the discovery of variation, this assumed new vigor. Here was an explanation of the aberration of the needle ready at hand, and it was promptly and universally adopted. When the chart of the New Continent was added to the Edition of 1508 of Ptolemy's geography, the magnetic rocks, having traversed the Indian Ocean and the Mediterranean, at last came to final anchorage north of Greenland, which was depicted as the eastern part of Asia, and the earth was given a magnetic pole in the shape of an insular mountain.1 The idea of a magnetic pole of the earth governing the compass, to which Peregrinus alludes but dismisses because of the wide distribution of mines of magnetic ore, had never been forgotten. Cecco d'Ascoli, satirist and astrologer, fifty years later expressly affirmed in his bitter poem, l'Acerba-a most heterogeneous gathering of learning of all sorts, and hence appropriately termed "the Heap" that both poles of the earth were magnetic and exercised attraction, and perhaps he would have gone further and found out the magnetic character of our globe, and made who knows what other discoveries, if he had not fallen foul of the Inquisition, which burned both him and his books. Between 1324 and 1508, however, great intellectual changes had taken place. Where people before assigned physical phenomena to causes entirely evolved from their inner consciousness, and hence without any foundation at all, they now explained them by physical facts wrongly selected; which, on the whole, was in the direction of progress. 3 1 Humboldt: Cosmos. Lond. 1872, vol. v., 56. 2 Poeti del Primo Secolo della lingua Ital. Florence, 1816. |