"Geographical Background of the First Voyage of Columbus"
    by Clarence B. Odell, Ph.D., and Dale Edward Case, Ph.D.

in "Cartocraft Teaching Aids" (Series 1962-63, Vol. III, No. 5)
     A Service Publication of The Geographical Research Institute
     A Division of the Denoyer-Geppert Company, Chicago
     Columbus did not search for a new continent.  He sought a
new path to an old world.(1)  His voyages were the most
spectacular and most far-reaching geographical discoveries in
recorded human history.  To the learned men of the 15th and 16th
centuries his four trips to the "New World" helped to reveal for
the first time the existence of one-half of the globe hitherto
     The explorations of Columbus and those of his contemporaries
completely revised the world picture.  As a result, cartographers
were stimulated to devise new methods for depicting the enlarged
world.  But the voyages did even more: they relegated the
Mediterranean to a secondary place in world affairs by diverting
trade between Europe and the Orient to the Atlantic. 
Furthermore, the voyages encouraged men to perfect their
scientific instruments of ocean navigation, to seek accurate and
advanced knowledge of the sphericity and size of the earth, and
to give thought to the patterns of atmospheric circulation, ocean
currents, magnetic forces, and other natural phenomena.
     The principal enterprise of Columbus was simply to reach
"The Indies" by sailing westward, but he never accomplished his
mission.(3)  Across his way lay land barriers without water-
throughways.  By accident, he discovered the coastlines of two
continents and their fringing off-shore islands.(4) 
Nevertheless, Columbus is honored by us for something which he
never intended to do and never knew what he had done.  Despite
the fact that he is one of the most controversial figures of
history, we honor him.  We are assured that no other mariner of
his generation had the persistence, the determination, and the
courage to strike out boldly across thousands of miles into
uncharted ocean until land was found.
Myths and Misconceptions
     The above pertinent facts may be recognized, discussed, and
analyzed in today's classrooms; and it is a fact that too often
class-members retain only the myths and misconceptions which have
been passed from one generation to another because teachers have
not given an "in-depth" treatment to the "Age of Discoveries". 
When asked what is remembered about the great mariner, invariably
an adult and a grade-school child give the rhythmic answer: "In
1492, Columbus first sailed the ocean blue."  To be sure, other
misconstrued answers may be given, such as "Columbus discovered
America," and "Columbus proved the earth to be round."  We need
to give careful thought to such answers and to evaluate them. 
This is especially true with such terms as "discovery" and
"sphericity".(5)  We also need to clarify any misconception that
Columbus and his crew-members had a "dinner-plate idea" f the
shape and form of the earth.
Geographical Framework
     The geographical framework upon which rests the Columbus
story is a part of every classroom discussion.  The framework
includes the attitudes and the conditions under which Columbus
and his crew worked, and the activities in which they were
engaged--the preparations for the voyages, the westbound passage,
the discoveries, and the homewardbound return.  It also includes
the physical forces to which the first enterprise was related--
the ocean currents, the zone of calms, the trade-wind belt, the
westerlies, the cyclonic storms, the magnetic lines and others. 
It is the geographical framework which helps to give meaning and
substance to the current events of that period of world history.
     Ask any grade-school child to describe the boundaries of the
"known world" of the 15th century, and in most cases you will
draw a blank.  There will be blind-spots, because it is difficult
to visualize the world as it was conceived to be during ancient
and medieval times--ancient because the scholars and men of
general learning of the late Middle Ages relied upon the world
concepts of earlier map-makers.
     When the "Age of Discoveries" is analyzed, we should keep
before our minds the quaint notions of the earlier philosophers,
friars, manuscript-scribes, scholars, and others.  We should
first begin by banishing the modern map from our thoughts and
substitute an ancient map in its place.(6)
Map of the Middle Ages
     An anonymous medieval map show geographers view of the world
in the 15th century as only containing Europe, Asia and Africa. 
There is no way of knowing whether Columbus was familiar with it. 
Dated 1485, the map was drawn by an anonymous cartographer who,
unknowingly, described the "eastern hemisphere" for the first
time.  Five interesting points stand out:
     * 1. The design is based on a world map of Ptolemy (170
          A.D.), one of the early scholars who advanced the
          theory of the earth's sphericity.
     * 2. The map shows the medieval Christian belief in an
          earthly Paradise which had been depicted on maps for
          over 1,000 years prior to the 15th century.  Four
          rivers--the Euphrates, the Tigris, the Indus, and the
          Nile--radiate out of the East (i.e., Eden and the place
          of the rising run).
     * 3. The map shows the known world divided into three parts
          (Europe, Asia, and Africa) and reaching to the edges of
          the drawing.  The ocean is limited to a narrow circle.
     * 4. The map shows the known mountains whose rivers are
          presented by conventional signs.
     * 5. Engrovelant (i.e., Greenland) is shown as a peninsula
          of the Eurasian continent, a word which had not been
          introduced by the geographers.
     During the time of Columbus, the map-makers continued to
base their work on mere half-mythical traditions, unrelieved and
uncorrected by the results of actual discoveries.  Their maps
were still much like picture-books, filled with biblical and
literary lore (e.g., dragons, four-wind symbols), indicating but
a slight attempt to incorporate exact measurements and outlines.
     Columbus was familiar with sailing charts, the Italian
portolano, which were attempts at geographical representation. 
The portalons were designed as practical aids to navigation for
Mediterranean and Bay of Biscay mariners and were based on
observations.  By Columbus' time the charts had reached a high
degree of accuracy.  The coasts, bays, islands, and promontories
were plotted and drawn with striking correctness.  They did not,
however, undertake to give the internal features of the countries
whose coastlines they depicted.  If European sailors should
follow the coast of Africa south of the 27 degree parallel, of
north latitude, or of Europe north of the 50 degree parallel, or
if they should direct their course into the western ocean beyond
the azores, they would be sailing into the unknown.
     Columbus had definite convictions regarding the size of the
world, its areal extent, its distribution of land and water
masses, and how to reach "The Indies".  His beliefs were based
upon the works of ancient and medieval scholars and map-makers. 
He firmly believed that ...
     * 1. The earth was a sphere and could be circumnavigated in
          an east-to-west journey.  Its circumference had a
          measurement of 360 degrees.
     * 2. At the equator, the circumference of the earth could
          divided into twenty-four parts (24 hours), each part
          containing 15 degrees.
     * 3. The "known" lands of the ancients covered fifteen parts
          (hours) of the earth's surface, and they stretched from
          the Canary Islands to the city of Thinae (some place on
          the eastern coast of Asia).
     * 4. The Portuguese had advanced the western frontier one
          additional part (one hour) by discovering the Azores
          and Cape Verde Islands.
     * 5. Eight parts (hours) remained unknown and unexplored,
          therefore, the most easterly part of Asia could not be
          separated from the Azores by more than one-third of the
     * 6. Peninsulas and islands of Asia could well fill the
          space remaining (i.e., eight parts--hours).
     * 7. A reduction of the size of the degree of longitude
          (east-west measurement) would make the earth's
          circumference even smaller.(8)
     * 8. By pursuing a direct course from east to west a
          navigator would arrive at the extremity of Asia and its
          offshore islands.
     The 15th century was one of general excitement to all who
were connected with marine life, or who resided in the vicinity
of the ocean.  Recent discoveries and rediscoveries (West Africa,
South Africa, Madeira and Azores islands) had inflamed the
imagination of people and had filled them with visions of other
islands to be discovered in the Atlantic Ocean.(9)  The story of
Antilla, "discovered" by the Carthaginians, was frequently cited,
and Plato's imaginary Atlantis once more found firm believers.
     One of the strongest symptoms of the excited state of the
popular mind at this eventful era was the prevalence of rumors
respecting unknown islands casually "seen" in the ocean.  Many of
these were fables.  All rumors of islands were noted with curious
care by Columbus, and may have had some influence over his
     The theory that the earth was spherical in shape was
familiar to the Greeks and Romans and was supported during and at
the close of the Middle Ages by the great authority of Aristotle. 
Astronomers, philosophers, scholars, and even navigators and
pilots were quite familiar with the idea and quite in the habit
of thinking of the earth as a sphere.(10)  There were those,
however, who were aware of the theory but found the idea to be
abstract.  One noted historian writes,
     "The conception of the sphericity of the earth was
     really a matter of mental training.  In the 15th
     century those who had gained this knowledge were fewer
     than in modern times, but the class who did so believe
     were no less sure of it."(11)
     One of the most popular Columbian myths pertains to the
"Case of Columbus versus the Council of Salamanca."  Several
writers, sensing a gripping struggle between two forces--an
obscure navigator and the learned professors and theologians--
elaborated and permitted their imaginations to run freely.  They
played up the drama of a non-academic person who sustains his
thesis of a spherical globe in opposition to the "pedantic
bigotry" of flat-earth churchmen.  Washington Irving was such a
     In his wonderful chapter, Irving describes the meetings of
the Council in 1486, at the University of Salamanca.(12)  Before
an imposing body of distinguished professors, friars, and church
dignitaries, Columbus appeared.  In an eloquent rhetorical style
Irving writes,
     "We are told that when he (Columbus) began to state the
     grounds of his belief, the friars of St. Stephen (one
     of the colleges of the university) alone paid attention
     to him....  At the very threshold of the discussion,
     instead of geographic objectives, Columbus was assailed
     with citations from the Bible and the Testament; the
     Book of Genesis, the Psalms of David, the prophets, the
     epistles, and the gospels....  Doctrinal points were
     mixed up with philosophical discussions, and a
     mathematical demonstration was allowed no weight, if it
     appeared to clash with a text of Scripture....  Thus,
     the possibility of antipodes, in the souther
     hemisphere, became a stumbling block with some of the
     sages of Salamanca."(13)
     One present-day writer who deeply appreciates the
contributions made by Irving, but who nevertheless criticizes the
above statements as a glorified myth, is Samuel Eliot Morison
(Pulitzer Prize Winner).  He writes,
     "What becomes of the celebrated sessions of the
     University of Salamanca, before whose professors of
     mathematics, geography, and astronomy Columbus argued
     his case, and was turned down because he could not
     convince them that the world was round?  That is pure
     moonshine.  Washington Irving ... took a fictitious
     account of this non-existent university council
     published 130 years after the event, elaborated on it,
     and let his imagination go completely."(14)
He further comments,
     "...the whole story is misleading and mischievous
     nonsense.  The University was not asked to decide.... 
     The sphericity of the globe was not in question.  The
     issue was the width of the ocean; and therein the
     opposition was right."(15)
     Columbus had one main objective, and it was simply to reach
"The Indies" by sailing westward.  That was the main idea to
which everything else was subordinate.  What did he expect to
     * 1. He expected to find gold, pearls,a nd spices or to get
          them either by trade or by conquest.
     * 2. He expected to find one or more islands on the way,
          which might prove convenient as ports of call, if they
          were not profitable in themselves.
     Between 1600 and 1892 leading historians accepted the thesis
that Columbus was looking for some portion of Asia, such as
Cipangu or Cathay, or both, and that America was his by chance. 
They accepted the writings of Columbus' generation.  However,
around 1900 men began to write about the Admiral in terms of
"hidden documents" and newer interpretations.  Many of them
advanced hypotheses that Columbus was not looking for "The
Indies," but was actually seeking new Atlantic islands in order
to found a valuable estate for himself and his heirs.(16)
     Space does not permit a complete discussion of the
preparations which were made for the first voyage.  A few details
will suffice in terms of the selection of Palos as the embarking
point, the types of ships employed, the recruitment of crew-
members, and the "shake-down cruise" to the Canary Islands.
Why Did the Ships Sail from Palos?
     The voyage of Columbus began at Palos de la Frontera a sea-
faring port on the Rio Tinto.  The town is situated on an
undulating coastal plain which is traversed by two tidal rivers--
the Odiel and the larger Tinto--which unite a few miles from the
Golfo de Cadiz.  Prior to 1481, Palos had been one of Castile's
seaports engaged in the African slave trade.(17)
     Cadiz, principal port of Andalusia, was preoccupied during
the summer of 1492 with the embarkation of the Jews, who were
forced into exile.  When Columbus arrived at Palos he found it to
be inactive.  Because the citizenry had committed municipal
demeanors, the Spanish Sovereigns (Queen Isabella and King
Ferdinand) levied fines on them.  The people were now asked to
furnish two caravels in ten days' time for the overseas
What Did the Vessels Look Like?
     Every school child knows that Columbus had three vessels for
the first expedition westward--the Santa Maria (the flagship),
the Nina (nicknamed the Santa Clara), and the Pinta--and that he
returned with the Nina and Pinta.  They may not know that the
Santa Maria was grounded on the north coast of Hispaniola. 
Before his return to Spain, Columbus ordered the dismantling of
the ship for the construction of a fort at La Navidad, located on
the northern coast of Hispaniola.
     According to Morison, no data, woodcuts, or documents exist
that might give measurements and descriptions of the three
     "Every picture of them is about 50% fancy, and almost
     all are inaccurate in some important aspect ... so-
     called models, replicas, or reproductions of the Santa
     Maria and her consorts are not models, since no plan,
     drawing, or dimension of them exists.  They merely
     represent what some naval architect, archeologist,
     artist, or ship-modeler thinks these vessels ought to
     have looked like."(18)
The vessels were not "crates" or "cockleshells," as some writers
would have us believe.(19)  They were seaworthy and functional,
in terms of negotiating wind and current.
How Many Men Comprised the Crew?
     Ninety men sailed on the first voyage: the Santa Maria, 40
men; the Pinta, 26 men; and the Nina, 24 men.  Most of the crew-
members came from some town or village in the Niebla region of
Rio Pinto (Palos, Moguer, Heulva, and Lepe).  Some came from the
towns of Andalusia (Cadiz, Seville, Cordova, Jerez, and Puerto
Santa Maria).  Only five were not Spaniards: one each from
Portugal, Calabria, and Venice; two, including, Columbus came
originally from Genoa.
     The crew included a number of landsmen with specific duties. 
Among them was Luis de Torres, a converted Jew, who was taken
along as an interpreter.  Others were a marshall, a secretary, a
comptroller (bookkeeper and recorder), a butler, a page-boy, and
surgeons.(20)  Some of the duties of the petty involved work in
carpentry, coopering, and boat-caulking.
How Did He Recruit His Men?
     As a Genoese, Columbus was a foreigner and a comparatively
unknown one in the Rio Tinto area; therefore, it is difficult to
believe that he could have induced seafaring men and boys to
embark with him on a voyage of dubious safety and improbably
success.  After all, the original Royal Order of the Sovereigns
wanted the expedition to be underway within ten days.  There is
some evidence that the Pinzon family, which arranged for the use
of the Santa Maria, had much to do with the recruitment of man
power for the three vessels.  No doubt the family also had
something to do with the procurement of naval stores, fittings,
and equipment.  Outfitting a fleet for a year would be no small
task for a single person; and then, too, there were some delays
in labor-recruitment.  According to later testimony, the local
seamen of Palos were held back less by fear than by skepticism:
"all thought that the enterprise was a vain one."(21)
     Some writers have mentioned that the crew included
cutthroats, murderers, and desperadoes.  Far from it!(22)  Most
of the members were local young men and their neighbors and
friends from near-by seaports.  In other words, Columbus' vessels
were "home-town ships," an expression commonly used in 19th
century New England.
     It was Friday, August 3, 1492, when Columbus and his pilots
and crew moved on high tide down the Rio Tinto toward the open
Atlantic.  Ten weeks had passed--well beyond the original Royal
decree of ten days--but the delay in preparation and recruitment
worked out finally to Columbus' later advantage: the first voyage
missed the September hurricanes of the North Atlantic.
     Many people had been drafted in readying the vessels.  Among
them were timber merchants, carpenters, ship-chandlers (i.e.,
dealers in small wares), bakers, provision dealers, other
     Columbus' plan was to sail to the Canaries, and then due
west to "The Indies".  His vessels entered the Atlantic Ocean. 
Their white sails were painted with crosses and possibly other
heraldic or religious devices.  This was to be an economic
expedition, one interested in trade and commerce; it was also to
be a religious one: the conversion of people of unknown lands to
the Christian faith.
Why Did He Consider the Canaries?
     The Canary islands belong to Spain.  The group of seven
islands is situated within the belt of the northeast trades,
known during the 15th century as the Portuguese Trades.  The
island-group is washed by an equatorward-moving cold current,
running parallel to the west coast of Africa, and known as the
Canary Current.  Moreover, the islands lie on the 28th parallel
of latitude, which happened to be also the latitude of the
"northern end of Cipangu," according to its supposed location in
the western Atlantic.(23)  Since the lack of chronometers in the
15th century made the calculation of longitude and time very
inaccurate, it was the custom for navigators to sail due north or
due south to the parallel of their proposed destination.  A
course due east or due west could then be set.
     Columbus' decision to negotiate a landfall at the Canary
islands served to determine the Bahamas as the first landing-
place in the "New World".  The Canaries as an outpost and the
beneficent trade winds combined to make the voyage into the
unknown one of short duration.(24)
Columbus Looks Westward
     Thirty-two weeks will pass before Columbus will see again
the port of Palos.  The successful achievement of the first
voyage will lead to three subsequent ones, and collectively the
four will set off a chain reaction to be felt throughout maritime
countries.  Fortunately, he will not live to experience
humiliation and to hear his claims of discovery and motives
challenged.  There will be denials, falsifications, forgeries,
and ridicule in the years which lie ahead.  Indeed, for four
centuries his "Journal" and the writings of his family and
friends will be attacked, and they will be microscopically
scrutinized by historian and professional researcher.  But there
will be glory; and there will be applause, too.  His likeness
will be perpetuated in stone, and his name will be commemorated
in both North and South America--in names of streets, cities,
rivers, states, and federated districts; and a "Columbus Day"
will be assigned to the calendar.  This is all in the future. 
Right now--as we see him--Columbus is poised for his first
journey westward, a voyage which will have a tremendous impact
upon world thought and opinion.
     In the weeks ahead, his "Journal" will carefully record his
observations and impressions.  Let us take a look at it.
Calendar of the Voyage with Comments
 * August 3 - September 9, 1492
     A five-week "shake-down cruise" permitted officers and crew
     to become accustomed to one another, to know the vessels--
     their seaworthiness and maneuverability.
     August 3 - August 9
     Six days' journey--1,000 nautical miles--from Palos to
     Canary islands.  Ocean between Spain and the Canaries is
     rough water, and Spaniards were generally required to take 8
     or 10 days.  They called it el Golfo de las Yeguas (the Sea
     of Mares), because so many brood mares shipped to the
     Canaries died on board.
     August 9 - September 9
     One month's stay in Canaries in order to repair rudder of
     Nina and to give her square-rigging.  Took on wood, salt
     meat, wine.
 * September 9 - October 12, 1492
     Thirty-three days covered from time of departure to first
     landfall.  Columbus made careful observations and notations
     in his "Journal" (log not invented until mid-16th century),
     keeping two records: one for the Sovereigns, one (falsified)
     for his crews.  He noted the following: speed, distance
     covered daily, direction taken by vessels, sargassum weed,
     magnetic needle variations, false landfalls, wind
     occurrences, birds in flight, dead-reckoning and celestial
     navigational observations.
 * October 12 - October 14, 1492
     First landfall--San Salvador (Guanahani, or Watlings island)
     in the Bahamas.  Columbus met "Indians" for the first time,
     remained on island for day and half.
 * October 14, 1492 - January 16, 1493
     Searched for Cipangu and Grand Khan of Cathay.  Vessels
     moved through Bahamas to north coast of Cuba (Oriente
     Province), to Hispaniola (northern Haiti and Santo Domingo). 
     The wrecked and dismantled Santa Maria became source of
     materials for the fort, La Navidad (Hispaniola), where 39
     men were left to establish a beachhead, and to be killed by
     the natives during Columbus' absence in Spain.
 * January 16 - February 12, 1493
     Homeward bound with the Nina and Pinta.  Vessels encountered
     rough seas and first of a series of winter cyclonic storms.
 * February 12 - February 24, 1493
     Forced to seek shelter in the Azores; Portuguese were not
     too friendly.
 * February 24 - March 13, 1493
     Nina and Pinta separated during second encounter with winter
     cyclonic storms.  Winter of 1492-93 was a severe one in
     Europe.  Columbus reached Lisbon, Portugal.
 * March 13 - March 15, 1493
     Nina reached the Rio Tinto first, but Pinta (under the
     Pinzons) immediately followed, and both vessels rode high
     tide together upstream to Palos.
     Columbus' "Journal" is a record of his day's work and is a
report of the courses steered and the distances covered.(25) 
Meticulously, he describes objects sighted at sea and lands
discovered.  Long descriptions are given of people seen, places
visited, and plant and animal life observed and gathered.  He
gives his own reflections and conclusions on cosmography (map--
and chart--construction), on future colonial policy--toward
established beachheads and enslavement of natives--and on many
other subjects.
     The Admiral identifies birds and their flight habits and
plants in their tropical habitats, but invariably he is incorrect
because he had little background in the fields of ornithology,
biology, zoology, and plant ecology.  He tries his hand at
celestial navigation but fumbles.  In his day he did not have
instruments of precision, and the art of celestial navigation was
in its infancy.  Neither he nor his shipmates knew very much
about it.  His observations of Polaris for latitude were of no
use to his navigation, because he never knew the proper
corrections to apply.  His "Journal" reveals that he was unable
to use the astrolabe knowingly in his first voyage, but for
having an eye for dead-reckoning navigation, Columbus was superb. 
He took his course off his mariner's compass.  This instrument
was the most reliable and most indispensable of his instruments
     Columbus' route was greatly affected by several natural
conditions.  Three may be recalled for our consideration: wind
and pressure patterns, ocean currents, and magnetic fields. 
First awareness of their existence in the North Atlantic Ocean
led to careful studies, analyses, and chartings--as effective
physical environmental influences (or controls)--which are today
going forward in the fields of meteorology, oceanography, and
Wind and Pressure Patterns
     In order to understand the planetary wind system of the
North Atlantic, it is necessary to recognize the existence of
large generalized pressure areas:
     The North Atlantic region is overlain, from north to
     south, by alternating high and low pressure areas;
     namely, the Arctic Dome (a high-pressure cell),
     centered over the North Pole; the Icelandic Trough (a
     low-pressure area), lying in the vicinity of Iceland
     and covering an area between Nova Scotia and Ireland;
     the Azores-Bermuda Ridge (a high-pressure area),
     stretching between West Africa and Bermuda; and the
     Equatorial Trough (a low-pressure area), lying astride
     the equator.  We must understand that these barometric
     pressure areas migrate north and south during the year.
          Consider the movement of air away from a high-
     pressure area toward a low-pressure area:
     * 1. Air flowing off the Arctic Dome and down the
          northern slope of the Icelandic Trough gives
          rise to the northeasterlies, or "easterlies";
          these are cold polar winds.
     * 2. Air flowing off the northern slope of the
          Azores-Bermuda Ridge and down the southern
          slope of the Icelandic Trough creates the
          prevailing southwesterly winds, or
          "westerlies"; these were the winds which
          aided Columbus in his return to Spain.
     * 3. Air draining down the southern slope of the
          Azores-Bermuda Ridge and into the Equatorial
          Trough produces the northeast trade winds. 
          Of all the winds these seem to be the most
     There is no hint in his "Journal" or elsewhere that Columbus
knew that the northeast trade winds would carry him across the
atlantic.  However, he must have observed on his earlier African
voyages that a westward course from the Canary islands would
enjoy a fair wind as soon as one passed away from the Azores.  It
was merely his good fortune that the same wind carried his fleet
all the way to his first landfall, or to be more specific, his
first "windfall".  Columbus sailed westward with the aid of the
northeast trades; he returned to Spain with the help of the
westerlies.  He had no way of knowing the basic wind-and-pressure
patterns; neither did he know about the convergence of warm-moist
and cold-dry air masses (the cyclonic storms) which are
associated with the westerlies.
Ocean Currents
     In general, the ocean currents of the North Atlantic Ocean
(and it may be applied also to the entire world picture) follow
the flow of air around the major air pressure systems.  Such
currents as the North Equatorial Current, the Gulf Stream, the
North Atlantic Drift, and the Canary Current flow at a slight
angle to the winds of the Azores-Bermuda Ridge and form a
complete circle around this pressure cell.
     The ocean-current circulation produces a clockwise gyre
which encloses a sea--relatively warm, salty, poor in phosphates,
and blue in color.  In the North Atlantic this is the Sargasso
     Many myths have been built around the dangers of the
     Sargasso Sea.  The sargassum weed (from the Portuguese)
     was known to most mariners of the 15th century, through
     actual experience or by hearsay; and we may assume that
     Columbus had heard tales of its existence.  The
     gulfweed gets its name from the indigenous, yellow-
     brown weed which is found throughout this portion of
     the Atlantic Ocean.  Columbus' ships moved without
     trouble through great floating masses, although his
     "Journal" reveals that his crew-members were somewhat
Magnetic Fields
     Certain ores, geological formations such as basaltic lavas
near the surface, and other conditions cause local irregularities
in the amount of magnetic compass declination.  When free to turn
in the horizontal plane, the direction of the magnetized needle,
relative to the geographical north which is true north, is called
the magnetic declination.  This is reckoned "positive" to the
east and "negative" to the west.
     The distribution of the declination over the earth's surface
can be indicated by lines along each of which declination is
constant.  These are called isogonic lines (or isogones).  The
two magnetic poles and the two geographical poles (North and
South Poles) are points toward which isogones converge, for all
values of declination.  The isogones for which declination equals
zero are called agonic lines.  Along these lines the compass
needle points to the true north or the true south (i.e., in the
southern hemisphere).
     Long before Columbus' generation mariners were familiar with
easterly variation, but not with westerly variation.  The real
test of the theory of compass declination came when mariners
began to navigate the Western Ocean.  Then the compass needle
began to act very strangely.  On his first voyage, Columbus noted
that far from pointing true north, his compasses--Flemish and
Genoese--showed a declination most of the time, depending on the
longitude, and that rarely ever did they point true north as they
did as a point 2.5 degrees east of Corvo in the Azores, where, he
reported, there was "no variation".
     The magnetic needle has been the subject of innumerable
controversies.  We must not doubt that Columbus was somewhat
aware of its variations.
     According to his "Journal", he reported as of September
     13 that the needles varied to the northwest of Polaris,
     and in the morning to the northeast....  On September
     17, the compasses showed northwesterly variation, but
     found the needles to be indicating true north in the
     morning.  Columbus reasoned that the cause was that
     Polaris appeared to move and not the needles.  he was
     right!  In 1492, Polaris described a radius of 3
     degrees, 27 minutes about the celestial poles, as
     against as 1 degree radius, or polar distance, today. 
     In other words, Columbus was one of the first
     navigators of the 15th century to discover that
     Polaris, is not directly overhead at the North Pole,
     but that it described a circle, during a 24-hour
     period, of more than 3 degrees from the celestial pole
     (an elongation of the geographical pole).
     Some writers have led us to believe that the poleward
"bulge" in Columbus' first voyage was a result of the concern of
his crew-members: they became mutinous when they learned of the
variations in the compasses.  This does not seem to be the case.
          During a six-day period (September 20-25) the
     fleet ran out of the northeast trades and had to change
     course.  Columbus' "Journal" reports, "... sailed this
     day (September 20) to the West by North and West-
     Northwest, because the winds were very variable."  The
     fleet had reached that part of the Atlantic Ocean that
     has the largest percentage of calms, light air
     currents, and variable (i.e., changeable) winds.  In
     this section of the Azores-Bermuda Ridge (the high-
     pressure area), air currents descend slowly to the
     Sargasso Sea, and vessels carrying sails have much
     trouble in movement.  Columbus was lucky to have had
     some wind.
          On September 25, Columbus reported having observed
     masses of gulfweed which were believed to be signs of
     land.  The fleet was now more than 750 leagues west of
     the Canary islands.  Pinzon believed Columbus had
     missed Cipangu and its associated islands; therefore,
     he urged Columbus to spend more time looking for them. 
     He was refused and the fleet continued on its westerly
     dead-reckoning course.  Although it has been claimed
     many times in the classroom that the compass variation
     accounts for the poleward bend in the dead-reckoning
     course, the "Journal" reports otherwise.
     We must recognize, however, that few navigators other than
Columbus had the task of quieting the panic and suppressing the
mutiny in a superstitious crew when word got around early--
September 14--that the compass was misbehaving.  Perhaps Columbus
was also alarmed, but he added to his own navigational problems
by carrying both Flemish and Genoese compasses, and while the
Genoese needle was set in line with the north point of his
compass card, the Flemish needle was probably offset to the east
of north by three-quarters of a point (8.4 degrees) as was the
     The first westbound Atlantic crossing was one of the easiest
voyages from a nautical point of view, because there were no
storms or prolonged calms, no foul winds or heavy seas, no
shortage of food or drink, and no practical differences.  Even
those differences which did occur were purely psychological.  The
three vessels were well-built, well-equipped, well-rigged, and
     The first voyage depended upon one principal consideration:
the distance between the Canary islands and Cipangu (Japan).  It
is here that Columbus was helped by an error which he shared with
many geographers of his day.  The Caribbean area was made known
to him because he underestimated the size of the earth and
overestimated the length of Asia.
     Not only did Columbus accept the earth's equatorial
circumference to be 20,400 geographical miles, which was
Ptolemy's estimate, but he accepted the distance around the world
at parallel 28 degrees north latitude to be about 14,000 miles. 
As a result of his wrong calculation, he estimated the distance
between the Canaries and Cipangu to be about 2,500 miles, a
figure which expresses the approximate distance between the
island and the West Indies.
     Therefore, in conclusion, we may say that the Columbus story
is based upon a case where the littleness of knowledge was not a
dangerous but a helpful thing.  If Columbus had proposed to sail
westward for nearly 12,000 miles, the approximate distance
between the Canaries and Japan, could he have expected his crew-
members to have made the voyage with him?  Hardly!  Under such
conditions there would have been no first voyage to record as of
the 15th century.
     1. Refer to Atlas A48p, "Our United States: Its History in
Maps" (Edited by Edgar B. Wesley), Denoyer-Geppert Company, p. 12.
     2. At no time during the life of Columbus, nor for some
years after his death, did anyone use the phrase "New World" with
conscious reference to his discoveries.
     3. In his "Geography in the Middle Ages", George H.T. Kimble
comments that the term "The Indies" is a vague term, for in the
Middle Ages there were at least three Indies; viz., India Minor,
India Major, and India Tertia, i.e., the Sind, Hind and Zinj of
the Arabs.  The first two were located in Asia, the last in
Africa (possibly Ethiopia).  The word India in the Middle Ages
had no exact geographical meaning to Europeans; it was a
convenient expression denoting the East beyond the Mohammendan
     4. During the 15th century the word continent was not used
to describe the land masses of continental status.  Medieval
geographers tended to contrast land with sea, zone with zone,
part with part, West with East, the known world with the unknown.
     5. For an informative discussion, read Wilcomb E. Washburn,
"The Meaning of 'Discovery' in the Fifteenth and Sixteenth
Centuries," "The American Historical Review", Vol. LXVIII, No. I,
(October 1962).
     6. Refer to Map B1, "Ancient World," "Denoyer-Geppert Social
Studies Map".  Illustrated are six maps of the world according to
Homer, Eratosthenes, Ptolemy, et al.
     7. The medieval map is discussed by Erich Woldan (Vienna) in
his article, "A Circular, Copper-Engraved, Medieval World Map,"
in "Imago Mundi" (Edited by Leo Bagrow), Vol. XI, pp. 13-16.
     8. Columbus proceeded to base his measurements on the
assumption that the length of a degree of longitude at the
equator was 56.6 geographical miles, instead of the correct
figure of 69.172 miles.  See "Cartocraft Teaching Aids", Vol. II,
No. 1 (Series 1961-62), Denoyer-Geppert Company.
     9. The legendary island of Antillia was thought to be in
front of, opposite to, or on the other side of the Atlantic.  The
Greater and Lesser Antilles of the Caribbean area have borrowed
the name.
     The journeys of the travelers of the later 13th and 14th
centuries were a veritable revelation to Europeans.  All made
Cathay (China) a land of intense interest; similarly, the great
island of Cipangu (Japan), lying a 1,000 miles further to the
eastward, though never actually visited by Marco Polo, and
described by him, was of equally keen interest.  Also of interest
were the "12,700 islands" at which he calculates the great
archipelagoes which lie in the Indian Ocean and the Pacific.
     For Marco Polo's travels, see Map WH8, "Mongol Ascendancy to
A.D. 1300," "Denoyer-Geppert World History Series" (Edited by
William H. McNeill), Edition 1958, Denoyer-Geppert Company.
     10. It is suggested that careful thought be given to the
"popular" children's stories which highly exaggerate and
dramatize the mutinous attitude of the crew-members of the first
voyage.  Columbus' "Journal" gives no clue that his men were
afraid of "falling off the edge of the earth".  Neither are there
any accounts to be found in the writings of Ferdinand Columbus,
Bartolome de las Casas ("Historia de las Indias"), Peter Martyr,
and Oviedo, contemporary writers of the period.  Debunkers of the
Columbus story published books, pamphlets, and articles after
1900, and although many have proved to be false, their
suppositions have made indelible impressions.  One such writer
was Henry Vignaud.  See footnote 16.
     11. Edward Potts Cheyney, "European Background of American
History," "The American Nation: A History--1300-1600" (Edited by
Albert Bushnell Hart), Vol. I (New York: Harper & Brothers, 1904,
p. 19.
     12. Refer to inset map "Columbus in Europe (1484-1492)," of
Map WA6, "The Age of Discovery, 1492-1580," "Our America, Wesley
Social Studies Series", (Edited by Edgar B. Wesley), Edition
1962, Denoyer-Geppert Company.
     13. "The Life and Voyages of Columbus," "The Works of
Washington Irving", (New York: Thomas Y. Crowell & Company),
p. 59.  Editor's note: the term antipodes refers to points
opposite (i.e., to a location or to a person on the other side of
the earth in the southern hemisphere).  Cosmus (535 A.D.) had
asked the question: "Are there antipodes, i.e., people, with
their feet opposite to ours: people who walk with their heels
upward, and their heads hanging down?"
     14 Samuel Eliot Morison, "Admiral of the Ocean Sea, A Life
of Christopher Columbus", (Boston: Little, Brown and Company,
1951), p. 89.  A paperback version (A Mentor Book) has been
published under the title, "Christopher Columbus, Mariner" (New
York: The New American Library of world Literature, Inc., 1962).
     15. Ibid.
     16. Henry Vignaud, who wrote two volumes and numerous
pamphlets, asserted that Columbus falsified his Journal, forged
the Toscanelli letter (not covered in this "Cartocraft Teaching
Aid"), and had no intention to look for "The Indies".  Vignaud's
theory is discussed in his book, "Toscanelli and Columbus"
(London: Sands & Co., 1902).
     17. Castile had renounced her African trade in the Treaty of
     18. Morison, op. cit., p. 113.  For a highly informative
discussion of the Santa Maria (a ship), and the Nina and Pinta
(caravels), read his Chapter IX.
     19. Ibid., p. 131.
     20. de Torres knew Hebrew and a little Arabic.  It was
commonly believed that Arabic was the mother of languages, and it
was expected that de Torres would be able to converse with the
Great Khan of Cathay.
     21. For more than fifty years after the death of Columbus,
the High Courts of Spain handled the claims of the heirs of
Columbus and of those of the Pinzon family.  Morison handles some
of the details in his volume (op. cit.), pp. 61-78.
     22. One crew-member had committed a murder.  He had been
held on the charge, along with three companions who tried to aid
in his escape.  All of the men later redeemed themselves, and
three sailed on the three subsequent voyages.
     23. From the Toscanelli letter which Columbus had in his
possession, as well as from an accompanying map, he deduced a
course due west from Lisbon to Quinsay (Cathay) to be about 5,000
nautical miles; however, there was an alternate route, possibly a
shorter one by way of Cipangu (Japan).  This one passed Antillia,
the island which was thought to lie 2,000 miles from Cipangu.
     24. Ellen Churchill Semple, "American History and Its
Geographic Conditions" (New York: Houghton Mifflin Company,
1903), p. 7.
     25. Technically, the "Journal" is known as the Book of the
"First Navigation and Discovery of the Indies".
     26. Lloyd A. Brown, "The Story of Maps" (Boston: Little,
Brown and Company), p. 133.