The History of Early Dead Reckoning and - New World Explorers

sailing directions also give a detailed description of en route sea characteristics but there is no
mention of the North Star to fix a position for reasons that are well known to navigators of far
northern latitudes. In the sailing season between May and October there is too much light for the
weak Polaris to be seen by the naked eye. However, the Norse were familiar with Polaris which
they called Leitharstjaerna, but since it was only visible in their dark stormy winter nights, it
probably was of interest only to astrologers and priests and of no use to the ocean navigator.
There is evidence that the Icelandic seafarers possessed a navigational instrument called a
Solskuggefjol or Sun shadow board, a circular board with an upright post in the center and
floating in a bowl of water. When sailing on an east or west heading, a measurement of the
shadow of the Sun at noon on successive days would indicate if the vessel had strayed north or
south of the desired course. But the discussion of offshore navigation in the Icelandic sagas
indicates that the well known seasonal winds were the primary directional factor used for
navigation (common also to early Mediterranean navigation) and there is no mention of use of
the Sun shadow board or any other sidereal measuring device. Thus the commonly held belief
that the early Norsemen used the North Star for offshore navigation (or latitude sailing) has no
merit.
Another common misconception is that the office of Pilot Major ( Piloto Mayor), which
was established soon after Columbus first voyage, gave instruction to Spanish pilots who
were then able to perform the New celestial navigation.
The Casa de Contratacion established the office of Pilot Major ( Piloto Mayor ) soon after
Columbus s discovery when it was realized that navigation to and from the New World was a
vital factor in success of the venture. Columbus was first offered the position of Pilot Major but
declined and continued his exploration. Peralonzo Nino was then appointed as the first Pilot
Major probably around 1496. The twenty-four year old Peralonzo, who learned his limited deadreckoning
skills from Columbus on the first voyage, was hardly qualified for the job so this was
manifestly a political appointment because his family owned the Santa Maria and was one of the
principal supporters of the enterprise. Amerigo Vespucci followed Nino as Pilot Major in 1508,
and in the next few decades, the office of Pilot Major passed from Vespucci to Juan de Solis, to
Sebastian Cabot, followed by Alonso de Chaves in 1552 which is the period covered by this
study.
Historians are quick to assume that because instruction in navigation was ordered by the
crown that it was indeed carried out, and thus (without foundation) report this instruction of the
pilots as historical fact. The historical fact is the office of Pilot Major was slow in growing into
an effective instrument of government because the political appointees to the office lacked the
ability to give instruction in either dead-reckoning or celestial navigation. This study will later
show that two of the most prominent Pilot Major s, Amerigo Vespucci and Sebastian Cabot, who
held the office for the longest period of time, were incompetent dilettantes who were incapable
of giving instruction in either
celestial navigation or dead-reckoning. The pilots did receive instruction but it was at sea in the
time honored apprentice program (60% of Columbus s crew were apprentice seamen) where they
learned only dead-reckoning.
The over-blown and inaccurate picture of the effectiveness of the office of the Pilot Major in
producing Spanish pilots who were proficient in celestial navigation originated for the most part
with English writers rather than Spanish sources. D. W. Waters, in his, The Art of Navigation
(1958), reports this admiration of the English for Spanish navigation expertise was
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