ry, been quite easily discovered and quite frequently explored, and
that the circuit of the whole terrestrial globe also has been more than
once circumnavigated by our own countrymen, Drake and Cavendish; a fact
which I wish to mention to the lasting memory of these men. For by the
pointing of the iron touched by a loadstone, the points of South, North,
East, and West, and the other quarters of the world are made known to
navigators even under an overcast sky and in the darkest night; so that
thus they always very easily understand to which point of the world they
ought to direct their ship's course; which before the discovery of this
wonderful virtue of the magnetick [Greek: boreodeixis] was clearly
impossible. Hence in old times (as is established in histories), an
incredible anxiety and immense danger was continually threatening sailors;
for at the coming on of a tempest and the obscuring of the view of sun and
stars, they were left entirely in ignorance whither they were making; nor
could they find out this by any reasoning or skill. With what joy then may
we suppose them to have been filled, to what feelings of delight must all
shipmasters have given utterance, when that index magnetical first offered
itself to them as a most sure guide, and as it were a Mercury, for their
journey? But neither was this sufficient for this magnetical Mercury; to
indicate, namely, the right way, and to point, as it were, a finger in the
direction toward which the course must be {iiij} directed; it began also
long ago to show distinctly the distance of the place toward which it
points. For since the index magnetical does not always in every place look
toward the same point of the North, but deviates from it often, either
toward the East or toward the West, yet always has the same deviation in
the same place, whatever the place is, and steadily preserves it; it has
come about that from that deviation, which they call variation, carefully
noticed and observed in any maritime places, the same places could
afterwards also be found by navigators from the drawing near and approach
to the same variation as that of these same places, taken in conjunction
with the observation of the latitude. Thus the Portuguese in their voyages
to the East Indies had the most certain indications of their approach to
the Cape of Good Hope; as appears from the narrations of Hugo van
Lynschoten and of the very learned Richard Hakluyt, our countryman. Hence
also the