e no mention of this phenomenon, knowing how
ready his people were to take alarm; but it soon attracted the attention
of the pilots, and filled them with consternation. It seemed as if the
laws of nature were changing as they advanced, and that they were entering
another world, subject to unknown influences. They apprehended that the
compass was about to lose its mysterious virtues; and without this guide,
what was to become of them in a vast and trackless ocean? Columbus tasked
his science and ingenuity for reasons with which to allay their terrors.
He told them that the direction of the needle was not the polar star, but
to some fixed and invisible point: the variation was not caused by any
failing in the compass, but because this point, like the heavenly bodies,
had its changes and revolutions, and every day described a circle round
the pole. The high opinion that the pilots entertained of Columbus as a
profound astronomer gave weight to his theory, and their alarm subsided."

Thus, although it is possible that the variation of the needle had been
noticed before the time of Columbus, it is evident that he had discovered
the amount of the variation, and that it varied in different latitudes.
The great philosopher Humboldt observes on this point, that "Columbus has
not only the incontestible merit of having first discovered a line without
magnetic variation, but also of having, by his considerations on the
progressive increase of westerly declination in receding from that line,
given the first impulse to the study of terrestrial magnetism in Europe."

With respect to the dip or inclination of the magnetic needle, which must
be regarded as the other element of magnetic direction, there is little
doubt that it was known long before the period usually assigned as the
date of its discovery--namely, in 1576; for it is difficult to conceive how
the variation of the needle should be observed and noted, and not its
deviation from a horizontal line. In the above year a person of the name
of Robert Norman, who styled himself "hydrographer," published a book
containing an account of this phenomenon. The title of this work is
sufficiently curious to be quoted. It runs: "The New Attractive;
containing a short Discourse of the Magnes or Loadstone, and amongst
others his Virtues, of a neue discovered Secret and Subtill Propertie,
concerning the Declination of the Needle touched therewith under the
Plaine of the Horizon, now first foun