XIII. The first regards the direction, or pointing of the magnetical needle to the pole. This admirable property, which was totally unknown to the antients, was discovered in the thirteenth century, and immediately applied to the improvement of navigation. Upon its first discovery, the philosophers, according to their wonted custom of pretending to discern the causes of things, imputed this effect, as derived from an occult sympathy with the pole, contained in the very essence, form, and substance of the loadstone; and as this is supposed to be invariable, they concluded, that the direction must infallibly be invariable also. They continued in this good faith for about four hundred years, at the end of which long period, Crinon, a pilot of Dieppe as some say, or Cabot, a Venetian Navigator as others believe, was the first who observed the declinations of the magnetical needle from the true north, that is, that it did not always point directly to the pole, but declined in different places, sometimes towards the west, and at others towards the east. The philosophers heard this novelty with great disgust, because it gave the lye to some of their most established maxims, and therefore they set about to contradict it with all their force. But in the end, they were obliged to submit to repeated experiments, authorized and confirmed, by the testimonies of people of undoubted credit. XIV. Having afterwards discovered, that under the meridian of the Azores or western islands, there was no variation of the magnetical needle at all, the astronomers and geographers, thought they had found out a fixed station, whereat to commence the first meridian, which had before been counted arbitrarily, from whatever place they chose to begin it. But this idea soon vanished, for a little while afterwards, they discovered two other meridians, where there was no variation; the one at a head-land near _the Cape of Good Hope_, to which, on this account they gave the name of _Needle Cape_; and another, at the spot where the city of Canton is situated. Upon this, they thought they had found out a certain principle, whereon to ground a compleat system for calculating or computing variations, by graduating them for the intermediate stations, in proportion to their greater or less distance from the mean space between the two places where there was no variation.