Which pole is the Boreal? How is it distinguished from the Austral?

One pole of the earth turns toward the constellation of the Cynosure. It constantly regards a fixed point in the heaven, except so far as it changes by the fixed stars being shifted in longitude, which motion we recognize as existing in the earth.

The other pole turns to the opposite face of heaven, unknown to the ancients, now visible on long voyages, and adorned with multitudinous stars.

In the same way, the loadstone has the property and power of directing itself North and South (the earth herself consenting and contributing force thereto) according to the conformation of nature, which arranges the movements of the stone towards its native situation.

Which thing is proved thus:

Place a magnetick stone (after finding the poles) in a round wooden vessel, a Bowl or dish. Place it together with the vessel (like a sailor in a skiff) upon water in some large vessel or cistern, so that it may be able to float freely in the middle, nor touch the edge of it, and where the air is not disturbed by winds, which would thwart the natural movement of the stone.

The stone placed as it were in a ship, in the middle of the surface of the still and unruffled water, will at once put itself in motion along with the vessel that carries it, and revolve circularly, until its austral pole points to the north, and its boreal pole to the south.

For it reverts from the contrary position to the poles: and although by the first too-vehement impulse it over-passes the poles; yet after returning again and again, it rests at length at the poles, or at the meridian (unless because of local reasons it is diverted some little from those points, or from the meridional line, by some sort of variation[66], the cause of which we will hereafter state).

However often you move it away from its place, so often by virtue of nature’s noble dower does it seek again those sure and {15}determined goals; and this is so, not only if the poles have been disposed in the vessel evenly with the plane of the horizon, but also in the case of one pole, whether austral or boreal, being raised in the vessel 10, or 20, or 30, or 50 or 80 degrees, above *the plane of the horizon, or lowered beneath it.

Still, the boreal part of the stone seeks the south. The austral part seek the north.

If the pole of the stone shall be only one degree distant from the Zenith and highest point of the heaven, in the case of a spherical stone, the whole stone revolves until the pole occupies its own site. Though not in the absolutely direct line, it will yet tend toward those parts, and come to rest in the meridian of the directive action.

With a like impulse too it is borne if the austral pole have been raised toward the upper quarters, the same as if the Boreal had been exalted above the Horizon.

But it is always to be noted that, though there are various kinds of unlikeness in the stones, and one loadstone may far surpass another in virtue and efficiency; yet all hold to the same limits, and are borne toward the same points.

People before our time wrote of the poles of the stone. These, along with craftsmen and navigators, considered:

• the part of the stone which tended to the north as the stone’s north pole
• the part which verged toward the south, the south pole.

This is very wrong.

So badly hitherto hath the whole magnetick philosophy been cultivated, even as to its foundation principles.