The Magnetic Art

Experiment VI.

Let a piece of iron supported by cork float in any small vessel, which, when a magnet is applied from the outside, is moved in a moment despite any impediments, and as if sensing the presence of a friend, without delay it leaves its place and, desiring to insinuate itself into its embrace, will move to the edge of the vessel. You meanwhile, with the magnet applied outside the vessel to wherever you please, will lead the floating needle inside, from which many most delightful spectacles can be produced to the eye, as we shall see in the practical corollaries.

THEOREM VII.

A circular diagram illustrates a terrella (spherical magnet) marked with meridians, an equator, and concentric lines, demonstrating how the magnet mirrors the globe.

The magnet, adapted into a spherical figure and having attained an orbicular form, is a true, homogeneous offspring of the earth of the same figure, which nature granted to the common mother, the Earth, from the beginning. It is a physical corpuscle imbued with most excellent virtues, and it cannot be poorly called a microge little earth or terrella little earth; for besides two poles responding to the poles of the world, it has an equator, parallels, meridians, and even its own horizon, which will become manifest in the following experiment.

Experiment VII.

With the magnet adapted into a round figure, hold the stone in your hand, and with a needle or iron spike placed upon the stone, you will immediately see the extremities of the iron designating the meridian or polar line for you, because, as is clear from the above, the spikes cannot rest, no matter how they are placed, unless upon their polar line. You will mark the stone where it is touched by the ends of the spikes