On the Magnet

Chap. 1. Of direction.
Chap. 2. What is the directing virtue, or versoria needles (which we call verticity); how it is in the magnet; how it is acquired when not innate.
Chap. 3. How iron acquires verticity through a magnet, and how that verticity is lost and changed.
Chap. 4. Why iron touched acquires contrary verticity, and why iron touched by the true northern side of the stone moves toward the north of the Earth, and by the true southern side toward the south; it is not turned to the south when rubbed by the northern point of the stone, and to the north by the southern, as all who have written about the magnet falsely supposed.
Chap. 5. Of the touching of irons of various shapes.
Chap. 6. The motion of magnetic bodies that seems contrary is a rightful flowing together toward unity.
Chap. 7. Distance, verticity, and disposing faculty compose magnetic bodies; not an attracting or pulling force; nor is coition alone or union stronger.
Chap. 8. Of the discords of iron tools upon the same pole of a magnet; and how they can agree and exist together.
Chap. 9. Directing figures indicating the varieties of conversions.
Chap. 10. Of the change of verticity and magnetic properties, or of the alteration of the vigor excited by a magnet.
Chap. 11. Of rubbing iron upon a magnet in places midway between the poles, and upon the equator of the terrella.
Chap. 12. How verticity exists in any smelted iron, not excited by a magnet.
Chap. 13. Why no other body (except a magnetic one) is imbued with verticity from the rubbing of a magnet; and why no body can impart and excite that virtue unless it is magnetic.
Chap. 14. The position of the magnet, now above, now below a magnetic body suspended in equilibrium, changes neither the virtue nor the verticity of the magnetic body.
Chap. 15. The poles, equator, and center remain whole and stand stably: they vary and acquire other seats from diminution and the separation of any part.
Chap. 16. If the southern part of the stone is diminished, something will also be taken away from the virtue of the northern part.
Chap. 17. Of the use and excellence of versoria compass needles: and how iron directing needles for clocks, as well as the threads of the nautical compass, should be rubbed so that they acquire a stronger verticity.

Chap. 1. Of variation.
Chap. 2. That variation is caused by the inequality of the Earth's prominent parts.
Chap. 3.