[Chap. 9]. Figures illustrating direction and showing varieties of rotations.
[Chap. 10]. On Mutation of Verticity and of Magnetick Properties, or on alteration in the power excited by a loadstone.
[Chap. 11]. On the Rubbing of a piece of Iron on a Loadstone in places midway between the poles, and upon the æquinoctial of a terrella.
[Chap. 12]. In what way Verticity exists in any Iron that has been smelted though not excited by a loadstone.
[Chap. 13]. Why no other Body, excepting a magnetick, is imbued with verticity by being rubbed on a loadstone, and why no body is able to instil and excite that virtue, unless it be a magnetick.
[Chap. 14]. The Placing of a Loadstone above or below a magnetick body suspended in æquilibrio changes neither the power nor the verticity of the magnetick body.
[Chap. 15]. The Poles, Æquator, Centre in an entire Loadstone remain and continue steady; by diminution and separation of some part they vary and acquire other positions.
[Chap. 16]. If the Southern Portion of a Stone be lessened, something is also taken away from the power of the Northern Portion.
[Chap. 17]. On the Use and Excellence of Versoria: and how iron versoria used as pointers in sun-dials, and the fine needles of the mariners' compass, are to be rubbed, that they may acquire stronger verticity.