Chap. V. In order to find the poles in a stone--which of them is the North and which the South--take a round wooden vessel shaped like a skiff (_paropsidis_, _parascidis_), and place the stone therein, then put the vessel containing the stone into another large vessel filled with water, so that the first-named vessel may float into the larger one: “The stone in the first vessel will be like a sailor in a ship, and the first vessel may float roomily into the second as does a ship in a river, and the stone so placed will turn its small vessel acting as the Northern pole in the direction of the Northern heaven.... If this pole were then turned away a thousand times, a thousand times would it return to its place by the will of God.” Chap. VI. Having found which pole is the Northern, mark it so that it may be known when necessary. Place the stone into a small vessel, as shown in Chap. V, then hold another stone in the hand and approach its Northern part to the Southern part of the stone floating in the vessel, and the floating stone will follow the other “as if it wished to adhere thereto.... Know that, as a rule, the Northern part of one stone attracts the Southern part of another stone and the Southern the Northern.” Chap. VII. When the needle or oblong piece of iron (alluded to in Chap. IV) has touched the magnet and been attached to a light piece of wood or stalk and then placed in a vessel of water, one part will be turned towards the mariner’s star because it is near the pole, “the fact being that it does not turn towards the aforesaid star but towards the pole.” That end of the iron which has touched the Southern end of the stone turns towards the Northern quarter of the sky, and _vice versa_. Chap. VIII. If you wish to attract iron floating on water, hold the Southern part of a loadstone to the Northern part of the iron and the iron will follow. But, if you bring the North end of the stone near the North end of the iron, the latter will avoid the stone. “If, however, violence is used towards the ends, so that, for instance, the Southern end of the iron which was touched with the Northern end of the magnet is now touched with the Southern end of the magnet ... the power in the iron will easily be changed, and that will become Southern which was previously Northern, and the converse.”