CHAP. XXXI.
On Long and Round Stones.
ieces of iron join more firmly with a long stone than with a round one, provided that the pole of the stone is at the extremity and end of its length; because, forsooth, in the case of a long stone, a magnetick is directed at the end straight towards the body in which the virtue proceeds in straighter lines and through the longer diameter. But a somewhat long stone has but little power on the side, much less indeed than a round one. It is demonstrable, indeed, that at A and B the coition is * stronger in a round stone than at C and D, at like distances from the pole.
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CHAP. XXXII.
Certain Problems and Magnetick Experiments about
the Coition, and Separation, and regular Motion
of bodies magnetical.
qual loadstones come together with equal incitation. *
Also magnetick bodies of iron, if alike in all respects, * come together when excited with similar incitation.
Furthermore, bodies of iron not excited by a * loadstone, if they are alike and not weighed down by their bulk, move towards one another with equal motion.
Two loadstones, disposed on the surface of some water in suit-able