contact.
In like manner if you set the boreal pole of the one you hold in your hand
opposite the austral pole of the swimming stone, they rush together and
follow each other in turn. For contrary poles allure contrary. If, however,
you apply in the same way the northern to the northern, and the austral to
the austral pole, the one stone puts the other to flight, and it turns
aside as though a pilot were pulling at the helm and it makes sail in the
opposite ward as one that ploughs the sea, and neither stands anywhere, nor
halts, if the other is in pursuit. For stone disposeth stone; the one turns
the other around, reduces it to range, and brings it back to harmony with
itself. When, however, they come together and are conjoined according to
the order of nature, they cohaere firmly mutually. For instance, if you
were to set the boreal pole of that stone which is in your hand before the
tropic of Capricorn of a round floating loadstone (for it will be well to
mark out on the round stone, that is the terrella, the mathematical circles
as we do on a globe itself), or before any point between the aequator and
the austral pole; at once the swimming stone revolves, and so arranges
itself that its austral pole touches the other's boreal pole, and forms a
close union with it. In the same way, again, at the other side of the
aequator, with the opposite poles, you may produce similar results; and
thus by this art and subtilty we exhibit attraction, repulsion, and
circular motion for attaining a position of agreement and for declining
hostile encounters. Moreover 'tis in one and the same stone that we are
thus able to demonstrate all these things and also how the same part of one
stone may on division become either boreal or austral. Let A D be an oblong
stone, in which A is the northern, D the southern pole; cut this into two
equal parts, then set part A in its vessel on the water[67], so as to
float.

[Illustration]

{17} And you will then see[68] that A the northern point will turn to the
south, as before; in like manner also the point D will move to the north,
in the divided stone, as in the whole one. Whereas, of the parts B and C,
which were before continuous, and are now divided, the one is southern B,
the other northern C. B draws C, desirous to be united, and to be brought
back into its pristine continuity: for these which are now two stones were
formed out of one: and for this cause C of the one turning itself to B of
t