ine Peter Peregrinus feigned many centuries before or else depicted one
which he had received from others, and one which was much better fitted for
the purpose. Johannes Taysnier published it also, spoiled by wretched
figures, and copied out the whole theory of it word for word. O that the
gods would at length bring to a miserable end such fictitious, crazy,
deformed labours, with which the minds of the studious are blinded!

* * * * *

{108} CHAP. XXXVI.

How a more robust Loadstone may be
_recognized_.

Very powerful loadstones sometimes lift into the air a weight of iron equal
to their own; a weak one barely attracts a slender wire. Those therefore
are more robust which appeal to and retain larger bodies, if there is no
defect in their form, or the pole of the stone is not suitably moved up.
Moreover, when placed in a boat a keener influence turns its own poles
round more quickly to the poles of the earth or the limits of variation on
the horizon. One which performs its function more feebly indicates a defect
and an effete nature. There must always be a similar preparation, a similar
figure, and a like size; for in such as are very dissimilar and unlike, the
experiment is doubtful. The method of testing the strength is the same also
with a versorium in a place somewhat remote from a loadstone; for the one
which is able to turn the versorium round at the greater distance, that one
conquers and is held the more potent. Rightly also is the force of a
loadstone weighed in a balance by B. Porta; a piece of loadstone is placed
in one scale-pan, in the other just as much weight of something else, so
that the scale-pans hang level. Soon a piece of iron lying on the table is
adjusted so that it sticks to the loadstone placed in the scale, and they
cling together most perfectly, according to their friendly points; into the
other scale-pan sand is gradually thrown, and that until the scale in which
the loadstone is placed is separated from the iron. Thus by weighing the
weight of sand, the magnetick force becomes known. Similarly also it will
be pleasing to try with another stone, in equilibrium, the weight of the
sand being observed, and to find out the stronger by means of the weights
of sand. Such is the experiment of Cardinal Cusan in his _De
Staticis_[185], from whom it would seem that B. Porta learnt the
experiment. The better loadstones turn themselves round more quickly toward
the pol