Chap. X. “Some weak inquirers have imagined that the power which the magnet exercises over iron lies in those mineral places in which the magnet is found ... but it is found in different parts of the world.... Besides, when iron or the magnet turns towards the Southern as well as to the Northern quarter, as is evident from what has already been said, we are compelled to decide that the attraction is exercised on the poles of the magnet not only from the locality of its quarry, from which ensues the evident result that, wheresoever a man may be, the direction of this stone appears to his eye, according to the position of his meridian circle. All the meridian circles, however, meet together at the poles of the globe, wherefore it is that the poles of the magnet receive their power from the poles of the world. From this, it manifestly appears that the direction of the magnet is not towards the mariner’s star, as the meridian circles do not meet there, but all the poles, for the mariner’s star is always found beyond the meridian circle of any region unless it be twice in a complete revolution of the firmament. Likewise from this, it is manifest that the parts of the magnet receive their power from the world’s poles ... the whole magnet from the whole heavens.”[18] Then follows a suggestive experiment looking towards perpetual motion, by which one may secure “a wonderful secret” and even “be saved the trouble of having any clock.” Here, it is given that a _terrella_, poised on its poles in the meridian, moves circularly with a complete revolution in twenty-four hours. This is explained by N. Cabæus in his “Phil. Magn.,” lib. iii. cap. 4. PART II