But it must be observed, that this island cannot move beyond the extent of the dominions below, nor can it rise above the height of four miles. For which the astronomers (who have written large systems concerning the stone) assign the following reason: that the magnetic virtue does not extend beyond the distance of four miles, and that the mineral, which acts upon the stone in the bowels of the earth, and in the sea about six leagues distant from the shore, is not diffused through the whole globe, but terminated with the limits of the king’s dominions; and it was easy, from the great advantage of such a superior situation, for a prince to bring under his obedience whatever country lay within the attraction of that magnet.

When the stone is put parallel to the plane of the horizon, the island stands still; for in that case the extremities of it, being at equal distance from the earth, act with equal force, the one in drawing downwards, the other in pushing upwards, and consequently no motion can ensue.

This loadstone is under the care of certain astronomers, who, from time to time, give it such positions as the monarch directs. They spend the greatest part of their lives in observing the celestial bodies, which they do by the assistance of glasses, far excelling ours in goodness. For, although their largest telescopes do not exceed three feet, they magnify much more than those of a hundred with us, and show the stars with greater clearness. This advantage has enabled them to extend their discoveries much further than our astronomers in Europe; for they have made a catalogue of ten thousand fixed stars, whereas the largest of ours do not contain above one third part of that number. They have likewise discovered two lesser stars, or satellites, which revolve about Mars; whereof the innermost is distant from the centre of the primary planet exactly three of his diameters, and the outermost, five; the former revolves in the space of ten hours, and the latter in twenty-one and a half; so that the squares of their periodical times are very near in the same proportion with the cubes of their distance from the centre of Mars; which evidently shows them to be governed by the same law of gravitation that influences the other heavenly bodies.

They have observed ninety-three different comets, and settled their periods with great exactness. If this be true (and they affirm it with great confidence) it is much to be wished, that their observations were made public, whereby the theory of comets, which at present is very lame and defective, might be brought to the same perfection with other arts of astronomy.

The king would be the most absolute prince in the universe, if he could but prevail on a ministry to join with him; but these having their estates below on the continent, and considering that the office of a favourite has a very uncertain tenure, would never consent to the enslaving of their country.