E ; where, if the stone be again turned upon its axle till it stands in the position EF , with its repelling point downwards, the island will rise obliquely towards F , where, by directing the attracting end towards G , the island may be carried to G , and from G to H , by turning the stone, so as to make its repelling extremity to point directly downward. And thus, by changing the situation of the stone, as often as there is occasion, the island is made to rise and fall by turns in an oblique direction, and by those alternate risings and fallings (the obliquity being not considerable) is conveyed from one part of the dominions to the other.