He assigns this probable cause of the circular revolution of the nucleus that the diurnal motion, being impressed from without, was not so exactly communicated to the internal parts as to give them the same precise velocity of rotation as the external, whence the nucleus, being left behind by the exterior earth, seems to move slowly in a contrary direction, as from east to west, with regard to the external earth, considered as at rest in respect of the other.

But to return to our voyage..