It is certain that the theory t)f the Earth’s rotundity and thatof its mobility must stand or fall together. A proof, then, of its immobilityis virtually a proof of its non-rotundity. Now, that theEarth does not move, either on an axis, or in an orhit round the Sunor anything else, is easily proven. If the Earth went through spaceat the rate of eleven-hundred miles in a minute of time, as astronomersteach 138, in a particular direction, there would unquestionably b e adifference in the result of firing off a projectile in that direction andin a direction the opposite of that one. But as, in fact, there is notthe slightest difference in any such case, it is clear that any allegedmotion of the Earth is disproved, and that, therefore, the Earth is not a globe