To understand this, we have only to consider that the first element, which is in the center of the vortex, can and does escape constantly through the intervals between the balls toward the circumference of the same vortex; and while this center or this star is being emptied through its equator, other of the first element must enter at its poles; for this star cannot be emptied from one side without being filled from the other, since there is no void in the world, as I assume here and which is easy to prove through natural effects,.e., through the transmission of light.