OF THE MOTION OF THE EARTH.
MOST of the philosophers say that the earth remains
fixed in the same place. Philolaus the Pythagorean, that
it is moved about the element of fire, in an oblique circle,
after the same manner of motion that the sun and moon
have. Heraclides of Pontus and Ecphantus the Pythagorean
assign a motion to the earth, but not progressive, but after
the manner of a wheel being carried on its own axis ; thus
the earth (they say) turns itself upon its own centre from
west to east. Democritus, that when the earth was first
formed it had a motion, the parts of it being small and
light; but in process of time the parts of it were condensed,
so that by its own weight it was poised and fixed.