And that it doth never (if at all) seem farther off, than it would if
it were beheld by the naked eye, but on the contrary it doth sometimes
appear much nearer. Nay, it is even certain that by how much the rays
falling on the eye do more converge by so much the nearer doth the OBJECT
seem to approach. For the eye being placed close to the point B, the
OBJECT A appears nearly in its own natural place, if the point B is taken
in the glass, or at the same distance, if in the speculum. The eye being
brought back to O, the OBJECT seems to draw near: and being come to P it
beholds it still nearer. And so on little and little, till at length the
eye being placed somewhere, suppose at Q, the OBJECT appearing extremely
near, begins to vanish into mere confusion. All which doth seem repugnant
to our principles, at least not rightly to agree with them. Nor is our
tenet alone struck at by this experiment, but likewise all others that
ever came to my knowledge are, every whit as much, endangered by it. The
ancient one especially (which is most commonly received, and comes
nearest to mine) seems to be so effectually overthrown thereby that the
most learned Tacquet has been forced to reject that principle, as false
and uncertain, on which alone he had built almost his whole CATOPTRICS;
and consequently by taking away the foundation, hath himself pulled down
the superstructure he had raised on it.
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