you see. The plane o p being always equally remote from the eye will reproduce the objects in a satisfactory way, so that they may be seen from place to place.
87.
How every large mass sends forth its images, which may diminish through infinity.
The images of any large mass being infinitely divisible may be infinitely diminished.
88.
Objects of equal size, situated in various places, will be seen by different pyramids which will each be smaller in proportion as the object is farther off.
89.
Perspective, in dealing with distances, makes use of two opposite pyramids, one of which has its apex in the eye and the base as distant as the horizon. The other has the base towards the eye and the apex on the horizon. Now, the first includes the [visible] universe, embracing all the mass of