_ joining these points take other two points A, 
156 S. Rowley on Vision. 
Or, to change the form of statement, the entire impressions — 
on the retine, before becoming objects of consciousness are pro- — 
jected in space upon surfaces bisecting each other (at an angle 
greater or less according to the distance) in a plane p ice 
ular to the plane of the axes—the component points of each 
impression being simultaneously referred outward in Lines pass- 
ing from them through a point a Little behind the center of the 
erystalline lens, but, excepting the expansion and the inversion — 
resulting from the crossing in the eye of the directions of out- 
ward reference, undergoing no change of relative position—the 
distance between the planes passing at right angles to the optic 
axis through any two of the successive concentric zones OY 
points, which make up the retinal impression, continuing the 
same. 
Ido not mean here to assert that an outward projection 
actually takes place, but that the effect of such @ projection, — 
produced by an intermediate process of mind, 18 presented 
to the consciousness, ae 
On a suitable plane surface take two points G, O' (fg. 1), 
1. | 
D ERR 
is inches apart, and in a line bisecting at right angle! = 
- po 
spectively from the point of bisection six and 
