J. LeConte on Binocular Vision. 
focal adjustment, and the inseparable association of it with 
axial adjustment. On re-commencing these experiments a few 
of the images were far more distinct than the real figures were 
es. 
‘ t 
indistinct but gradually it became perfectly defined—every 
thread-hole as clear and distinct as it is possible to conceive. 
I succeeded, though with greater difficulty, in getting a perfectly 
distinct image of the buttons on all the planes. It was evident 
therefore that the indistinctness of the figures of the image on 
the higher planes, was not the result of the want of focal ad- 
justment but of imperfection in the pattern. The subsequent 
experiments with the ruled diagram proved this beyond the 
possibility of doubt. The images in this case were obtained 
with much more ease and the lines were defined with the most 
perfect sharpness even when the image was brought nearly to 
the root of the nose. 
In all cases, however, the image when first obtained was a 
little indistinct, and then gradually became clear. With un- 
= en tl is first obtained 
the o tic axes, the lenses, and the pupil, are all consensually 
adjusted for vision at the distance of the image: and 
