8 Mr. Home’s Lecture on the Power of the Eye, 
each other at 12-j; inches, as the near distance; and at 28- 
inches, as the furthest distance. The experiment was repeated 
several different times, and the results were very nearly the 
same/ 
My own eye made the lines intersect at i2f inches, as the 
near distance ; and at 2 g~ inches, as the furthest distance. 
A man servant of Sir Henry Englefield’s, twenty-five years 
of age, made the lines intersect at 12 inches, and at 3 if inches. 
Henry Miles, fifty years of age, whose eye had been de- 
prived of the crystalline lens for three years, made the lines 
intersect at 8 T 3 - inches, as the near distance; and at 13^—, as 
the furthest distance. 
This experiment was repeated two different times in the fore- 
noon, with the same result, and again in the afternoon, without 
there being any considerable variation; but, upon trying it 
again, after the eye had been fatigued, he was unable to make 
the lines cross nearer than 1 if inches, although he could make 
them cross at 13-— inches; so that adjusting the eye to a 
near distance, was more difficult after it had been much used, 
than before. 
Henry Miles was unable, in the optometer with the lens, to 
produce any change in the crossing of the lines, nor did he see 
them cross with sufficient distinctness to make us consider it a 
fair experiment. 
The following experiment was made upon Miles’s eye, at 
the suggestion of Sir Henry Englefield, with a view to ascer- 
tain in another though less decisive way, whether any change 
took place in it, when directed from a near object to a more 
distant one. 
A piece of pasteboard, in which a black circle, about f of an 
