On Refraction. 251 
we take our ideas immediately from the object, and not from the 
inverted image of that object seeming to float on the posterior 
surface of the solid sphere? To argue that we could see better at 
a distance than close tu any object, would be absurd. Indeed it 
is evident from this experiment, as well as from the former, that 
we take our ideas from the inverted image-floating on the poste- 
rior surface of the globe, and not from the object, which is as in- 
visible as if it were placed behind our backs. When an oar ap- 
pears bent in the water, the image of the immersed part is one- 
fourth nearer to the eye than the rest, consequently it appears 
bent, or as if broken. 
Exp. 3.—When we hold a black’ pencil or any other substance 
‘behind a cylindrical tumbler of clear water, when the pencil is 
close behind the glass we perceive a magnified image; on with- 
drawing the pencil to yet a greater distance, this image becomes 
more and more magnified, and tivo other images iaterally everted 
are seen at the sides of the tumbler; at yet a greater distance we 
lose sight of the anterior or magnified image}; the two lateral ones 
floating towards each other, at last form one well defined everted 
image at the posterior surface, from which, and not immediately 
from the object, we take our ideas, the object itself being per- 
fectly invisible. 
Rays of light diverge, instead of converging, in a convex lens ; 
neither do they cross to form pictures of objects, as generally 
believed. 
Should I be enabled to establish these as facts, I strike at the 
very root of optical science, which I am sanguine enough to be- 
lieve is likely at no very distant period to undergo as great, if 
not a greater revolution than the science of chemistry. From 
the earliest zera, when lenses were first discovered, to the present 
time, philosophers seeing that on emergence the rays formed a 
cone, and then crossed, laid it down as an analogical inference, 
that they also converged in the body of the glass medium. When 
we find mathematicians measuring the sines of refraction, with 
a ridiculous accuracy, we cannot help smiling at such waste of, 
time and trouble, when informed by direct and incontroyertible 
experiments, that nature and the philosophers were travelling very 
opposite roads, Although every school-boy on looking through 
his burning-glass, and every old woman through her spectacles, 
saw objects enlarged; yet the philosophers, instead of repeating the 
experiments, set about explaining their fanciful theories by the 
greatest absurdities, and it is looked on as a sort of sacrilege to 
call in question the opinions of a Newton. However, it should be 
remembered that in former ages the avros e¢y of Pythagoras 
was held in equal if not greater estimation, and that it is only 
1i2 within 
