374 E. B. Hunt on our Sense of the Vertical and Horizontal, Sc. 
much elongated in ‘appearance, while the vertical. axis, havi ing no 
intervening objects to aid, is seemingly shortened... Doubtless 
the causé “assigned by Huler, or the absorption of light by its 
oblique passage through the lower or misty strata in the vicinity 
of the horizon, may have a considerable agency in this phe- 
meeriagon. 
. IL was once of a party to observe Saturn through the West 
Point equatorial, and the several persons observing declared that 
the apparent size of the disc — according to one, the size of an 
orange, according to another, arge as a cart-wheel, &c. 
this case, the lack of ee a saoakes the visual angle the sole 
guide, except the obscure sense of in ba by which the in- 
strumental pencils may affect the eye. ce the utter vague- 
ness of all estimates of a sae, which must depend on a 
baseless imagination as to distan 
7. In sailing on Boston iathos T have twice seen the phenom- 
ena of diverging and converging rays, or what is commonly 
called “the sun drawing water,’ both towards the sun in the 
west and towards the point symmetrically below the horizon in 
the east. Clear as it was rationally, that these two ray systems 
beams of light, I could not by any effort make them seem so 
sensationally. The att ray systems would not blend and I 
could not make them seem connected. The visual thinning of 
each beam near the perpendicular made the connection wholly 
invisible and so completed the illusory projection of the beams on 
the sky-dome. Hence an apparent widening of each beam, as it 
appearance shows a complete subjection of the mental to the 
ee or oe 
reat power of the two eyes to determine distances by 
the converseam of their axes, was strikingly shown when I was 
observing the reflection of a gas-burner globe from a street win- 
dow of the room in which I was during the decline of day in 
New York. When looking with both eyes, this reflection seemed 
firmly established just by a branch of a tree, some ten feet out- 
side the window. On closing one eye, I found it easy to transfer 
the image entirely across the : street, by a mere exercise of imagin- 
ation. In fact, when using only one eye, the rigid stability of 
the binocular vision was gone entirely, and the apparent distance 
seemed almost to become the subject of direct volition. 
9. If in looking out over a landscape, we, by lying down or 
otherwise, bring the line of the two eyes into a vertical position, 
the scene will be found to undergo some remarkable changes. 
Hills will seem to recede into the “distance, so as to look like far 
off mountains. The perspective will be found to lose very much 
of its relief and we seem rather to be looking at a picture on @ 
