Eye at an Aperture and Water Rebounding at Equal Angles
Red-chalk notes on vision through a hole and the reflection of a water jet
At the top, in red chalk, an eye peers through a square aperture (with a small square marked A) toward a spreading bundle of rays. Leonardo notes that the eye does not comprehend the near luminous angle, and that the line traced by a course of water, after striking a surface, rebounds between equal angles, like reflected light. A separate caption concerns the narrowing of a channel, and two feathery sprays at the foot of the page appear to illustrate water striking and rebounding.
On this page
Eye peering through a square aperture
An eye is drawn looking through a square opening, with a small square marked A, toward converging rays of light. Leonardo remarks that the eye does not comprehend the near luminous angle.
Water rebounding between equal angles
The line made by the course of the water, after its impact, rebounds between equal angles. The two feathery sprays at the foot of the page appear to show this rebound.