A Treatise on Painting
by Leonardo da Vinci, translated by John Francis Rigaud
Reflexes in the Water, and particularly those of the Air
4010572A Treatise on Painting — Reflexes in the Water, and particularly those of the AirJohn Francis RigaudLeonardo da Vinci

Chap. CCXXI.Reflexes in the Water, and particularly those of the Air.

The only portion of air that will be seen reflected in the water, will be that which is reflected by the surface of the water to the eye between equal angles; that is to say, the angle of incidence must be equal to the angle of reflexion.