Light-ray and shadow angle diagrams, with a maxim of Anaxagoras
Rays radiating from points and circles illustrate how angle governs light and shade
Across the blue sheet Leonardo draws several schemes of rays radiating from points, small circles and half-circles, studying how the width of an angle governs brightness and darkness. His notes state that light is brighter where its angle is wider and that shadow is darker where it is born at a more acute angle, with lettered points c b a marking the rays. He also copies a philosophical maxim attributed to Anaxagoras on everything coming from and returning into everything through the elements, and sketches two intersecting circles labelled a c b. A boxed mechanism and a further device drawn at the top of the sheet are not transcribed.
On this page
Maxim of Anaxagoras on the elements
Anaxagoras: everything comes from everything, and from everything all things are made, and everything returns into everything, because what is in the elements is made from those same elements.
Brighter light comes from a wider angle
A diagram of light rays is labelled with 'shadow'. The accompanying rule states that the light is brighter which forms a wider angle.
Darker shadow is born of a more acute angle
In an analogous diagram Leonardo notes that the shadow is darker which is born at a more acute angle. The paired schemes contrast wide and narrow angles of light and shade.
Ray scheme with points c b a
On the left half a further diagram of light rays is drawn, its points marked c, b and a. The radiating lines fan out from the lettered origins.
Intersecting circles a c b
Two circles cutting one another are drawn and labelled with the points a, c and b at their intersection. The construction accompanies the optical studies on the sheet.