How light rays penetrate liquids: two refraction experiments
Nested water-filled vessels and split glass spheres to test whether a solar ray bends
Leonardo sets out two experiments to test how light rays penetrate liquids. In the first, two cylindrical vessels are nested one inside the other and filled with water, a small clear opening the size of a lens left uncovered so a solar ray can pass through and be checked for whether it keeps its straightness. In the second, two glass balls of different size are cut in half, joined, sealed and filled with water so a solar ray can be watched to see whether it bends or curves, offered as a model for how sunlight passes through the curved sphere of the air. Two pen diagrams of the apparatus are drawn at the right margin.
On this page
Aim: to test how rays penetrate liquid bodies
The page opens by stating its purpose: a way to experiment how rays penetrate liquid bodies. The two figures that follow are built to make a solar ray visible as it passes through enclosed water.
Solar ray through two nested water-filled vessels
Two parallel cylindrical vessels, one four or five times smaller than the other but of equal height, are set one inside the other and painted over except for a lens-sized clear window. A solar ray from a door or window opening is passed through, and one observes whether the ray keeps within the water the straightness it had outside.
Solar ray through joined water-filled glass hemispheres
Two glass balls, one twice as large as the other and as round as possible, are cut through the middle, fitted together, sealed at the fronts and filled with water. A solar ray is passed inside to see whether it bends or curves, as a model for how solar rays penetrate the curvature of the sphere of the air.