Plot a graph of angle of incidence, i in o on the y-axis against angle of refraction, r in o on the x-axis and draw the line of best fit. We can see from the graph that as the angle of incidence ...

When a wave or light ray moves from one medium to another its speed changes. The direction of the ray may also change. This property of waves is called refraction and commonly occurs with light rays.

that there arises a series of complications due to variations in the amount and effect of refraction, or in that of the plumb-line deflection, which have been by no means exhaustively investigated ...