Note 20 — Chapter I
Reading edition
For the sake of simplicity, the wave is shown broken at o′ and its two halves straight. The surface of the wave, however, is really a curve, with its concavity turned in the direction of its propagation.
Reading edition
For the sake of simplicity, the wave is shown broken at o′ and its two halves straight. The surface of the wave, however, is really a curve, with its concavity turned in the direction of its propagation.