Proceedings of the Symposium on the Rotation of the Earth and Atomic Time Standards: Part II. The rotation of the earth: Ephemeris time

. In this article is described the measurement of time from a more general point of view than has been taken before. it is shown that mean solar time and ephemeris time are two particular applications of the general principle of measuring time by observing angular motions, a principle that can be applied to any angular motion whatever, provided that an adequate theory of the motion is available.