Scientific needs for accurate time‐service

Abstract

Many important lines of investigation involve the accurate measurement of time and the overall precision of the work may in fact rest upon the precision with which measurement of time can he carried out. Examples are to be found in the determination of longitude, in the measurement of the rate of propagation of seismic disturbances, and in isostatic problems involving a precise determination of the acceleration of gravity at various paints over the Earth's surface. To these examples may be added the many uses of time by the physicist, which broadly speaking center around the measurement of frequencies, velocities, and accelerations.