A specialist review. Atomic time and standard-frequency transmissions

Three units of time are at present in use, and, in order to satisfy as many requirements as possible, standard-frequency transmissions are operated so as to give an immediate and accurate value of all three. The existence of three units leads to the possibility of confusion. This could be avoided if the atomic unit only were made immediately available and Tables of corrections were used for converting atomic time into astronomical time when this is required.