The Post Office Speaking Clock in Great Britain

Abstract

UP to the beginning of the nineteenth century the time in most towns was taken from public clocks of various kinds, which occasionally varied appreciably from one another. This was a serious obstacle to the postal services, and led to the practice on mail coaches and trains of carrying chronometers to synchronize local post office clocks with a standard clock in London. Shortly after the introduction of the electric telegraph, electro-mechanical devices of various kinds were controlled by telegraphed signals. But it was not until 1874, a few years after the Government acquired the telegraph system, that successful distribution of the 10.00 a.m. Greenwich time signal was accomplished over sixty different lines. The development of this service into the very accurate International Time Signal transmitted from Rugby radio station at 10.00 and 18.00 G.M.T. daily was made in 1927. This service has the disadvantage of not always being available in the home. The well known six ‘pips' of the B.B.C. have the disadvantage of being only available at certain times. Then came the synchronous motor-clocks running on frequency-controlled mains, but at present these clocks are far from being in universal use.