Here’s something interesting about the prehistory of radio. Commercial telegraphy in the generation before Marconi grew in sophistication very fast, and its infrastructure was put to use for a lot of things besides telegraphy. Time regulation was one of them. We were ambitious and demanding about electric communications countrywide, and this explains our readiness to receive radio when it came.
We lacked time zones across North America until the 1880’s. But a uniform time standard across the country was under development by the 1870’s; this had been done in England already. It was necessary because if time was a local affair, having to do with the position of the sun overhead, then long-distance scheduling of trains of higher and higher speed was bound to be impractical. Altoona time was ten minutes fast of Pittsburgh. Columbus was thirteen minutes slow. The longer the distance, the worse the problem. Observatories did the regulating. An early example is the Allegheny Observatory, in the Ohio River Valley, in concert with the Penn Central RR in 1869. Jewelers in Pittsburgh had already been using Allegheny time in their stores, for setting timepieces. By 1873 the Allegheny regulated all time between Philadelphia, Lake Erie, and Chicago. It was probably one of the biggest systems of its kind in the world. Besides the jewelers’ and railroad lines, they managed a third ‘city loop’ for ad hoc messages, such as answering requests for sidereal time — a measure of the precision they expected. ‘Sidereal’ is time reckoned against stars, instead of the sun. The Allegheny kept pushing, and so did other observatories, in collaboration with other railroads. The general idea was to decrease the number of local times east of the Mississippi, and then work on the west, in preparation for one nationwide standard of time. The city loop was to be developed into the regulator of city clocks, which would themselves regulate local police stations. It was all mechanized. Clock wheel teeth activated cascades of relays, which made an online beat, heard in offices as a small bell, with regular interruptions for denoting minutes and hours. It was exactly like the atomic clock beat we hams used to listen to on shortwave in the ’70’s. The observatory clocks were battery-powered. Sidereal corrections were made with a transit every fair night of the year except on Sunday. Measurements for barometric and temperature corrections also took place, twice daily.
Who says: S.P. Langley, “On the Allegheny system of electric time signals,” Journal of the Society of Telegraph Engineers, 1873, pp. 433-441.