If you are a visitor to Sheffield, or even a jumpy local, you may be taken by surprise if you walk through the city centre at the right time. Since 1874, a siren has sounded by the entrance to HL Brown, a watchmaker and jeweler, every day. Those with a keen eye will see a small metal plate, much like a street sign, reading “1 o’clock time signal,” alongside the siren that alerts all who hear it that it is indeed 1 p.m.

Its location above a watchmaker hints at the siren’s historic purpose. In the 1800s, before its instillation, timepieces were less reliable and our modern system of standardized time zones was in its infancy. As trains connected once disparate cities and towns, their staff and riders had to contend with the chaos of every town keeping its own time. According to The Global Transformation of Time, 1870-1950by Vanessa Ogle, Chicago alone had three time zones, and German train departures might be listed in “Berlin, Munich, Stuttgart, Karlsruhe, Ludwigshafen, or Frankfurt time.” Even within the same town, one’s sense of the time was inconsistent from person to person.

When the signal, which was not always a siren, was first installed, it was linked to Greenwich, London, via the telegraph. It’s believed that local factories counted on the signal to herald the end of workers’ lunch breaks, and that the watch company benefitted from the connection so as to set their watches precisely. Today it’s a quirky tradition, and a reminder of a time when the concept of time was a bit fuzzier.