In 1836, it was hard to get a straight answer to the question “What time is it?” The Royal Observatory at Greenwich knew what time it was, down to the second, but it had few methods for sharing that information with the public.

Enter John Henry Belville, an astronomer and meteorologist who worked as an assistant at the observatory. Belville did a brisk side business selling time. Customers paid an annual subscription fee in return for a weekly visit from Belville and his trusty timepiece, a pocket chronometer tuned to the observatory’s clock to within a tenth of a second. The chronometer was so reliable it even had a name: Arnold.

After Belville’s death in 1856, his much younger widow, Maria, took over the time-supply service to stave off poverty. With the blessing of the observatory, Maria and her daughter Ruth carried Arnold on a circuitous trek through London’s dockyards, business districts, instrument shops, and shipping offices for the next 36 years. When Maria retired at 81, Ruth inherited both Arnold and the job of being “the Greenwich time lady.” Technological developments—the telegraph, the radio, and, finally, the telephone “speaking clock” service—threatened Ruth’s business, but her reliability and loyal customers kept her working until her own retirement in 1940.

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