Tag

dent

28
Jan
2019
7

What is a chronometer when it’s at OS?

Built around 1852, this precision timepiece on the wall at OS HQ has intrigued many of us here. According to the accompanying plaque, this Dent Master Chronometer was the standard on which all other mobile chronometers owned by OS were checked against before being used in the field astronomical observations by surveyors. An accurate knowledge of time is necessary in the calculation of latitude and longitude.

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