What chronometers were used on HMS Beagle?

During its three main survey voyages from 1826 to 1843, HMS Beagle carried at least 34 recorded marine chronometers to accurately calculate longitude. On its famous second voyage with Charles Darwin, the ship carried an unprecedented 22 chronometers, which were housed in a dedicated cabin. These precision instruments included units owned by the Navy, on loan from manufacturers, and six provided personally by Captain Robert FitzRoy.

What we know

• HMS Beagle carried a total of at least 34 recorded chronometers across its three main survey voyages between 1826 and 1843. [3]
• During the second voyage with Charles Darwin on board, the ship carried 22 chronometers housed in a dedicated cabin. [3]
• Six of the chronometers on the second voyage were owned personally by the ship's captain, Robert FitzRoy. [3]
• At least one nautical chronometer used on HMS Beagle was made by the British watchmaker Thomas Earnshaw, who helped simplify the process of marine chronometer production. [2, 3]

Where to go next

• how it workedHow do marine chronometers help determine longitude?
• the bigger pictureWhat was the purpose of the second voyage of HMS Beagle?
• whoWho was Thomas Earnshaw?
• what followedWhat did Charles Darwin achieve on the Beagle expedition?
• whenHow were chronometers used by James Cook?
• an unexpected connectionHow did a pocket watchmaker influence the Armagh Observatory?Thomas Earnshaw, whose marine chronometers guided HMS Beagle, also built an airtight astronomical clock for the Armagh Observatory that was praised as the world's most accurate.

Sources

• [1]Thomas Earnshaw (Wikidata Q2423581) · CC0 1.0
• [2]Thomas Earnshaw · CC BY-SA 4.0
• [3]Ship's chronometer from HMS Beagle · CC BY-SA 4.0
• [4]Second voyage of HMS Beagle · CC BY-SA 4.0
• [5]List of chronometers on HMS Beagle · CC BY-SA 4.0