On a recent visit to the Royal Observatory at Greenwich I was struck by its proximity to the Naval Academy next door. The theme of the history of clocks and development of astronomy was driven by the need to stop ships crashing due to navigation failures. In theory you could solve this by better clocks and better astronomical models. Still they spent hundreds of years on the problem.
Included in the themed display was Captain Cook’s trip to Tahiti to observe the transit of Venus. At the time Captain Cook didn’t carry a chronometer because they were too rare at the time. (He carried them on subsequent voyages.) The problem he was trying to solve was the size of the solar system (which a good observation of Venus would solve.)
The method of determining longitude was lunar distances, where you measure the angle of the moon and compare it to the angle of a star, compare this to a logbook and do a lot of calculations.
Now it seems to me that one of the ‘stars’ referred to in the lunar distances calculation could have been a planet. This would explain why Captain Cook’s measurement would improve navigation.
Alternatively there may have been an alternative method to lunar distances based on ‘planet distances ‘ that Captain Cooks measurement would assist with.
But it’s not clear to me how Captain Cook’s trip was going to improve Naval Navigation. It seems improbable that his trip was funded on the basis of an academic question about the size of the solar system.
My question is: Was Captain Cook’s voyage to observe the transit of Venus going to enable better ship navigation at the time?