Digital ACT Reading Practice Question #1591

Why were standard 18th-century pendulum clocks ineffective aboard ocean-going sailing vessels? Passage Excerpt (Social Science): In 1714, the British Parliament enacted the Longitude Act, offering a staggering £20,000 prize for any method capable of determining a ship's longitude at sea within thirty nautical miles after a voyage to the West Indies. Navigators had long determined latitude by measuring the altitude of Polaris or the noontime sun, but calculating longitude required knowing the exact time at the home meridian simultaneously with local solar time. Ordinary pendulum clocks were useless on pitching ship decks, where temperature swings thickened lubricating oils and rolling swells disrupted balance escapements. The scientific establishment, led by Astronomer Royal Nevil Maskelyne, favored complex astronomical calculations using the lunar distance method. Yet it was a self-taught Yorkshire carpenter, John Harrison, who solved the riddle through sheer mechanical genius, crafting friction-free wooden bimetallic clocks that kept time to within seconds over months of transatlantic voyage.