article_snippet.sent: The time was measured using a radio-controlled clock, which received the national time signal, and the BT speaking clock.
article_snippet.sent: When The modern-day clock was measured The modern-day clock was reading UTC time to within a quarter of a second.
article_snippet.sent: Although latitude was relatively easy to determine using the sun, longitude was harder.
article_snippet.sent: By knowing the amount of time the ship had been at sea and the local time by using the sun, sailors would be able to determine longitude accurately.
article_snippet.sent: Local time is one hour ahead for every 15 degrees of longitude east and one hour behind for every 15 degrees of longitude west.
highlights_snippet.sent: Time measured using a radio-controlled clock and the BT speaking clock .
  