Let us see what it was like, that Christmas of 1942, at 42 deg. of longitude east of Greenwich.
让我们看看是什么样子的，那个圣诞节，在42 deg。1942年的经度东格林威治。
The book Longitude by Dava Sobel tells the story of John Harrison who figured out how to calculate how far east or west a ship was on the ocean.
达瓦索贝尔写的这本书《经度》讲述了约翰哈里森如何计算出轮船在海面上从东到西航行距离的故事。
But they believed the magnetism to be of little use in judging longitude, leaving it a mystery as to how the turtles know their east from west.
然而，他们认为在辨识经度上磁场帮不上忙，所以海龟如何分辨东西方位仍然是个谜。
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